1 #ifndef __LINUX_GPIO_DRIVER_H
2 #define __LINUX_GPIO_DRIVER_H
4 #include <linux/types.h>
5 #include <linux/module.h>
7 #include <linux/irqchip/chained_irq.h>
8 #include <linux/irqdomain.h>
12 struct of_phandle_args
;
19 * struct gpio_chip - abstract a GPIO controller
20 * @label: for diagnostics
21 * @dev: optional device providing the GPIOs
22 * @owner: helps prevent removal of modules exporting active GPIOs
23 * @list: links gpio_chips together for traversal
24 * @request: optional hook for chip-specific activation, such as
25 * enabling module power and clock; may sleep
26 * @free: optional hook for chip-specific deactivation, such as
27 * disabling module power and clock; may sleep
28 * @get_direction: returns direction for signal "offset", 0=out, 1=in,
29 * (same as GPIOF_DIR_XXX), or negative error
30 * @direction_input: configures signal "offset" as input, or returns error
31 * @direction_output: configures signal "offset" as output, or returns error
32 * @get: returns value for signal "offset"; for output signals this
33 * returns either the value actually sensed, or zero
34 * @set: assigns output value for signal "offset"
35 * @set_debounce: optional hook for setting debounce time for specified gpio in
36 * interrupt triggered gpio chips
37 * @to_irq: optional hook supporting non-static gpio_to_irq() mappings;
38 * implementation may not sleep
39 * @dbg_show: optional routine to show contents in debugfs; default code
40 * will be used when this is omitted, but custom code can show extra
41 * state (such as pullup/pulldown configuration).
42 * @base: identifies the first GPIO number handled by this chip; or, if
43 * negative during registration, requests dynamic ID allocation.
44 * @ngpio: the number of GPIOs handled by this controller; the last GPIO
45 * handled is (base + ngpio - 1).
46 * @desc: array of ngpio descriptors. Private.
47 * @names: if set, must be an array of strings to use as alternative
48 * names for the GPIOs in this chip. Any entry in the array
49 * may be NULL if there is no alias for the GPIO, however the
50 * array must be @ngpio entries long. A name can include a single printk
51 * format specifier for an unsigned int. It is substituted by the actual
53 * @can_sleep: flag must be set iff get()/set() methods sleep, as they
54 * must while accessing GPIO expander chips over I2C or SPI. This
55 * implies that if the chip supports IRQs, these IRQs need to be threaded
56 * as the chip access may sleep when e.g. reading out the IRQ status
58 * @exported: flags if the gpiochip is exported for use from sysfs. Private.
60 * A gpio_chip can help platforms abstract various sources of GPIOs so
61 * they can all be accessed through a common programing interface.
62 * Example sources would be SOC controllers, FPGAs, multifunction
63 * chips, dedicated GPIO expanders, and so on.
65 * Each chip controls a number of signals, identified in method calls
66 * by "offset" values in the range 0..(@ngpio - 1). When those signals
67 * are referenced through calls like gpio_get_value(gpio), the offset
68 * is calculated by subtracting @base from the gpio number.
74 struct list_head list
;
76 int (*request
)(struct gpio_chip
*chip
,
78 void (*free
)(struct gpio_chip
*chip
,
80 int (*get_direction
)(struct gpio_chip
*chip
,
82 int (*direction_input
)(struct gpio_chip
*chip
,
84 int (*direction_output
)(struct gpio_chip
*chip
,
85 unsigned offset
, int value
);
86 int (*get
)(struct gpio_chip
*chip
,
88 void (*set
)(struct gpio_chip
*chip
,
89 unsigned offset
, int value
);
90 int (*set_debounce
)(struct gpio_chip
*chip
,
94 int (*to_irq
)(struct gpio_chip
*chip
,
97 void (*dbg_show
)(struct seq_file
*s
,
98 struct gpio_chip
*chip
);
101 struct gpio_desc
*desc
;
102 const char *const *names
;
106 #ifdef CONFIG_GPIOLIB_IRQCHIP
108 * With CONFIG_GPIO_IRQCHIP we get an irqchip inside the gpiolib
109 * to handle IRQs for most practical cases.
