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-rw-r--r--include/linux/gpio/driver.h184
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diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
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1#ifndef __LINUX_GPIO_DRIVER_H
2#define __LINUX_GPIO_DRIVER_H
3
4#include <linux/types.h>
5
6struct device;
7struct gpio_desc;
8struct seq_file;
9
10/**
11 * struct gpio_chip - abstract a GPIO controller
12 * @label: for diagnostics
13 * @dev: optional device providing the GPIOs
14 * @owner: helps prevent removal of modules exporting active GPIOs
15 * @list: links gpio_chips together for traversal
16 * @request: optional hook for chip-specific activation, such as
17 * enabling module power and clock; may sleep
18 * @free: optional hook for chip-specific deactivation, such as
19 * disabling module power and clock; may sleep
20 * @get_direction: returns direction for signal "offset", 0=out, 1=in,
21 * (same as GPIOF_DIR_XXX), or negative error
22 * @direction_input: configures signal "offset" as input, or returns error
23 * @direction_output: configures signal "offset" as output, or returns error
24 * @get: returns value for signal "offset"; for output signals this
25 * returns either the value actually sensed, or zero
26 * @set: assigns output value for signal "offset"
27 * @set_debounce: optional hook for setting debounce time for specified gpio in
28 * interrupt triggered gpio chips
29 * @to_irq: optional hook supporting non-static gpio_to_irq() mappings;
30 * implementation may not sleep
31 * @dbg_show: optional routine to show contents in debugfs; default code
32 * will be used when this is omitted, but custom code can show extra
33 * state (such as pullup/pulldown configuration).
34 * @base: identifies the first GPIO number handled by this chip; or, if
35 * negative during registration, requests dynamic ID allocation.
36 * @ngpio: the number of GPIOs handled by this controller; the last GPIO
37 * handled is (base + ngpio - 1).
38 * @desc: array of ngpio descriptors. Private.
39 * @can_sleep: flag must be set iff get()/set() methods sleep, as they
40 * must while accessing GPIO expander chips over I2C or SPI
41 * @names: if set, must be an array of strings to use as alternative
42 * names for the GPIOs in this chip. Any entry in the array
43 * may be NULL if there is no alias for the GPIO, however the
44 * array must be @ngpio entries long. A name can include a single printk
45 * format specifier for an unsigned int. It is substituted by the actual
46 * number of the gpio.
47 *
48 * A gpio_chip can help platforms abstract various sources of GPIOs so
49 * they can all be accessed through a common programing interface.
50 * Example sources would be SOC controllers, FPGAs, multifunction
51 * chips, dedicated GPIO expanders, and so on.
52 *
53 * Each chip controls a number of signals, identified in method calls
54 * by "offset" values in the range 0..(@ngpio - 1). When those signals
55 * are referenced through calls like gpio_get_value(gpio), the offset
56 * is calculated by subtracting @base from the gpio number.
57 */
58struct gpio_chip {
59 const char *label;
60 struct device *dev;
61 struct module *owner;
62 struct list_head list;
63
64 int (*request)(struct gpio_chip *chip,
65 unsigned offset);
66 void (*free)(struct gpio_chip *chip,
67 unsigned offset);
68 int (*get_direction)(struct gpio_chip *chip,
69 unsigned offset);
70 int (*direction_input)(struct gpio_chip *chip,
71 unsigned offset);
72 int (*direction_output)(struct gpio_chip *chip,
73 unsigned offset, int value);
74 int (*get)(struct gpio_chip *chip,
75 unsigned offset);
76 void (*set)(struct gpio_chip *chip,
77 unsigned offset, int value);
78 int (*set_debounce)(struct gpio_chip *chip,
79 unsigned offset,
80 unsigned debounce);
81
82 int (*to_irq)(struct gpio_chip *chip,
83 unsigned offset);
84
85 void (*dbg_show)(struct seq_file *s,
86 struct gpio_chip *chip);
87 int base;
88 u16 ngpio;
89 struct gpio_desc *desc;
90 const char *const *names;
91 unsigned can_sleep:1;
92 unsigned exported:1;
93
94#if defined(CONFIG_OF_GPIO)
95 /*
96 * If CONFIG_OF is enabled, then all GPIO controllers described in the
97 * device tree automatically may have an OF translation
98 */
99 struct device_node *of_node;
100 int of_gpio_n_cells;
101 int (*of_xlate)(struct gpio_chip *gc,
102 const struct of_phandle_args *gpiospec, u32 *flags);
103#endif
104#ifdef CONFIG_PINCTRL
105 /*
106 * If CONFIG_PINCTRL is enabled, then gpio controllers can optionally
107 * describe the actual pin range which they serve in an SoC. This
108 * information would be used by pinctrl subsystem to configure
109 * corresponding pins for gpio usage.
110 */
111 struct list_head pin_ranges;
112#endif
113};
114
115extern const char *gpiochip_is_requested(struct gpio_chip *chip,
116 unsigned offset);
117
118/* add/remove chips */
119extern int gpiochip_add(struct gpio_chip *chip);
120extern int __must_check gpiochip_remove(struct gpio_chip *chip);
121extern struct gpio_chip *gpiochip_find(void *data,
122 int (*match)(struct gpio_chip *chip, void *data));
123
124/* lock/unlock as IRQ */
125int gpiod_lock_as_irq(struct gpio_desc *desc);
126void gpiod_unlock_as_irq(struct gpio_desc *desc);
127
128/**
129 * Lookup table for associating GPIOs to specific devices and functions using
130 * platform data.
131 */
132struct gpiod_lookup {
133 struct list_head list;
134 /*
135 * name of the chip the GPIO belongs to
136 */
137 const char *chip_label;
138 /*
139 * hardware number (i.e. relative to the chip) of the GPIO
140 */
141 u16 chip_hwnum;
142 /*
143 * name of device that can claim this GPIO
144 */
145 const char *dev_id;
146 /*
147 * name of the GPIO from the device's point of view
148 */
149 const char *con_id;
150 /*
151 * index of the GPIO in case several GPIOs share the same name
152 */
153 unsigned int idx;
154 /*
155 * mask of GPIOF_* values
156 */
157 unsigned long flags;
158};
159
160/*
161 * Simple definition of a single GPIO under a con_id
162 */
163#define GPIO_LOOKUP(_chip_label, _chip_hwnum, _dev_id, _con_id, _flags) \
164 GPIO_LOOKUP_IDX(_chip_label, _chip_hwnum, _dev_id, _con_id, 0, _flags)
165
166/*
167 * Use this macro if you need to have several GPIOs under the same con_id.
168 * Each GPIO needs to use a different index and can be accessed using
169 * gpiod_get_index()
170 */
171#define GPIO_LOOKUP_IDX(_chip_label, _chip_hwnum, _dev_id, _con_id, _idx, \
172 _flags) \
173{ \
174 .chip_label = _chip_label, \
175 .chip_hwnum = _chip_hwnum, \
176 .dev_id = _dev_id, \
177 .con_id = _con_id, \
178 .idx = _idx, \
179 .flags = _flags, \
180}
181
182void gpiod_add_table(struct gpiod_lookup *table, size_t size);
183
184#endif
generated by cgit v1.2.2 (git 2.25.0) at 2026-05-30 15:32:49 -0400