blob: 761013f8b82f5a3d7c534f201a45f2c5902cd188 [file] [log] [blame]
David Brownelld2876d02008-02-04 22:28:20 -08001#include <linux/kernel.h>
2#include <linux/module.h>
Daniel Glöcknerff77c352009-09-22 16:46:38 -07003#include <linux/interrupt.h>
David Brownelld2876d02008-02-04 22:28:20 -08004#include <linux/irq.h>
5#include <linux/spinlock.h>
Alexandre Courbot1a989d02013-02-03 01:29:24 +09006#include <linux/list.h>
David Brownelld8f388d2008-07-25 01:46:07 -07007#include <linux/device.h>
8#include <linux/err.h>
9#include <linux/debugfs.h>
10#include <linux/seq_file.h>
11#include <linux/gpio.h>
Anton Vorontsov391c9702010-06-08 07:48:17 -060012#include <linux/of_gpio.h>
Daniel Glöcknerff77c352009-09-22 16:46:38 -070013#include <linux/idr.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090014#include <linux/slab.h>
Rafael J. Wysocki7b199812013-11-11 22:41:56 +010015#include <linux/acpi.h>
Alexandre Courbot53e7cac2013-11-16 21:44:52 +090016#include <linux/gpio/driver.h>
David Brownelld2876d02008-02-04 22:28:20 -080017
Mika Westerberg664e3e52014-01-08 12:40:54 +020018#include "gpiolib.h"
19
Uwe Kleine-König3f397c212011-05-20 00:40:19 -060020#define CREATE_TRACE_POINTS
21#include <trace/events/gpio.h>
David Brownelld2876d02008-02-04 22:28:20 -080022
Alexandre Courbot79a9bec2013-10-17 10:21:36 -070023/* Implementation infrastructure for GPIO interfaces.
David Brownelld2876d02008-02-04 22:28:20 -080024 *
Alexandre Courbot79a9bec2013-10-17 10:21:36 -070025 * The GPIO programming interface allows for inlining speed-critical
26 * get/set operations for common cases, so that access to SOC-integrated
27 * GPIOs can sometimes cost only an instruction or two per bit.
David Brownelld2876d02008-02-04 22:28:20 -080028 */
29
30
31/* When debugging, extend minimal trust to callers and platform code.
32 * Also emit diagnostic messages that may help initial bringup, when
33 * board setup or driver bugs are most common.
34 *
35 * Otherwise, minimize overhead in what may be bitbanging codepaths.
36 */
37#ifdef DEBUG
38#define extra_checks 1
39#else
40#define extra_checks 0
41#endif
42
43/* gpio_lock prevents conflicts during gpio_desc[] table updates.
44 * While any GPIO is requested, its gpio_chip is not removable;
45 * each GPIO's "requested" flag serves as a lock and refcount.
46 */
47static DEFINE_SPINLOCK(gpio_lock);
48
49struct gpio_desc {
50 struct gpio_chip *chip;
51 unsigned long flags;
52/* flag symbols are bit numbers */
53#define FLAG_REQUESTED 0
54#define FLAG_IS_OUT 1
Alexandre Courbot710b40e2013-02-02 23:44:06 +090055#define FLAG_EXPORT 2 /* protected by sysfs_lock */
56#define FLAG_SYSFS 3 /* exported via /sys/class/gpio/control */
57#define FLAG_TRIG_FALL 4 /* trigger on falling edge */
58#define FLAG_TRIG_RISE 5 /* trigger on rising edge */
Alexandre Courbot79a9bec2013-10-17 10:21:36 -070059#define FLAG_ACTIVE_LOW 6 /* value has active low */
Alexandre Courbot710b40e2013-02-02 23:44:06 +090060#define FLAG_OPEN_DRAIN 7 /* Gpio is open drain type */
61#define FLAG_OPEN_SOURCE 8 /* Gpio is open source type */
Linus Walleijd468bf92013-09-24 11:54:38 +020062#define FLAG_USED_AS_IRQ 9 /* GPIO is connected to an IRQ */
Daniel Glöcknerff77c352009-09-22 16:46:38 -070063
Daniel Gl?ckner5ba18212010-08-10 18:02:25 -070064#define ID_SHIFT 16 /* add new flags before this one */
Daniel Glöcknerff77c352009-09-22 16:46:38 -070065
Daniel Gl?ckner5ba18212010-08-10 18:02:25 -070066#define GPIO_FLAGS_MASK ((1 << ID_SHIFT) - 1)
Daniel Glöcknerff77c352009-09-22 16:46:38 -070067#define GPIO_TRIGGER_MASK (BIT(FLAG_TRIG_FALL) | BIT(FLAG_TRIG_RISE))
David Brownelld2876d02008-02-04 22:28:20 -080068
69#ifdef CONFIG_DEBUG_FS
70 const char *label;
71#endif
72};
73static struct gpio_desc gpio_desc[ARCH_NR_GPIOS];
74
Alexandre Courbot6c0b4e62013-02-03 01:29:30 +090075#define GPIO_OFFSET_VALID(chip, offset) (offset >= 0 && offset < chip->ngpio)
76
Alexandre Courbotbae48da2013-10-17 10:21:38 -070077static DEFINE_MUTEX(gpio_lookup_lock);
78static LIST_HEAD(gpio_lookup_list);
Alexandre Courbot1a989d02013-02-03 01:29:24 +090079static LIST_HEAD(gpio_chips);
80
Daniel Glöcknerff77c352009-09-22 16:46:38 -070081#ifdef CONFIG_GPIO_SYSFS
Daniel Gl?ckner5ba18212010-08-10 18:02:25 -070082static DEFINE_IDR(dirent_idr);
Daniel Glöcknerff77c352009-09-22 16:46:38 -070083#endif
84
Alexandre Courbot372e7222013-02-03 01:29:29 +090085static int gpiod_request(struct gpio_desc *desc, const char *label);
86static void gpiod_free(struct gpio_desc *desc);
Alexandre Courbot372e7222013-02-03 01:29:29 +090087
Andy Shevchenko1a2a99c2013-12-05 11:26:24 +020088/* With descriptor prefix */
89
Mark Brown7b17b592013-09-09 10:33:50 +010090#ifdef CONFIG_DEBUG_FS
Andy Shevchenko7589e592013-12-05 11:26:23 +020091#define gpiod_emerg(desc, fmt, ...) \
92 pr_emerg("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\
Mark Brown7b17b592013-09-09 10:33:50 +010093 ##__VA_ARGS__)
Andy Shevchenko7589e592013-12-05 11:26:23 +020094#define gpiod_crit(desc, fmt, ...) \
95 pr_crit("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
Mark Brown7b17b592013-09-09 10:33:50 +010096 ##__VA_ARGS__)
Andy Shevchenko7589e592013-12-05 11:26:23 +020097#define gpiod_err(desc, fmt, ...) \
98 pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
Mark Brown7b17b592013-09-09 10:33:50 +010099 ##__VA_ARGS__)
Andy Shevchenko7589e592013-12-05 11:26:23 +0200100#define gpiod_warn(desc, fmt, ...) \
101 pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
Mark Brown7b17b592013-09-09 10:33:50 +0100102 ##__VA_ARGS__)
Andy Shevchenko7589e592013-12-05 11:26:23 +0200103#define gpiod_info(desc, fmt, ...) \
104 pr_info("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
Mark Brown7b17b592013-09-09 10:33:50 +0100105 ##__VA_ARGS__)
Andy Shevchenko7589e592013-12-05 11:26:23 +0200106#define gpiod_dbg(desc, fmt, ...) \
107 pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\
Mark Brown7b17b592013-09-09 10:33:50 +0100108 ##__VA_ARGS__)
109#else
Andy Shevchenko7589e592013-12-05 11:26:23 +0200110#define gpiod_emerg(desc, fmt, ...) \
Mark Brown6424de52013-09-09 10:33:49 +0100111 pr_emerg("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__)
Andy Shevchenko7589e592013-12-05 11:26:23 +0200112#define gpiod_crit(desc, fmt, ...) \
Mark Brown6424de52013-09-09 10:33:49 +0100113 pr_crit("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__)
Andy Shevchenko7589e592013-12-05 11:26:23 +0200114#define gpiod_err(desc, fmt, ...) \
Mark Brown6424de52013-09-09 10:33:49 +0100115 pr_err("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__)
Andy Shevchenko7589e592013-12-05 11:26:23 +0200116#define gpiod_warn(desc, fmt, ...) \
Mark Brown6424de52013-09-09 10:33:49 +0100117 pr_warn("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__)
Andy Shevchenko7589e592013-12-05 11:26:23 +0200118#define gpiod_info(desc, fmt, ...) \
Mark Brown6424de52013-09-09 10:33:49 +0100119 pr_info("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__)
Andy Shevchenko7589e592013-12-05 11:26:23 +0200120#define gpiod_dbg(desc, fmt, ...) \
Mark Brown6424de52013-09-09 10:33:49 +0100121 pr_debug("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__)
Mark Brown7b17b592013-09-09 10:33:50 +0100122#endif
Alexandre Courbot372e7222013-02-03 01:29:29 +0900123
Andy Shevchenko1a2a99c2013-12-05 11:26:24 +0200124/* With chip prefix */
125
126#define chip_emerg(chip, fmt, ...) \
127 pr_emerg("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__)
128#define chip_crit(chip, fmt, ...) \
129 pr_crit("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__)
130#define chip_err(chip, fmt, ...) \
131 pr_err("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__)
132#define chip_warn(chip, fmt, ...) \
133 pr_warn("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__)
134#define chip_info(chip, fmt, ...) \
135 pr_info("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__)
136#define chip_dbg(chip, fmt, ...) \
137 pr_debug("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__)
138
David Brownelld2876d02008-02-04 22:28:20 -0800139static inline void desc_set_label(struct gpio_desc *d, const char *label)
140{
141#ifdef CONFIG_DEBUG_FS
142 d->label = label;
143#endif
144}
145
Alexandre Courbot372e7222013-02-03 01:29:29 +0900146/*
147 * Return the GPIO number of the passed descriptor relative to its chip
148 */
149static int gpio_chip_hwgpio(const struct gpio_desc *desc)
150{
Alexandre Courbot6c0b4e62013-02-03 01:29:30 +0900151 return desc - &desc->chip->desc[0];
Alexandre Courbot372e7222013-02-03 01:29:29 +0900152}
153
154/**
155 * Convert a GPIO number to its descriptor
156 */
Alexandre Courbot79a9bec2013-10-17 10:21:36 -0700157struct gpio_desc *gpio_to_desc(unsigned gpio)
Alexandre Courbot372e7222013-02-03 01:29:29 +0900158{
159 if (WARN(!gpio_is_valid(gpio), "invalid GPIO %d\n", gpio))
160 return NULL;
161 else
162 return &gpio_desc[gpio];
163}
Alexandre Courbot79a9bec2013-10-17 10:21:36 -0700164EXPORT_SYMBOL_GPL(gpio_to_desc);
Alexandre Courbot372e7222013-02-03 01:29:29 +0900165
166/**
Alexandre Courbotbb1e88c2014-02-09 17:43:54 +0900167 * Get the GPIO descriptor corresponding to the given hw number for this chip.
Linus Walleijd468bf92013-09-24 11:54:38 +0200168 */
Alexandre Courbotbb1e88c2014-02-09 17:43:54 +0900169struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip,
170 u16 hwnum)
Linus Walleijd468bf92013-09-24 11:54:38 +0200171{
Alexandre Courbotbb1e88c2014-02-09 17:43:54 +0900172 if (hwnum >= chip->ngpio)
Alexandre Courbotb7d0a282013-12-03 12:31:11 +0900173 return ERR_PTR(-EINVAL);
Linus Walleijd468bf92013-09-24 11:54:38 +0200174
Alexandre Courbotbb1e88c2014-02-09 17:43:54 +0900175 return &chip->desc[hwnum];
Linus Walleijd468bf92013-09-24 11:54:38 +0200176}
Alexandre Courbotbb1e88c2014-02-09 17:43:54 +0900177EXPORT_SYMBOL_GPL(gpiochip_get_desc);
Alexandre Courbot372e7222013-02-03 01:29:29 +0900178
179/**
180 * Convert a GPIO descriptor to the integer namespace.
181 * This should disappear in the future but is needed since we still
182 * use GPIO numbers for error messages and sysfs nodes
183 */
Alexandre Courbot79a9bec2013-10-17 10:21:36 -0700184int desc_to_gpio(const struct gpio_desc *desc)
Alexandre Courbot372e7222013-02-03 01:29:29 +0900185{
Alexandre Courbot8c0fca82013-10-04 10:59:57 -0700186 return desc - &gpio_desc[0];
Alexandre Courbot372e7222013-02-03 01:29:29 +0900187}
Alexandre Courbot79a9bec2013-10-17 10:21:36 -0700188EXPORT_SYMBOL_GPL(desc_to_gpio);
Alexandre Courbot372e7222013-02-03 01:29:29 +0900189
190
David Brownelld2876d02008-02-04 22:28:20 -0800191/* Warn when drivers omit gpio_request() calls -- legal but ill-advised
192 * when setting direction, and otherwise illegal. Until board setup code
193 * and drivers use explicit requests everywhere (which won't happen when
194 * those calls have no teeth) we can't avoid autorequesting. This nag
David Brownell35e8bb52008-10-15 22:03:16 -0700195 * message should motivate switching to explicit requests... so should
196 * the weaker cleanup after faults, compared to gpio_request().
David Brownell8a0cecf2009-04-02 16:57:06 -0700197 *
198 * NOTE: the autorequest mechanism is going away; at this point it's
199 * only "legal" in the sense that (old) code using it won't break yet,
200 * but instead only triggers a WARN() stack dump.
David Brownelld2876d02008-02-04 22:28:20 -0800201 */
Alexandre Courbot372e7222013-02-03 01:29:29 +0900202static int gpio_ensure_requested(struct gpio_desc *desc)
David Brownelld2876d02008-02-04 22:28:20 -0800203{
David Brownell8a0cecf2009-04-02 16:57:06 -0700204 const struct gpio_chip *chip = desc->chip;
Alexandre Courbot372e7222013-02-03 01:29:29 +0900205 const int gpio = desc_to_gpio(desc);
David Brownell35e8bb52008-10-15 22:03:16 -0700206
David Brownell8a0cecf2009-04-02 16:57:06 -0700207 if (WARN(test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0,
208 "autorequest GPIO-%d\n", gpio)) {
David Brownell35e8bb52008-10-15 22:03:16 -0700209 if (!try_module_get(chip->owner)) {
Andy Shevchenko7589e592013-12-05 11:26:23 +0200210 gpiod_err(desc, "%s: module can't be gotten\n",
211 __func__);
David Brownell35e8bb52008-10-15 22:03:16 -0700212 clear_bit(FLAG_REQUESTED, &desc->flags);
213 /* lose */
214 return -EIO;
215 }
David Brownelld2876d02008-02-04 22:28:20 -0800216 desc_set_label(desc, "[auto]");
David Brownell35e8bb52008-10-15 22:03:16 -0700217 /* caller must chip->request() w/o spinlock */
218 if (chip->request)
219 return 1;
David Brownelld2876d02008-02-04 22:28:20 -0800220 }
David Brownell35e8bb52008-10-15 22:03:16 -0700221 return 0;
David Brownelld2876d02008-02-04 22:28:20 -0800222}
223
Alexandre Courbot79a9bec2013-10-17 10:21:36 -0700224/**
225 * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
226 * @desc: descriptor to return the chip of
227 */
228struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
Alexandre Courbot372e7222013-02-03 01:29:29 +0900229{
Alexandre Courbotbcabdef2013-02-15 14:46:14 +0900230 return desc ? desc->chip : NULL;
Alexandre Courbot372e7222013-02-03 01:29:29 +0900231}
Alexandre Courbot79a9bec2013-10-17 10:21:36 -0700232EXPORT_SYMBOL_GPL(gpiod_to_chip);
David Brownelld2876d02008-02-04 22:28:20 -0800233
Anton Vorontsov8d0aab22008-04-28 02:14:46 -0700234/* dynamic allocation of GPIOs, e.g. on a hotplugged device */
235static int gpiochip_find_base(int ngpio)
236{
Alexandre Courbot83cabe32013-02-03 01:29:28 +0900237 struct gpio_chip *chip;
238 int base = ARCH_NR_GPIOS - ngpio;
Anton Vorontsov8d0aab22008-04-28 02:14:46 -0700239
Alexandre Courbot83cabe32013-02-03 01:29:28 +0900240 list_for_each_entry_reverse(chip, &gpio_chips, list) {
241 /* found a free space? */
242 if (chip->base + chip->ngpio <= base)
243 break;
244 else
245 /* nope, check the space right before the chip */
246 base = chip->base - ngpio;
Anton Vorontsov8d0aab22008-04-28 02:14:46 -0700247 }
248
Alexandre Courbot83cabe32013-02-03 01:29:28 +0900249 if (gpio_is_valid(base)) {
Anton Vorontsov8d0aab22008-04-28 02:14:46 -0700250 pr_debug("%s: found new base at %d\n", __func__, base);
Alexandre Courbot83cabe32013-02-03 01:29:28 +0900251 return base;
252 } else {
253 pr_err("%s: cannot find free range\n", __func__);
254 return -ENOSPC;
Anton Vorontsov169b6a72008-04-28 02:14:47 -0700255 }
Anton Vorontsov169b6a72008-04-28 02:14:47 -0700256}
257
Alexandre Courbot79a9bec2013-10-17 10:21:36 -0700258/**
259 * gpiod_get_direction - return the current direction of a GPIO
260 * @desc: GPIO to get the direction of
261 *
262 * Return GPIOF_DIR_IN or GPIOF_DIR_OUT, or an error code in case of error.
263 *
264 * This function may sleep if gpiod_cansleep() is true.
265 */
266int gpiod_get_direction(const struct gpio_desc *desc)
Mathias Nyman80b0a602012-10-24 17:25:27 +0300267{
268 struct gpio_chip *chip;
Alexandre Courbot372e7222013-02-03 01:29:29 +0900269 unsigned offset;
Mathias Nyman80b0a602012-10-24 17:25:27 +0300270 int status = -EINVAL;
271
Alexandre Courbot372e7222013-02-03 01:29:29 +0900272 chip = gpiod_to_chip(desc);
273 offset = gpio_chip_hwgpio(desc);
Mathias Nyman80b0a602012-10-24 17:25:27 +0300274
275 if (!chip->get_direction)
276 return status;
277
Alexandre Courbot372e7222013-02-03 01:29:29 +0900278 status = chip->get_direction(chip, offset);
Mathias Nyman80b0a602012-10-24 17:25:27 +0300279 if (status > 0) {
280 /* GPIOF_DIR_IN, or other positive */
281 status = 1;
Alexandre Courbotdef63432013-02-15 14:46:15 +0900282 /* FLAG_IS_OUT is just a cache of the result of get_direction(),
283 * so it does not affect constness per se */
284 clear_bit(FLAG_IS_OUT, &((struct gpio_desc *)desc)->flags);
Mathias Nyman80b0a602012-10-24 17:25:27 +0300285 }
286 if (status == 0) {
287 /* GPIOF_DIR_OUT */
Alexandre Courbotdef63432013-02-15 14:46:15 +0900288 set_bit(FLAG_IS_OUT, &((struct gpio_desc *)desc)->flags);
Mathias Nyman80b0a602012-10-24 17:25:27 +0300289 }
290 return status;
291}
Alexandre Courbot79a9bec2013-10-17 10:21:36 -0700292EXPORT_SYMBOL_GPL(gpiod_get_direction);
Mathias Nyman80b0a602012-10-24 17:25:27 +0300293
David Brownelld8f388d2008-07-25 01:46:07 -0700294#ifdef CONFIG_GPIO_SYSFS
295
296/* lock protects against unexport_gpio() being called while
297 * sysfs files are active.
