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[PATCH/RFC,131/390] gpio: add flags to export GPIOs when requesting

Message ID 1364525119-31791-132-git-send-email-horms+renesas@verge.net.au (mailing list archive)
State New, archived
Headers show

Commit Message

Simon Horman March 29, 2013, 2:41 a.m. UTC 
From: Wolfram Sang <w.sang@pengutronix.de>

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: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
(cherry picked from commit fc3a1f04f5040255cbc086c419e4237f29f89f88)

Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
---
 Documentation/gpio.txt |    3 +++
 drivers/gpio/gpiolib.c |   12 +++++++++++-
 include/linux/gpio.h   |    5 +++++
 3 files changed, 19 insertions(+), 1 deletion(-)
diff mbox

Patch

diff --git a/Documentation/gpio.txt b/Documentation/gpio.txt
index 620a078..e08a883 100644
--- a/Documentation/gpio.txt
+++ b/Documentation/gpio.txt
@@ -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:
 
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 112c16e..267b3f2 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1306,8 +1306,18 @@  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);
diff --git a/include/linux/gpio.h b/include/linux/gpio.h
index 6155ecf..af511a6 100644
--- a/include/linux/gpio.h
+++ b/include/linux/gpio.h
@@ -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