| 1 | From fc3a1f04f5040255cbc086c419e4237f29f89f88 Mon Sep 17 00:00:00 2001 |
| 2 | From: Wolfram Sang <w.sang@pengutronix.de> |
| 3 | Date: Tue, 13 Dec 2011 18:34:01 +0100 |
| 4 | Subject: [PATCH] gpio: add flags to export GPIOs when requesting |
| 5 | |
| 6 | commit fc3a1f04f5040255cbc086c419e4237f29f89f88 upstream. |
| 7 | |
| 8 | Introduce new flags to automatically export GPIOs when using the convenience |
| 9 | functions gpio_request_one() or gpio_request_array(). This eases support for |
| 10 | custom boards where lots of GPIOs need to be exported for customer |
| 11 | applications. |
| 12 | |
| 13 | Signed-off-by: Wolfram Sang <w.sang@pengutronix.de> |
| 14 | Signed-off-by: Grant Likely <grant.likely@secretlab.ca> |
| 15 | --- |
| 16 | Documentation/gpio.txt | 3 +++ |
| 17 | drivers/gpio/gpiolib.c | 12 +++++++++++- |
| 18 | include/linux/gpio.h | 5 +++++ |
| 19 | 3 files changed, 19 insertions(+), 1 deletion(-) |
| 20 | |
| 21 | --- a/Documentation/gpio.txt |
| 22 | +++ b/Documentation/gpio.txt |
| 23 | @@ -303,6 +303,9 @@ where 'flags' is currently defined to sp |
| 24 | * GPIOF_INIT_LOW - as output, set initial level to LOW |
| 25 | * GPIOF_INIT_HIGH - as output, set initial level to HIGH |
| 26 | |
| 27 | + * GPIOF_EXPORT_DIR_FIXED - export gpio to sysfs, keep direction |
| 28 | + * GPIOF_EXPORT_DIR_CHANGEABLE - also export, allow changing direction |
| 29 | + |
| 30 | since GPIOF_INIT_* are only valid when configured as output, so group valid |
| 31 | combinations as: |
| 32 | |
| 33 | --- a/drivers/gpio/gpiolib.c |
| 34 | +++ b/drivers/gpio/gpiolib.c |
| 35 | @@ -1289,8 +1289,18 @@ int gpio_request_one(unsigned gpio, unsi |
| 36 | (flags & GPIOF_INIT_HIGH) ? 1 : 0); |
| 37 | |
| 38 | if (err) |
| 39 | - gpio_free(gpio); |
| 40 | + goto free_gpio; |
| 41 | |
| 42 | + if (flags & GPIOF_EXPORT) { |
| 43 | + err = gpio_export(gpio, flags & GPIOF_EXPORT_CHANGEABLE); |
| 44 | + if (err) |
| 45 | + goto free_gpio; |
| 46 | + } |
| 47 | + |
| 48 | + return 0; |
| 49 | + |
| 50 | + free_gpio: |
| 51 | + gpio_free(gpio); |
| 52 | return err; |
| 53 | } |
| 54 | EXPORT_SYMBOL_GPL(gpio_request_one); |
| 55 | --- a/include/linux/gpio.h |
| 56 | +++ b/include/linux/gpio.h |
| 57 | @@ -14,6 +14,11 @@ |
| 58 | #define GPIOF_OUT_INIT_LOW (GPIOF_DIR_OUT | GPIOF_INIT_LOW) |
| 59 | #define GPIOF_OUT_INIT_HIGH (GPIOF_DIR_OUT | GPIOF_INIT_HIGH) |
| 60 | |
| 61 | +#define GPIOF_EXPORT (1 << 2) |
| 62 | +#define GPIOF_EXPORT_CHANGEABLE (1 << 3) |
| 63 | +#define GPIOF_EXPORT_DIR_FIXED (GPIOF_EXPORT) |
| 64 | +#define GPIOF_EXPORT_DIR_CHANGEABLE (GPIOF_EXPORT | GPIOF_EXPORT_CHANGEABLE) |
| 65 | + |
| 66 | /** |
| 67 | * struct gpio - a structure describing a GPIO with configuration |
| 68 | * @gpio: the GPIO number |
| 69 | |
