1 #ifndef _ASM_GENERIC_GPIO_H
2 #define _ASM_GENERIC_GPIO_H
4 #include <linux/kernel.h>
5 #include <linux/types.h>
6 #include <linux/errno.h>
8 #include <linux/pinctrl/pinctrl.h>
12 #include <linux/compiler.h>
14 /* Platforms may implement their GPIO interface with library code,
15 * at a small performance cost for non-inlined operations and some
16 * extra memory (for code and for per-GPIO table entries).
18 * While the GPIO programming interface defines valid GPIO numbers
19 * to be in the range 0..MAX_INT, this library restricts them to the
20 * smaller range 0..ARCH_NR_GPIOS-1.
22 * ARCH_NR_GPIOS is somewhat arbitrary; it usually reflects the sum of
23 * builtin/SoC GPIOs plus a number of GPIOs on expanders; the latter is
24 * actually an estimate of a board-specific value.
28 #define ARCH_NR_GPIOS 256
32 * "valid" GPIO numbers are nonnegative and may be passed to
33 * setup routines like gpio_request(). only some valid numbers
34 * can successfully be requested and used.
36 * Invalid GPIO numbers are useful for indicating no-such-GPIO in
37 * platform data and other tables.
40 static inline bool gpio_is_valid(int number
)
42 return number
>= 0 && number
< ARCH_NR_GPIOS
;
52 * struct gpio_chip - abstract a GPIO controller
53 * @label: for diagnostics
54 * @dev: optional device providing the GPIOs
55 * @owner: helps prevent removal of modules exporting active GPIOs
56 * @list: links gpio_chips together for traversal
57 * @request: optional hook for chip-specific activation, such as
58 * enabling module power and clock; may sleep
59 * @free: optional hook for chip-specific deactivation, such as
60 * disabling module power and clock; may sleep
61 * @get_direction: returns direction for signal "offset", 0=out, 1=in,
62 * (same as GPIOF_DIR_XXX), or negative error
63 * @direction_input: configures signal "offset" as input, or returns error
64 * @get: returns value for signal "offset"; for output signals this
65 * returns either the value actually sensed, or zero
66 * @direction_output: configures signal "offset" as output, or returns error
67 * @set_debounce: optional hook for setting debounce time for specified gpio in
68 * interrupt triggered gpio chips
69 * @set: assigns output value for signal "offset"
70 * @to_irq: optional hook supporting non-static gpio_to_irq() mappings;
71 * implementation may not sleep
72 * @dbg_show: optional routine to show contents in debugfs; default code
73 * will be used when this is omitted, but custom code can show extra
74 * state (such as pullup/pulldown configuration).
75 * @base: identifies the first GPIO number handled by this chip; or, if
76 * negative during registration, requests dynamic ID allocation.
77 * @ngpio: the number of GPIOs handled by this controller; the last GPIO
78 * handled is (base + ngpio - 1).
79 * @can_sleep: flag must be set iff get()/set() methods sleep, as they
80 * must while accessing GPIO expander chips over I2C or SPI
81 * @names: if set, must be an array of strings to use as alternative
82 * names for the GPIOs in this chip. Any entry in the array
83 * may be NULL if there is no alias for the GPIO, however the
84 * array must be @ngpio entries long. A name can include a single printk
85 * format specifier for an unsigned int. It is substituted by the actual
88 * A gpio_chip can help platforms abstract various sources of GPIOs so
89 * they can all be accessed through a common programing interface.
90 * Example sources would be SOC controllers, FPGAs, multifunction
91 * chips, dedicated GPIO expanders, and so on.
93 * Each chip controls a number of signals, identified in method calls
94 * by "offset" values in the range 0..(@ngpio - 1). When those signals
95 * are referenced through calls like gpio_get_value(gpio), the offset
96 * is calculated by subtracting @base from the gpio number.
101 struct module
*owner
;
102 struct list_head list
;
104 int (*request
)(struct gpio_chip
*chip
,
106 void (*free
)(struct gpio_chip
*chip
,
108 int (*get_direction
)(struct gpio_chip
*chip
,
110 int (*direction_input
)(struct gpio_chip
*chip
,
112 int (*get
)(struct gpio_chip
*chip
,
114 int (*direction_output
)(struct gpio_chip
*chip
,
115 unsigned offset
, int value
);
116 int (*set_debounce
)(struct gpio_chip
*chip
,
117 unsigned offset
, unsigned debounce
);
119 void (*set
)(struct gpio_chip
*chip
,
120 unsigned offset
, int value
);
122 int (*to_irq
)(struct gpio_chip
*chip
,
125 void (*dbg_show
)(struct seq_file
*s
,
126 struct gpio_chip
*chip
);
129 const char *const *names
;
130 unsigned can_sleep
:1;
133 #if defined(CONFIG_OF_GPIO)
135 * If CONFIG_OF is enabled, then all GPIO controllers described in the
136 * device tree automatically may have an OF translation
138 struct device_node
*of_node
;
140 int (*of_xlate
)(struct gpio_chip
*gc
,
141 const struct of_phandle_args
*gpiospec
, u32
*flags
);
143 #ifdef CONFIG_PINCTRL
145 * If CONFIG_PINCTRL is enabled, then gpio controllers can optionally
146 * describe the actual pin range which they serve in an SoC. This
147 * information would be used by pinctrl subsystem to configure
148 * corresponding pins for gpio usage.
