blob: 1ff4e221cb4dfc705e58ff7155835c0c68459dc9 [file] [log] [blame]
David Brownell4c203862007-02-12 00:53:11 -08001#ifndef _ASM_GENERIC_GPIO_H
2#define _ASM_GENERIC_GPIO_H
3
Mike Frysingerb3db4a82009-10-01 15:43:56 -07004#include <linux/kernel.h>
David Brownell6ea02052008-05-23 13:04:58 -07005#include <linux/types.h>
Atsushi Nemoto25947d52008-07-28 15:46:38 -07006#include <linux/errno.h>
Grant Likely15c9a0a2011-12-12 09:25:57 -07007#include <linux/of.h>
David Brownell6ea02052008-05-23 13:04:58 -07008
Michael Buesch7444a722008-07-25 01:46:11 -07009#ifdef CONFIG_GPIOLIB
David Brownelld2876d02008-02-04 22:28:20 -080010
David Brownell6ea02052008-05-23 13:04:58 -070011#include <linux/compiler.h>
12
David Brownelld2876d02008-02-04 22:28:20 -080013/* Platforms may implement their GPIO interface with library code,
14 * at a small performance cost for non-inlined operations and some
15 * extra memory (for code and for per-GPIO table entries).
16 *
17 * While the GPIO programming interface defines valid GPIO numbers
18 * to be in the range 0..MAX_INT, this library restricts them to the
Michael Buesch6a9436d2008-07-26 15:22:26 -070019 * smaller range 0..ARCH_NR_GPIOS-1.
David Brownellc9561262010-09-09 16:38:03 -070020 *
21 * ARCH_NR_GPIOS is somewhat arbitrary; it usually reflects the sum of
22 * builtin/SoC GPIOs plus a number of GPIOs on expanders; the latter is
23 * actually an estimate of a board-specific value.
David Brownelld2876d02008-02-04 22:28:20 -080024 */
25
26#ifndef ARCH_NR_GPIOS
27#define ARCH_NR_GPIOS 256
28#endif
29
David Brownellc9561262010-09-09 16:38:03 -070030/*
31 * "valid" GPIO numbers are nonnegative and may be passed to
32 * setup routines like gpio_request(). only some valid numbers
33 * can successfully be requested and used.
34 *
35 * Invalid GPIO numbers are useful for indicating no-such-GPIO in
36 * platform data and other tables.
37 */
38
Joe Perches3474cb32011-05-10 16:23:07 -070039static inline bool gpio_is_valid(int number)
Guennadi Liakhovetskie6de1802008-04-28 02:14:46 -070040{
Joe Perches3474cb32011-05-10 16:23:07 -070041 return number >= 0 && number < ARCH_NR_GPIOS;
Guennadi Liakhovetskie6de1802008-04-28 02:14:46 -070042}
43
Mike Frysinger1f018c82009-12-09 06:53:39 -050044struct device;
Mark Brownfeb83692011-10-24 15:24:10 +020045struct gpio;
David Brownelld2876d02008-02-04 22:28:20 -080046struct seq_file;
Guennadi Liakhovetski438d8902008-04-28 02:14:44 -070047struct module;
Anton Vorontsova19e3da2010-06-08 07:48:16 -060048struct device_node;
David Brownelld2876d02008-02-04 22:28:20 -080049
50/**
51 * struct gpio_chip - abstract a GPIO controller
52 * @label: for diagnostics
David Brownelld8f388d2008-07-25 01:46:07 -070053 * @dev: optional device providing the GPIOs
54 * @owner: helps prevent removal of modules exporting active GPIOs
David Brownell35e8bb52008-10-15 22:03:16 -070055 * @request: optional hook for chip-specific activation, such as
56 * enabling module power and clock; may sleep
57 * @free: optional hook for chip-specific deactivation, such as
58 * disabling module power and clock; may sleep
David Brownelld2876d02008-02-04 22:28:20 -080059 * @direction_input: configures signal "offset" as input, or returns error
60 * @get: returns value for signal "offset"; for output signals this
61 * returns either the value actually sensed, or zero
62 * @direction_output: configures signal "offset" as output, or returns error
63 * @set: assigns output value for signal "offset"
David Brownell0f6d5042008-10-15 22:03:14 -070064 * @to_irq: optional hook supporting non-static gpio_to_irq() mappings;
65 * implementation may not sleep
David Brownelld2876d02008-02-04 22:28:20 -080066 * @dbg_show: optional routine to show contents in debugfs; default code
67 * will be used when this is omitted, but custom code can show extra
68 * state (such as pullup/pulldown configuration).
69 * @base: identifies the first GPIO number handled by this chip; or, if
70 * negative during registration, requests dynamic ID allocation.
71 * @ngpio: the number of GPIOs handled by this controller; the last GPIO
72 * handled is (base + ngpio - 1).
