Lines Matching refs:GPIO

1 GPIO Sysfs Interface for Userspace
6 debugfs interface, since it provides control over GPIO direction and
11 know for example that GPIO #23 controls the write protect line used to
13 may need to temporarily remove that protection, first importing a GPIO,
15 the write protection. In normal use, GPIO #23 would never be touched,
19 userspace GPIO can be used to determine system configuration data that
21 GPIO drivers could be all that the system really needs.
24 GPIO tasks:  "leds-gpio" and "gpio_keys", respectively. Use those
37    -	GPIO controllers ("gpio_chip" instances).
46 		a GPIO to userspace by writing its number to this file.
49 		for GPIO #19, if that's not requested by kernel code.
56 GPIO signals have paths like /sys/class/gpio/gpio42/ (for GPIO #42)
65 		configure the GPIO as an output with that initial value.
68 		doesn't support changing the direction of a GPIO, or
70 		allow userspace to reconfigure this GPIO's direction.
72 	"value" ... reads as either 0 (low) or 1 (high). If the GPIO
100 GPIO controllers have paths like /sys/class/gpio/gpiochip42/ (for the
106     	"base" ... same as N, the first GPIO managed by this chip
117 the correct GPIO number to use for a given signal.
125 	/* export the GPIO to userspace */
131 	/* create a sysfs link to an exported GPIO node */
135 	/* change the polarity of a GPIO node in sysfs */
138 After a kernel driver requests a GPIO, it may only be made available in
147 After the GPIO has been exported, gpiod_export_link() allows creating
148 symlinks from elsewhere in sysfs to the GPIO sysfs node. Drivers can
152 Drivers can use gpiod_sysfs_set_active_low() to hide GPIO line polarity