someOS/linux
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

mmc: slot-gpio: Add debouncing capability to mmc_gpio_request_cd()

Browse Source 
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>
This commit is contained in:
Laurent Pinchart
2013-08-08 12:38:31 +02:00
committed by Chris Ball
parent 7725a52c03
commit 214fc309d1
10 changed files with 25 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
drivers/mmc/core/host.c
View File

@@ -374,7 +374,7 @@ int mmc_of_parse(struct mmc_host *host)
if (!(flags & OF_GPIO_ACTIVE_LOW))
gpio_inv_cd = true;
ret = mmc_gpio_request_cd(host, gpio);
ret = mmc_gpio_request_cd(host, gpio, 0);
if (ret < 0) {
dev_err(host->parent,
"Failed to request CD GPIO #%d: %d!\n",

14
drivers/mmc/core/slot-gpio.c
View File

@@ -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