73 * @can_sleep: flag must be set iff get()/set() methods sleep, as they
74 * must while accessing GPIO expander chips over I2C or SPI
Daniel Silverstone926b6632009-04-02 16:57:05 -070075 * @names: if set, must be an array of strings to use as alternative
76 * names for the GPIOs in this chip. Any entry in the array
77 * may be NULL if there is no alias for the GPIO, however the
Uwe Kleine-König7839ec72010-05-26 14:42:18 -070078 * array must be @ngpio entries long. A name can include a single printk
79 * format specifier for an unsigned int. It is substituted by the actual
80 * number of the gpio.
David Brownelld2876d02008-02-04 22:28:20 -080081 *
82 * A gpio_chip can help platforms abstract various sources of GPIOs so
83 * they can all be accessed through a common programing interface.
84 * Example sources would be SOC controllers, FPGAs, multifunction
85 * chips, dedicated GPIO expanders, and so on.
86 *
87 * Each chip controls a number of signals, identified in method calls
88 * by "offset" values in the range 0..(@ngpio - 1). When those signals
89 * are referenced through calls like gpio_get_value(gpio), the offset
90 * is calculated by subtracting @base from the gpio number.
91 */
92struct gpio_chip {
Dmitry Baryshkov4fd54632008-10-15 22:03:10 -070093 const char *label;
David Brownelld8f388d2008-07-25 01:46:07 -070094 struct device *dev;
Guennadi Liakhovetski438d8902008-04-28 02:14:44 -070095 struct module *owner;
David Brownelld2876d02008-02-04 22:28:20 -080096
David Brownell35e8bb52008-10-15 22:03:16 -070097 int (*request)(struct gpio_chip *chip,
98 unsigned offset);
99 void (*free)(struct gpio_chip *chip,
100 unsigned offset);
101
David Brownelld2876d02008-02-04 22:28:20 -0800102 int (*direction_input)(struct gpio_chip *chip,
103 unsigned offset);
104 int (*get)(struct gpio_chip *chip,
105 unsigned offset);
106 int (*direction_output)(struct gpio_chip *chip,
107 unsigned offset, int value);
Felipe Balbic4b5be92010-05-26 14:42:23 -0700108 int (*set_debounce)(struct gpio_chip *chip,
109 unsigned offset, unsigned debounce);
110
David Brownelld2876d02008-02-04 22:28:20 -0800111 void (*set)(struct gpio_chip *chip,
112 unsigned offset, int value);
David Brownell0f6d5042008-10-15 22:03:14 -0700113
114 int (*to_irq)(struct gpio_chip *chip,
115 unsigned offset);
116
David Brownelld2876d02008-02-04 22:28:20 -0800117 void (*dbg_show)(struct seq_file *s,
118 struct gpio_chip *chip);
119 int base;
120 u16 ngpio;
Uwe Kleine-König62154992010-05-26 14:42:17 -0700121 const char *const *names;
David Brownelld2876d02008-02-04 22:28:20 -0800122 unsigned can_sleep:1;
David Brownelld8f388d2008-07-25 01:46:07 -0700123 unsigned exported:1;
Anton Vorontsova19e3da2010-06-08 07:48:16 -0600124
125#if defined(CONFIG_OF_GPIO)
126 /*
127 * If CONFIG_OF is enabled, then all GPIO controllers described in the
128 * device tree automatically may have an OF translation
129 */
130 struct device_node *of_node;
131 int of_gpio_n_cells;
Grant Likely15c9a0a2011-12-12 09:25:57 -0700132 int (*of_xlate)(struct gpio_chip *gc,
133 const struct of_phandle_args *gpiospec, u32 *flags);
Anton Vorontsova19e3da2010-06-08 07:48:16 -0600134#endif
David Brownelld2876d02008-02-04 22:28:20 -0800135};
136
137extern const char *gpiochip_is_requested(struct gpio_chip *chip,
138 unsigned offset);
Grant Likely1a2d3972011-12-12 09:25:57 -0700139extern struct gpio_chip *gpio_to_chip(unsigned gpio);
David Brownell6ea02052008-05-23 13:04:58 -0700140extern int __must_check gpiochip_reserve(int start, int ngpio);
David Brownelld2876d02008-02-04 22:28:20 -0800141
142/* add/remove chips */
143extern int gpiochip_add(struct gpio_chip *chip);
144extern int __must_check gpiochip_remove(struct gpio_chip *chip);
Grant Likely594fa262010-06-08 07:48:16 -0600145extern struct gpio_chip *gpiochip_find(void *data,
146 int (*match)(struct gpio_chip *chip,
147 void *data));
David Brownelld2876d02008-02-04 22:28:20 -0800148
149
150/* Always use the library code for GPIO management calls,
151 * or when sleeping may be involved.
152 */
Linus Torvaldsd8a35152011-01-13 17:26:46 -0800153extern int gpio_request(unsigned gpio, const char *label);
David Brownelld2876d02008-02-04 22:28:20 -0800154extern void gpio_free(unsigned gpio);
155
Linus Torvaldsd8a35152011-01-13 17:26:46 -0800156extern int gpio_direction_input(unsigned gpio);
157extern int gpio_direction_output(unsigned gpio, int value);
David Brownelld2876d02008-02-04 22:28:20 -0800158
Felipe Balbic4b5be92010-05-26 14:42:23 -0700159extern int gpio_set_debounce(unsigned gpio, unsigned debounce);
160
David Brownelld2876d02008-02-04 22:28:20 -0800161extern int gpio_get_value_cansleep(unsigned gpio);
162extern void gpio_set_value_cansleep(unsigned gpio, int value);
163
164
165/* A platform's <asm/gpio.h> code may want to inline the I/O calls when
166 * the GPIO is constant and refers to some always-present controller,
167 * giving direct access to chip registers and tight bitbanging loops.