298 */
299static DEFINE_MUTEX(sysfs_lock);
300
301/*
302 * /sys/class/gpio/gpioN... only for GPIOs that are exported
303 * /direction
304 * * MAY BE OMITTED if kernel won't allow direction changes
305 * * is read/write as "in" or "out"
306 * * may also be written as "high" or "low", initializing
307 * output value as specified ("out" implies "low")
308 * /value
309 * * always readable, subject to hardware behavior
310 * * may be writable, as zero/nonzero
Daniel Glöcknerff77c352009-09-22 16:46:38 -0700311 * /edge
312 * * configures behavior of poll(2) on /value
313 * * available only if pin can generate IRQs on input
314 * * is read/write as "none", "falling", "rising", or "both"
Jani Nikula07697462009-12-15 16:46:20 -0800315 * /active_low
316 * * configures polarity of /value
317 * * is read/write as zero/nonzero
318 * * also affects existing and subsequent "falling" and "rising"
319 * /edge configuration
David Brownelld8f388d2008-07-25 01:46:07 -0700320 */
321
322static ssize_t gpio_direction_show(struct device *dev,
323 struct device_attribute *attr, char *buf)
324{
Alexandre Courbotdef63432013-02-15 14:46:15 +0900325 const struct gpio_desc *desc = dev_get_drvdata(dev);
David Brownelld8f388d2008-07-25 01:46:07 -0700326 ssize_t status;
327
328 mutex_lock(&sysfs_lock);
329
Alexandre Courbot476171ce2013-02-04 17:42:04 +0900330 if (!test_bit(FLAG_EXPORT, &desc->flags)) {
David Brownelld8f388d2008-07-25 01:46:07 -0700331 status = -EIO;
Alexandre Courbot476171ce2013-02-04 17:42:04 +0900332 } else {
Alexandre Courbot372e7222013-02-03 01:29:29 +0900333 gpiod_get_direction(desc);
David Brownelld8f388d2008-07-25 01:46:07 -0700334 status = sprintf(buf, "%s\n",
335 test_bit(FLAG_IS_OUT, &desc->flags)
336 ? "out" : "in");
Alexandre Courbot476171ce2013-02-04 17:42:04 +0900337 }
David Brownelld8f388d2008-07-25 01:46:07 -0700338
339 mutex_unlock(&sysfs_lock);
340 return status;
341}
342
343static ssize_t gpio_direction_store(struct device *dev,
344 struct device_attribute *attr, const char *buf, size_t size)
345{
Alexandre Courbot372e7222013-02-03 01:29:29 +0900346 struct gpio_desc *desc = dev_get_drvdata(dev);
David Brownelld8f388d2008-07-25 01:46:07 -0700347 ssize_t status;
348
349 mutex_lock(&sysfs_lock);
350
351 if (!test_bit(FLAG_EXPORT, &desc->flags))
352 status = -EIO;
353 else if (sysfs_streq(buf, "high"))
Philipp Zabelef70bbe2014-01-07 12:34:11 +0100354 status = gpiod_direction_output_raw(desc, 1);
David Brownelld8f388d2008-07-25 01:46:07 -0700355 else if (sysfs_streq(buf, "out") || sysfs_streq(buf, "low"))
Philipp Zabelef70bbe2014-01-07 12:34:11 +0100356 status = gpiod_direction_output_raw(desc, 0);
David Brownelld8f388d2008-07-25 01:46:07 -0700357 else if (sysfs_streq(buf, "in"))
Alexandre Courbot372e7222013-02-03 01:29:29 +0900358 status = gpiod_direction_input(desc);
David Brownelld8f388d2008-07-25 01:46:07 -0700359 else
360 status = -EINVAL;
361
362 mutex_unlock(&sysfs_lock);
363 return status ? : size;
364}
365
Jani Nikula07697462009-12-15 16:46:20 -0800366static /* const */ DEVICE_ATTR(direction, 0644,
David Brownelld8f388d2008-07-25 01:46:07 -0700367 gpio_direction_show, gpio_direction_store);
368
369static ssize_t gpio_value_show(struct device *dev,
370 struct device_attribute *attr, char *buf)
371{
Alexandre Courbot372e7222013-02-03 01:29:29 +0900372 struct gpio_desc *desc = dev_get_drvdata(dev);
David Brownelld8f388d2008-07-25 01:46:07 -0700373 ssize_t status;
374
375 mutex_lock(&sysfs_lock);
376
Alexandre Courbot79a9bec2013-10-17 10:21:36 -0700377 if (!test_bit(FLAG_EXPORT, &desc->flags))
David Brownelld8f388d2008-07-25 01:46:07 -0700378 status = -EIO;
Alexandre Courbot79a9bec2013-10-17 10:21:36 -0700379 else
380 status = sprintf(buf, "%d\n", gpiod_get_value_cansleep(desc));
David Brownelld8f388d2008-07-25 01:46:07 -0700381
382 mutex_unlock(&sysfs_lock);
383 return status;
384}
385
386static ssize_t gpio_value_store(struct device *dev,
387 struct device_attribute *attr, const char *buf, size_t size)
388{
Alexandre Courbot372e7222013-02-03 01:29:29 +0900389 struct gpio_desc *desc = dev_get_drvdata(dev);
David Brownelld8f388d2008-07-25 01:46:07 -0700390 ssize_t status;
391
392 mutex_lock(&sysfs_lock);
393
394 if (!test_bit(FLAG_EXPORT, &desc->flags))
395 status = -EIO;
396 else if (!test_bit(FLAG_IS_OUT, &desc->flags))
397 status = -EPERM;
398 else {
399 long value;
400
Jingoo Hana3d88c92013-07-19 16:12:50 +0900401 status = kstrtol(buf, 0, &value);
David Brownelld8f388d2008-07-25 01:46:07 -0700402 if (status == 0) {
Alexandre Courbot79a9bec2013-10-17 10:21:36 -0700403 gpiod_set_value_cansleep(desc, value);
David Brownelld8f388d2008-07-25 01:46:07 -0700404 status = size;
405 }
406 }
407
408 mutex_unlock(&sysfs_lock);
409 return status;
410}
411
Jani Nikula07697462009-12-15 16:46:20 -0800412static const DEVICE_ATTR(value, 0644,
David Brownelld8f388d2008-07-25 01:46:07 -0700413 gpio_value_show, gpio_value_store);
414
Daniel Glöcknerff77c352009-09-22 16:46:38 -0700415static irqreturn_t gpio_sysfs_irq(int irq, void *priv)
416{
Tejun Heo324a56e2013-12-11 14:11:53 -0500417 struct kernfs_node *value_sd = priv;
Daniel Glöcknerff77c352009-09-22 16:46:38 -0700418
Daniel Gl?ckner5ba18212010-08-10 18:02:25 -0700419 sysfs_notify_dirent(value_sd);
Daniel Glöcknerff77c352009-09-22 16:46:38 -0700420 return IRQ_HANDLED;
421}
422
Daniel Glöcknerff77c352009-09-22 16:46:38 -0700423static int gpio_setup_irq(struct gpio_desc *desc, struct device *dev,
424 unsigned long gpio_flags)
425{
Tejun Heo324a56e2013-12-11 14:11:53 -0500426 struct kernfs_node *value_sd;
Daniel Glöcknerff77c352009-09-22 16:46:38 -0700427 unsigned long irq_flags;
428 int ret, irq, id;
429
430 if ((desc->flags & GPIO_TRIGGER_MASK) == gpio_flags)
431 return 0;
432
Alexandre Courbot372e7222013-02-03 01:29:29 +0900433 irq = gpiod_to_irq(desc);
Daniel Glöcknerff77c352009-09-22 16:46:38 -0700434 if (irq < 0)
435 return -EIO;
436
Daniel Gl?ckner5ba18212010-08-10 18:02:25 -0700437 id = desc->flags >> ID_SHIFT;
438 value_sd = idr_find(&dirent_idr, id);
439 if (value_sd)
440 free_irq(irq, value_sd);
Daniel Glöcknerff77c352009-09-22 16:46:38 -0700441
442 desc->flags &= ~GPIO_TRIGGER_MASK;
443
444 if (!gpio_flags) {
Linus Walleijd468bf92013-09-24 11:54:38 +0200445 gpiod_unlock_as_irq(desc);
Daniel Glöcknerff77c352009-09-22 16:46:38 -0700446 ret = 0;
Daniel Gl?ckner5ba18212010-08-10 18:02:25 -0700447 goto free_id;
Daniel Glöcknerff77c352009-09-22 16:46:38 -0700448 }
449
450 irq_flags = IRQF_SHARED;
451 if (test_bit(FLAG_TRIG_FALL, &gpio_flags))
Jani Nikula07697462009-12-15 16:46:20 -0800452 irq_flags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ?
453 IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING;
Daniel Glöcknerff77c352009-09-22 16:46:38 -0700454 if (test_bit(FLAG_TRIG_RISE, &gpio_flags))
Jani Nikula07697462009-12-15 16:46:20 -0800455 irq_flags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ?
456 IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING;
Daniel Glöcknerff77c352009-09-22 16:46:38 -0700457
Daniel Gl?ckner5ba18212010-08-10 18:02:25 -0700458 if (!value_sd) {
Tejun Heo388975c2013-09-11 23:19:13 -0400459 value_sd = sysfs_get_dirent(dev->kobj.sd, "value");
Daniel Gl?ckner5ba18212010-08-10 18:02:25 -0700460 if (!value_sd) {
461 ret = -ENODEV;
Daniel Glöcknerff77c352009-09-22 16:46:38 -0700462 goto err_out;
463 }
464
Tejun Heo62f516b2013-02-27 17:04:06 -0800465 ret = idr_alloc(&dirent_idr, value_sd, 1, 0, GFP_KERNEL);
466 if (ret < 0)
Daniel Gl?ckner5ba18212010-08-10 18:02:25 -0700467 goto free_sd;
Tejun Heo62f516b2013-02-27 17:04:06 -0800468 id = ret;
Daniel Glöcknerff77c352009-09-22 16:46:38 -0700469
470 desc->flags &= GPIO_FLAGS_MASK;
Daniel Gl?ckner5ba18212010-08-10 18:02:25 -0700471 desc->flags |= (unsigned long)id << ID_SHIFT;
Daniel Glöcknerff77c352009-09-22 16:46:38 -0700472
Daniel Gl?ckner5ba18212010-08-10 18:02:25 -0700473 if (desc->flags >> ID_SHIFT != id) {
Daniel Glöcknerff77c352009-09-22 16:46:38 -0700474 ret = -ERANGE;
475 goto free_id;
476 }
Daniel Glöcknerff77c352009-09-22 16:46:38 -0700477 }
478
Daniel Gl?ckner364fadb32010-08-10 18:02:26 -0700479 ret = request_any_context_irq(irq, gpio_sysfs_irq, irq_flags,
Daniel Gl?ckner5ba18212010-08-10 18:02:25 -0700480 "gpiolib", value_sd);
Daniel Gl?ckner364fadb32010-08-10 18:02:26 -0700481 if (ret < 0)
Daniel Gl?ckner5ba18212010-08-10 18:02:25 -0700482 goto free_id;
Daniel Glöcknerff77c352009-09-22 16:46:38 -0700483
Linus Walleijd468bf92013-09-24 11:54:38 +0200484 ret = gpiod_lock_as_irq(desc);
485 if (ret < 0) {
486 gpiod_warn(desc, "failed to flag the GPIO for IRQ\n");
487 goto free_id;
488 }
489
Daniel Glöcknerff77c352009-09-22 16:46:38 -0700490 desc->flags |= gpio_flags;
491 return 0;
492
Daniel Glöcknerff77c352009-09-22 16:46:38 -0700493free_id:
Daniel Gl?ckner5ba18212010-08-10 18:02:25 -0700494 idr_remove(&dirent_idr, id);
Daniel Glöcknerff77c352009-09-22 16:46:38 -0700495 desc->flags &= GPIO_FLAGS_MASK;
Daniel Gl?ckner5ba18212010-08-10 18:02:25 -0700496free_sd:
497 if (value_sd)
498 sysfs_put(value_sd);
Daniel Glöcknerff77c352009-09-22 16:46:38 -0700499err_out:
500 return ret;
501}
502
503static const struct {
504 const char *name;
505 unsigned long flags;
506} trigger_types[] = {
507 { "none", 0 },
508 { "falling", BIT(FLAG_TRIG_FALL) },
509 { "rising", BIT(FLAG_TRIG_RISE) },
510 { "both", BIT(FLAG_TRIG_FALL) | BIT(FLAG_TRIG_RISE) },
511};
512
513static ssize_t gpio_edge_show(struct device *dev,
514 struct device_attribute *attr, char *buf)
515{
516 const struct gpio_desc *desc = dev_get_drvdata(dev);
517 ssize_t status;
518
519 mutex_lock(&sysfs_lock);
520
521 if (!test_bit(FLAG_EXPORT, &desc->flags))
522 status = -EIO;
523 else {
524 int i;
525
526 status = 0;
527 for (i = 0; i < ARRAY_SIZE(trigger_types); i++)
528 if ((desc->flags & GPIO_TRIGGER_MASK)
529 == trigger_types[i].flags) {
530 status = sprintf(buf, "%s\n",
531 trigger_types[i].name);
532 break;
533 }
534 }
535
536 mutex_unlock(&sysfs_lock);
537 return status;
538}
539
540static ssize_t gpio_edge_store(struct device *dev,
541 struct device_attribute *attr, const char *buf, size_t size)
542{
543 struct gpio_desc *desc = dev_get_drvdata(dev);
544 ssize_t status;
545 int i;
546
547 for (i = 0; i < ARRAY_SIZE(trigger_types); i++)
548 if (sysfs_streq(trigger_types[i].name, buf))
549 goto found;
550 return -EINVAL;
551
552found:
553 mutex_lock(&sysfs_lock);
554
555 if (!test_bit(FLAG_EXPORT, &desc->flags))
556 status = -EIO;
557 else {
558 status = gpio_setup_irq(desc, dev, trigger_types[i].flags);
559 if (!status)
560 status = size;
561 }
562
563 mutex_unlock(&sysfs_lock);
564
565 return status;
566}
567
568static DEVICE_ATTR(edge, 0644, gpio_edge_show, gpio_edge_store);
569
Jani Nikula07697462009-12-15 16:46:20 -0800570static int sysfs_set_active_low(struct gpio_desc *desc, struct device *dev,
571 int value)
572{
573 int status = 0;
574
575 if (!!test_bit(FLAG_ACTIVE_LOW, &desc->flags) == !!value)
576 return 0;
577
578 if (value)
579 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
580 else
581 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
582
583 /* reconfigure poll(2) support if enabled on one edge only */
584 if (dev != NULL && (!!test_bit(FLAG_TRIG_RISE, &desc->flags) ^
585 !!test_bit(FLAG_TRIG_FALL, &desc->flags))) {
586 unsigned long trigger_flags = desc->flags & GPIO_TRIGGER_MASK;
587
588 gpio_setup_irq(desc, dev, 0);
589 status = gpio_setup_irq(desc, dev, trigger_flags);
590 }
591
592 return status;
593}
594
595static ssize_t gpio_active_low_show(struct device *dev,
596 struct device_attribute *attr, char *buf)
597{
598 const struct gpio_desc *desc = dev_get_drvdata(dev);
599 ssize_t status;
600
601 mutex_lock(&sysfs_lock);
602
603 if (!test_bit(FLAG_EXPORT, &desc->flags))
604 status = -EIO;
605 else
606 status = sprintf(buf, "%d\n",
607 !!test_bit(FLAG_ACTIVE_LOW, &desc->flags));
608
609 mutex_unlock(&sysfs_lock);
610
611 return status;
612}
613
614static ssize_t gpio_active_low_store(struct device *dev,
615 struct device_attribute *attr, const char *buf, size_t size)
616{
617 struct gpio_desc *desc = dev_get_drvdata(dev);
618 ssize_t status;
619
620 mutex_lock(&sysfs_lock);
621
622 if (!test_bit(FLAG_EXPORT, &desc->flags)) {
623 status = -EIO;
624 } else {
625 long value;
626
Jingoo Hana3d88c92013-07-19 16:12:50 +0900627 status = kstrtol(buf, 0, &value);
Jani Nikula07697462009-12-15 16:46:20 -0800628 if (status == 0)
629 status = sysfs_set_active_low(desc, dev, value != 0);
630 }
631
632 mutex_unlock(&sysfs_lock);
633
634 return status ? : size;
635}
636
637static const DEVICE_ATTR(active_low, 0644,
638 gpio_active_low_show, gpio_active_low_store);
639
David Brownelld8f388d2008-07-25 01:46:07 -0700640static const struct attribute *gpio_attrs[] = {
David Brownelld8f388d2008-07-25 01:46:07 -0700641 &dev_attr_value.attr,
Jani Nikula07697462009-12-15 16:46:20 -0800642 &dev_attr_active_low.attr,
David Brownelld8f388d2008-07-25 01:46:07 -0700643 NULL,
644};
645
646static const struct attribute_group gpio_attr_group = {
647 .attrs = (struct attribute **) gpio_attrs,
648};
649
650/*
651 * /sys/class/gpio/gpiochipN/
652 * /base ... matching gpio_chip.base (N)
653 * /label ... matching gpio_chip.label
654 * /ngpio ... matching gpio_chip.ngpio
655 */
656
657static ssize_t chip_base_show(struct device *dev,
658 struct device_attribute *attr, char *buf)
659{
660 const struct gpio_chip *chip = dev_get_drvdata(dev);
661
662 return sprintf(buf, "%d\n", chip->base);
663}
664static DEVICE_ATTR(base, 0444, chip_base_show, NULL);
665
666static ssize_t chip_label_show(struct device *dev,
667 struct device_attribute *attr, char *buf)
668{
669 const struct gpio_chip *chip = dev_get_drvdata(dev);
670
671 return sprintf(buf, "%s\n", chip->label ? : "");
672}
673static DEVICE_ATTR(label, 0444, chip_label_show, NULL);
674
675static ssize_t chip_ngpio_show(struct device *dev,
676 struct device_attribute *attr, char *buf)
677{
678 const struct gpio_chip *chip = dev_get_drvdata(dev);
679
680 return sprintf(buf, "%u\n", chip->ngpio);
681}
682static DEVICE_ATTR(ngpio, 0444, chip_ngpio_show, NULL);
683
684static const struct attribute *gpiochip_attrs[] = {
685 &dev_attr_base.attr,
686 &dev_attr_label.attr,
687 &dev_attr_ngpio.attr,
688 NULL,
689};
690
691static const struct attribute_group gpiochip_attr_group = {
692 .attrs = (struct attribute **) gpiochip_attrs,
693};
694
695/*
696 * /sys/class/gpio/export ... write-only
697 * integer N ... number of GPIO to export (full access)
698 * /sys/class/gpio/unexport ... write-only
699 * integer N ... number of GPIO to unexport
700 */
Andi Kleen28812fe2010-01-05 12:48:07 +0100701static ssize_t export_store(struct class *class,
702 struct class_attribute *attr,
703 const char *buf, size_t len)
David Brownelld8f388d2008-07-25 01:46:07 -0700704{
Alexandre Courbot372e7222013-02-03 01:29:29 +0900705 long gpio;
706 struct gpio_desc *desc;
707 int status;
David Brownelld8f388d2008-07-25 01:46:07 -0700708
Jingoo Hana3d88c92013-07-19 16:12:50 +0900709 status = kstrtol(buf, 0, &gpio);
David Brownelld8f388d2008-07-25 01:46:07 -0700710 if (status < 0)
711 goto done;
712
Alexandre Courbot372e7222013-02-03 01:29:29 +0900713 desc = gpio_to_desc(gpio);
Alexandre Courbotbcabdef2013-02-15 14:46:14 +0900714 /* reject invalid GPIOs */
715 if (!desc) {
716 pr_warn("%s: invalid GPIO %ld\n", __func__, gpio);
717 return -EINVAL;
718 }
Alexandre Courbot372e7222013-02-03 01:29:29 +0900719
David Brownelld8f388d2008-07-25 01:46:07 -0700720 /* No extra locking here; FLAG_SYSFS just signifies that the
721 * request and export were done by on behalf of userspace, so
722 * they may be undone on its behalf too.
