Commit fc3a1f04 authored by Wolfram Sang's avatar Wolfram Sang Committed by Grant Likely
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gpio: add flags to export GPIOs when requesting 



Introduce new flags to automatically export GPIOs when using the convenience
functions gpio_request_one() or gpio_request_array(). This eases support for
custom boards where lots of GPIOs need to be exported for customer
applications.

Signed-off-by: default avatarWolfram Sang <w.sang@pengutronix.de>
Signed-off-by: default avatarGrant Likely <grant.likely@secretlab.ca>
parent dd775ae2

Documentation/gpio.txt

+3 −0
Original line number Diff line number Diff line
@@ -322,6 +322,9 @@ where 'flags' is currently defined to specify the following properties: 
	* GPIOF_OPEN_DRAIN	- gpio pin is open drain type.

	* GPIOF_OPEN_SOURCE	- gpio pin is open source type.



	* GPIOF_EXPORT_DIR_FIXED	- export gpio to sysfs, keep direction

	* GPIOF_EXPORT_DIR_CHANGEABLE	- also export, allow changing direction



since GPIOF_INIT_* are only valid when configured as output, so group valid

combinations as:

drivers/gpio/gpiolib.c

+11 −1
Original line number Diff line number Diff line
@@ -1302,8 +1302,18 @@ int gpio_request_one(unsigned gpio, unsigned long flags, const char *label) 
				(flags & GPIOF_INIT_HIGH) ? 1 : 0);



	if (err)

		gpio_free(gpio);

		goto free_gpio;



	if (flags & GPIOF_EXPORT) {

		err = gpio_export(gpio, flags & GPIOF_EXPORT_CHANGEABLE);

		if (err)

			goto free_gpio;

	}



	return 0;



 free_gpio:

	gpio_free(gpio);

	return err;

}

EXPORT_SYMBOL_GPL(gpio_request_one);

include/linux/gpio.h

+5 −0
Original line number Diff line number Diff line
@@ -20,6 +20,11 @@ 
/* Gpio pin is open source */

#define GPIOF_OPEN_SOURCE	(1 << 3)



#define GPIOF_EXPORT		(1 << 2)

#define GPIOF_EXPORT_CHANGEABLE	(1 << 3)

#define GPIOF_EXPORT_DIR_FIXED	(GPIOF_EXPORT)

#define GPIOF_EXPORT_DIR_CHANGEABLE (GPIOF_EXPORT | GPIOF_EXPORT_CHANGEABLE)



/**

 * struct gpio - a structure describing a GPIO with configuration

 * @gpio:	the GPIO number