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authorLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>2013-08-08 12:38:31 +0200
committerChris Ball <cjb@laptop.org>2013-08-24 23:45:09 -0400
commit214fc309d1387e822d606a33a10e31cacfe83520 (patch)
tree2c266dd95d8da7f54d7b43c20e5c2c0ebe6165be /drivers/mmc/core/slot-gpio.c
parent7725a52c03df4dff3ac3fc621749407fb319d47f (diff)
downloadblackbird-obmc-linux-214fc309d1387e822d606a33a10e31cacfe83520.tar.gz
blackbird-obmc-linux-214fc309d1387e822d606a33a10e31cacfe83520.zip
mmc: slot-gpio: Add debouncing capability to mmc_gpio_request_cd()
Add a debounce parameter to the mmc_gpio_request_cd() function that enables GPIO debouncing when set to a non-zero value. This can be used by MMC host drivers to enable debouncing on the card detect signal. Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: Chris Ball <cjb@laptop.org>
Diffstat (limited to 'drivers/mmc/core/slot-gpio.c')
-rw-r--r--drivers/mmc/core/slot-gpio.c14
1 files changed, 13 insertions, 1 deletions
diff --git a/drivers/mmc/core/slot-gpio.c b/drivers/mmc/core/slot-gpio.c
index 324235105519..46596b71a32f 100644
--- a/drivers/mmc/core/slot-gpio.c
+++ b/drivers/mmc/core/slot-gpio.c
@@ -135,6 +135,7 @@ EXPORT_SYMBOL(mmc_gpio_request_ro);
* mmc_gpio_request_cd - request a gpio for card-detection
* @host: mmc host
* @gpio: gpio number requested
+ * @debounce: debounce time in microseconds
*
* As devm_* managed functions are used in mmc_gpio_request_cd(), client
* drivers do not need to explicitly call mmc_gpio_free_cd() for freeing up,
@@ -143,9 +144,14 @@ EXPORT_SYMBOL(mmc_gpio_request_ro);
* switching for card-detection, they are responsible for calling
* mmc_gpio_request_cd() and mmc_gpio_free_cd() as a pair on their own.
*
+ * If GPIO debouncing is desired, set the debounce parameter to a non-zero
+ * value. The caller is responsible for ensuring that the GPIO driver associated
+ * with the GPIO supports debouncing, otherwise an error will be returned.
+ *
* Returns zero on success, else an error.
*/
-int mmc_gpio_request_cd(struct mmc_host *host, unsigned int gpio)
+int mmc_gpio_request_cd(struct mmc_host *host, unsigned int gpio,
+ unsigned int debounce)
{
struct mmc_gpio *ctx;
int irq = gpio_to_irq(gpio);
@@ -167,6 +173,12 @@ int mmc_gpio_request_cd(struct mmc_host *host, unsigned int gpio)
*/
return ret;
+ if (debounce) {
+ ret = gpio_set_debounce(gpio, debounce);
+ if (ret < 0)
+ return ret;
+ }
+
/*
* Even if gpio_to_irq() returns a valid IRQ number, the platform might
* still prefer to poll, e.g., because that IRQ number is already used
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