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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>
David Brownell6ea02052008-05-23 13:04:58 -07007
Michael Buesch7444a722008-07-25 01:46:11 -07008#ifdef CONFIG_GPIOLIB
David Brownelld2876d02008-02-04 22:28:20 -08009
David Brownell6ea02052008-05-23 13:04:58 -070010#include <linux/compiler.h>
11
David Brownelld2876d02008-02-04 22:28:20 -080012/* Platforms may implement their GPIO interface with library code,
13 * at a small performance cost for non-inlined operations and some
14 * extra memory (for code and for per-GPIO table entries).
15 *
16 * While the GPIO programming interface defines valid GPIO numbers
17 * to be in the range 0..MAX_INT, this library restricts them to the
Michael Buesch6a9436d2008-07-26 15:22:26 -070018 * smaller range 0..ARCH_NR_GPIOS-1.
David Brownellc9561262010-09-09 16:38:03 -070019 *
20 * ARCH_NR_GPIOS is somewhat arbitrary; it usually reflects the sum of
21 * builtin/SoC GPIOs plus a number of GPIOs on expanders; the latter is
22 * actually an estimate of a board-specific value.
David Brownelld2876d02008-02-04 22:28:20 -080023 */
24
25#ifndef ARCH_NR_GPIOS
26#define ARCH_NR_GPIOS 256
27#endif
28
David Brownellc9561262010-09-09 16:38:03 -070029/*
30 * "valid" GPIO numbers are nonnegative and may be passed to
31 * setup routines like gpio_request(). only some valid numbers
32 * can successfully be requested and used.
33 *
34 * Invalid GPIO numbers are useful for indicating no-such-GPIO in
35 * platform data and other tables.
36 */
37
Guennadi Liakhovetskie6de1802008-04-28 02:14:46 -070038static inline int gpio_is_valid(int number)
39{
Guennadi Liakhovetskie6de1802008-04-28 02:14:46 -070040 return ((unsigned)number) < ARCH_NR_GPIOS;
41}
42
Mike Frysinger1f018c82009-12-09 06:53:39 -050043struct device;
David Brownelld2876d02008-02-04 22:28:20 -080044struct seq_file;
Guennadi Liakhovetski438d8902008-04-28 02:14:44 -070045struct module;
Anton Vorontsova19e3da2010-06-08 07:48:16 -060046struct device_node;
David Brownelld2876d02008-02-04 22:28:20 -080047
48/**
49 * struct gpio_chip - abstract a GPIO controller
50 * @label: for diagnostics
David Brownelld8f388d2008-07-25 01:46:07 -070051 * @dev: optional device providing the GPIOs
52 * @owner: helps prevent removal of modules exporting active GPIOs
David Brownell35e8bb52008-10-15 22:03:16 -070053 * @request: optional hook for chip-specific activation, such as
54 * enabling module power and clock; may sleep
55 * @free: optional hook for chip-specific deactivation, such as
56 * disabling module power and clock; may sleep
David Brownelld2876d02008-02-04 22:28:20 -080057 * @direction_input: configures signal "offset" as input, or returns error
58 * @get: returns value for signal "offset"; for output signals this
59 * returns either the value actually sensed, or zero
60 * @direction_output: configures signal "offset" as output, or returns error
61 * @set: assigns output value for signal "offset"
David Brownell0f6d5042008-10-15 22:03:14 -070062 * @to_irq: optional hook supporting non-static gpio_to_irq() mappings;
63 * implementation may not sleep
David Brownelld2876d02008-02-04 22:28:20 -080064 * @dbg_show: optional routine to show contents in debugfs; default code
65 * will be used when this is omitted, but custom code can show extra
66 * state (such as pullup/pulldown configuration).
67 * @base: identifies the first GPIO number handled by this chip; or, if
68 * negative during registration, requests dynamic ID allocation.
69 * @ngpio: the number of GPIOs handled by this controller; the last GPIO
70 * handled is (base + ngpio - 1).
71 * @can_sleep: flag must be set iff get()/set() methods sleep, as they
72 * must while accessing GPIO expander chips over I2C or SPI
Daniel Silverstone926b6632009-04-02 16:57:05 -070073 * @names: if set, must be an array of strings to use as alternative
74 * names for the GPIOs in this chip. Any entry in the array
75 * may be NULL if there is no alias for the GPIO, however the
Uwe Kleine-König7839ec72010-05-26 14:42:18 -070076 * array must be @ngpio entries long. A name can include a single printk
77 * format specifier for an unsigned int. It is substituted by the actual
78 * number of the gpio.
David Brownelld2876d02008-02-04 22:28:20 -080079 *
80 * A gpio_chip can help platforms abstract various sources of GPIOs so
81 * they can all be accessed through a common programing interface.
82 * Example sources would be SOC controllers, FPGAs, multifunction
83 * chips, dedicated GPIO expanders, and so on.
