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: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
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 @@
* 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 5a75510..566d012 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1302,8 +1302,18 @@
(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