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>

diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c
index 6fb6f77450cba2237cd2d07a18fc951b5b1397cc..49bc403e31f02f7f10358d33c49030f9fddcf0d1 100644 (file)
--- 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 324235105519ec0045f2f54c6a833bc6fa639b6e..46596b71a32f49d5934c62d3f5323b26cf6c1658 100644 (file)
--- 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 d058f0c85f4372c83fae46d1945534a090e5f255..66516339e3a0fe474533f62fae475283180d701b 100644 (file)
--- 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 4ddd83f9865852445602623d53c5e273da63cdab..06c5b0b28ebc99f547b88fb9be47a43196872ff8 100644 (file)
--- 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 1dd5ba858754320126a67e08469755429a1a2d1c..abc8cf01e6e3317ecc3e95d32aa66236def768e9 100644 (file)
--- 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 bf99359a3a90cbcc647c2433288243846a0f5eb1..793dacd3b8413c5cd4eae8fc39c420c4f3ffdb5c 100644 (file)
--- 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 62a4a835acc67d11a1e7985d7c8f6484c6264f80..696122c1b468b315968128fb5a414fee21c740bd 100644 (file)
--- 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 6706b5e3b9747ae78bf47f1c9f7267ac3123f772..35f61cc3a392da7f4ad6482d0f00e0384be5b820 100644 (file)
--- 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 718843cfacfca1f6712410f73072d5abcd825c8f..17f7fa99376e4289b614b724c8382684acd34d12 100644 (file)
--- 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;

diff --git a/include/linux/mmc/slot-gpio.h b/include/linux/mmc/slot-gpio.h
index 7d88d27bfafaf9a337dc201bc8b3296b59fdb6d1..b0c73e4cacea1484fe4790a49514cb004e0af024 100644 (file)
--- a/include/linux/mmc/slot-gpio.h
+++ b/include/linux/mmc/slot-gpio.h
@@ -18,7 +18,8 @@ int mmc_gpio_request_ro(struct mmc_host *host, unsigned int gpio);
 void mmc_gpio_free_ro(struct mmc_host *host);
 
 int mmc_gpio_get_cd(struct mmc_host *host);
-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);
 void mmc_gpio_free_cd(struct mmc_host *host);
 
 #endif