84 *
85 * Each chip controls a number of signals, identified in method calls
86 * by "offset" values in the range 0..(@ngpio - 1). When those signals
87 * are referenced through calls like gpio_get_value(gpio), the offset
88 * is calculated by subtracting @base from the gpio number.
89 */
90struct gpio_chip {
Dmitry Baryshkov4fd54632008-10-15 22:03:10 -070091 const char *label;
David Brownelld8f388d2008-07-25 01:46:07 -070092 struct device *dev;
Guennadi Liakhovetski438d8902008-04-28 02:14:44 -070093 struct module *owner;
David Brownelld2876d02008-02-04 22:28:20 -080094
David Brownell35e8bb52008-10-15 22:03:16 -070095 int (*request)(struct gpio_chip *chip,
96 unsigned offset);
97 void (*free)(struct gpio_chip *chip,
98 unsigned offset);
99
David Brownelld2876d02008-02-04 22:28:20 -0800100 int (*direction_input)(struct gpio_chip *chip,
101 unsigned offset);
102 int (*get)(struct gpio_chip *chip,
103 unsigned offset);
104 int (*direction_output)(struct gpio_chip *chip,
105 unsigned offset, int value);
Felipe Balbic4b5be92010-05-26 14:42:23 -0700106 int (*set_debounce)(struct gpio_chip *chip,
107 unsigned offset, unsigned debounce);
108
David Brownelld2876d02008-02-04 22:28:20 -0800109 void (*set)(struct gpio_chip *chip,
110 unsigned offset, int value);
David Brownell0f6d5042008-10-15 22:03:14 -0700111
112 int (*to_irq)(struct gpio_chip *chip,
113 unsigned offset);
114
David Brownelld2876d02008-02-04 22:28:20 -0800115 void (*dbg_show)(struct seq_file *s,
116 struct gpio_chip *chip);
117 int base;
118 u16 ngpio;
Uwe Kleine-König62154992010-05-26 14:42:17 -0700119 const char *const *names;
David Brownelld2876d02008-02-04 22:28:20 -0800120 unsigned can_sleep:1;
David Brownelld8f388d2008-07-25 01:46:07 -0700121 unsigned exported:1;
Anton Vorontsova19e3da2010-06-08 07:48:16 -0600122
123#if defined(CONFIG_OF_GPIO)
124 /*
125 * If CONFIG_OF is enabled, then all GPIO controllers described in the
126 * device tree automatically may have an OF translation
127 */
128 struct device_node *of_node;
129 int of_gpio_n_cells;
130 int (*of_xlate)(struct gpio_chip *gc, struct device_node *np,
131 const void *gpio_spec, u32 *flags);
132#endif
David Brownelld2876d02008-02-04 22:28:20 -0800133};
134
135extern const char *gpiochip_is_requested(struct gpio_chip *chip,
136 unsigned offset);
David Brownell6ea02052008-05-23 13:04:58 -0700137extern int __must_check gpiochip_reserve(int start, int ngpio);
David Brownelld2876d02008-02-04 22:28:20 -0800138
139/* add/remove chips */
140extern int gpiochip_add(struct gpio_chip *chip);
141extern int __must_check gpiochip_remove(struct gpio_chip *chip);
Grant Likely594fa262010-06-08 07:48:16 -0600142extern struct gpio_chip *gpiochip_find(void *data,
143 int (*match)(struct gpio_chip *chip,
144 void *data));
David Brownelld2876d02008-02-04 22:28:20 -0800145
146
147/* Always use the library code for GPIO management calls,
148 * or when sleeping may be involved.
149 */
Linus Torvaldsd8a35152011-01-13 17:26:46 -0800150extern int gpio_request(unsigned gpio, const char *label);
David Brownelld2876d02008-02-04 22:28:20 -0800151extern void gpio_free(unsigned gpio);
152
Linus Torvaldsd8a35152011-01-13 17:26:46 -0800153extern int gpio_direction_input(unsigned gpio);
154extern int gpio_direction_output(unsigned gpio, int value);
David Brownelld2876d02008-02-04 22:28:20 -0800155
Felipe Balbic4b5be92010-05-26 14:42:23 -0700156extern int gpio_set_debounce(unsigned gpio, unsigned debounce);
157
David Brownelld2876d02008-02-04 22:28:20 -0800158extern int gpio_get_value_cansleep(unsigned gpio);
159extern void gpio_set_value_cansleep(unsigned gpio, int value);
160
161
162/* A platform's <asm/gpio.h> code may want to inline the I/O calls when
163 * the GPIO is constant and refers to some always-present controller,
164 * giving direct access to chip registers and tight bitbanging loops.