723 */
724
Alexandre Courbot372e7222013-02-03 01:29:29 +0900725 status = gpiod_request(desc, "sysfs");
Mathias Nymanad2fab32012-10-25 14:03:03 +0300726 if (status < 0) {
727 if (status == -EPROBE_DEFER)
728 status = -ENODEV;
David Brownelld8f388d2008-07-25 01:46:07 -0700729 goto done;
Mathias Nymanad2fab32012-10-25 14:03:03 +0300730 }
Alexandre Courbot372e7222013-02-03 01:29:29 +0900731 status = gpiod_export(desc, true);
David Brownelld8f388d2008-07-25 01:46:07 -0700732 if (status < 0)
Alexandre Courbot372e7222013-02-03 01:29:29 +0900733 gpiod_free(desc);
David Brownelld8f388d2008-07-25 01:46:07 -0700734 else
Alexandre Courbot372e7222013-02-03 01:29:29 +0900735 set_bit(FLAG_SYSFS, &desc->flags);
David Brownelld8f388d2008-07-25 01:46:07 -0700736
737done:
738 if (status)
739 pr_debug("%s: status %d\n", __func__, status);
740 return status ? : len;
741}
742
Andi Kleen28812fe2010-01-05 12:48:07 +0100743static ssize_t unexport_store(struct class *class,
744 struct class_attribute *attr,
745 const char *buf, size_t len)
David Brownelld8f388d2008-07-25 01:46:07 -0700746{
Alexandre Courbot372e7222013-02-03 01:29:29 +0900747 long gpio;
748 struct gpio_desc *desc;
749 int status;
David Brownelld8f388d2008-07-25 01:46:07 -0700750
Jingoo Hana3d88c92013-07-19 16:12:50 +0900751 status = kstrtol(buf, 0, &gpio);
David Brownelld8f388d2008-07-25 01:46:07 -0700752 if (status < 0)
753 goto done;
754
Alexandre Courbot372e7222013-02-03 01:29:29 +0900755 desc = gpio_to_desc(gpio);
David Brownelld8f388d2008-07-25 01:46:07 -0700756 /* reject bogus commands (gpio_unexport ignores them) */
Alexandre Courbotbcabdef2013-02-15 14:46:14 +0900757 if (!desc) {
758 pr_warn("%s: invalid GPIO %ld\n", __func__, gpio);
759 return -EINVAL;
760 }
761
762 status = -EINVAL;
David Brownelld8f388d2008-07-25 01:46:07 -0700763
764 /* No extra locking here; FLAG_SYSFS just signifies that the
765 * request and export were done by on behalf of userspace, so
766 * they may be undone on its behalf too.
767 */
Alexandre Courbot372e7222013-02-03 01:29:29 +0900768 if (test_and_clear_bit(FLAG_SYSFS, &desc->flags)) {
David Brownelld8f388d2008-07-25 01:46:07 -0700769 status = 0;
Alexandre Courbot372e7222013-02-03 01:29:29 +0900770 gpiod_free(desc);
David Brownelld8f388d2008-07-25 01:46:07 -0700771 }
772done:
773 if (status)
774 pr_debug("%s: status %d\n", __func__, status);
775 return status ? : len;
776}
777
778static struct class_attribute gpio_class_attrs[] = {
779 __ATTR(export, 0200, NULL, export_store),
780 __ATTR(unexport, 0200, NULL, unexport_store),
781 __ATTR_NULL,
782};
783
784static struct class gpio_class = {
785 .name = "gpio",
786 .owner = THIS_MODULE,
787
788 .class_attrs = gpio_class_attrs,
789};
790
791
792/**
Alexandre Courbot79a9bec2013-10-17 10:21:36 -0700793 * gpiod_export - export a GPIO through sysfs
David Brownelld8f388d2008-07-25 01:46:07 -0700794 * @gpio: gpio to make available, already requested
795 * @direction_may_change: true if userspace may change gpio direction
796 * Context: arch_initcall or later
797 *
798 * When drivers want to make a GPIO accessible to userspace after they
799 * have requested it -- perhaps while debugging, or as part of their
800 * public interface -- they may use this routine. If the GPIO can
801 * change direction (some can't) and the caller allows it, userspace
802 * will see "direction" sysfs attribute which may be used to change
803 * the gpio's direction. A "value" attribute will always be provided.
804 *
805 * Returns zero on success, else an error.
806 */
Alexandre Courbot79a9bec2013-10-17 10:21:36 -0700807int gpiod_export(struct gpio_desc *desc, bool direction_may_change)
David Brownelld8f388d2008-07-25 01:46:07 -0700808{
809 unsigned long flags;
Ryan Mallonfc4e2512012-10-22 11:39:12 +1100810 int status;
Uwe Kleine-König62154992010-05-26 14:42:17 -0700811 const char *ioname = NULL;
Ryan Mallonfc4e2512012-10-22 11:39:12 +1100812 struct device *dev;
Alexandre Courbot372e7222013-02-03 01:29:29 +0900813 int offset;
David Brownelld8f388d2008-07-25 01:46:07 -0700814
815 /* can't export until sysfs is available ... */
816 if (!gpio_class.p) {
817 pr_debug("%s: called too early!\n", __func__);
818 return -ENOENT;
819 }
820
Alexandre Courbot372e7222013-02-03 01:29:29 +0900821 if (!desc) {
822 pr_debug("%s: invalid gpio descriptor\n", __func__);
Ryan Mallonfc4e2512012-10-22 11:39:12 +1100823 return -EINVAL;
824 }
David Brownelld8f388d2008-07-25 01:46:07 -0700825
826 mutex_lock(&sysfs_lock);
827
828 spin_lock_irqsave(&gpio_lock, flags);
Ryan Mallonfc4e2512012-10-22 11:39:12 +1100829 if (!test_bit(FLAG_REQUESTED, &desc->flags) ||
830 test_bit(FLAG_EXPORT, &desc->flags)) {
831 spin_unlock_irqrestore(&gpio_lock, flags);
Andy Shevchenko7589e592013-12-05 11:26:23 +0200832 gpiod_dbg(desc, "%s: unavailable (requested=%d, exported=%d)\n",
833 __func__,
Ryan Mallonfc4e2512012-10-22 11:39:12 +1100834 test_bit(FLAG_REQUESTED, &desc->flags),
835 test_bit(FLAG_EXPORT, &desc->flags));
Dan Carpenter529f2ad2012-10-26 09:59:43 +0300836 status = -EPERM;
837 goto fail_unlock;
David Brownelld8f388d2008-07-25 01:46:07 -0700838 }
Ryan Mallonfc4e2512012-10-22 11:39:12 +1100839
840 if (!desc->chip->direction_input || !desc->chip->direction_output)
841 direction_may_change = false;
David Brownelld8f388d2008-07-25 01:46:07 -0700842 spin_unlock_irqrestore(&gpio_lock, flags);
843
Alexandre Courbot372e7222013-02-03 01:29:29 +0900844 offset = gpio_chip_hwgpio(desc);
845 if (desc->chip->names && desc->chip->names[offset])
846 ioname = desc->chip->names[offset];
Daniel Silverstone926b6632009-04-02 16:57:05 -0700847
Ryan Mallonfc4e2512012-10-22 11:39:12 +1100848 dev = device_create(&gpio_class, desc->chip->dev, MKDEV(0, 0),
Alexandre Courbot372e7222013-02-03 01:29:29 +0900849 desc, ioname ? ioname : "gpio%u",
850 desc_to_gpio(desc));
Ryan Mallonfc4e2512012-10-22 11:39:12 +1100851 if (IS_ERR(dev)) {
852 status = PTR_ERR(dev);
853 goto fail_unlock;
David Brownelld8f388d2008-07-25 01:46:07 -0700854 }
855
Ryan Mallonfc4e2512012-10-22 11:39:12 +1100856 status = sysfs_create_group(&dev->kobj, &gpio_attr_group);
David Brownelld8f388d2008-07-25 01:46:07 -0700857 if (status)
Ryan Mallonfc4e2512012-10-22 11:39:12 +1100858 goto fail_unregister_device;
David Brownelld8f388d2008-07-25 01:46:07 -0700859
Ryan Mallonfc4e2512012-10-22 11:39:12 +1100860 if (direction_may_change) {
861 status = device_create_file(dev, &dev_attr_direction);
862 if (status)
863 goto fail_unregister_device;
864 }
865
Alexandre Courbot372e7222013-02-03 01:29:29 +0900866 if (gpiod_to_irq(desc) >= 0 && (direction_may_change ||
Ryan Mallonfc4e2512012-10-22 11:39:12 +1100867 !test_bit(FLAG_IS_OUT, &desc->flags))) {
868 status = device_create_file(dev, &dev_attr_edge);
869 if (status)
870 goto fail_unregister_device;
871 }
872
873 set_bit(FLAG_EXPORT, &desc->flags);
874 mutex_unlock(&sysfs_lock);
875 return 0;
876
877fail_unregister_device:
878 device_unregister(dev);
879fail_unlock:
880 mutex_unlock(&sysfs_lock);
Andy Shevchenko7589e592013-12-05 11:26:23 +0200881 gpiod_dbg(desc, "%s: status %d\n", __func__, status);
David Brownelld8f388d2008-07-25 01:46:07 -0700882 return status;
883}
Alexandre Courbot79a9bec2013-10-17 10:21:36 -0700884EXPORT_SYMBOL_GPL(gpiod_export);
David Brownelld8f388d2008-07-25 01:46:07 -0700885
Michał Mirosław9f3b7952013-02-01 20:40:17 +0100886static int match_export(struct device *dev, const void *data)
David Brownelld8f388d2008-07-25 01:46:07 -0700887{
888 return dev_get_drvdata(dev) == data;
889}
890
891/**
Alexandre Courbot79a9bec2013-10-17 10:21:36 -0700892 * gpiod_export_link - create a sysfs link to an exported GPIO node
Jani Nikulaa4177ee2009-09-22 16:46:33 -0700893 * @dev: device under which to create symlink
894 * @name: name of the symlink
895 * @gpio: gpio to create symlink to, already exported
896 *
897 * Set up a symlink from /sys/.../dev/name to /sys/class/gpio/gpioN
898 * node. Caller is responsible for unlinking.
899 *
900 * Returns zero on success, else an error.
901 */
Alexandre Courbot79a9bec2013-10-17 10:21:36 -0700902int gpiod_export_link(struct device *dev, const char *name,
903 struct gpio_desc *desc)
Jani Nikulaa4177ee2009-09-22 16:46:33 -0700904{
Jani Nikulaa4177ee2009-09-22 16:46:33 -0700905 int status = -EINVAL;
906
Alexandre Courbotbcabdef2013-02-15 14:46:14 +0900907 if (!desc) {
908 pr_warn("%s: invalid GPIO\n", __func__);
909 return -EINVAL;
910 }
Jani Nikulaa4177ee2009-09-22 16:46:33 -0700911
912 mutex_lock(&sysfs_lock);
913
Jani Nikulaa4177ee2009-09-22 16:46:33 -0700914 if (test_bit(FLAG_EXPORT, &desc->flags)) {
915 struct device *tdev;
916
917 tdev = class_find_device(&gpio_class, NULL, desc, match_export);
918 if (tdev != NULL) {
919 status = sysfs_create_link(&dev->kobj, &tdev->kobj,
920 name);
921 } else {
922 status = -ENODEV;
923 }
924 }
925
926 mutex_unlock(&sysfs_lock);
927
Jani Nikulaa4177ee2009-09-22 16:46:33 -0700928 if (status)
Andy Shevchenko7589e592013-12-05 11:26:23 +0200929 gpiod_dbg(desc, "%s: status %d\n", __func__, status);
Jani Nikulaa4177ee2009-09-22 16:46:33 -0700930
931 return status;
932}
Alexandre Courbot79a9bec2013-10-17 10:21:36 -0700933EXPORT_SYMBOL_GPL(gpiod_export_link);
Jani Nikula07697462009-12-15 16:46:20 -0800934
935/**
Alexandre Courbot79a9bec2013-10-17 10:21:36 -0700936 * gpiod_sysfs_set_active_low - set the polarity of gpio sysfs value
Jani Nikula07697462009-12-15 16:46:20 -0800937 * @gpio: gpio to change
938 * @value: non-zero to use active low, i.e. inverted values
939 *
940 * Set the polarity of /sys/class/gpio/gpioN/value sysfs attribute.
941 * The GPIO does not have to be exported yet. If poll(2) support has
942 * been enabled for either rising or falling edge, it will be
943 * reconfigured to follow the new polarity.
944 *
945 * Returns zero on success, else an error.
946 */
Alexandre Courbot79a9bec2013-10-17 10:21:36 -0700947int gpiod_sysfs_set_active_low(struct gpio_desc *desc, int value)
Jani Nikula07697462009-12-15 16:46:20 -0800948{
Jani Nikula07697462009-12-15 16:46:20 -0800949 struct device *dev = NULL;
950 int status = -EINVAL;
951
Alexandre Courbotbcabdef2013-02-15 14:46:14 +0900952 if (!desc) {
953 pr_warn("%s: invalid GPIO\n", __func__);
954 return -EINVAL;
955 }
Jani Nikula07697462009-12-15 16:46:20 -0800956
957 mutex_lock(&sysfs_lock);
958
Jani Nikula07697462009-12-15 16:46:20 -0800959 if (test_bit(FLAG_EXPORT, &desc->flags)) {
Jani Nikula07697462009-12-15 16:46:20 -0800960 dev = class_find_device(&gpio_class, NULL, desc, match_export);
961 if (dev == NULL) {
962 status = -ENODEV;
963 goto unlock;
964 }
965 }
966
967 status = sysfs_set_active_low(desc, dev, value);
968
969unlock:
970 mutex_unlock(&sysfs_lock);
971
Jani Nikula07697462009-12-15 16:46:20 -0800972 if (status)
Andy Shevchenko7589e592013-12-05 11:26:23 +0200973 gpiod_dbg(desc, "%s: status %d\n", __func__, status);
Jani Nikula07697462009-12-15 16:46:20 -0800974
975 return status;
976}
Alexandre Courbot79a9bec2013-10-17 10:21:36 -0700977EXPORT_SYMBOL_GPL(gpiod_sysfs_set_active_low);
Jani Nikula07697462009-12-15 16:46:20 -0800978
Jani Nikulaa4177ee2009-09-22 16:46:33 -0700979/**
Alexandre Courbot79a9bec2013-10-17 10:21:36 -0700980 * gpiod_unexport - reverse effect of gpio_export()
David Brownelld8f388d2008-07-25 01:46:07 -0700981 * @gpio: gpio to make unavailable
982 *
983 * This is implicit on gpio_free().
984 */
Alexandre Courbot79a9bec2013-10-17 10:21:36 -0700985void gpiod_unexport(struct gpio_desc *desc)
David Brownelld8f388d2008-07-25 01:46:07 -0700986{
Jon Povey6a99ad42010-07-27 13:18:06 -0700987 int status = 0;
Ming Lei864533c2012-02-13 22:53:20 +0800988 struct device *dev = NULL;
David Brownelld8f388d2008-07-25 01:46:07 -0700989
Alexandre Courbot372e7222013-02-03 01:29:29 +0900990 if (!desc) {
Alexandre Courbotbcabdef2013-02-15 14:46:14 +0900991 pr_warn("%s: invalid GPIO\n", __func__);
992 return;
Jon Povey6a99ad42010-07-27 13:18:06 -0700993 }
David Brownelld8f388d2008-07-25 01:46:07 -0700994
995 mutex_lock(&sysfs_lock);
996
David Brownelld8f388d2008-07-25 01:46:07 -0700997 if (test_bit(FLAG_EXPORT, &desc->flags)) {
David Brownelld8f388d2008-07-25 01:46:07 -0700998
999 dev = class_find_device(&gpio_class, NULL, desc, match_export);
1000 if (dev) {
Daniel Glöcknerff77c352009-09-22 16:46:38 -07001001 gpio_setup_irq(desc, dev, 0);
David Brownelld8f388d2008-07-25 01:46:07 -07001002 clear_bit(FLAG_EXPORT, &desc->flags);
David Brownelld8f388d2008-07-25 01:46:07 -07001003 } else
1004 status = -ENODEV;
1005 }
1006
1007 mutex_unlock(&sysfs_lock);
Alexandre Courbot372e7222013-02-03 01:29:29 +09001008
Ming Lei864533c2012-02-13 22:53:20 +08001009 if (dev) {
1010 device_unregister(dev);
1011 put_device(dev);
1012 }
Alexandre Courbotbcabdef2013-02-15 14:46:14 +09001013
David Brownelld8f388d2008-07-25 01:46:07 -07001014 if (status)
Andy Shevchenko7589e592013-12-05 11:26:23 +02001015 gpiod_dbg(desc, "%s: status %d\n", __func__, status);
Alexandre Courbot372e7222013-02-03 01:29:29 +09001016}
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07001017EXPORT_SYMBOL_GPL(gpiod_unexport);
David Brownelld8f388d2008-07-25 01:46:07 -07001018
1019static int gpiochip_export(struct gpio_chip *chip)
1020{
1021 int status;
1022 struct device *dev;
1023
1024 /* Many systems register gpio chips for SOC support very early,
1025 * before driver model support is available. In those cases we
1026 * export this later, in gpiolib_sysfs_init() ... here we just
1027 * verify that _some_ field of gpio_class got initialized.
1028 */
1029 if (!gpio_class.p)
1030 return 0;
1031
1032 /* use chip->base for the ID; it's already known to be unique */
1033 mutex_lock(&sysfs_lock);
1034 dev = device_create(&gpio_class, chip->dev, MKDEV(0, 0), chip,
1035 "gpiochip%d", chip->base);
Sergei Shtylyovd62668e2009-11-11 14:26:50 -08001036 if (!IS_ERR(dev)) {
David Brownelld8f388d2008-07-25 01:46:07 -07001037 status = sysfs_create_group(&dev->kobj,
1038 &gpiochip_attr_group);
1039 } else
Sergei Shtylyovd62668e2009-11-11 14:26:50 -08001040 status = PTR_ERR(dev);
David Brownelld8f388d2008-07-25 01:46:07 -07001041 chip->exported = (status == 0);
1042 mutex_unlock(&sysfs_lock);
1043
1044 if (status) {
1045 unsigned long flags;
1046 unsigned gpio;
1047
1048 spin_lock_irqsave(&gpio_lock, flags);
Alexandre Courbot6c0b4e62013-02-03 01:29:30 +09001049 gpio = 0;
1050 while (gpio < chip->ngpio)
1051 chip->desc[gpio++].chip = NULL;
David Brownelld8f388d2008-07-25 01:46:07 -07001052 spin_unlock_irqrestore(&gpio_lock, flags);
1053
Andy Shevchenko1a2a99c2013-12-05 11:26:24 +02001054 chip_dbg(chip, "%s: status %d\n", __func__, status);
David Brownelld8f388d2008-07-25 01:46:07 -07001055 }
1056
1057 return status;
1058}
1059
1060static void gpiochip_unexport(struct gpio_chip *chip)
1061{
1062 int status;
1063 struct device *dev;
1064
1065 mutex_lock(&sysfs_lock);
1066 dev = class_find_device(&gpio_class, NULL, chip, match_export);
1067 if (dev) {
1068 put_device(dev);
1069 device_unregister(dev);
Linus Walleij9fb1f392013-12-04 14:42:46 +01001070 chip->exported = false;
David Brownelld8f388d2008-07-25 01:46:07 -07001071 status = 0;
1072 } else
1073 status = -ENODEV;
1074 mutex_unlock(&sysfs_lock);
1075
1076 if (status)
Andy Shevchenko1a2a99c2013-12-05 11:26:24 +02001077 chip_dbg(chip, "%s: status %d\n", __func__, status);
David Brownelld8f388d2008-07-25 01:46:07 -07001078}
1079
1080static int __init gpiolib_sysfs_init(void)
1081{
1082 int status;
1083 unsigned long flags;
Alexandre Courbot65493e32013-02-03 01:29:25 +09001084 struct gpio_chip *chip;
David Brownelld8f388d2008-07-25 01:46:07 -07001085
1086 status = class_register(&gpio_class);
1087 if (status < 0)
1088 return status;
1089
1090 /* Scan and register the gpio_chips which registered very
1091 * early (e.g. before the class_register above was called).