168 */
169extern int __gpio_get_value(unsigned gpio);
170extern void __gpio_set_value(unsigned gpio, int value);
171
172extern int __gpio_cansleep(unsigned gpio);
173
David Brownell0f6d5042008-10-15 22:03:14 -0700174extern int __gpio_to_irq(unsigned gpio);
David Brownelld2876d02008-02-04 22:28:20 -0800175
Linus Torvaldsd8a35152011-01-13 17:26:46 -0800176extern int gpio_request_one(unsigned gpio, unsigned long flags, const char *label);
Lars-Peter Clausen7c295972011-05-25 16:20:31 -0700177extern int gpio_request_array(const struct gpio *array, size_t num);
178extern void gpio_free_array(const struct gpio *array, size_t num);
Eric Miao3e45f1d2010-03-05 13:44:35 -0800179
John Crispin1a0703e2011-12-20 21:40:21 +0100180/* bindings for managed devices that want to request gpios */
181int devm_gpio_request(struct device *dev, unsigned gpio, const char *label);
182void devm_gpio_free(struct device *dev, unsigned int gpio);
183
David Brownelld8f388d2008-07-25 01:46:07 -0700184#ifdef CONFIG_GPIO_SYSFS
185
186/*
187 * A sysfs interface can be exported by individual drivers if they want,
188 * but more typically is configured entirely from userspace.
189 */
190extern int gpio_export(unsigned gpio, bool direction_may_change);
Jani Nikulaa4177ee2009-09-22 16:46:33 -0700191extern int gpio_export_link(struct device *dev, const char *name,
192 unsigned gpio);
Jani Nikula07697462009-12-15 16:46:20 -0800193extern int gpio_sysfs_set_active_low(unsigned gpio, int value);
David Brownelld8f388d2008-07-25 01:46:07 -0700194extern void gpio_unexport(unsigned gpio);
195
196#endif /* CONFIG_GPIO_SYSFS */
197
Anton Vorontsov09cd9522010-10-27 15:33:16 -0700198#else /* !CONFIG_GPIOLIB */
David Brownelld2876d02008-02-04 22:28:20 -0800199
Joe Perches3474cb32011-05-10 16:23:07 -0700200static inline bool gpio_is_valid(int number)
Guennadi Liakhovetskie6de1802008-04-28 02:14:46 -0700201{
202 /* only non-negative numbers are valid */
203 return number >= 0;
204}
205
David Brownell4c203862007-02-12 00:53:11 -0800206/* platforms that don't directly support access to GPIOs through I2C, SPI,
207 * or other blocking infrastructure can use these wrappers.
208 */
209
210static inline int gpio_cansleep(unsigned gpio)
211{
212 return 0;
213}
214
215static inline int gpio_get_value_cansleep(unsigned gpio)
216{
217 might_sleep();
Hamoeb9ae7f2011-10-21 09:38:32 +0800218 return __gpio_get_value(gpio);
David Brownell4c203862007-02-12 00:53:11 -0800219}
220
221static inline void gpio_set_value_cansleep(unsigned gpio, int value)
222{
223 might_sleep();
Hamoeb9ae7f2011-10-21 09:38:32 +0800224 __gpio_set_value(gpio, value);
David Brownell4c203862007-02-12 00:53:11 -0800225}
226
Anton Vorontsov09cd9522010-10-27 15:33:16 -0700227#endif /* !CONFIG_GPIOLIB */
David Brownelld8f388d2008-07-25 01:46:07 -0700228
229#ifndef CONFIG_GPIO_SYSFS
230
Mike Frysinger1f018c82009-12-09 06:53:39 -0500231struct device;
232
David Brownelld8f388d2008-07-25 01:46:07 -0700233/* sysfs support is only available with gpiolib, where it's optional */
234
235static inline int gpio_export(unsigned gpio, bool direction_may_change)
236{
237 return -ENOSYS;
238}
239
Jani Nikulaa4177ee2009-09-22 16:46:33 -0700240static inline int gpio_export_link(struct device *dev, const char *name,
241 unsigned gpio)
242{
243 return -ENOSYS;
244}
245
Jani Nikula07697462009-12-15 16:46:20 -0800246static inline int gpio_sysfs_set_active_low(unsigned gpio, int value)
247{
248 return -ENOSYS;
249}
250
David Brownelld8f388d2008-07-25 01:46:07 -0700251static inline void gpio_unexport(unsigned gpio)
252{
253}
254#endif /* CONFIG_GPIO_SYSFS */
David Brownelld2876d02008-02-04 22:28:20 -0800255
David Brownell4c203862007-02-12 00:53:11 -0800256#endif /* _ASM_GENERIC_GPIO_H */