150 struct list_head pin_ranges
;
154 extern const char *gpiochip_is_requested(struct gpio_chip
*chip
,
156 extern struct gpio_chip
*gpio_to_chip(unsigned gpio
);
158 /* add/remove chips */
159 extern int gpiochip_add(struct gpio_chip
*chip
);
160 extern int __must_check
gpiochip_remove(struct gpio_chip
*chip
);
161 extern struct gpio_chip
*gpiochip_find(void *data
,
162 int (*match
)(struct gpio_chip
*chip
,
166 /* Always use the library code for GPIO management calls,
167 * or when sleeping may be involved.
169 extern int gpio_request(unsigned gpio
, const char *label
);
170 extern void gpio_free(unsigned gpio
);
172 extern int gpio_direction_input(unsigned gpio
);
173 extern int gpio_direction_output(unsigned gpio
, int value
);
175 extern int gpio_set_debounce(unsigned gpio
, unsigned debounce
);
177 extern int gpio_get_value_cansleep(unsigned gpio
);
178 extern void gpio_set_value_cansleep(unsigned gpio
, int value
);
181 /* A platform's <asm/gpio.h> code may want to inline the I/O calls when
182 * the GPIO is constant and refers to some always-present controller,
183 * giving direct access to chip registers and tight bitbanging loops.
185 extern int __gpio_get_value(unsigned gpio
);
186 extern void __gpio_set_value(unsigned gpio
, int value
);
188 extern int __gpio_cansleep(unsigned gpio
);
190 extern int __gpio_to_irq(unsigned gpio
);
192 extern int gpio_request_one(unsigned gpio
, unsigned long flags
, const char *label
);
193 extern int gpio_request_array(const struct gpio
*array
, size_t num
);
194 extern void gpio_free_array(const struct gpio
*array
, size_t num
);
196 #ifdef CONFIG_GPIO_SYSFS
199 * A sysfs interface can be exported by individual drivers if they want,
200 * but more typically is configured entirely from userspace.
202 extern int gpio_export(unsigned gpio
, bool direction_may_change
);
203 extern int gpio_export_link(struct device
*dev
, const char *name
,
205 extern int gpio_sysfs_set_active_low(unsigned gpio
, int value
);
206 extern void gpio_unexport(unsigned gpio
);
208 #endif /* CONFIG_GPIO_SYSFS */
210 #ifdef CONFIG_PINCTRL
213 * struct gpio_pin_range - pin range controlled by a gpio chip
214 * @head: list for maintaining set of pin ranges, used internally
215 * @pctldev: pinctrl device which handles corresponding pins
216 * @range: actual range of pins controlled by a gpio controller
219 struct gpio_pin_range
{
220 struct list_head node
;
221 struct pinctrl_dev
*pctldev
;
222 struct pinctrl_gpio_range range
;
225 int gpiochip_add_pin_range(struct gpio_chip
*chip
, const char *pinctl_name
,
226 unsigned int gpio_offset
, unsigned int pin_offset
,
228 void gpiochip_remove_pin_ranges(struct gpio_chip
*chip
);
233 gpiochip_add_pin_range(struct gpio_chip
*chip
, const char *pinctl_name
,
234 unsigned int gpio_offset
, unsigned int pin_offset
,
241 gpiochip_remove_pin_ranges(struct gpio_chip
*chip
)
245 #endif /* CONFIG_PINCTRL */
247 #else /* !CONFIG_GPIOLIB */
249 static inline bool gpio_is_valid(int number
)
251 /* only non-negative numbers are valid */
255 /* platforms that don't directly support access to GPIOs through I2C, SPI,
256 * or other blocking infrastructure can use these wrappers.
259 static inline int gpio_cansleep(unsigned gpio
)
264 static inline int gpio_get_value_cansleep(unsigned gpio
)
267 return __gpio_get_value(gpio
);
270 static inline void gpio_set_value_cansleep(unsigned gpio
, int value
)
273 __gpio_set_value(gpio
, value
);
276 #endif /* !CONFIG_GPIOLIB */
278 #ifndef CONFIG_GPIO_SYSFS
282 /* sysfs support is only available with gpiolib, where it's optional */
284 static inline int gpio_export(unsigned gpio
, bool direction_may_change
)
289 static inline int gpio_export_link(struct device
*dev
, const char *name
,
295 static inline int gpio_sysfs_set_active_low(unsigned gpio
, int value
)
300 static inline void gpio_unexport(unsigned gpio
)
303 #endif /* CONFIG_GPIO_SYSFS */
305 #endif /* _ASM_GENERIC_GPIO_H */
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