[mirror_ubuntu-artful-kernel.git] / include / linux / gpio / driver.h

#ifndef __LINUX_GPIO_DRIVER_H
#define __LINUX_GPIO_DRIVER_H

#include <linux/types.h>

struct device;
struct gpio_desc;

/**
 * struct gpio_chip - abstract a GPIO controller
 * @label: for diagnostics
 * @dev: optional device providing the GPIOs
 * @owner: helps prevent removal of modules exporting active GPIOs
 * @list: links gpio_chips together for traversal
 * @request: optional hook for chip-specific activation, such as
 *	enabling module power and clock; may sleep
 * @free: optional hook for chip-specific deactivation, such as
 *	disabling module power and clock; may sleep
 * @get_direction: returns direction for signal "offset", 0=out, 1=in,
 *	(same as GPIOF_DIR_XXX), or negative error
 * @direction_input: configures signal "offset" as input, or returns error
 * @direction_output: configures signal "offset" as output, or returns error
 * @get: returns value for signal "offset"; for output signals this
 *	returns either the value actually sensed, or zero
 * @set: assigns output value for signal "offset"
 * @set_debounce: optional hook for setting debounce time for specified gpio in
 *      interrupt triggered gpio chips
 * @to_irq: optional hook supporting non-static gpio_to_irq() mappings;
 *	implementation may not sleep
 * @dbg_show: optional routine to show contents in debugfs; default code
 *	will be used when this is omitted, but custom code can show extra
 *	state (such as pullup/pulldown configuration).
 * @base: identifies the first GPIO number handled by this chip; or, if
 *	negative during registration, requests dynamic ID allocation.
 * @ngpio: the number of GPIOs handled by this controller; the last GPIO
 *	handled is (base + ngpio - 1).
 * @desc: array of ngpio descriptors. Private.
 * @can_sleep: flag must be set iff get()/set() methods sleep, as they
 *	must while accessing GPIO expander chips over I2C or SPI
 * @names: if set, must be an array of strings to use as alternative
 *      names for the GPIOs in this chip. Any entry in the array
 *      may be NULL if there is no alias for the GPIO, however the
 *      array must be @ngpio entries long.  A name can include a single printk
 *      format specifier for an unsigned int.  It is substituted by the actual
 *      number of the gpio.
 *
 * A gpio_chip can help platforms abstract various sources of GPIOs so
 * they can all be accessed through a common programing interface.
 * Example sources would be SOC controllers, FPGAs, multifunction
 * chips, dedicated GPIO expanders, and so on.
 *
 * Each chip controls a number of signals, identified in method calls
 * by "offset" values in the range 0..(@ngpio - 1).  When those signals
 * are referenced through calls like gpio_get_value(gpio), the offset
 * is calculated by subtracting @base from the gpio number.
 */
struct gpio_chip {
	const char		*label;
	struct device		*dev;
	struct module		*owner;
	struct list_head        list;

	int			(*request)(struct gpio_chip *chip,
						unsigned offset);
	void			(*free)(struct gpio_chip *chip,
						unsigned offset);
	int			(*get_direction)(struct gpio_chip *chip,
						unsigned offset);
	int			(*direction_input)(struct gpio_chip *chip,
						unsigned offset);
	int			(*direction_output)(struct gpio_chip *chip,
						unsigned offset, int value);
	int			(*get)(struct gpio_chip *chip,
						unsigned offset);
	void			(*set)(struct gpio_chip *chip,
						unsigned offset, int value);
	int			(*set_debounce)(struct gpio_chip *chip,
						unsigned offset,
						unsigned debounce);

	int			(*to_irq)(struct gpio_chip *chip,
						unsigned offset);

	void			(*dbg_show)(struct seq_file *s,
						struct gpio_chip *chip);
	int			base;
	u16			ngpio;
	struct gpio_desc	*desc;
	const char		*const *names;
	unsigned		can_sleep:1;
	unsigned		exported:1;

#if defined(CONFIG_OF_GPIO)
	/*
	 * If CONFIG_OF is enabled, then all GPIO controllers described in the
	 * device tree automatically may have an OF translation
	 */
	struct device_node *of_node;
	int of_gpio_n_cells;
	int (*of_xlate)(struct gpio_chip *gc,
			const struct of_phandle_args *gpiospec, u32 *flags);
#endif
#ifdef CONFIG_PINCTRL
	/*
	 * If CONFIG_PINCTRL is enabled, then gpio controllers can optionally
	 * describe the actual pin range which they serve in an SoC. This
	 * information would be used by pinctrl subsystem to configure
	 * corresponding pins for gpio usage.
	 */
	struct list_head pin_ranges;
#endif
};

extern const char *gpiochip_is_requested(struct gpio_chip *chip,
			unsigned offset);