1092 *
1093 * We run before arch_initcall() so chip->dev nodes can have
1094 * registered, and so arch_initcall() can always gpio_export().
1095 */
1096 spin_lock_irqsave(&gpio_lock, flags);
Alexandre Courbot65493e32013-02-03 01:29:25 +09001097 list_for_each_entry(chip, &gpio_chips, list) {
David Brownelld8f388d2008-07-25 01:46:07 -07001098 if (!chip || chip->exported)
1099 continue;
1100
1101 spin_unlock_irqrestore(&gpio_lock, flags);
1102 status = gpiochip_export(chip);
1103 spin_lock_irqsave(&gpio_lock, flags);
1104 }
1105 spin_unlock_irqrestore(&gpio_lock, flags);
1106
1107
1108 return status;
1109}
1110postcore_initcall(gpiolib_sysfs_init);
1111
1112#else
1113static inline int gpiochip_export(struct gpio_chip *chip)
1114{
1115 return 0;
1116}
1117
1118static inline void gpiochip_unexport(struct gpio_chip *chip)
1119{
1120}
1121
1122#endif /* CONFIG_GPIO_SYSFS */
1123
Alexandre Courbot1a989d02013-02-03 01:29:24 +09001124/*
1125 * Add a new chip to the global chips list, keeping the list of chips sorted
1126 * by base order.
1127 *
1128 * Return -EBUSY if the new chip overlaps with some other chip's integer
1129 * space.
1130 */
1131static int gpiochip_add_to_list(struct gpio_chip *chip)
1132{
1133 struct list_head *pos = &gpio_chips;
1134 struct gpio_chip *_chip;
1135 int err = 0;
1136
1137 /* find where to insert our chip */
1138 list_for_each(pos, &gpio_chips) {
1139 _chip = list_entry(pos, struct gpio_chip, list);
1140 /* shall we insert before _chip? */
1141 if (_chip->base >= chip->base + chip->ngpio)
1142 break;
1143 }
1144
1145 /* are we stepping on the chip right before? */
1146 if (pos != &gpio_chips && pos->prev != &gpio_chips) {
1147 _chip = list_entry(pos->prev, struct gpio_chip, list);
1148 if (_chip->base + _chip->ngpio > chip->base) {
1149 dev_err(chip->dev,
1150 "GPIO integer space overlap, cannot add chip\n");
1151 err = -EBUSY;
1152 }
1153 }
1154
1155 if (!err)
1156 list_add_tail(&chip->list, pos);
1157
1158 return err;
1159}
1160
Anton Vorontsov169b6a72008-04-28 02:14:47 -07001161/**
David Brownelld2876d02008-02-04 22:28:20 -08001162 * gpiochip_add() - register a gpio_chip
1163 * @chip: the chip to register, with chip->base initialized
1164 * Context: potentially before irqs or kmalloc will work
1165 *
1166 * Returns a negative errno if the chip can't be registered, such as
1167 * because the chip->base is invalid or already associated with a
1168 * different chip. Otherwise it returns zero as a success code.
Anton Vorontsov8d0aab22008-04-28 02:14:46 -07001169 *
David Brownelld8f388d2008-07-25 01:46:07 -07001170 * When gpiochip_add() is called very early during boot, so that GPIOs
1171 * can be freely used, the chip->dev device must be registered before
1172 * the gpio framework's arch_initcall(). Otherwise sysfs initialization
1173 * for GPIOs will fail rudely.
1174 *
Anton Vorontsov8d0aab22008-04-28 02:14:46 -07001175 * If chip->base is negative, this requests dynamic assignment of
1176 * a range of valid GPIOs.
David Brownelld2876d02008-02-04 22:28:20 -08001177 */
1178int gpiochip_add(struct gpio_chip *chip)
1179{
1180 unsigned long flags;
1181 int status = 0;
1182 unsigned id;
Anton Vorontsov8d0aab22008-04-28 02:14:46 -07001183 int base = chip->base;
David Brownelld2876d02008-02-04 22:28:20 -08001184
Trent Piephobff5fda2008-05-23 13:04:44 -07001185 if ((!gpio_is_valid(base) || !gpio_is_valid(base + chip->ngpio - 1))
Anton Vorontsov8d0aab22008-04-28 02:14:46 -07001186 && base >= 0) {
David Brownelld2876d02008-02-04 22:28:20 -08001187 status = -EINVAL;
1188 goto fail;
1189 }
1190
1191 spin_lock_irqsave(&gpio_lock, flags);
1192
Anton Vorontsov8d0aab22008-04-28 02:14:46 -07001193 if (base < 0) {
1194 base = gpiochip_find_base(chip->ngpio);
1195 if (base < 0) {
1196 status = base;
David Brownelld8f388d2008-07-25 01:46:07 -07001197 goto unlock;
Anton Vorontsov8d0aab22008-04-28 02:14:46 -07001198 }
1199 chip->base = base;
1200 }
1201
Alexandre Courbot1a989d02013-02-03 01:29:24 +09001202 status = gpiochip_add_to_list(chip);
1203
David Brownelld2876d02008-02-04 22:28:20 -08001204 if (status == 0) {
Alexandre Courbot6c0b4e62013-02-03 01:29:30 +09001205 chip->desc = &gpio_desc[chip->base];
1206
1207 for (id = 0; id < chip->ngpio; id++) {
1208 struct gpio_desc *desc = &chip->desc[id];
1209 desc->chip = chip;
David Brownelld8f388d2008-07-25 01:46:07 -07001210
1211 /* REVISIT: most hardware initializes GPIOs as
1212 * inputs (often with pullups enabled) so power
1213 * usage is minimized. Linux code should set the
1214 * gpio direction first thing; but until it does,
Mathias Nyman80b0a602012-10-24 17:25:27 +03001215 * and in case chip->get_direction is not set,
David Brownelld8f388d2008-07-25 01:46:07 -07001216 * we may expose the wrong direction in sysfs.
1217 */
Alexandre Courbot6c0b4e62013-02-03 01:29:30 +09001218 desc->flags = !chip->direction_input
David Brownelld8f388d2008-07-25 01:46:07 -07001219 ? (1 << FLAG_IS_OUT)
1220 : 0;
David Brownelld2876d02008-02-04 22:28:20 -08001221 }
1222 }
1223
Zhangfei Gao3bae4812013-06-09 11:08:32 +08001224 spin_unlock_irqrestore(&gpio_lock, flags);
1225
Shiraz Hashimf23f1512012-10-27 15:21:36 +05301226#ifdef CONFIG_PINCTRL
1227 INIT_LIST_HEAD(&chip->pin_ranges);
1228#endif
1229
Anton Vorontsov391c9702010-06-08 07:48:17 -06001230 of_gpiochip_add(chip);
Mika Westerberg664e3e52014-01-08 12:40:54 +02001231 acpi_gpiochip_add(chip);
Anton Vorontsov391c9702010-06-08 07:48:17 -06001232
Anton Vorontsovcedb1882010-06-08 07:48:15 -06001233 if (status)
1234 goto fail;
1235
1236 status = gpiochip_export(chip);
1237 if (status)
1238 goto fail;
1239
Andy Shevchenko7589e592013-12-05 11:26:23 +02001240 pr_debug("%s: registered GPIOs %d to %d on device: %s\n", __func__,
Grant Likely64842aa2011-11-06 11:36:18 -07001241 chip->base, chip->base + chip->ngpio - 1,
1242 chip->label ? : "generic");
1243
Anton Vorontsovcedb1882010-06-08 07:48:15 -06001244 return 0;
Zhangfei Gao3bae4812013-06-09 11:08:32 +08001245
1246unlock:
1247 spin_unlock_irqrestore(&gpio_lock, flags);
David Brownelld2876d02008-02-04 22:28:20 -08001248fail:
1249 /* failures here can mean systems won't boot... */
Andy Shevchenko7589e592013-12-05 11:26:23 +02001250 pr_err("%s: GPIOs %d..%d (%s) failed to register\n", __func__,
Anton Vorontsovcedb1882010-06-08 07:48:15 -06001251 chip->base, chip->base + chip->ngpio - 1,
1252 chip->label ? : "generic");
David Brownelld2876d02008-02-04 22:28:20 -08001253 return status;
1254}
1255EXPORT_SYMBOL_GPL(gpiochip_add);
1256
Linus Walleij14250522014-03-25 10:40:18 +01001257/* Forward-declaration */
1258static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
1259
David Brownelld2876d02008-02-04 22:28:20 -08001260/**
1261 * gpiochip_remove() - unregister a gpio_chip
1262 * @chip: the chip to unregister
1263 *
1264 * A gpio_chip with any GPIOs still requested may not be removed.
1265 */
1266int gpiochip_remove(struct gpio_chip *chip)
1267{
1268 unsigned long flags;
1269 int status = 0;
1270 unsigned id;
1271
Mika Westerberg6072b9d2014-03-10 14:54:53 +02001272 acpi_gpiochip_remove(chip);
1273
David Brownelld2876d02008-02-04 22:28:20 -08001274 spin_lock_irqsave(&gpio_lock, flags);
1275
Linus Walleij14250522014-03-25 10:40:18 +01001276 gpiochip_irqchip_remove(chip);
Linus Walleij9ef0d6f2012-11-06 15:15:44 +01001277 gpiochip_remove_pin_ranges(chip);
Anton Vorontsov391c9702010-06-08 07:48:17 -06001278 of_gpiochip_remove(chip);
1279
Alexandre Courbot6c0b4e62013-02-03 01:29:30 +09001280 for (id = 0; id < chip->ngpio; id++) {
1281 if (test_bit(FLAG_REQUESTED, &chip->desc[id].flags)) {
David Brownelld2876d02008-02-04 22:28:20 -08001282 status = -EBUSY;
1283 break;
1284 }
1285 }
1286 if (status == 0) {
Alexandre Courbot6c0b4e62013-02-03 01:29:30 +09001287 for (id = 0; id < chip->ngpio; id++)
1288 chip->desc[id].chip = NULL;
Alexandre Courbot1a989d02013-02-03 01:29:24 +09001289
1290 list_del(&chip->list);
David Brownelld2876d02008-02-04 22:28:20 -08001291 }
1292
1293 spin_unlock_irqrestore(&gpio_lock, flags);
David Brownelld8f388d2008-07-25 01:46:07 -07001294
1295 if (status == 0)
1296 gpiochip_unexport(chip);
1297
David Brownelld2876d02008-02-04 22:28:20 -08001298 return status;
1299}
1300EXPORT_SYMBOL_GPL(gpiochip_remove);
1301
Grant Likely594fa262010-06-08 07:48:16 -06001302/**
1303 * gpiochip_find() - iterator for locating a specific gpio_chip
1304 * @data: data to pass to match function
1305 * @callback: Callback function to check gpio_chip
1306 *
1307 * Similar to bus_find_device. It returns a reference to a gpio_chip as
1308 * determined by a user supplied @match callback. The callback should return
1309 * 0 if the device doesn't match and non-zero if it does. If the callback is
1310 * non-zero, this function will return to the caller and not iterate over any
1311 * more gpio_chips.
1312 */
Grant Likely07ce8ec2012-05-18 23:01:05 -06001313struct gpio_chip *gpiochip_find(void *data,
Grant Likely6e2cf652012-03-02 15:56:03 -07001314 int (*match)(struct gpio_chip *chip,
Grant Likely3d0f7cf2012-05-17 13:54:40 -06001315 void *data))
Grant Likely594fa262010-06-08 07:48:16 -06001316{
Alexandre Courbot125eef92013-02-03 01:29:26 +09001317 struct gpio_chip *chip;
Grant Likely594fa262010-06-08 07:48:16 -06001318 unsigned long flags;
Grant Likely594fa262010-06-08 07:48:16 -06001319
1320 spin_lock_irqsave(&gpio_lock, flags);
Alexandre Courbot125eef92013-02-03 01:29:26 +09001321 list_for_each_entry(chip, &gpio_chips, list)
1322 if (match(chip, data))
Grant Likely594fa262010-06-08 07:48:16 -06001323 break;
Alexandre Courbot125eef92013-02-03 01:29:26 +09001324
1325 /* No match? */
1326 if (&chip->list == &gpio_chips)
1327 chip = NULL;
Grant Likely594fa262010-06-08 07:48:16 -06001328 spin_unlock_irqrestore(&gpio_lock, flags);
1329
1330 return chip;
1331}
Jean Delvare8fa0c9b2011-05-20 00:40:18 -06001332EXPORT_SYMBOL_GPL(gpiochip_find);
David Brownelld2876d02008-02-04 22:28:20 -08001333
Alexandre Courbot79697ef2013-11-16 21:39:32 +09001334static int gpiochip_match_name(struct gpio_chip *chip, void *data)
1335{
1336 const char *name = data;
1337
1338 return !strcmp(chip->label, name);
1339}
1340
1341static struct gpio_chip *find_chip_by_name(const char *name)
1342{
1343 return gpiochip_find((void *)name, gpiochip_match_name);
1344}
1345
Linus Walleij14250522014-03-25 10:40:18 +01001346#ifdef CONFIG_GPIOLIB_IRQCHIP
1347
1348/*
1349 * The following is irqchip helper code for gpiochips.
1350 */
1351
1352/**
1353 * gpiochip_add_chained_irqchip() - adds a chained irqchip to a gpiochip
1354 * @gpiochip: the gpiochip to add the irqchip to
1355 * @irqchip: the irqchip to add to the gpiochip
1356 * @parent_irq: the irq number corresponding to the parent IRQ for this
1357 * chained irqchip
1358 * @parent_handler: the parent interrupt handler for the accumulated IRQ
1359 * coming out of the gpiochip
1360 */
1361void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
1362 struct irq_chip *irqchip,
1363 int parent_irq,
1364 irq_flow_handler_t parent_handler)
1365{
1366 irq_set_chained_handler(parent_irq, parent_handler);
1367 /*
1368 * The parent irqchip is already using the chip_data for this
1369 * irqchip, so our callbacks simply use the handler_data.
1370 */
1371 irq_set_handler_data(parent_irq, gpiochip);
1372}
1373EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip);
1374
1375/**
1376 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
1377 * @d: the irqdomain used by this irqchip
1378 * @irq: the global irq number used by this GPIO irqchip irq
1379 * @hwirq: the local IRQ/GPIO line offset on this gpiochip
1380 *
1381 * This function will set up the mapping for a certain IRQ line on a
1382 * gpiochip by assigning the gpiochip as chip data, and using the irqchip
1383 * stored inside the gpiochip.
1384 */
1385static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
1386 irq_hw_number_t hwirq)
1387{
1388 struct gpio_chip *chip = d->host_data;
1389
1390 irq_set_chip_and_handler(irq, chip->irqchip, chip->irq_handler);
1391 irq_set_chip_data(irq, chip);
1392#ifdef CONFIG_ARM
1393 set_irq_flags(irq, IRQF_VALID);
1394#else
1395 irq_set_noprobe(irq);
1396#endif
1397 irq_set_irq_type(irq, chip->irq_default_type);
1398
1399 return 0;
1400}
1401
Linus Walleijc3626fd2014-03-28 20:42:01 +01001402static void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
1403{
1404#ifdef CONFIG_ARM
1405 set_irq_flags(irq, 0);
1406#endif
1407 irq_set_chip_and_handler(irq, NULL, NULL);
1408 irq_set_chip_data(irq, NULL);
1409}
1410
Linus Walleij14250522014-03-25 10:40:18 +01001411static const struct irq_domain_ops gpiochip_domain_ops = {
1412 .map = gpiochip_irq_map,
Linus Walleijc3626fd2014-03-28 20:42:01 +01001413 .unmap = gpiochip_irq_unmap,
Linus Walleij14250522014-03-25 10:40:18 +01001414 /* Virtually all GPIO irqchips are twocell:ed */
1415 .xlate = irq_domain_xlate_twocell,
1416};
1417
1418static int gpiochip_irq_reqres(struct irq_data *d)
1419{
1420 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1421
1422 if (gpio_lock_as_irq(chip, d->hwirq)) {
1423 chip_err(chip,
1424 "unable to lock HW IRQ %lu for IRQ\n",
1425 d->hwirq);
1426 return -EINVAL;
1427 }
1428 return 0;
1429}
1430
1431static void gpiochip_irq_relres(struct irq_data *d)
1432{
1433 struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
1434
1435 gpio_unlock_as_irq(chip, d->hwirq);
1436}
1437
1438static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset)
1439{
1440 return irq_find_mapping(chip->irqdomain, offset);
1441}
1442
1443/**
1444 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
1445 * @gpiochip: the gpiochip to remove the irqchip from
1446 *
1447 * This is called only from gpiochip_remove()
1448 */
1449static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
1450{
Linus Walleijc3626fd2014-03-28 20:42:01 +01001451 unsigned int offset;
1452
1453 /* Remove all IRQ mappings and delete the domain */
1454 if (gpiochip->irqdomain) {
1455 for (offset = 0; offset < gpiochip->ngpio; offset++)
1456 irq_dispose_mapping(gpiochip->irq_base + offset);
Linus Walleij14250522014-03-25 10:40:18 +01001457 irq_domain_remove(gpiochip->irqdomain);
Linus Walleijc3626fd2014-03-28 20:42:01 +01001458 }
Linus Walleij14250522014-03-25 10:40:18 +01001459
1460 if (gpiochip->irqchip) {
1461 gpiochip->irqchip->irq_request_resources = NULL;
1462 gpiochip->irqchip->irq_release_resources = NULL;
1463 gpiochip->irqchip = NULL;
1464 }
1465}
1466
1467/**
1468 * gpiochip_irqchip_add() - adds an irqchip to a gpiochip
1469 * @gpiochip: the gpiochip to add the irqchip to
1470 * @irqchip: the irqchip to add to the gpiochip
1471 * @first_irq: if not dynamically assigned, the base (first) IRQ to
1472 * allocate gpiochip irqs from
1473 * @handler: the irq handler to use (often a predefined irq core function)
1474 * @type: the default type for IRQs on this irqchip
1475 *
1476 * This function closely associates a certain irqchip with a certain
1477 * gpiochip, providing an irq domain to translate the local IRQs to
1478 * global irqs in the gpiolib core, and making sure that the gpiochip
1479 * is passed as chip data to all related functions. Driver callbacks
1480 * need to use container_of() to get their local state containers back
1481 * from the gpiochip passed as chip data. An irqdomain will be stored
1482 * in the gpiochip that shall be used by the driver to handle IRQ number
1483 * translation. The gpiochip will need to be initialized and registered
1484 * before calling this function.
1485 *
Linus Walleijc3626fd2014-03-28 20:42:01 +01001486 * This function will handle two cell:ed simple IRQs and assumes all
1487 * the pins on the gpiochip can generate a unique IRQ. Everything else
Linus Walleij14250522014-03-25 10:40:18 +01001488 * need to be open coded.
