1 #ifndef __LINUX_GPIO_DRIVER_H
2 #define __LINUX_GPIO_DRIVER_H
4 #include <linux/types.h>
5 #include <linux/module.h>
9 struct of_phandle_args
;
14 * struct gpio_chip - abstract a GPIO controller
15 * @label: for diagnostics
16 * @dev: optional device providing the GPIOs
17 * @owner: helps prevent removal of modules exporting active GPIOs
18 * @list: links gpio_chips together for traversal
19 * @request: optional hook for chip-specific activation, such as
20 * enabling module power and clock; may sleep
21 * @free: optional hook for chip-specific deactivation, such as
22 * disabling module power and clock; may sleep
23 * @get_direction: returns direction for signal "offset", 0=out, 1=in,
24 * (same as GPIOF_DIR_XXX), or negative error
25 * @direction_input: configures signal "offset" as input, or returns error
26 * @direction_output: configures signal "offset" as output, or returns error
27 * @get: returns value for signal "offset"; for output signals this
28 * returns either the value actually sensed, or zero
29 * @set: assigns output value for signal "offset"
30 * @set_debounce: optional hook for setting debounce time for specified gpio in
31 * interrupt triggered gpio chips
32 * @to_irq: optional hook supporting non-static gpio_to_irq() mappings;
33 * implementation may not sleep
34 * @dbg_show: optional routine to show contents in debugfs; default code
35 * will be used when this is omitted, but custom code can show extra
36 * state (such as pullup/pulldown configuration).
37 * @base: identifies the first GPIO number handled by this chip; or, if
38 * negative during registration, requests dynamic ID allocation.
39 * @ngpio: the number of GPIOs handled by this controller; the last GPIO
40 * handled is (base + ngpio - 1).
41 * @desc: array of ngpio descriptors. Private.
42 * @can_sleep: flag must be set iff get()/set() methods sleep, as they
43 * must while accessing GPIO expander chips over I2C or SPI
44 * @names: if set, must be an array of strings to use as alternative
45 * names for the GPIOs in this chip. Any entry in the array
46 * may be NULL if there is no alias for the GPIO, however the
47 * array must be @ngpio entries long. A name can include a single printk
48 * format specifier for an unsigned int. It is substituted by the actual
51 * A gpio_chip can help platforms abstract various sources of GPIOs so
52 * they can all be accessed through a common programing interface.
53 * Example sources would be SOC controllers, FPGAs, multifunction
54 * chips, dedicated GPIO expanders, and so on.
56 * Each chip controls a number of signals, identified in method calls
57 * by "offset" values in the range 0..(@ngpio - 1). When those signals
58 * are referenced through calls like gpio_get_value(gpio), the offset
59 * is calculated by subtracting @base from the gpio number.
65 struct list_head list
;
67 int (*request
)(struct gpio_chip
*chip
,
69 void (*free
)(struct gpio_chip
*chip
,
71 int (*get_direction
)(struct gpio_chip
*chip
,
73 int (*direction_input
)(struct gpio_chip
*chip
,
75 int (*direction_output
)(struct gpio_chip
*chip
,
76 unsigned offset
, int value
);
77 int (*get
)(struct gpio_chip
*chip
,
79 void (*set
)(struct gpio_chip
*chip
,
80 unsigned offset
, int value
);
81 int (*set_debounce
)(struct gpio_chip
*chip
,
85 int (*to_irq
)(struct gpio_chip
*chip
,
88 void (*dbg_show
)(struct seq_file
*s
,
89 struct gpio_chip
*chip
);
92 struct gpio_desc
*desc
;
93 const char *const *names
;
97 #if defined(CONFIG_OF_GPIO)
99 * If CONFIG_OF is enabled, then all GPIO controllers described in the
100 * device tree automatically may have an OF translation
102 struct device_node
*of_node
;
104 int (*of_xlate
)(struct gpio_chip
*gc
,
105 const struct of_phandle_args
*gpiospec
, u32
*flags
);
107 #ifdef CONFIG_PINCTRL
109 * If CONFIG_PINCTRL is enabled, then gpio controllers can optionally
110 * describe the actual pin range which they serve in an SoC. This
111 * information would be used by pinctrl subsystem to configure
112 * corresponding pins for gpio usage.
114 struct list_head pin_ranges
;
118 extern const char *gpiochip_is_requested(struct gpio_chip
*chip
,
121 /* add/remove chips */
122 extern int gpiochip_add(struct gpio_chip
*chip
);
123 extern int __must_check
gpiochip_remove(struct gpio_chip
*chip
);
124 extern struct gpio_chip
*gpiochip_find(void *data
,
125 int (*match
)(struct gpio_chip
*chip
, void *data
));
127 /* lock/unlock as IRQ */
128 int gpiod_lock_as_irq(struct gpio_desc
*desc
);
129 void gpiod_unlock_as_irq(struct gpio_desc
*desc
);
131 enum gpio_lookup_flags
{
132 GPIO_ACTIVE_HIGH
= (0 << 0),
133 GPIO_ACTIVE_LOW
= (1 << 0),
134 GPIO_OPEN_DRAIN
= (1 << 1),
135 GPIO_OPEN_SOURCE
= (1 << 2),
139 * Lookup table for associating GPIOs to specific devices and functions using
142 struct gpiod_lookup
{
143 struct list_head list
;
145 * name of the chip the GPIO belongs to
147 const char *chip_label
;
149 * hardware number (i.e. relative to the chip) of the GPIO
153 * name of device that can claim this GPIO
157 * name of the GPIO from the device's point of view
161 * index of the GPIO in case several GPIOs share the same name
165 * mask of GPIO_* values
167 enum gpio_lookup_flags flags
;
171 * Simple definition of a single GPIO under a con_id
173 #define GPIO_LOOKUP(_chip_label, _chip_hwnum, _dev_id, _con_id, _flags) \
174 GPIO_LOOKUP_IDX(_chip_label, _chip_hwnum, _dev_id, _con_id, 0, _flags)
177 * Use this macro if you need to have several GPIOs under the same con_id.
178 * Each GPIO needs to use a different index and can be accessed using
181 #define GPIO_LOOKUP_IDX(_chip_label, _chip_hwnum, _dev_id, _con_id, _idx, \
184 .chip_label = _chip_label, \
185 .chip_hwnum = _chip_hwnum, \
192 void gpiod_add_table(struct gpiod_lookup
*table
, size_t size
);
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