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>

9 files changed, 23 insertions, 9 deletions

diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c
index 6fb6f77450cb..49bc403e31f0 100644
--- a/drivers/mmc/core/host.c
+++ b/drivers/mmc/core/host.c
@@ -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",
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
diff --git a/drivers/mmc/host/jz4740_mmc.c b/drivers/mmc/host/jz4740_mmc.c
index d058f0c85f43..66516339e3a0 100644
--- a/drivers/mmc/host/jz4740_mmc.c
+++ b/drivers/mmc/host/jz4740_mmc.c
@@ -713,7 +713,7 @@ static int jz4740_mmc_request_gpios(struct mmc_host *mmc,
                 mmc->caps2 |= MMC_CAP2_RO_ACTIVE_HIGH;
 
         if (gpio_is_valid(pdata->gpio_card_detect)) {
-                ret = mmc_gpio_request_cd(mmc, pdata->gpio_card_detect);
+                ret = mmc_gpio_request_cd(mmc, pdata->gpio_card_detect, 0);
                 if (ret)
                         return ret;
         }
diff --git a/drivers/mmc/host/mvsdio.c b/drivers/mmc/host/mvsdio.c
index 4ddd83f98658..06c5b0b28ebc 100644
--- a/drivers/mmc/host/mvsdio.c
+++ b/drivers/mmc/host/mvsdio.c
@@ -757,7 +757,8 @@ static int __init mvsd_probe(struct platform_device *pdev)
                 if (mvsd_data->gpio_card_detect &&
                     gpio_is_valid(mvsd_data->gpio_card_detect)) {
                         ret = mmc_gpio_request_cd(mmc,
-                                                  mvsd_data->gpio_card_detect);
+                                                  mvsd_data->gpio_card_detect,
+                                                  0);
                         if (ret)
                                 goto out;
                 } else {
diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
index 1dd5ba858754..abc8cf01e6e3 100644
--- a/drivers/mmc/host/sdhci-esdhc-imx.c
+++ b/drivers/mmc/host/sdhci-esdhc-imx.c
@@ -616,7 +616,7 @@ static int sdhci_esdhc_imx_probe(struct platform_device *pdev)
         /* card_detect */
         switch (boarddata->cd_type) {
         case ESDHC_CD_GPIO:
-                err = mmc_gpio_request_cd(host->mmc, boarddata->cd_gpio);
+                err = mmc_gpio_request_cd(host->mmc, boarddata->cd_gpio, 0);
                 if (err) {
                         dev_err(mmc_dev(host->mmc),
                                 "failed to request card-detect gpio!\n");
diff --git a/drivers/mmc/host/sdhci-pxav3.c b/drivers/mmc/host/sdhci-pxav3.c
index bf99359a3a90..793dacd3b841 100644
--- a/drivers/mmc/host/sdhci-pxav3.c
+++ b/drivers/mmc/host/sdhci-pxav3.c
@@ -278,7 +278,8 @@ static int sdhci_pxav3_probe(struct platform_device *pdev)
                         host->mmc->pm_caps |= pdata->pm_caps;
 
                 if (gpio_is_valid(pdata->ext_cd_gpio)) {
-                        ret = mmc_gpio_request_cd(host->mmc, pdata->ext_cd_gpio);
+                        ret = mmc_gpio_request_cd(host->mmc, pdata->ext_cd_gpio,
+                                                  0);
                         if (ret) {
                                 dev_err(mmc_dev(host->mmc),
                                         "failed to allocate card detect gpio\n");
diff --git a/drivers/mmc/host/sdhci-sirf.c b/drivers/mmc/host/sdhci-sirf.c
index 62a4a835acc6..696122c1b468 100644
--- a/drivers/mmc/host/sdhci-sirf.c
+++ b/drivers/mmc/host/sdhci-sirf.c
@@ -84,7 +84,7 @@ static int sdhci_sirf_probe(struct platform_device *pdev)
          * gets setup in sdhci_add_host() and we oops.
          */
         if (gpio_is_valid(priv->gpio_cd)) {
-                ret = mmc_gpio_request_cd(host->mmc, priv->gpio_cd);
+                ret = mmc_gpio_request_cd(host->mmc, priv->gpio_cd, 0);
                 if (ret) {
                         dev_err(&pdev->dev, "card detect irq request failed: %d\n",
                                 ret);
diff --git a/drivers/mmc/host/sh_mmcif.c b/drivers/mmc/host/sh_mmcif.c
index 6706b5e3b974..35f61cc3a392 100644
--- a/drivers/mmc/host/sh_mmcif.c
+++ b/drivers/mmc/host/sh_mmcif.c
@@ -1436,7 +1436,7 @@ static int sh_mmcif_probe(struct platform_device *pdev)
         }
 
         if (pd && pd->use_cd_gpio) {
-                ret = mmc_gpio_request_cd(mmc, pd->cd_gpio);
+                ret = mmc_gpio_request_cd(mmc, pd->cd_gpio, 0);
                 if (ret < 0)
                         goto erqcd;
         }
diff --git a/drivers/mmc/host/tmio_mmc_pio.c b/drivers/mmc/host/tmio_mmc_pio.c
index 718843cfacfc..17f7fa99376e 100644
--- a/drivers/mmc/host/tmio_mmc_pio.c
+++ b/drivers/mmc/host/tmio_mmc_pio.c
@@ -1110,7 +1110,7 @@ int tmio_mmc_host_probe(struct tmio_mmc_host **host,
         dev_pm_qos_expose_latency_limit(&pdev->dev, 100);
 
         if (pdata->flags & TMIO_MMC_USE_GPIO_CD) {
-                ret = mmc_gpio_request_cd(mmc, pdata->cd_gpio);
+                ret = mmc_gpio_request_cd(mmc, pdata->cd_gpio, 0);
                 if (ret < 0) {
                         tmio_mmc_host_remove(_host);
                         return ret;