1489 */
1490int gpiochip_irqchip_add(struct gpio_chip *gpiochip,
1491 struct irq_chip *irqchip,
1492 unsigned int first_irq,
1493 irq_flow_handler_t handler,
1494 unsigned int type)
1495{
1496 struct device_node *of_node;
1497 unsigned int offset;
Linus Walleijc3626fd2014-03-28 20:42:01 +01001498 unsigned irq_base = 0;
Linus Walleij14250522014-03-25 10:40:18 +01001499
1500 if (!gpiochip || !irqchip)
1501 return -EINVAL;
1502
1503 if (!gpiochip->dev) {
1504 pr_err("missing gpiochip .dev parent pointer\n");
1505 return -EINVAL;
1506 }
1507 of_node = gpiochip->dev->of_node;
1508#ifdef CONFIG_OF_GPIO
1509 /*
1510 * If the gpiochip has an assigned OF node this takes precendence
1511 * FIXME: get rid of this and use gpiochip->dev->of_node everywhere
1512 */
1513 if (gpiochip->of_node)
1514 of_node = gpiochip->of_node;
1515#endif
1516 gpiochip->irqchip = irqchip;
1517 gpiochip->irq_handler = handler;
1518 gpiochip->irq_default_type = type;
1519 gpiochip->to_irq = gpiochip_to_irq;
1520 gpiochip->irqdomain = irq_domain_add_simple(of_node,
1521 gpiochip->ngpio, first_irq,
1522 &gpiochip_domain_ops, gpiochip);
1523 if (!gpiochip->irqdomain) {
1524 gpiochip->irqchip = NULL;
1525 return -EINVAL;
1526 }
1527 irqchip->irq_request_resources = gpiochip_irq_reqres;
1528 irqchip->irq_release_resources = gpiochip_irq_relres;
1529
1530 /*
1531 * Prepare the mapping since the irqchip shall be orthogonal to
1532 * any gpiochip calls. If the first_irq was zero, this is
1533 * necessary to allocate descriptors for all IRQs.
1534 */
Linus Walleijc3626fd2014-03-28 20:42:01 +01001535 for (offset = 0; offset < gpiochip->ngpio; offset++) {
1536 irq_base = irq_create_mapping(gpiochip->irqdomain, offset);
1537 if (offset == 0)
1538 /*
1539 * Store the base into the gpiochip to be used when
1540 * unmapping the irqs.
1541 */
1542 gpiochip->irq_base = irq_base;
1543 }
Linus Walleij14250522014-03-25 10:40:18 +01001544
1545 return 0;
1546}
1547EXPORT_SYMBOL_GPL(gpiochip_irqchip_add);
1548
1549#else /* CONFIG_GPIOLIB_IRQCHIP */
1550
1551static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}
1552
1553#endif /* CONFIG_GPIOLIB_IRQCHIP */
1554
Shiraz Hashimf23f1512012-10-27 15:21:36 +05301555#ifdef CONFIG_PINCTRL
Linus Walleij165adc92012-11-06 14:49:39 +01001556
Linus Walleij3f0f8672012-11-20 12:40:15 +01001557/**
Christian Ruppert586a87e2013-10-15 15:37:54 +02001558 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
1559 * @chip: the gpiochip to add the range for
1560 * @pinctrl: the dev_name() of the pin controller to map to
1561 * @gpio_offset: the start offset in the current gpio_chip number space
1562 * @pin_group: name of the pin group inside the pin controller
1563 */
1564int gpiochip_add_pingroup_range(struct gpio_chip *chip,
1565 struct pinctrl_dev *pctldev,
1566 unsigned int gpio_offset, const char *pin_group)
1567{
1568 struct gpio_pin_range *pin_range;
1569 int ret;
1570
1571 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
1572 if (!pin_range) {
Andy Shevchenko1a2a99c2013-12-05 11:26:24 +02001573 chip_err(chip, "failed to allocate pin ranges\n");
Christian Ruppert586a87e2013-10-15 15:37:54 +02001574 return -ENOMEM;
1575 }
1576
1577 /* Use local offset as range ID */
1578 pin_range->range.id = gpio_offset;
1579 pin_range->range.gc = chip;
1580 pin_range->range.name = chip->label;
1581 pin_range->range.base = chip->base + gpio_offset;
1582 pin_range->pctldev = pctldev;
1583
1584 ret = pinctrl_get_group_pins(pctldev, pin_group,
1585 &pin_range->range.pins,
1586 &pin_range->range.npins);
Michal Nazarewicz61c63752013-11-13 21:20:39 +01001587 if (ret < 0) {
1588 kfree(pin_range);
Christian Ruppert586a87e2013-10-15 15:37:54 +02001589 return ret;
Michal Nazarewicz61c63752013-11-13 21:20:39 +01001590 }
Christian Ruppert586a87e2013-10-15 15:37:54 +02001591
1592 pinctrl_add_gpio_range(pctldev, &pin_range->range);
1593
Andy Shevchenko1a2a99c2013-12-05 11:26:24 +02001594 chip_dbg(chip, "created GPIO range %d->%d ==> %s PINGRP %s\n",
1595 gpio_offset, gpio_offset + pin_range->range.npins - 1,
Christian Ruppert586a87e2013-10-15 15:37:54 +02001596 pinctrl_dev_get_devname(pctldev), pin_group);
1597
1598 list_add_tail(&pin_range->node, &chip->pin_ranges);
1599
1600 return 0;
1601}
1602EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
1603
1604/**
Linus Walleij3f0f8672012-11-20 12:40:15 +01001605 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
1606 * @chip: the gpiochip to add the range for
1607 * @pinctrl_name: the dev_name() of the pin controller to map to
Linus Walleij316511c2012-11-21 08:48:09 +01001608 * @gpio_offset: the start offset in the current gpio_chip number space
1609 * @pin_offset: the start offset in the pin controller number space
Linus Walleij3f0f8672012-11-20 12:40:15 +01001610 * @npins: the number of pins from the offset of each pin space (GPIO and
1611 * pin controller) to accumulate in this range
1612 */
Linus Walleij1e63d7b2012-11-06 16:03:35 +01001613int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
Linus Walleij316511c2012-11-21 08:48:09 +01001614 unsigned int gpio_offset, unsigned int pin_offset,
Linus Walleij3f0f8672012-11-20 12:40:15 +01001615 unsigned int npins)
Shiraz Hashimf23f1512012-10-27 15:21:36 +05301616{
1617 struct gpio_pin_range *pin_range;
Axel Linb4d4b1f2012-11-21 14:33:56 +08001618 int ret;
Shiraz Hashimf23f1512012-10-27 15:21:36 +05301619
Linus Walleij3f0f8672012-11-20 12:40:15 +01001620 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
Shiraz Hashimf23f1512012-10-27 15:21:36 +05301621 if (!pin_range) {
Andy Shevchenko1a2a99c2013-12-05 11:26:24 +02001622 chip_err(chip, "failed to allocate pin ranges\n");
Linus Walleij1e63d7b2012-11-06 16:03:35 +01001623 return -ENOMEM;
Shiraz Hashimf23f1512012-10-27 15:21:36 +05301624 }
1625
Linus Walleij3f0f8672012-11-20 12:40:15 +01001626 /* Use local offset as range ID */
Linus Walleij316511c2012-11-21 08:48:09 +01001627 pin_range->range.id = gpio_offset;
Linus Walleij3f0f8672012-11-20 12:40:15 +01001628 pin_range->range.gc = chip;
Shiraz Hashimf23f1512012-10-27 15:21:36 +05301629 pin_range->range.name = chip->label;
Linus Walleij316511c2012-11-21 08:48:09 +01001630 pin_range->range.base = chip->base + gpio_offset;
1631 pin_range->range.pin_base = pin_offset;
Shiraz Hashimf23f1512012-10-27 15:21:36 +05301632 pin_range->range.npins = npins;
Linus Walleij192c3692012-11-20 14:03:37 +01001633 pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
Shiraz Hashimf23f1512012-10-27 15:21:36 +05301634 &pin_range->range);
Linus Walleij8f23ca12012-11-20 14:56:25 +01001635 if (IS_ERR(pin_range->pctldev)) {
Axel Linb4d4b1f2012-11-21 14:33:56 +08001636 ret = PTR_ERR(pin_range->pctldev);
Andy Shevchenko1a2a99c2013-12-05 11:26:24 +02001637 chip_err(chip, "could not create pin range\n");
Linus Walleij3f0f8672012-11-20 12:40:15 +01001638 kfree(pin_range);
Axel Linb4d4b1f2012-11-21 14:33:56 +08001639 return ret;
Linus Walleij3f0f8672012-11-20 12:40:15 +01001640 }
Andy Shevchenko1a2a99c2013-12-05 11:26:24 +02001641 chip_dbg(chip, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
1642 gpio_offset, gpio_offset + npins - 1,
Linus Walleij316511c2012-11-21 08:48:09 +01001643 pinctl_name,
1644 pin_offset, pin_offset + npins - 1);
Shiraz Hashimf23f1512012-10-27 15:21:36 +05301645
1646 list_add_tail(&pin_range->node, &chip->pin_ranges);
Linus Walleij1e63d7b2012-11-06 16:03:35 +01001647
1648 return 0;
Shiraz Hashimf23f1512012-10-27 15:21:36 +05301649}
Linus Walleij165adc92012-11-06 14:49:39 +01001650EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
Shiraz Hashimf23f1512012-10-27 15:21:36 +05301651
Linus Walleij3f0f8672012-11-20 12:40:15 +01001652/**
1653 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
1654 * @chip: the chip to remove all the mappings for
1655 */
Shiraz Hashimf23f1512012-10-27 15:21:36 +05301656void gpiochip_remove_pin_ranges(struct gpio_chip *chip)
1657{
1658 struct gpio_pin_range *pin_range, *tmp;
1659
1660 list_for_each_entry_safe(pin_range, tmp, &chip->pin_ranges, node) {
1661 list_del(&pin_range->node);
1662 pinctrl_remove_gpio_range(pin_range->pctldev,
1663 &pin_range->range);
Linus Walleij3f0f8672012-11-20 12:40:15 +01001664 kfree(pin_range);
Shiraz Hashimf23f1512012-10-27 15:21:36 +05301665 }
1666}
Linus Walleij165adc92012-11-06 14:49:39 +01001667EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
1668
1669#endif /* CONFIG_PINCTRL */
Shiraz Hashimf23f1512012-10-27 15:21:36 +05301670
David Brownelld2876d02008-02-04 22:28:20 -08001671/* These "optional" allocation calls help prevent drivers from stomping
1672 * on each other, and help provide better diagnostics in debugfs.
1673 * They're called even less than the "set direction" calls.
1674 */
Mika Westerberg77c2d792014-03-10 14:54:50 +02001675static int __gpiod_request(struct gpio_desc *desc, const char *label)
David Brownelld2876d02008-02-04 22:28:20 -08001676{
Mika Westerberg77c2d792014-03-10 14:54:50 +02001677 struct gpio_chip *chip = desc->chip;
1678 int status;
David Brownelld2876d02008-02-04 22:28:20 -08001679 unsigned long flags;
1680
1681 spin_lock_irqsave(&gpio_lock, flags);
1682
David Brownelld2876d02008-02-04 22:28:20 -08001683 /* NOTE: gpio_request() can be called in early boot,
David Brownell35e8bb52008-10-15 22:03:16 -07001684 * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
David Brownelld2876d02008-02-04 22:28:20 -08001685 */
1686
1687 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
1688 desc_set_label(desc, label ? : "?");
1689 status = 0;
Guennadi Liakhovetski438d8902008-04-28 02:14:44 -07001690 } else {
David Brownelld2876d02008-02-04 22:28:20 -08001691 status = -EBUSY;
Magnus Damm7460db52009-01-29 14:25:12 -08001692 goto done;
David Brownell35e8bb52008-10-15 22:03:16 -07001693 }
1694
1695 if (chip->request) {
1696 /* chip->request may sleep */
1697 spin_unlock_irqrestore(&gpio_lock, flags);
Alexandre Courbot372e7222013-02-03 01:29:29 +09001698 status = chip->request(chip, gpio_chip_hwgpio(desc));
David Brownell35e8bb52008-10-15 22:03:16 -07001699 spin_lock_irqsave(&gpio_lock, flags);
1700
1701 if (status < 0) {
1702 desc_set_label(desc, NULL);
David Brownell35e8bb52008-10-15 22:03:16 -07001703 clear_bit(FLAG_REQUESTED, &desc->flags);
Mathias Nyman80b0a602012-10-24 17:25:27 +03001704 goto done;
David Brownell35e8bb52008-10-15 22:03:16 -07001705 }
Guennadi Liakhovetski438d8902008-04-28 02:14:44 -07001706 }
Mathias Nyman80b0a602012-10-24 17:25:27 +03001707 if (chip->get_direction) {
1708 /* chip->get_direction may sleep */
1709 spin_unlock_irqrestore(&gpio_lock, flags);
Alexandre Courbot372e7222013-02-03 01:29:29 +09001710 gpiod_get_direction(desc);
Mathias Nyman80b0a602012-10-24 17:25:27 +03001711 spin_lock_irqsave(&gpio_lock, flags);
1712 }
David Brownelld2876d02008-02-04 22:28:20 -08001713done:
Mika Westerberg77c2d792014-03-10 14:54:50 +02001714 spin_unlock_irqrestore(&gpio_lock, flags);
1715 return status;
1716}
1717
1718static int gpiod_request(struct gpio_desc *desc, const char *label)
1719{
1720 int status = -EPROBE_DEFER;
1721 struct gpio_chip *chip;
1722
1723 if (!desc) {
1724 pr_warn("%s: invalid GPIO\n", __func__);
1725 return -EINVAL;
1726 }
1727
1728 chip = desc->chip;
1729 if (!chip)
1730 goto done;
1731
1732 if (try_module_get(chip->owner)) {
1733 status = __gpiod_request(desc, label);
1734 if (status < 0)
1735 module_put(chip->owner);
1736 }
1737
1738done:
David Brownelld2876d02008-02-04 22:28:20 -08001739 if (status)
Andy Shevchenko7589e592013-12-05 11:26:23 +02001740 gpiod_dbg(desc, "%s: status %d\n", __func__, status);
Mika Westerberg77c2d792014-03-10 14:54:50 +02001741
David Brownelld2876d02008-02-04 22:28:20 -08001742 return status;
1743}
Alexandre Courbot372e7222013-02-03 01:29:29 +09001744
1745int gpio_request(unsigned gpio, const char *label)
1746{
1747 return gpiod_request(gpio_to_desc(gpio), label);
1748}
David Brownelld2876d02008-02-04 22:28:20 -08001749EXPORT_SYMBOL_GPL(gpio_request);
1750
Mika Westerberg77c2d792014-03-10 14:54:50 +02001751static bool __gpiod_free(struct gpio_desc *desc)
David Brownelld2876d02008-02-04 22:28:20 -08001752{
Mika Westerberg77c2d792014-03-10 14:54:50 +02001753 bool ret = false;
David Brownelld2876d02008-02-04 22:28:20 -08001754 unsigned long flags;
David Brownell35e8bb52008-10-15 22:03:16 -07001755 struct gpio_chip *chip;
David Brownelld2876d02008-02-04 22:28:20 -08001756
Uwe Kleine-König3d599d12008-10-15 22:03:12 -07001757 might_sleep();
1758
Alexandre Courbot372e7222013-02-03 01:29:29 +09001759 gpiod_unexport(desc);
David Brownelld8f388d2008-07-25 01:46:07 -07001760
David Brownelld2876d02008-02-04 22:28:20 -08001761 spin_lock_irqsave(&gpio_lock, flags);
1762
David Brownell35e8bb52008-10-15 22:03:16 -07001763 chip = desc->chip;
1764 if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) {
1765 if (chip->free) {
1766 spin_unlock_irqrestore(&gpio_lock, flags);
David Brownell9c4ba942010-08-10 18:02:24 -07001767 might_sleep_if(chip->can_sleep);
Alexandre Courbot372e7222013-02-03 01:29:29 +09001768 chip->free(chip, gpio_chip_hwgpio(desc));
David Brownell35e8bb52008-10-15 22:03:16 -07001769 spin_lock_irqsave(&gpio_lock, flags);
1770 }
David Brownelld2876d02008-02-04 22:28:20 -08001771 desc_set_label(desc, NULL);
Jani Nikula07697462009-12-15 16:46:20 -08001772 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
David Brownell35e8bb52008-10-15 22:03:16 -07001773 clear_bit(FLAG_REQUESTED, &desc->flags);
Laxman Dewanganaca5ce12012-02-17 20:26:21 +05301774 clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
Laxman Dewangan25553ff2012-02-17 20:26:22 +05301775 clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
Mika Westerberg77c2d792014-03-10 14:54:50 +02001776 ret = true;
1777 }
David Brownelld2876d02008-02-04 22:28:20 -08001778
1779 spin_unlock_irqrestore(&gpio_lock, flags);
Mika Westerberg77c2d792014-03-10 14:54:50 +02001780 return ret;
1781}
1782
1783static void gpiod_free(struct gpio_desc *desc)
1784{
1785 if (desc && __gpiod_free(desc))
1786 module_put(desc->chip->owner);
1787 else
1788 WARN_ON(extra_checks);
David Brownelld2876d02008-02-04 22:28:20 -08001789}
Alexandre Courbot372e7222013-02-03 01:29:29 +09001790
1791void gpio_free(unsigned gpio)
1792{
1793 gpiod_free(gpio_to_desc(gpio));
1794}
David Brownelld2876d02008-02-04 22:28:20 -08001795EXPORT_SYMBOL_GPL(gpio_free);
1796
Eric Miao3e45f1d2010-03-05 13:44:35 -08001797/**
1798 * gpio_request_one - request a single GPIO with initial configuration
1799 * @gpio: the GPIO number
1800 * @flags: GPIO configuration as specified by GPIOF_*
1801 * @label: a literal description string of this GPIO
1802 */
1803int gpio_request_one(unsigned gpio, unsigned long flags, const char *label)
1804{
Alexandre Courbot372e7222013-02-03 01:29:29 +09001805 struct gpio_desc *desc;
Eric Miao3e45f1d2010-03-05 13:44:35 -08001806 int err;
1807
Alexandre Courbot372e7222013-02-03 01:29:29 +09001808 desc = gpio_to_desc(gpio);
1809
1810 err = gpiod_request(desc, label);
Eric Miao3e45f1d2010-03-05 13:44:35 -08001811 if (err)
1812 return err;
1813
Laxman Dewanganaca5ce12012-02-17 20:26:21 +05301814 if (flags & GPIOF_OPEN_DRAIN)
Alexandre Courbot372e7222013-02-03 01:29:29 +09001815 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
Laxman Dewanganaca5ce12012-02-17 20:26:21 +05301816
Laxman Dewangan25553ff2012-02-17 20:26:22 +05301817 if (flags & GPIOF_OPEN_SOURCE)
Alexandre Courbot372e7222013-02-03 01:29:29 +09001818 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
Laxman Dewangan25553ff2012-02-17 20:26:22 +05301819
Eric Miao3e45f1d2010-03-05 13:44:35 -08001820 if (flags & GPIOF_DIR_IN)
Alexandre Courbot372e7222013-02-03 01:29:29 +09001821 err = gpiod_direction_input(desc);
Eric Miao3e45f1d2010-03-05 13:44:35 -08001822 else
Philipp Zabelef70bbe2014-01-07 12:34:11 +01001823 err = gpiod_direction_output_raw(desc,
Eric Miao3e45f1d2010-03-05 13:44:35 -08001824 (flags & GPIOF_INIT_HIGH) ? 1 : 0);
1825
Aaro Koskinene2548112010-12-21 17:24:22 -08001826 if (err)
Wolfram Sangfc3a1f02011-12-13 18:34:01 +01001827 goto free_gpio;
Aaro Koskinene2548112010-12-21 17:24:22 -08001828
Wolfram Sangfc3a1f02011-12-13 18:34:01 +01001829 if (flags & GPIOF_EXPORT) {
Alexandre Courbot372e7222013-02-03 01:29:29 +09001830 err = gpiod_export(desc, flags & GPIOF_EXPORT_CHANGEABLE);
Wolfram Sangfc3a1f02011-12-13 18:34:01 +01001831 if (err)
1832 goto free_gpio;
1833 }
1834
1835 return 0;
1836
1837 free_gpio:
Alexandre Courbot372e7222013-02-03 01:29:29 +09001838 gpiod_free(desc);
Eric Miao3e45f1d2010-03-05 13:44:35 -08001839 return err;
1840}
1841EXPORT_SYMBOL_GPL(gpio_request_one);
1842
1843/**
1844 * gpio_request_array - request multiple GPIOs in a single call
1845 * @array: array of the 'struct gpio'
1846 * @num: how many GPIOs in the array
1847 */
Lars-Peter Clausen7c295972011-05-25 16:20:31 -07001848int gpio_request_array(const struct gpio *array, size_t num)
Eric Miao3e45f1d2010-03-05 13:44:35 -08001849{
1850 int i, err;
1851
1852 for (i = 0; i < num; i++, array++) {
1853 err = gpio_request_one(array->gpio, array->flags, array->label);
1854 if (err)
1855 goto err_free;
1856 }
1857 return 0;
1858
1859err_free:
1860 while (i--)
1861 gpio_free((--array)->gpio);
1862 return err;
1863}
1864EXPORT_SYMBOL_GPL(gpio_request_array);
1865
1866/**
1867 * gpio_free_array - release multiple GPIOs in a single call
1868 * @array: array of the 'struct gpio'
1869 * @num: how many GPIOs in the array
1870 */
Lars-Peter Clausen7c295972011-05-25 16:20:31 -07001871void gpio_free_array(const struct gpio *array, size_t num)
Eric Miao3e45f1d2010-03-05 13:44:35 -08001872{
1873 while (num--)
1874 gpio_free((array++)->gpio);
1875}
1876EXPORT_SYMBOL_GPL(gpio_free_array);
David Brownelld2876d02008-02-04 22:28:20 -08001877
1878/**
1879 * gpiochip_is_requested - return string iff signal was requested
1880 * @chip: controller managing the signal
1881 * @offset: of signal within controller's 0..(ngpio - 1) range
1882 *
1883 * Returns NULL if the GPIO is not currently requested, else a string.