111 struct irq_chip
*irqchip
;
112 struct irq_domain
*irqdomain
;
113 unsigned int irq_base
;
114 irq_flow_handler_t irq_handler
;
115 unsigned int irq_default_type
;
118 #if defined(CONFIG_OF_GPIO)
120 * If CONFIG_OF is enabled, then all GPIO controllers described in the
121 * device tree automatically may have an OF translation
123 struct device_node
*of_node
;
125 int (*of_xlate
)(struct gpio_chip
*gc
,
126 const struct of_phandle_args
*gpiospec
, u32
*flags
);
128 #ifdef CONFIG_PINCTRL
130 * If CONFIG_PINCTRL is enabled, then gpio controllers can optionally
131 * describe the actual pin range which they serve in an SoC. This
132 * information would be used by pinctrl subsystem to configure
133 * corresponding pins for gpio usage.
135 struct list_head pin_ranges
;
139 extern const char *gpiochip_is_requested(struct gpio_chip
*chip
,
142 /* add/remove chips */
143 extern int gpiochip_add(struct gpio_chip
*chip
);
144 extern int __must_check
gpiochip_remove(struct gpio_chip
*chip
);
145 extern struct gpio_chip
*gpiochip_find(void *data
,
146 int (*match
)(struct gpio_chip
*chip
, void *data
));
148 /* lock/unlock as IRQ */
149 int gpiod_lock_as_irq(struct gpio_desc
*desc
);
150 void gpiod_unlock_as_irq(struct gpio_desc
*desc
);
152 struct gpio_chip
*gpiod_to_chip(const struct gpio_desc
*desc
);
154 struct gpio_desc
*gpiochip_get_desc(struct gpio_chip
*chip
,
157 enum gpio_lookup_flags
{
158 GPIO_ACTIVE_HIGH
= (0 << 0),
159 GPIO_ACTIVE_LOW
= (1 << 0),
160 GPIO_OPEN_DRAIN
= (1 << 1),
161 GPIO_OPEN_SOURCE
= (1 << 2),
165 * struct gpiod_lookup - lookup table
166 * @chip_label: name of the chip the GPIO belongs to
167 * @chip_hwnum: hardware number (i.e. relative to the chip) of the GPIO
168 * @con_id: name of the GPIO from the device's point of view
169 * @idx: index of the GPIO in case several GPIOs share the same name
170 * @flags: mask of GPIO_* values
172 * gpiod_lookup is a lookup table for associating GPIOs to specific devices and
173 * functions using platform data.
175 struct gpiod_lookup
{
176 const char *chip_label
;
180 enum gpio_lookup_flags flags
;
183 struct gpiod_lookup_table
{
184 struct list_head list
;
186 struct gpiod_lookup table
[];
190 * Simple definition of a single GPIO under a con_id
192 #define GPIO_LOOKUP(_chip_label, _chip_hwnum, _con_id, _flags) \
193 GPIO_LOOKUP_IDX(_chip_label, _chip_hwnum, _con_id, 0, _flags)
196 * Use this macro if you need to have several GPIOs under the same con_id.
197 * Each GPIO needs to use a different index and can be accessed using
200 #define GPIO_LOOKUP_IDX(_chip_label, _chip_hwnum, _con_id, _idx, _flags) \
202 .chip_label = _chip_label, \
203 .chip_hwnum = _chip_hwnum, \
209 void gpiod_add_lookup_table(struct gpiod_lookup_table
*table
);
211 #ifdef CONFIG_GPIOLIB_IRQCHIP
213 void gpiochip_set_chained_irqchip(struct gpio_chip
*gpiochip
,
214 struct irq_chip
*irqchip
,
216 irq_flow_handler_t parent_handler
);
218 int gpiochip_irqchip_add(struct gpio_chip
*gpiochip
,
219 struct irq_chip
*irqchip
,
220 unsigned int first_irq
,
221 irq_flow_handler_t handler
,
224 #endif /* CONFIG_GPIO_IRQCHIP */
226 #else /* CONFIG_GPIOLIB */
228 static inline struct gpio_chip
*gpiod_to_chip(const struct gpio_desc
*desc
)
230 /* GPIO can never have been requested */
232 return ERR_PTR(-ENODEV
);
235 #endif /* CONFIG_GPIOLIB */