xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

gpio: add core support for pull-up/pull-down configuration

Browse Source 
This commit adds support for configuring the pull-up and pull-down
resistors available in some GPIO controllers. While configuring
pull-up/pull-down is already possible through the pinctrl subsystem,
some GPIO controllers, especially simple ones such as GPIO expanders
on I2C, don't have any pinmuxing capability and therefore do not use
the pinctrl subsystem.

This commit implements the GPIO_PULL_UP and GPIO_PULL_DOWN flags,
which can be used from the Device Tree, to enable a pull-up or
pull-down resistor on a given GPIO.

The flag is simply propagated all the way to the core GPIO subsystem,
where it is used to call the gpio_chip ->set_config callback with the
appropriate existing PIN_CONFIG_BIAS_* values.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This commit is contained in:
Thomas Petazzoni
2019-02-07 17:28:58 +01:00
committed by Linus Walleij
parent 6581eaf0e8
commit d449991c4d
5 changed files with 29 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
drivers/gpio/gpiolib.h
View File

@@ -219,6 +219,8 @@ struct gpio_desc {
#define FLAG_IRQ_IS_ENABLED 10 /* GPIO is connected to an enabled IRQ */
#define FLAG_IS_HOGGED 11 /* GPIO is hogged */
#define FLAG_TRANSITORY 12 /* GPIO may lose value in sleep or reset */
#define FLAG_PULL_UP 13 /* GPIO has pull up enabled */
#define FLAG_PULL_DOWN 14 /* GPIO has pull down enabled */
/* Connection label */
const char *label;