1884 * If debugfs support is enabled, the string returned is the label passed
1885 * to gpio_request(); otherwise it is a meaningless constant.
1886 *
1887 * This function is for use by GPIO controller drivers. The label can
1888 * help with diagnostics, and knowing that the signal is used as a GPIO
1889 * can help avoid accidentally multiplexing it to another controller.
1890 */
1891const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset)
1892{
Alexandre Courbot6c0b4e62013-02-03 01:29:30 +09001893 struct gpio_desc *desc;
David Brownelld2876d02008-02-04 22:28:20 -08001894
Alexandre Courbot6c0b4e62013-02-03 01:29:30 +09001895 if (!GPIO_OFFSET_VALID(chip, offset))
David Brownelld2876d02008-02-04 22:28:20 -08001896 return NULL;
Alexandre Courbot6c0b4e62013-02-03 01:29:30 +09001897
1898 desc = &chip->desc[offset];
1899
Alexandre Courbot372e7222013-02-03 01:29:29 +09001900 if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
David Brownelld2876d02008-02-04 22:28:20 -08001901 return NULL;
1902#ifdef CONFIG_DEBUG_FS
Alexandre Courbot372e7222013-02-03 01:29:29 +09001903 return desc->label;
David Brownelld2876d02008-02-04 22:28:20 -08001904#else
1905 return "?";
1906#endif
1907}
1908EXPORT_SYMBOL_GPL(gpiochip_is_requested);
1909
Mika Westerberg77c2d792014-03-10 14:54:50 +02001910/**
1911 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
1912 * @desc: GPIO descriptor to request
1913 * @label: label for the GPIO
1914 *
1915 * Function allows GPIO chip drivers to request and use their own GPIO
1916 * descriptors via gpiolib API. Difference to gpiod_request() is that this
1917 * function will not increase reference count of the GPIO chip module. This
1918 * allows the GPIO chip module to be unloaded as needed (we assume that the
1919 * GPIO chip driver handles freeing the GPIOs it has requested).
1920 */
1921int gpiochip_request_own_desc(struct gpio_desc *desc, const char *label)
1922{
1923 if (!desc || !desc->chip)
1924 return -EINVAL;
1925
1926 return __gpiod_request(desc, label);
1927}
1928
1929/**
1930 * gpiochip_free_own_desc - Free GPIO requested by the chip driver
1931 * @desc: GPIO descriptor to free
1932 *
1933 * Function frees the given GPIO requested previously with
1934 * gpiochip_request_own_desc().
1935 */
1936void gpiochip_free_own_desc(struct gpio_desc *desc)
1937{
1938 if (desc)
1939 __gpiod_free(desc);
1940}
David Brownelld2876d02008-02-04 22:28:20 -08001941
1942/* Drivers MUST set GPIO direction before making get/set calls. In
1943 * some cases this is done in early boot, before IRQs are enabled.
1944 *
1945 * As a rule these aren't called more than once (except for drivers
1946 * using the open-drain emulation idiom) so these are natural places
1947 * to accumulate extra debugging checks. Note that we can't (yet)
1948 * rely on gpio_request() having been called beforehand.
1949 */
1950
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07001951/**
1952 * gpiod_direction_input - set the GPIO direction to input
1953 * @desc: GPIO to set to input
1954 *
1955 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
1956 * be called safely on it.
1957 *
1958 * Return 0 in case of success, else an error code.
1959 */
1960int gpiod_direction_input(struct gpio_desc *desc)
David Brownelld2876d02008-02-04 22:28:20 -08001961{
1962 unsigned long flags;
1963 struct gpio_chip *chip;
David Brownelld2876d02008-02-04 22:28:20 -08001964 int status = -EINVAL;
Alexandre Courbot372e7222013-02-03 01:29:29 +09001965 int offset;
David Brownelld2876d02008-02-04 22:28:20 -08001966
Linus Walleijbe1a4b12013-08-30 09:41:45 +02001967 if (!desc || !desc->chip) {
Alexandre Courbotbcabdef2013-02-15 14:46:14 +09001968 pr_warn("%s: invalid GPIO\n", __func__);
1969 return -EINVAL;
1970 }
1971
Linus Walleijbe1a4b12013-08-30 09:41:45 +02001972 chip = desc->chip;
1973 if (!chip->get || !chip->direction_input) {
Mark Brown6424de52013-09-09 10:33:49 +01001974 gpiod_warn(desc,
1975 "%s: missing get() or direction_input() operations\n",
Andy Shevchenko7589e592013-12-05 11:26:23 +02001976 __func__);
Linus Walleijbe1a4b12013-08-30 09:41:45 +02001977 return -EIO;
1978 }
1979
David Brownelld2876d02008-02-04 22:28:20 -08001980 spin_lock_irqsave(&gpio_lock, flags);
1981
Alexandre Courbot372e7222013-02-03 01:29:29 +09001982 status = gpio_ensure_requested(desc);
David Brownell35e8bb52008-10-15 22:03:16 -07001983 if (status < 0)
1984 goto fail;
David Brownelld2876d02008-02-04 22:28:20 -08001985
1986 /* now we know the gpio is valid and chip won't vanish */
1987
1988 spin_unlock_irqrestore(&gpio_lock, flags);
1989
David Brownell9c4ba942010-08-10 18:02:24 -07001990 might_sleep_if(chip->can_sleep);
David Brownelld2876d02008-02-04 22:28:20 -08001991
Alexandre Courbot372e7222013-02-03 01:29:29 +09001992 offset = gpio_chip_hwgpio(desc);
David Brownell35e8bb52008-10-15 22:03:16 -07001993 if (status) {
Alexandre Courbot372e7222013-02-03 01:29:29 +09001994 status = chip->request(chip, offset);
David Brownell35e8bb52008-10-15 22:03:16 -07001995 if (status < 0) {
Andy Shevchenko7589e592013-12-05 11:26:23 +02001996 gpiod_dbg(desc, "%s: chip request fail, %d\n",
1997 __func__, status);
David Brownell35e8bb52008-10-15 22:03:16 -07001998 /* and it's not available to anyone else ...
1999 * gpio_request() is the fully clean solution.
2000 */
2001 goto lose;
2002 }
2003 }
2004
Alexandre Courbot372e7222013-02-03 01:29:29 +09002005 status = chip->direction_input(chip, offset);
David Brownelld2876d02008-02-04 22:28:20 -08002006 if (status == 0)
2007 clear_bit(FLAG_IS_OUT, &desc->flags);
Uwe Kleine-König3f397c212011-05-20 00:40:19 -06002008
Alexandre Courbot372e7222013-02-03 01:29:29 +09002009 trace_gpio_direction(desc_to_gpio(desc), 1, status);
David Brownell35e8bb52008-10-15 22:03:16 -07002010lose:
David Brownelld2876d02008-02-04 22:28:20 -08002011 return status;
2012fail:
2013 spin_unlock_irqrestore(&gpio_lock, flags);
Alexandre Courbotbcabdef2013-02-15 14:46:14 +09002014 if (status)
Andy Shevchenko7589e592013-12-05 11:26:23 +02002015 gpiod_dbg(desc, "%s: status %d\n", __func__, status);
David Brownelld2876d02008-02-04 22:28:20 -08002016 return status;
2017}
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002018EXPORT_SYMBOL_GPL(gpiod_direction_input);
Alexandre Courbot372e7222013-02-03 01:29:29 +09002019
Philipp Zabelef70bbe2014-01-07 12:34:11 +01002020static int _gpiod_direction_output_raw(struct gpio_desc *desc, int value)
David Brownelld2876d02008-02-04 22:28:20 -08002021{
2022 unsigned long flags;
2023 struct gpio_chip *chip;
David Brownelld2876d02008-02-04 22:28:20 -08002024 int status = -EINVAL;
Alexandre Courbot372e7222013-02-03 01:29:29 +09002025 int offset;
David Brownelld2876d02008-02-04 22:28:20 -08002026
Linus Walleijd468bf92013-09-24 11:54:38 +02002027 /* GPIOs used for IRQs shall not be set as output */
2028 if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) {
2029 gpiod_err(desc,
2030 "%s: tried to set a GPIO tied to an IRQ as output\n",
2031 __func__);
2032 return -EIO;
2033 }
2034
Laxman Dewanganaca5ce12012-02-17 20:26:21 +05302035 /* Open drain pin should not be driven to 1 */
2036 if (value && test_bit(FLAG_OPEN_DRAIN, &desc->flags))
Alexandre Courbot372e7222013-02-03 01:29:29 +09002037 return gpiod_direction_input(desc);
Laxman Dewanganaca5ce12012-02-17 20:26:21 +05302038
Laxman Dewangan25553ff2012-02-17 20:26:22 +05302039 /* Open source pin should not be driven to 0 */
2040 if (!value && test_bit(FLAG_OPEN_SOURCE, &desc->flags))
Alexandre Courbot372e7222013-02-03 01:29:29 +09002041 return gpiod_direction_input(desc);
Laxman Dewangan25553ff2012-02-17 20:26:22 +05302042
Linus Walleijbe1a4b12013-08-30 09:41:45 +02002043 chip = desc->chip;
2044 if (!chip->set || !chip->direction_output) {
Mark Brown6424de52013-09-09 10:33:49 +01002045 gpiod_warn(desc,
2046 "%s: missing set() or direction_output() operations\n",
2047 __func__);
Linus Walleijbe1a4b12013-08-30 09:41:45 +02002048 return -EIO;
2049 }
2050
David Brownelld2876d02008-02-04 22:28:20 -08002051 spin_lock_irqsave(&gpio_lock, flags);
2052
Alexandre Courbot372e7222013-02-03 01:29:29 +09002053 status = gpio_ensure_requested(desc);
David Brownell35e8bb52008-10-15 22:03:16 -07002054 if (status < 0)
2055 goto fail;
David Brownelld2876d02008-02-04 22:28:20 -08002056
2057 /* now we know the gpio is valid and chip won't vanish */
2058
2059 spin_unlock_irqrestore(&gpio_lock, flags);
2060
David Brownell9c4ba942010-08-10 18:02:24 -07002061 might_sleep_if(chip->can_sleep);
David Brownelld2876d02008-02-04 22:28:20 -08002062
Alexandre Courbot372e7222013-02-03 01:29:29 +09002063 offset = gpio_chip_hwgpio(desc);
David Brownell35e8bb52008-10-15 22:03:16 -07002064 if (status) {
Alexandre Courbot372e7222013-02-03 01:29:29 +09002065 status = chip->request(chip, offset);
David Brownell35e8bb52008-10-15 22:03:16 -07002066 if (status < 0) {
Andy Shevchenko7589e592013-12-05 11:26:23 +02002067 gpiod_dbg(desc, "%s: chip request fail, %d\n",
2068 __func__, status);
David Brownell35e8bb52008-10-15 22:03:16 -07002069 /* and it's not available to anyone else ...
2070 * gpio_request() is the fully clean solution.
2071 */
2072 goto lose;
2073 }
2074 }
2075
Alexandre Courbot372e7222013-02-03 01:29:29 +09002076 status = chip->direction_output(chip, offset, value);
David Brownelld2876d02008-02-04 22:28:20 -08002077 if (status == 0)
2078 set_bit(FLAG_IS_OUT, &desc->flags);
Alexandre Courbot372e7222013-02-03 01:29:29 +09002079 trace_gpio_value(desc_to_gpio(desc), 0, value);
2080 trace_gpio_direction(desc_to_gpio(desc), 0, status);
David Brownell35e8bb52008-10-15 22:03:16 -07002081lose:
David Brownelld2876d02008-02-04 22:28:20 -08002082 return status;
2083fail:
2084 spin_unlock_irqrestore(&gpio_lock, flags);
Alexandre Courbotbcabdef2013-02-15 14:46:14 +09002085 if (status)
Mark Brown6424de52013-09-09 10:33:49 +01002086 gpiod_dbg(desc, "%s: gpio status %d\n", __func__, status);
David Brownelld2876d02008-02-04 22:28:20 -08002087 return status;
2088}
Philipp Zabelef70bbe2014-01-07 12:34:11 +01002089
2090/**
2091 * gpiod_direction_output_raw - set the GPIO direction to output
2092 * @desc: GPIO to set to output
2093 * @value: initial output value of the GPIO
2094 *
2095 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2096 * be called safely on it. The initial value of the output must be specified
2097 * as raw value on the physical line without regard for the ACTIVE_LOW status.
2098 *
2099 * Return 0 in case of success, else an error code.
2100 */
2101int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
2102{
2103 if (!desc || !desc->chip) {
2104 pr_warn("%s: invalid GPIO\n", __func__);
2105 return -EINVAL;
2106 }
2107 return _gpiod_direction_output_raw(desc, value);
2108}
2109EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
2110
2111/**
Rahul Bedarkar90df4fe2014-02-08 11:55:25 +05302112 * gpiod_direction_output - set the GPIO direction to output
Philipp Zabelef70bbe2014-01-07 12:34:11 +01002113 * @desc: GPIO to set to output
2114 * @value: initial output value of the GPIO
2115 *
2116 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
2117 * be called safely on it. The initial value of the output must be specified
2118 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2119 * account.
2120 *
2121 * Return 0 in case of success, else an error code.
2122 */
2123int gpiod_direction_output(struct gpio_desc *desc, int value)
2124{
2125 if (!desc || !desc->chip) {
2126 pr_warn("%s: invalid GPIO\n", __func__);
2127 return -EINVAL;
2128 }
2129 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2130 value = !value;
2131 return _gpiod_direction_output_raw(desc, value);
2132}
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002133EXPORT_SYMBOL_GPL(gpiod_direction_output);
David Brownelld2876d02008-02-04 22:28:20 -08002134
Felipe Balbic4b5be92010-05-26 14:42:23 -07002135/**
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002136 * gpiod_set_debounce - sets @debounce time for a @gpio
Felipe Balbic4b5be92010-05-26 14:42:23 -07002137 * @gpio: the gpio to set debounce time
2138 * @debounce: debounce time is microseconds
Linus Walleij65d87652013-09-04 14:17:08 +02002139 *
2140 * returns -ENOTSUPP if the controller does not support setting
2141 * debounce.
Felipe Balbic4b5be92010-05-26 14:42:23 -07002142 */
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002143int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
Felipe Balbic4b5be92010-05-26 14:42:23 -07002144{
2145 unsigned long flags;
2146 struct gpio_chip *chip;
Felipe Balbic4b5be92010-05-26 14:42:23 -07002147 int status = -EINVAL;
Alexandre Courbot372e7222013-02-03 01:29:29 +09002148 int offset;
Felipe Balbic4b5be92010-05-26 14:42:23 -07002149
Linus Walleijbe1a4b12013-08-30 09:41:45 +02002150 if (!desc || !desc->chip) {
Alexandre Courbotbcabdef2013-02-15 14:46:14 +09002151 pr_warn("%s: invalid GPIO\n", __func__);
2152 return -EINVAL;
2153 }
2154
Felipe Balbic4b5be92010-05-26 14:42:23 -07002155 chip = desc->chip;
Linus Walleijbe1a4b12013-08-30 09:41:45 +02002156 if (!chip->set || !chip->set_debounce) {
Mark Brown6424de52013-09-09 10:33:49 +01002157 gpiod_dbg(desc,
2158 "%s: missing set() or set_debounce() operations\n",
2159 __func__);
Linus Walleij65d87652013-09-04 14:17:08 +02002160 return -ENOTSUPP;
Linus Walleijbe1a4b12013-08-30 09:41:45 +02002161 }
2162
2163 spin_lock_irqsave(&gpio_lock, flags);
Alexandre Courbot372e7222013-02-03 01:29:29 +09002164
2165 status = gpio_ensure_requested(desc);
Felipe Balbic4b5be92010-05-26 14:42:23 -07002166 if (status < 0)
2167 goto fail;
2168
2169 /* now we know the gpio is valid and chip won't vanish */
2170
2171 spin_unlock_irqrestore(&gpio_lock, flags);
2172
David Brownell9c4ba942010-08-10 18:02:24 -07002173 might_sleep_if(chip->can_sleep);
Felipe Balbic4b5be92010-05-26 14:42:23 -07002174
Alexandre Courbot372e7222013-02-03 01:29:29 +09002175 offset = gpio_chip_hwgpio(desc);
2176 return chip->set_debounce(chip, offset, debounce);
Felipe Balbic4b5be92010-05-26 14:42:23 -07002177
2178fail:
2179 spin_unlock_irqrestore(&gpio_lock, flags);
Alexandre Courbotbcabdef2013-02-15 14:46:14 +09002180 if (status)
Mark Brown6424de52013-09-09 10:33:49 +01002181 gpiod_dbg(desc, "%s: status %d\n", __func__, status);
Felipe Balbic4b5be92010-05-26 14:42:23 -07002182
2183 return status;
2184}
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002185EXPORT_SYMBOL_GPL(gpiod_set_debounce);
Alexandre Courbot372e7222013-02-03 01:29:29 +09002186
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002187/**
2188 * gpiod_is_active_low - test whether a GPIO is active-low or not
2189 * @desc: the gpio descriptor to test
2190 *
2191 * Returns 1 if the GPIO is active-low, 0 otherwise.