165 */
166extern int __gpio_get_value(unsigned gpio);
167extern void __gpio_set_value(unsigned gpio, int value);
168
169extern int __gpio_cansleep(unsigned gpio);
170
David Brownell0f6d5042008-10-15 22:03:14 -0700171extern int __gpio_to_irq(unsigned gpio);
David Brownelld2876d02008-02-04 22:28:20 -0800172
Eric Miao3e45f1d2010-03-05 13:44:35 -0800173#define GPIOF_DIR_OUT (0 << 0)
174#define GPIOF_DIR_IN (1 << 0)
175
176#define GPIOF_INIT_LOW (0 << 1)
177#define GPIOF_INIT_HIGH (1 << 1)
178
179#define GPIOF_IN (GPIOF_DIR_IN)
180#define GPIOF_OUT_INIT_LOW (GPIOF_DIR_OUT | GPIOF_INIT_LOW)
181#define GPIOF_OUT_INIT_HIGH (GPIOF_DIR_OUT | GPIOF_INIT_HIGH)
182
183/**
184 * struct gpio - a structure describing a GPIO with configuration
185 * @gpio: the GPIO number
186 * @flags: GPIO configuration as specified by GPIOF_*
187 * @label: a literal description string of this GPIO
188 */
189struct gpio {
190 unsigned gpio;
191 unsigned long flags;
192 const char *label;
193};
194
Linus Torvaldsd8a35152011-01-13 17:26:46 -0800195extern int gpio_request_one(unsigned gpio, unsigned long flags, const char *label);
196extern int gpio_request_array(struct gpio *array, size_t num);
Eric Miao3e45f1d2010-03-05 13:44:35 -0800197extern void gpio_free_array(struct gpio *array, size_t num);
198
David Brownelld8f388d2008-07-25 01:46:07 -0700199#ifdef CONFIG_GPIO_SYSFS
200
201/*
202 * A sysfs interface can be exported by individual drivers if they want,
203 * but more typically is configured entirely from userspace.
204 */
205extern int gpio_export(unsigned gpio, bool direction_may_change);
Jani Nikulaa4177ee2009-09-22 16:46:33 -0700206extern int gpio_export_link(struct device *dev, const char *name,
207 unsigned gpio);
Jani Nikula07697462009-12-15 16:46:20 -0800208extern int gpio_sysfs_set_active_low(unsigned gpio, int value);
David Brownelld8f388d2008-07-25 01:46:07 -0700209extern void gpio_unexport(unsigned gpio);
210
211#endif /* CONFIG_GPIO_SYSFS */
212
Anton Vorontsov09cd9522010-10-27 15:33:16 -0700213#else /* !CONFIG_GPIOLIB */
David Brownelld2876d02008-02-04 22:28:20 -0800214
Guennadi Liakhovetskie6de1802008-04-28 02:14:46 -0700215static inline int gpio_is_valid(int number)
216{
217 /* only non-negative numbers are valid */
218 return number >= 0;
219}
220
David Brownell4c203862007-02-12 00:53:11 -0800221/* platforms that don't directly support access to GPIOs through I2C, SPI,
222 * or other blocking infrastructure can use these wrappers.
223 */
224
225static inline int gpio_cansleep(unsigned gpio)
226{
227 return 0;
228}
229
230static inline int gpio_get_value_cansleep(unsigned gpio)
231{
232 might_sleep();
233 return gpio_get_value(gpio);
234}
235
236static inline void gpio_set_value_cansleep(unsigned gpio, int value)
237{
238 might_sleep();
239 gpio_set_value(gpio, value);
240}
241
Anton Vorontsov09cd9522010-10-27 15:33:16 -0700242#endif /* !CONFIG_GPIOLIB */
David Brownelld8f388d2008-07-25 01:46:07 -0700243
244#ifndef CONFIG_GPIO_SYSFS
245
Mike Frysinger1f018c82009-12-09 06:53:39 -0500246struct device;
247
David Brownelld8f388d2008-07-25 01:46:07 -0700248/* sysfs support is only available with gpiolib, where it's optional */
249
250static inline int gpio_export(unsigned gpio, bool direction_may_change)
251{
252 return -ENOSYS;
253}
254
Jani Nikulaa4177ee2009-09-22 16:46:33 -0700255static inline int gpio_export_link(struct device *dev, const char *name,
256 unsigned gpio)
257{
258 return -ENOSYS;
259}
260
Jani Nikula07697462009-12-15 16:46:20 -0800261static inline int gpio_sysfs_set_active_low(unsigned gpio, int value)
262{
263 return -ENOSYS;
264}
265
David Brownelld8f388d2008-07-25 01:46:07 -0700266static inline void gpio_unexport(unsigned gpio)
267{
268}
269#endif /* CONFIG_GPIO_SYSFS */
David Brownelld2876d02008-02-04 22:28:20 -0800270
David Brownell4c203862007-02-12 00:53:11 -0800271#endif /* _ASM_GENERIC_GPIO_H */