include/asm-generic/gpio.h

14  * at a small performance cost for non-inlined operations and some
15  * extra memory (for code and for per-GPIO table entries).
19  * smaller range 0..ARCH_NR_GPIOS-1.
23  * actually an estimate of a board-specific value.
35  * Invalid GPIO numbers are useful for indicating no-such-GPIO in
51  * struct gpio_chip - abstract a GPIO controller
55  * @request: optional hook for chip-specific activation, such as
56  *	enabling module power and clock; may sleep
57  * @free: optional hook for chip-specific deactivation, such as
58  *	disabling module power and clock; may sleep
60  * @get: returns value for signal "offset"; for output signals this
62  * @direction_output: configures signal "offset" as output, or returns error
63  * @set: assigns output value for signal "offset"
64  * @to_irq: optional hook supporting non-static gpio_to_irq() mappings;
72  *	handled is (base + ngpio - 1).
75  * @names: if set, must be an array of strings to use as alternative
76  *      names for the GPIOs in this chip. Any entry in the array
88  * by "offset" values in the range 0..(@ngpio - 1).  When those signals
121 	const char		*const *names;  member
166  * the GPIO is constant and refers to some always-present controller,
202 	/* only non-negative numbers are valid */  in gpio_is_valid()
237 	return -ENOSYS;  in gpio_export()
243 	return -ENOSYS;  in gpio_export_link()
248 	return -ENOSYS;  in gpio_sysfs_set_active_low()