2192 */
2193int gpiod_is_active_low(const struct gpio_desc *desc)
Alexandre Courbot372e7222013-02-03 01:29:29 +09002194{
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002195 return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
Alexandre Courbot372e7222013-02-03 01:29:29 +09002196}
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002197EXPORT_SYMBOL_GPL(gpiod_is_active_low);
David Brownelld2876d02008-02-04 22:28:20 -08002198
2199/* I/O calls are only valid after configuration completed; the relevant
2200 * "is this a valid GPIO" error checks should already have been done.
2201 *
2202 * "Get" operations are often inlinable as reading a pin value register,
2203 * and masking the relevant bit in that register.
2204 *
2205 * When "set" operations are inlinable, they involve writing that mask to
2206 * one register to set a low value, or a different register to set it high.
2207 * Otherwise locking is needed, so there may be little value to inlining.
2208 *
2209 *------------------------------------------------------------------------
2210 *
2211 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers
2212 * have requested the GPIO. That can include implicit requesting by
2213 * a direction setting call. Marking a gpio as requested locks its chip
2214 * in memory, guaranteeing that these table lookups need no more locking
2215 * and that gpiochip_remove() will fail.
2216 *
2217 * REVISIT when debugging, consider adding some instrumentation to ensure
2218 * that the GPIO was actually requested.
2219 */
2220
Alexandre Courbot23600962014-03-11 15:52:09 +09002221static bool _gpiod_get_raw_value(const struct gpio_desc *desc)
David Brownelld2876d02008-02-04 22:28:20 -08002222{
2223 struct gpio_chip *chip;
Alexandre Courbot23600962014-03-11 15:52:09 +09002224 bool value;
Alexandre Courbot372e7222013-02-03 01:29:29 +09002225 int offset;
David Brownelld2876d02008-02-04 22:28:20 -08002226
Alexandre Courbot372e7222013-02-03 01:29:29 +09002227 chip = desc->chip;
2228 offset = gpio_chip_hwgpio(desc);
Alexandre Courbot23600962014-03-11 15:52:09 +09002229 value = chip->get ? chip->get(chip, offset) : false;
Alexandre Courbot372e7222013-02-03 01:29:29 +09002230 trace_gpio_value(desc_to_gpio(desc), 1, value);
Uwe Kleine-König3f397c212011-05-20 00:40:19 -06002231 return value;
David Brownelld2876d02008-02-04 22:28:20 -08002232}
Alexandre Courbot372e7222013-02-03 01:29:29 +09002233
David Brownelld2876d02008-02-04 22:28:20 -08002234/**
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002235 * gpiod_get_raw_value() - return a gpio's raw value
2236 * @desc: gpio whose value will be returned
David Brownelld2876d02008-02-04 22:28:20 -08002237 *
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002238 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
2239 * its ACTIVE_LOW status.
2240 *
2241 * This function should be called from contexts where we cannot sleep, and will
2242 * complain if the GPIO chip functions potentially sleep.
David Brownelld2876d02008-02-04 22:28:20 -08002243 */
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002244int gpiod_get_raw_value(const struct gpio_desc *desc)
Alexandre Courbot372e7222013-02-03 01:29:29 +09002245{
David Brownelld2876d02008-02-04 22:28:20 -08002246 if (!desc)
2247 return 0;
David Brownelld2876d02008-02-04 22:28:20 -08002248 /* Should be using gpio_get_value_cansleep() */
Alexandre Courbotd8e0ac02013-09-04 20:29:25 +09002249 WARN_ON(desc->chip->can_sleep);
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002250 return _gpiod_get_raw_value(desc);
Alexandre Courbot372e7222013-02-03 01:29:29 +09002251}
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002252EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
David Brownelld2876d02008-02-04 22:28:20 -08002253
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002254/**
2255 * gpiod_get_value() - return a gpio's value
2256 * @desc: gpio whose value will be returned
2257 *
2258 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2259 * account.
2260 *
2261 * This function should be called from contexts where we cannot sleep, and will
2262 * complain if the GPIO chip functions potentially sleep.
2263 */
2264int gpiod_get_value(const struct gpio_desc *desc)
David Brownelld2876d02008-02-04 22:28:20 -08002265{
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002266 int value;
2267 if (!desc)
2268 return 0;
2269 /* Should be using gpio_get_value_cansleep() */
2270 WARN_ON(desc->chip->can_sleep);
2271
2272 value = _gpiod_get_raw_value(desc);
2273 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2274 value = !value;
2275
2276 return value;
David Brownelld2876d02008-02-04 22:28:20 -08002277}
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002278EXPORT_SYMBOL_GPL(gpiod_get_value);
David Brownelld2876d02008-02-04 22:28:20 -08002279
Laxman Dewanganaca5ce12012-02-17 20:26:21 +05302280/*
2281 * _gpio_set_open_drain_value() - Set the open drain gpio's value.
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002282 * @desc: gpio descriptor whose state need to be set.
Laxman Dewanganaca5ce12012-02-17 20:26:21 +05302283 * @value: Non-zero for setting it HIGH otherise it will set to LOW.
2284 */
Alexandre Courbot23600962014-03-11 15:52:09 +09002285static void _gpio_set_open_drain_value(struct gpio_desc *desc, bool value)
Laxman Dewanganaca5ce12012-02-17 20:26:21 +05302286{
2287 int err = 0;
Alexandre Courbot372e7222013-02-03 01:29:29 +09002288 struct gpio_chip *chip = desc->chip;
2289 int offset = gpio_chip_hwgpio(desc);
2290
Laxman Dewanganaca5ce12012-02-17 20:26:21 +05302291 if (value) {
Alexandre Courbot372e7222013-02-03 01:29:29 +09002292 err = chip->direction_input(chip, offset);
Laxman Dewanganaca5ce12012-02-17 20:26:21 +05302293 if (!err)
Alexandre Courbot372e7222013-02-03 01:29:29 +09002294 clear_bit(FLAG_IS_OUT, &desc->flags);
Laxman Dewanganaca5ce12012-02-17 20:26:21 +05302295 } else {
Alexandre Courbot372e7222013-02-03 01:29:29 +09002296 err = chip->direction_output(chip, offset, 0);
Laxman Dewanganaca5ce12012-02-17 20:26:21 +05302297 if (!err)
Alexandre Courbot372e7222013-02-03 01:29:29 +09002298 set_bit(FLAG_IS_OUT, &desc->flags);
Laxman Dewanganaca5ce12012-02-17 20:26:21 +05302299 }
Alexandre Courbot372e7222013-02-03 01:29:29 +09002300 trace_gpio_direction(desc_to_gpio(desc), value, err);
Laxman Dewanganaca5ce12012-02-17 20:26:21 +05302301 if (err < 0)
Mark Brown6424de52013-09-09 10:33:49 +01002302 gpiod_err(desc,
2303 "%s: Error in set_value for open drain err %d\n",
2304 __func__, err);
Laxman Dewanganaca5ce12012-02-17 20:26:21 +05302305}
2306
Laxman Dewangan25553ff2012-02-17 20:26:22 +05302307/*
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002308 * _gpio_set_open_source_value() - Set the open source gpio's value.
2309 * @desc: gpio descriptor whose state need to be set.
Laxman Dewangan25553ff2012-02-17 20:26:22 +05302310 * @value: Non-zero for setting it HIGH otherise it will set to LOW.
2311 */
Alexandre Courbot23600962014-03-11 15:52:09 +09002312static void _gpio_set_open_source_value(struct gpio_desc *desc, bool value)
Laxman Dewangan25553ff2012-02-17 20:26:22 +05302313{
2314 int err = 0;
Alexandre Courbot372e7222013-02-03 01:29:29 +09002315 struct gpio_chip *chip = desc->chip;
2316 int offset = gpio_chip_hwgpio(desc);
2317
Laxman Dewangan25553ff2012-02-17 20:26:22 +05302318 if (value) {
Alexandre Courbot372e7222013-02-03 01:29:29 +09002319 err = chip->direction_output(chip, offset, 1);
Laxman Dewangan25553ff2012-02-17 20:26:22 +05302320 if (!err)
Alexandre Courbot372e7222013-02-03 01:29:29 +09002321 set_bit(FLAG_IS_OUT, &desc->flags);
Laxman Dewangan25553ff2012-02-17 20:26:22 +05302322 } else {
Alexandre Courbot372e7222013-02-03 01:29:29 +09002323 err = chip->direction_input(chip, offset);
Laxman Dewangan25553ff2012-02-17 20:26:22 +05302324 if (!err)
Alexandre Courbot372e7222013-02-03 01:29:29 +09002325 clear_bit(FLAG_IS_OUT, &desc->flags);
Laxman Dewangan25553ff2012-02-17 20:26:22 +05302326 }
Alexandre Courbot372e7222013-02-03 01:29:29 +09002327 trace_gpio_direction(desc_to_gpio(desc), !value, err);
Laxman Dewangan25553ff2012-02-17 20:26:22 +05302328 if (err < 0)
Mark Brown6424de52013-09-09 10:33:49 +01002329 gpiod_err(desc,
2330 "%s: Error in set_value for open source err %d\n",
2331 __func__, err);
Laxman Dewangan25553ff2012-02-17 20:26:22 +05302332}
2333
Alexandre Courbot23600962014-03-11 15:52:09 +09002334static void _gpiod_set_raw_value(struct gpio_desc *desc, bool value)
David Brownelld2876d02008-02-04 22:28:20 -08002335{
2336 struct gpio_chip *chip;
2337
Alexandre Courbot372e7222013-02-03 01:29:29 +09002338 chip = desc->chip;
Alexandre Courbot372e7222013-02-03 01:29:29 +09002339 trace_gpio_value(desc_to_gpio(desc), 0, value);
2340 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
2341 _gpio_set_open_drain_value(desc, value);
2342 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
2343 _gpio_set_open_source_value(desc, value);
Laxman Dewanganaca5ce12012-02-17 20:26:21 +05302344 else
Alexandre Courbot372e7222013-02-03 01:29:29 +09002345 chip->set(chip, gpio_chip_hwgpio(desc), value);
2346}
2347
David Brownelld2876d02008-02-04 22:28:20 -08002348/**
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002349 * gpiod_set_raw_value() - assign a gpio's raw value
2350 * @desc: gpio whose value will be assigned
David Brownelld2876d02008-02-04 22:28:20 -08002351 * @value: value to assign
David Brownelld2876d02008-02-04 22:28:20 -08002352 *
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002353 * Set the raw value of the GPIO, i.e. the value of its physical line without
2354 * regard for its ACTIVE_LOW status.
2355 *
2356 * This function should be called from contexts where we cannot sleep, and will
2357 * complain if the GPIO chip functions potentially sleep.
David Brownelld2876d02008-02-04 22:28:20 -08002358 */
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002359void gpiod_set_raw_value(struct gpio_desc *desc, int value)
Alexandre Courbot372e7222013-02-03 01:29:29 +09002360{
David Brownelld2876d02008-02-04 22:28:20 -08002361 if (!desc)
2362 return;
David Brownelld2876d02008-02-04 22:28:20 -08002363 /* Should be using gpio_set_value_cansleep() */
Alexandre Courbotd8e0ac02013-09-04 20:29:25 +09002364 WARN_ON(desc->chip->can_sleep);
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002365 _gpiod_set_raw_value(desc, value);
David Brownelld2876d02008-02-04 22:28:20 -08002366}
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002367EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
David Brownelld2876d02008-02-04 22:28:20 -08002368
2369/**
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002370 * gpiod_set_value() - assign a gpio's value
2371 * @desc: gpio whose value will be assigned
2372 * @value: value to assign
David Brownelld2876d02008-02-04 22:28:20 -08002373 *
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002374 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2375 * account
2376 *
2377 * This function should be called from contexts where we cannot sleep, and will
2378 * complain if the GPIO chip functions potentially sleep.
David Brownelld2876d02008-02-04 22:28:20 -08002379 */
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002380void gpiod_set_value(struct gpio_desc *desc, int value)
2381{
2382 if (!desc)
2383 return;
2384 /* Should be using gpio_set_value_cansleep() */
2385 WARN_ON(desc->chip->can_sleep);
2386 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2387 value = !value;
2388 _gpiod_set_raw_value(desc, value);
2389}
2390EXPORT_SYMBOL_GPL(gpiod_set_value);
2391
2392/**
2393 * gpiod_cansleep() - report whether gpio value access may sleep
2394 * @desc: gpio to check
2395 *
2396 */
2397int gpiod_cansleep(const struct gpio_desc *desc)
Alexandre Courbot372e7222013-02-03 01:29:29 +09002398{
Alexandre Courbotbcabdef2013-02-15 14:46:14 +09002399 if (!desc)
2400 return 0;
Alexandre Courbot372e7222013-02-03 01:29:29 +09002401 return desc->chip->can_sleep;
2402}
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002403EXPORT_SYMBOL_GPL(gpiod_cansleep);
David Brownelld2876d02008-02-04 22:28:20 -08002404
David Brownell0f6d5042008-10-15 22:03:14 -07002405/**
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002406 * gpiod_to_irq() - return the IRQ corresponding to a GPIO
2407 * @desc: gpio whose IRQ will be returned (already requested)
David Brownell0f6d5042008-10-15 22:03:14 -07002408 *
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002409 * Return the IRQ corresponding to the passed GPIO, or an error code in case of
2410 * error.
David Brownell0f6d5042008-10-15 22:03:14 -07002411 */
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002412int gpiod_to_irq(const struct gpio_desc *desc)
David Brownell0f6d5042008-10-15 22:03:14 -07002413{
2414 struct gpio_chip *chip;
Alexandre Courbot372e7222013-02-03 01:29:29 +09002415 int offset;
David Brownell0f6d5042008-10-15 22:03:14 -07002416
Alexandre Courbotbcabdef2013-02-15 14:46:14 +09002417 if (!desc)
2418 return -EINVAL;
Alexandre Courbot372e7222013-02-03 01:29:29 +09002419 chip = desc->chip;
2420 offset = gpio_chip_hwgpio(desc);
2421 return chip->to_irq ? chip->to_irq(chip, offset) : -ENXIO;
2422}
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002423EXPORT_SYMBOL_GPL(gpiod_to_irq);
Alexandre Courbot372e7222013-02-03 01:29:29 +09002424
Linus Walleijd468bf92013-09-24 11:54:38 +02002425/**
2426 * gpiod_lock_as_irq() - lock a GPIO to be used as IRQ
2427 * @gpio: the GPIO line to lock as used for IRQ
2428 *
2429 * This is used directly by GPIO drivers that want to lock down
Linus Walleijf438acd2014-03-07 10:12:49 +08002430 * a certain GPIO line to be used for IRQs.
David Brownelld2876d02008-02-04 22:28:20 -08002431 */
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002432int gpiod_lock_as_irq(struct gpio_desc *desc)
David Brownelld2876d02008-02-04 22:28:20 -08002433{
Linus Walleijd468bf92013-09-24 11:54:38 +02002434 if (!desc)
2435 return -EINVAL;
2436
2437 if (test_bit(FLAG_IS_OUT, &desc->flags)) {
2438 gpiod_err(desc,
2439 "%s: tried to flag a GPIO set as output for IRQ\n",
2440 __func__);
2441 return -EIO;
2442 }
2443
2444 set_bit(FLAG_USED_AS_IRQ, &desc->flags);
2445 return 0;
2446}
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002447EXPORT_SYMBOL_GPL(gpiod_lock_as_irq);
Linus Walleijd468bf92013-09-24 11:54:38 +02002448
2449int gpio_lock_as_irq(struct gpio_chip *chip, unsigned int offset)
2450{
Alexandre Courbotbb1e88c2014-02-09 17:43:54 +09002451 return gpiod_lock_as_irq(gpiochip_get_desc(chip, offset));
Linus Walleijd468bf92013-09-24 11:54:38 +02002452}
2453EXPORT_SYMBOL_GPL(gpio_lock_as_irq);
2454
2455/**
2456 * gpiod_unlock_as_irq() - unlock a GPIO used as IRQ
2457 * @gpio: the GPIO line to unlock from IRQ usage
2458 *
2459 * This is used directly by GPIO drivers that want to indicate
2460 * that a certain GPIO is no longer used exclusively for IRQ.
2461 */
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002462void gpiod_unlock_as_irq(struct gpio_desc *desc)
Linus Walleijd468bf92013-09-24 11:54:38 +02002463{
2464 if (!desc)
2465 return;
2466
2467 clear_bit(FLAG_USED_AS_IRQ, &desc->flags);
2468}
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002469EXPORT_SYMBOL_GPL(gpiod_unlock_as_irq);
Linus Walleijd468bf92013-09-24 11:54:38 +02002470
2471void gpio_unlock_as_irq(struct gpio_chip *chip, unsigned int offset)
2472{
Alexandre Courbotbb1e88c2014-02-09 17:43:54 +09002473 return gpiod_unlock_as_irq(gpiochip_get_desc(chip, offset));
Linus Walleijd468bf92013-09-24 11:54:38 +02002474}
2475EXPORT_SYMBOL_GPL(gpio_unlock_as_irq);
David Brownelld2876d02008-02-04 22:28:20 -08002476
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002477/**
2478 * gpiod_get_raw_value_cansleep() - return a gpio's raw value
2479 * @desc: gpio whose value will be returned
2480 *
2481 * Return the GPIO's raw value, i.e. the value of the physical line disregarding
2482 * its ACTIVE_LOW status.
2483 *
2484 * This function is to be called from contexts that can sleep.
David Brownelld2876d02008-02-04 22:28:20 -08002485 */
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002486int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
David Brownelld2876d02008-02-04 22:28:20 -08002487{
David Brownelld2876d02008-02-04 22:28:20 -08002488 might_sleep_if(extra_checks);
Alexandre Courbotbcabdef2013-02-15 14:46:14 +09002489 if (!desc)
2490 return 0;
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002491 return _gpiod_get_raw_value(desc);
David Brownelld2876d02008-02-04 22:28:20 -08002492}
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002493EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
Alexandre Courbot372e7222013-02-03 01:29:29 +09002494
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002495/**
2496 * gpiod_get_value_cansleep() - return a gpio's value
2497 * @desc: gpio whose value will be returned
2498 *
2499 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
2500 * account.
2501 *
2502 * This function is to be called from contexts that can sleep.
2503 */
2504int gpiod_get_value_cansleep(const struct gpio_desc *desc)
Alexandre Courbot372e7222013-02-03 01:29:29 +09002505{
David Brownelld2876d02008-02-04 22:28:20 -08002506 int value;
David Brownelld2876d02008-02-04 22:28:20 -08002507
2508 might_sleep_if(extra_checks);
2509 if (!desc)
2510 return 0;
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002511
2512 value = _gpiod_get_raw_value(desc);
2513 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2514 value = !value;
2515
David Brownelld2876d02008-02-04 22:28:20 -08002516 return value;
2517}
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002518EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
Alexandre Courbot372e7222013-02-03 01:29:29 +09002519
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002520/**
2521 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
2522 * @desc: gpio whose value will be assigned
2523 * @value: value to assign
2524 *
2525 * Set the raw value of the GPIO, i.e. the value of its physical line without
2526 * regard for its ACTIVE_LOW status.
2527 *
2528 * This function is to be called from contexts that can sleep.
2529 */
2530void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
Alexandre Courbot372e7222013-02-03 01:29:29 +09002531{
David Brownelld2876d02008-02-04 22:28:20 -08002532 might_sleep_if(extra_checks);
Alexandre Courbotbcabdef2013-02-15 14:46:14 +09002533 if (!desc)
2534 return;
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002535 _gpiod_set_raw_value(desc, value);
Alexandre Courbot372e7222013-02-03 01:29:29 +09002536}
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002537EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
Alexandre Courbot372e7222013-02-03 01:29:29 +09002538
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002539/**
2540 * gpiod_set_value_cansleep() - assign a gpio's value
2541 * @desc: gpio whose value will be assigned
2542 * @value: value to assign
2543 *
2544 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
2545 * account
2546 *
2547 * This function is to be called from contexts that can sleep.