/* add/remove chips */
extern int gpiochip_add(struct gpio_chip *chip);
extern int __must_check gpiochip_remove(struct gpio_chip *chip);
extern struct gpio_chip *gpiochip_find(void *data,
			      int (*match)(struct gpio_chip *chip, void *data));

/* lock/unlock as IRQ */
int gpiod_lock_as_irq(struct gpio_desc *desc);
void gpiod_unlock_as_irq(struct gpio_desc *desc);

/**
 * Lookup table for associating GPIOs to specific devices and functions using
 * platform data.
 */
struct gpiod_lookup {
	struct list_head list;
	/*
	 * name of the chip the GPIO belongs to
	 */
	const char *chip_label;
	/*
	 * hardware number (i.e. relative to the chip) of the GPIO
	 */
	u16 chip_hwnum;
	/*
	 * name of device that can claim this GPIO
	 */
	const char *dev_id;
	/*
	 * name of the GPIO from the device's point of view
	 */
	const char *con_id;
	/*
	 * index of the GPIO in case several GPIOs share the same name
	 */
	unsigned int idx;
	/*
	 * mask of GPIOF_* values
	 */
	unsigned long flags;
};

/*
 * Simple definition of a single GPIO under a con_id
 */
#define GPIO_LOOKUP(_chip_label, _chip_hwnum, _dev_id, _con_id, _flags) \
	GPIO_LOOKUP_IDX(_chip_label, _chip_hwnum, _dev_id, _con_id, 0, _flags)

/*
 * Use this macro if you need to have several GPIOs under the same con_id.
 * Each GPIO needs to use a different index and can be accessed using
 * gpiod_get_index()
 */
#define GPIO_LOOKUP_IDX(_chip_label, _chip_hwnum, _dev_id, _con_id, _idx, \
			_flags)                                           \
{                                                                         \
	.chip_label = _chip_label,                                        \
	.chip_hwnum = _chip_hwnum,                                        \
	.dev_id = _dev_id,                                                \
	.con_id = _con_id,                                                \
	.idx = _idx,                                                      \
	.flags = _flags,                                                  \
}

void gpiod_add_table(struct gpiod_lookup *table, size_t size);

