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.
59 * @irq_not_threaded: flag must be set if @can_sleep is set but the
60 * IRQs don't need to be threaded
62 * A gpio_chip can help platforms abstract various sources of GPIOs so
63 * they can all be accessed through a common programing interface.
64 * Example sources would be SOC controllers, FPGAs, multifunction
65 * chips, dedicated GPIO expanders, and so on.
67 * Each chip controls a number of signals, identified in method calls
68 * by "offset" values in the range 0..(@ngpio - 1). When those signals
69 * are referenced through calls like gpio_get_value(gpio), the offset
70 * is calculated by subtracting @base from the gpio number.
76 struct list_head list;
78 int (*request)(struct gpio_chip *chip,
80 void (*free)(struct gpio_chip *chip,
82 int (*get_direction)(struct gpio_chip *chip,
84 int (*direction_input)(struct gpio_chip *chip,
86 int (*direction_output)(struct gpio_chip *chip,
87 unsigned offset, int value);
88 int (*get)(struct gpio_chip *chip,
90 void (*set)(struct gpio_chip *chip,
91 unsigned offset, int value);
92 int (*set_debounce)(struct gpio_chip *chip,
96 int (*to_irq)(struct gpio_chip *chip,
99 void (*dbg_show)(struct seq_file *s,
100 struct gpio_chip *chip);
103 struct gpio_desc *desc;
104 const char *const *names;
106 bool irq_not_threaded;
109 #ifdef CONFIG_GPIOLIB_IRQCHIP
111 * With CONFIG_GPIOLIB_IRQCHIP we get an irqchip inside the gpiolib
112 * to handle IRQs for most practical cases.
114 struct irq_chip *irqchip;
115 struct irq_domain *irqdomain;
116 unsigned int irq_base;
117 irq_flow_handler_t irq_handler;
118 unsigned int irq_default_type;
121 #if defined(CONFIG_OF_GPIO)
123 * If CONFIG_OF is enabled, then all GPIO controllers described in the
124 * device tree automatically may have an OF translation
126 struct device_node *of_node;
128 int (*of_xlate)(struct gpio_chip *gc,
129 const struct of_phandle_args *gpiospec, u32 *flags);
131 #ifdef CONFIG_PINCTRL
133 * If CONFIG_PINCTRL is enabled, then gpio controllers can optionally
134 * describe the actual pin range which they serve in an SoC. This
135 * information would be used by pinctrl subsystem to configure
136 * corresponding pins for gpio usage.
138 struct list_head pin_ranges;
142 extern const char *gpiochip_is_requested(struct gpio_chip *chip,
145 /* add/remove chips */
146 extern int gpiochip_add(struct gpio_chip *chip);
147 extern void gpiochip_remove(struct gpio_chip *chip);
148 extern struct gpio_chip *gpiochip_find(void *data,
149 int (*match)(struct gpio_chip *chip, void *data));
151 /* lock/unlock as IRQ */
152 int gpio_lock_as_irq(struct gpio_chip *chip, unsigned int offset);
153 void gpio_unlock_as_irq(struct gpio_chip *chip, unsigned int offset);
155 struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc);
157 #ifdef CONFIG_GPIOLIB_IRQCHIP
159 void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
160 struct irq_chip *irqchip,
162 irq_flow_handler_t parent_handler);
164 int gpiochip_irqchip_add(struct gpio_chip *gpiochip,
165 struct irq_chip *irqchip,
166 unsigned int first_irq,
167 irq_flow_handler_t handler,
170 #endif /* CONFIG_GPIOLIB_IRQCHIP */
172 struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum,
174 void gpiochip_free_own_desc(struct gpio_desc *desc);
176 #else /* CONFIG_GPIOLIB */
178 static inline struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
180 /* GPIO can never have been requested */
182 return ERR_PTR(-ENODEV);
185 #endif /* CONFIG_GPIOLIB */