2548 */
2549void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
Alexandre Courbot372e7222013-02-03 01:29:29 +09002550{
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002551 might_sleep_if(extra_checks);
2552 if (!desc)
2553 return;
2554
2555 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
2556 value = !value;
2557 _gpiod_set_raw_value(desc, value);
David Brownelld2876d02008-02-04 22:28:20 -08002558}
Alexandre Courbot79a9bec2013-10-17 10:21:36 -07002559EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
David Brownelld2876d02008-02-04 22:28:20 -08002560
Alexandre Courbotbae48da2013-10-17 10:21:38 -07002561/**
Alexandre Courbotad824782013-12-03 12:20:11 +09002562 * gpiod_add_lookup_table() - register GPIO device consumers
2563 * @table: table of consumers to register
Alexandre Courbotbae48da2013-10-17 10:21:38 -07002564 */
Alexandre Courbotad824782013-12-03 12:20:11 +09002565void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
Alexandre Courbotbae48da2013-10-17 10:21:38 -07002566{
2567 mutex_lock(&gpio_lookup_lock);
2568
Alexandre Courbotad824782013-12-03 12:20:11 +09002569 list_add_tail(&table->list, &gpio_lookup_list);
Alexandre Courbotbae48da2013-10-17 10:21:38 -07002570
2571 mutex_unlock(&gpio_lookup_lock);
David Brownelld2876d02008-02-04 22:28:20 -08002572}
2573
Alexandre Courbotbae48da2013-10-17 10:21:38 -07002574#ifdef CONFIG_OF
2575static struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
Alexandre Courbot53e7cac2013-11-16 21:44:52 +09002576 unsigned int idx,
2577 enum gpio_lookup_flags *flags)
Alexandre Courbotbae48da2013-10-17 10:21:38 -07002578{
2579 char prop_name[32]; /* 32 is max size of property name */
2580 enum of_gpio_flags of_flags;
2581 struct gpio_desc *desc;
2582
2583 if (con_id)
2584 snprintf(prop_name, 32, "%s-gpios", con_id);
2585 else
2586 snprintf(prop_name, 32, "gpios");
2587
2588 desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx,
2589 &of_flags);
2590
2591 if (IS_ERR(desc))
2592 return desc;
2593
2594 if (of_flags & OF_GPIO_ACTIVE_LOW)
Alexandre Courbot53e7cac2013-11-16 21:44:52 +09002595 *flags |= GPIO_ACTIVE_LOW;
Alexandre Courbotbae48da2013-10-17 10:21:38 -07002596
2597 return desc;
2598}
2599#else
2600static struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
Alexandre Courbot209e64f2013-11-19 10:37:29 +09002601 unsigned int idx,
2602 enum gpio_lookup_flags *flags)
Alexandre Courbotbae48da2013-10-17 10:21:38 -07002603{
2604 return ERR_PTR(-ENODEV);
2605}
2606#endif
2607
Mika Westerberg81f59e92013-10-10 11:01:09 +03002608static struct gpio_desc *acpi_find_gpio(struct device *dev, const char *con_id,
Alexandre Courbot53e7cac2013-11-16 21:44:52 +09002609 unsigned int idx,
2610 enum gpio_lookup_flags *flags)
Mika Westerberg81f59e92013-10-10 11:01:09 +03002611{
Mika Westerberge01f4402013-10-10 11:01:10 +03002612 struct acpi_gpio_info info;
2613 struct gpio_desc *desc;
2614
2615 desc = acpi_get_gpiod_by_index(dev, idx, &info);
2616 if (IS_ERR(desc))
2617 return desc;
2618
2619 if (info.gpioint && info.active_low)
Alexandre Courbot53e7cac2013-11-16 21:44:52 +09002620 *flags |= GPIO_ACTIVE_LOW;
Mika Westerberge01f4402013-10-10 11:01:10 +03002621
2622 return desc;
Mika Westerberg81f59e92013-10-10 11:01:09 +03002623}
2624
Alexandre Courbotad824782013-12-03 12:20:11 +09002625static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
2626{
2627 const char *dev_id = dev ? dev_name(dev) : NULL;
2628 struct gpiod_lookup_table *table;
2629
2630 mutex_lock(&gpio_lookup_lock);
2631
2632 list_for_each_entry(table, &gpio_lookup_list, list) {
2633 if (table->dev_id && dev_id) {
2634 /*
2635 * Valid strings on both ends, must be identical to have
2636 * a match
2637 */
2638 if (!strcmp(table->dev_id, dev_id))
2639 goto found;
2640 } else {
2641 /*
2642 * One of the pointers is NULL, so both must be to have
2643 * a match
2644 */
2645 if (dev_id == table->dev_id)
2646 goto found;
2647 }
2648 }
2649 table = NULL;
2650
2651found:
2652 mutex_unlock(&gpio_lookup_lock);
2653 return table;
2654}
2655
Alexandre Courbotbae48da2013-10-17 10:21:38 -07002656static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
Alexandre Courbot53e7cac2013-11-16 21:44:52 +09002657 unsigned int idx,
2658 enum gpio_lookup_flags *flags)
Alexandre Courbotbae48da2013-10-17 10:21:38 -07002659{
Alexandre Courbot2a3cf6a2013-12-11 11:32:28 +09002660 struct gpio_desc *desc = ERR_PTR(-ENOENT);
Alexandre Courbotad824782013-12-03 12:20:11 +09002661 struct gpiod_lookup_table *table;
Alexandre Courbotbae48da2013-10-17 10:21:38 -07002662 struct gpiod_lookup *p;
2663
Alexandre Courbotad824782013-12-03 12:20:11 +09002664 table = gpiod_find_lookup_table(dev);
2665 if (!table)
2666 return desc;
Alexandre Courbotbae48da2013-10-17 10:21:38 -07002667
Alexandre Courbotad824782013-12-03 12:20:11 +09002668 for (p = &table->table[0]; p->chip_label; p++) {
2669 struct gpio_chip *chip;
Alexandre Courbotbae48da2013-10-17 10:21:38 -07002670
Alexandre Courbotad824782013-12-03 12:20:11 +09002671 /* idx must always match exactly */
Alexandre Courbotbae48da2013-10-17 10:21:38 -07002672 if (p->idx != idx)
2673 continue;
2674
Alexandre Courbotad824782013-12-03 12:20:11 +09002675 /* If the lookup entry has a con_id, require exact match */
2676 if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
2677 continue;
Alexandre Courbotbae48da2013-10-17 10:21:38 -07002678
Alexandre Courbotad824782013-12-03 12:20:11 +09002679 chip = find_chip_by_name(p->chip_label);
Alexandre Courbotbae48da2013-10-17 10:21:38 -07002680
Alexandre Courbotad824782013-12-03 12:20:11 +09002681 if (!chip) {
Alexandre Courbot2a3cf6a2013-12-11 11:32:28 +09002682 dev_err(dev, "cannot find GPIO chip %s\n",
2683 p->chip_label);
2684 return ERR_PTR(-ENODEV);
Alexandre Courbotbae48da2013-10-17 10:21:38 -07002685 }
Alexandre Courbotbae48da2013-10-17 10:21:38 -07002686
Alexandre Courbotad824782013-12-03 12:20:11 +09002687 if (chip->ngpio <= p->chip_hwnum) {
Alexandre Courbot2a3cf6a2013-12-11 11:32:28 +09002688 dev_err(dev,
2689 "requested GPIO %d is out of range [0..%d] for chip %s\n",
2690 idx, chip->ngpio, chip->label);
2691 return ERR_PTR(-EINVAL);
Alexandre Courbotad824782013-12-03 12:20:11 +09002692 }
2693
Alexandre Courbotbb1e88c2014-02-09 17:43:54 +09002694 desc = gpiochip_get_desc(chip, p->chip_hwnum);
Alexandre Courbotad824782013-12-03 12:20:11 +09002695 *flags = p->flags;
Alexandre Courbot2a3cf6a2013-12-11 11:32:28 +09002696
2697 return desc;
Alexandre Courbotad824782013-12-03 12:20:11 +09002698 }
Alexandre Courbotbae48da2013-10-17 10:21:38 -07002699
2700 return desc;
2701}
2702
2703/**
2704 * gpio_get - obtain a GPIO for a given GPIO function
Alexandre Courbotad824782013-12-03 12:20:11 +09002705 * @dev: GPIO consumer, can be NULL for system-global GPIOs
Alexandre Courbotbae48da2013-10-17 10:21:38 -07002706 * @con_id: function within the GPIO consumer
2707 *
2708 * Return the GPIO descriptor corresponding to the function con_id of device
Alexandre Courbot2a3cf6a2013-12-11 11:32:28 +09002709 * dev, -ENOENT if no GPIO has been assigned to the requested function, or
2710 * another IS_ERR() code if an error occured while trying to acquire the GPIO.
Alexandre Courbotbae48da2013-10-17 10:21:38 -07002711 */
2712struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id)
2713{
2714 return gpiod_get_index(dev, con_id, 0);
2715}
2716EXPORT_SYMBOL_GPL(gpiod_get);
2717
2718/**
2719 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
Andy Shevchenkofdd6a5f2013-12-05 11:26:26 +02002720 * @dev: GPIO consumer, can be NULL for system-global GPIOs
Alexandre Courbotbae48da2013-10-17 10:21:38 -07002721 * @con_id: function within the GPIO consumer
2722 * @idx: index of the GPIO to obtain in the consumer
2723 *
2724 * This variant of gpiod_get() allows to access GPIOs other than the first
2725 * defined one for functions that define several GPIOs.
2726 *
Alexandre Courbot2a3cf6a2013-12-11 11:32:28 +09002727 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
2728 * requested function and/or index, or another IS_ERR() code if an error
2729 * occured while trying to acquire the GPIO.
Alexandre Courbotbae48da2013-10-17 10:21:38 -07002730 */
2731struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
2732 const char *con_id,
2733 unsigned int idx)
2734{
Alexandre Courbot35c5d7f2013-11-23 19:34:50 +09002735 struct gpio_desc *desc = NULL;
Alexandre Courbotbae48da2013-10-17 10:21:38 -07002736 int status;
Alexandre Courbot53e7cac2013-11-16 21:44:52 +09002737 enum gpio_lookup_flags flags = 0;
Alexandre Courbotbae48da2013-10-17 10:21:38 -07002738
2739 dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
2740
2741 /* Using device tree? */
2742 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node) {
2743 dev_dbg(dev, "using device tree for GPIO lookup\n");
2744 desc = of_find_gpio(dev, con_id, idx, &flags);
Mika Westerberg81f59e92013-10-10 11:01:09 +03002745 } else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev)) {
2746 dev_dbg(dev, "using ACPI for GPIO lookup\n");
2747 desc = acpi_find_gpio(dev, con_id, idx, &flags);
Alexandre Courbot35c5d7f2013-11-23 19:34:50 +09002748 }
2749
2750 /*
2751 * Either we are not using DT or ACPI, or their lookup did not return
2752 * a result. In that case, use platform lookup as a fallback.
2753 */
Alexandre Courbot2a3cf6a2013-12-11 11:32:28 +09002754 if (!desc || desc == ERR_PTR(-ENOENT)) {
Alexandre Courbotbae48da2013-10-17 10:21:38 -07002755 dev_dbg(dev, "using lookup tables for GPIO lookup");
Alexandre Courbot2a3cf6a2013-12-11 11:32:28 +09002756 desc = gpiod_find(dev, con_id, idx, &flags);
Alexandre Courbotbae48da2013-10-17 10:21:38 -07002757 }
2758
2759 if (IS_ERR(desc)) {
Heikki Krogerus351cfe02013-11-29 15:47:34 +02002760 dev_dbg(dev, "lookup for GPIO %s failed\n", con_id);
Alexandre Courbotbae48da2013-10-17 10:21:38 -07002761 return desc;
2762 }
2763
2764 status = gpiod_request(desc, con_id);
2765
2766 if (status < 0)
2767 return ERR_PTR(status);
2768
Alexandre Courbot53e7cac2013-11-16 21:44:52 +09002769 if (flags & GPIO_ACTIVE_LOW)
Alexandre Courbotbae48da2013-10-17 10:21:38 -07002770 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
Alexandre Courbot53e7cac2013-11-16 21:44:52 +09002771 if (flags & GPIO_OPEN_DRAIN)
2772 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
2773 if (flags & GPIO_OPEN_SOURCE)
2774 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
Alexandre Courbotbae48da2013-10-17 10:21:38 -07002775
2776 return desc;
2777}
2778EXPORT_SYMBOL_GPL(gpiod_get_index);
2779
2780/**
2781 * gpiod_put - dispose of a GPIO descriptor
2782 * @desc: GPIO descriptor to dispose of
2783 *
2784 * No descriptor can be used after gpiod_put() has been called on it.
2785 */
2786void gpiod_put(struct gpio_desc *desc)
2787{
2788 gpiod_free(desc);
2789}
2790EXPORT_SYMBOL_GPL(gpiod_put);
David Brownelld2876d02008-02-04 22:28:20 -08002791
David Brownelld2876d02008-02-04 22:28:20 -08002792#ifdef CONFIG_DEBUG_FS
2793
2794static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip)
2795{
2796 unsigned i;
2797 unsigned gpio = chip->base;
Alexandre Courbot6c0b4e62013-02-03 01:29:30 +09002798 struct gpio_desc *gdesc = &chip->desc[0];
David Brownelld2876d02008-02-04 22:28:20 -08002799 int is_out;
Linus Walleijd468bf92013-09-24 11:54:38 +02002800 int is_irq;
David Brownelld2876d02008-02-04 22:28:20 -08002801
2802 for (i = 0; i < chip->ngpio; i++, gpio++, gdesc++) {
2803 if (!test_bit(FLAG_REQUESTED, &gdesc->flags))
2804 continue;
2805
Alexandre Courbot372e7222013-02-03 01:29:29 +09002806 gpiod_get_direction(gdesc);
David Brownelld2876d02008-02-04 22:28:20 -08002807 is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
Linus Walleijd468bf92013-09-24 11:54:38 +02002808 is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
2809 seq_printf(s, " gpio-%-3d (%-20.20s) %s %s %s",
David Brownelld2876d02008-02-04 22:28:20 -08002810 gpio, gdesc->label,
2811 is_out ? "out" : "in ",
2812 chip->get
2813 ? (chip->get(chip, i) ? "hi" : "lo")
Linus Walleijd468bf92013-09-24 11:54:38 +02002814 : "? ",
2815 is_irq ? "IRQ" : " ");
David Brownelld2876d02008-02-04 22:28:20 -08002816 seq_printf(s, "\n");
2817 }
2818}
2819
Thierry Redingf9c4a312012-04-12 13:26:01 +02002820static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
David Brownelld2876d02008-02-04 22:28:20 -08002821{
Grant Likely362432a2013-02-09 09:41:49 +00002822 unsigned long flags;
Thierry Redingf9c4a312012-04-12 13:26:01 +02002823 struct gpio_chip *chip = NULL;
Alexandre Courbotcb1650d2013-02-03 01:29:27 +09002824 loff_t index = *pos;
Thierry Redingf9c4a312012-04-12 13:26:01 +02002825
2826 s->private = "";
2827
Grant Likely362432a2013-02-09 09:41:49 +00002828 spin_lock_irqsave(&gpio_lock, flags);
Alexandre Courbotcb1650d2013-02-03 01:29:27 +09002829 list_for_each_entry(chip, &gpio_chips, list)
Grant Likely362432a2013-02-09 09:41:49 +00002830 if (index-- == 0) {
2831 spin_unlock_irqrestore(&gpio_lock, flags);
Alexandre Courbotcb1650d2013-02-03 01:29:27 +09002832 return chip;
Grant Likely362432a2013-02-09 09:41:49 +00002833 }
2834 spin_unlock_irqrestore(&gpio_lock, flags);
Alexandre Courbotcb1650d2013-02-03 01:29:27 +09002835
2836 return NULL;
Thierry Redingf9c4a312012-04-12 13:26:01 +02002837}
2838
2839static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
2840{
Grant Likely362432a2013-02-09 09:41:49 +00002841 unsigned long flags;
Thierry Redingf9c4a312012-04-12 13:26:01 +02002842 struct gpio_chip *chip = v;
Thierry Redingf9c4a312012-04-12 13:26:01 +02002843 void *ret = NULL;
2844
Grant Likely362432a2013-02-09 09:41:49 +00002845 spin_lock_irqsave(&gpio_lock, flags);
Alexandre Courbotcb1650d2013-02-03 01:29:27 +09002846 if (list_is_last(&chip->list, &gpio_chips))
2847 ret = NULL;
2848 else
2849 ret = list_entry(chip->list.next, struct gpio_chip, list);
Grant Likely362432a2013-02-09 09:41:49 +00002850 spin_unlock_irqrestore(&gpio_lock, flags);
Thierry Redingf9c4a312012-04-12 13:26:01 +02002851
2852 s->private = "\n";
2853 ++*pos;
2854
2855 return ret;
2856}
2857
2858static void gpiolib_seq_stop(struct seq_file *s, void *v)
2859{
2860}
2861
2862static int gpiolib_seq_show(struct seq_file *s, void *v)
2863{
2864 struct gpio_chip *chip = v;
2865 struct device *dev;
2866
2867 seq_printf(s, "%sGPIOs %d-%d", (char *)s->private,
2868 chip->base, chip->base + chip->ngpio - 1);
2869 dev = chip->dev;
2870 if (dev)
2871 seq_printf(s, ", %s/%s", dev->bus ? dev->bus->name : "no-bus",
2872 dev_name(dev));
2873 if (chip->label)
2874 seq_printf(s, ", %s", chip->label);
2875 if (chip->can_sleep)
2876 seq_printf(s, ", can sleep");
2877 seq_printf(s, ":\n");
2878
2879 if (chip->dbg_show)
2880 chip->dbg_show(s, chip);
2881 else
2882 gpiolib_dbg_show(s, chip);
2883
David Brownelld2876d02008-02-04 22:28:20 -08002884 return 0;
2885}
2886
Thierry Redingf9c4a312012-04-12 13:26:01 +02002887static const struct seq_operations gpiolib_seq_ops = {
2888 .start = gpiolib_seq_start,
2889 .next = gpiolib_seq_next,
2890 .stop = gpiolib_seq_stop,
2891 .show = gpiolib_seq_show,
2892};
2893
David Brownelld2876d02008-02-04 22:28:20 -08002894static int gpiolib_open(struct inode *inode, struct file *file)
2895{
Thierry Redingf9c4a312012-04-12 13:26:01 +02002896 return seq_open(file, &gpiolib_seq_ops);
David Brownelld2876d02008-02-04 22:28:20 -08002897}
2898
Alexey Dobriyan828c0952009-10-01 15:43:56 -07002899static const struct file_operations gpiolib_operations = {
Thierry Redingf9c4a312012-04-12 13:26:01 +02002900 .owner = THIS_MODULE,
David Brownelld2876d02008-02-04 22:28:20 -08002901 .open = gpiolib_open,
2902 .read = seq_read,
2903 .llseek = seq_lseek,
Thierry Redingf9c4a312012-04-12 13:26:01 +02002904 .release = seq_release,
David Brownelld2876d02008-02-04 22:28:20 -08002905};
2906
2907static int __init gpiolib_debugfs_init(void)
2908{
2909 /* /sys/kernel/debug/gpio */
2910 (void) debugfs_create_file("gpio", S_IFREG | S_IRUGO,
2911 NULL, NULL, &gpiolib_operations);
2912 return 0;
2913}
2914subsys_initcall(gpiolib_debugfs_init);
2915
2916#endif /* DEBUG_FS */