#endif
Commit	Line	Data
79a9becd AC	1	#ifndef __LINUX_GPIO_DRIVER_H
	2	#define __LINUX_GPIO_DRIVER_H
	3
	4	#include <linux/types.h>
	5
	6	struct device;
	7	struct gpio_desc;
	8
	9	/**
	10	* struct gpio_chip - abstract a GPIO controller
	11	* @label: for diagnostics
	12	* @dev: optional device providing the GPIOs
	13	* @owner: helps prevent removal of modules exporting active GPIOs
	14	* @list: links gpio_chips together for traversal
	15	* @request: optional hook for chip-specific activation, such as
	16	* enabling module power and clock; may sleep
	17	* @free: optional hook for chip-specific deactivation, such as
	18	* disabling module power and clock; may sleep
	19	* @get_direction: returns direction for signal "offset", 0=out, 1=in,
	20	* (same as GPIOF_DIR_XXX), or negative error
	21	* @direction_input: configures signal "offset" as input, or returns error
	22	* @direction_output: configures signal "offset" as output, or returns error
	23	* @get: returns value for signal "offset"; for output signals this
	24	* returns either the value actually sensed, or zero
	25	* @set: assigns output value for signal "offset"
	26	* @set_debounce: optional hook for setting debounce time for specified gpio in
	27	* interrupt triggered gpio chips
	28	* @to_irq: optional hook supporting non-static gpio_to_irq() mappings;
	29	* implementation may not sleep
	30	* @dbg_show: optional routine to show contents in debugfs; default code
	31	* will be used when this is omitted, but custom code can show extra
	32	* state (such as pullup/pulldown configuration).
	33	* @base: identifies the first GPIO number handled by this chip; or, if
	34	* negative during registration, requests dynamic ID allocation.
	35	* @ngpio: the number of GPIOs handled by this controller; the last GPIO
	36	* handled is (base + ngpio - 1).
	37	* @desc: array of ngpio descriptors. Private.
	38	* @can_sleep: flag must be set iff get()/set() methods sleep, as they
	39	* must while accessing GPIO expander chips over I2C or SPI
	40	* @names: if set, must be an array of strings to use as alternative
	41	* names for the GPIOs in this chip. Any entry in the array
	42	* may be NULL if there is no alias for the GPIO, however the
	43	* array must be @ngpio entries long. A name can include a single printk
	44	* format specifier for an unsigned int. It is substituted by the actual
	45	* number of the gpio.
	46	*
	47	* A gpio_chip can help platforms abstract various sources of GPIOs so
	48	* they can all be accessed through a common programing interface.
	49	* Example sources would be SOC controllers, FPGAs, multifunction
	50	* chips, dedicated GPIO expanders, and so on.
	51	*
	52	* Each chip controls a number of signals, identified in method calls
	53	* by "offset" values in the range 0..(@ngpio - 1). When those signals
	54	* are referenced through calls like gpio_get_value(gpio), the offset
	55	* is calculated by subtracting @base from the gpio number.
	56	*/
	57	struct gpio_chip {
	58	const char *label;
	59	struct device *dev;
	60	struct module *owner;
	61	struct list_head list;
	62
	63	int (request)(struct gpio_chip chip,
	64	unsigned offset);
65	void (free)(struct gpio_chip chip,
66	unsigned offset);
67	int (get_direction)(struct gpio_chip chip,
68	unsigned offset);
69	int (direction_input)(struct gpio_chip chip,
70	unsigned offset);
71	int (direction_output)(struct gpio_chip chip,
72	unsigned offset, int value);
73	int (get)(struct gpio_chip chip,
74	unsigned offset);
75	void (set)(struct gpio_chip chip,
76	unsigned offset, int value);
77	int (set_debounce)(struct gpio_chip chip,
78	unsigned offset,
79	unsigned debounce);
80
81	int (to_irq)(struct gpio_chip chip,
82	unsigned offset);
83
84	void (dbg_show)(struct seq_file s,
85	struct gpio_chip *chip);
86	int base;
87	u16 ngpio;
88	struct gpio_desc *desc;
89	const char const names;
90	unsigned can_sleep:1;
91	unsigned exported:1;
92
93	#if defined(CONFIG_OF_GPIO)
94	/*
95	* If CONFIG_OF is enabled, then all GPIO controllers described in the
96	* device tree automatically may have an OF translation
97	*/
98	struct device_node *of_node;
99	int of_gpio_n_cells;
100	int (of_xlate)(struct gpio_chip gc,
101	const struct of_phandle_args gpiospec, u32 flags);
102	#endif
103	#ifdef CONFIG_PINCTRL
104	/*
105	* If CONFIG_PINCTRL is enabled, then gpio controllers can optionally
106	* describe the actual pin range which they serve in an SoC. This
107	* information would be used by pinctrl subsystem to configure
108	* corresponding pins for gpio usage.
109	*/
110	struct list_head pin_ranges;
111	#endif
112	};
113
114	extern const char gpiochip_is_requested(struct gpio_chip chip,
115	unsigned offset);
116
117	/* add/remove chips */
118	extern int gpiochip_add(struct gpio_chip *chip);
119	extern int __must_check gpiochip_remove(struct gpio_chip *chip);
120	extern struct gpio_chip gpiochip_find(void data,
121	int (match)(struct gpio_chip chip, void *data));
122
123	/* lock/unlock as IRQ */
124	int gpiod_lock_as_irq(struct gpio_desc *desc);
125	void gpiod_unlock_as_irq(struct gpio_desc *desc);
126
bae48da2 AC	127	/**
	128	* Lookup table for associating GPIOs to specific devices and functions using
	129	* platform data.
	130	*/
	131	struct gpiod_lookup {
	132	struct list_head list;
	133	/*
	134	* name of the chip the GPIO belongs to
	135	*/
	136	const char *chip_label;
	137	/*
	138	* hardware number (i.e. relative to the chip) of the GPIO
	139	*/
	140	u16 chip_hwnum;
	141	/*
	142	* name of device that can claim this GPIO
	143	*/
	144	const char *dev_id;
	145	/*
	146	* name of the GPIO from the device's point of view
	147	*/
	148	const char *con_id;
	149	/*
	150	* index of the GPIO in case several GPIOs share the same name
	151	*/
	152	unsigned int idx;
	153	/*
	154	* mask of GPIOF_* values
	155	*/
	156	unsigned long flags;
	157	};
	158
	159	/*
	160	* Simple definition of a single GPIO under a con_id
	161	*/
	162	#define GPIO_LOOKUP(_chip_label, _chip_hwnum, _dev_id, _con_id, _flags) \
	163	GPIO_LOOKUP_IDX(_chip_label, _chip_hwnum, _dev_id, _con_id, 0, _flags)
	164
	165	/*
	166	* Use this macro if you need to have several GPIOs under the same con_id.
	167	* Each GPIO needs to use a different index and can be accessed using
	168	* gpiod_get_index()
	169	*/
	170	#define GPIO_LOOKUP_IDX(_chip_label, _chip_hwnum, _dev_id, _con_id, _idx, \
	171	_flags) \
	172	{ \
	173	.chip_label = _chip_label, \
	174	.chip_hwnum = _chip_hwnum, \
	175	.dev_id = _dev_id, \
	176	.con_id = _con_id, \
	177	.idx = _idx, \
	178	.flags = _flags, \
	179	}
	180
	181	void gpiod_add_table(struct gpiod_lookup *table, size_t size);
	182
79a9becd	183	#endif