mmc: core: add WP pin handler to slot functions

Card Write-Protect pin is often implemented, using a GPIO, which makes
it simple to provide a generic handler for it.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>

diff --git a/drivers/mmc/core/slot-gpio.c b/drivers/mmc/core/slot-gpio.c
index 41689da14b8d66a698f74a4178791ae220856e01..058242916cef1089ee2a8a22e8901464df7f4997 100644 (file)
--- a/drivers/mmc/core/slot-gpio.c
+++ b/drivers/mmc/core/slot-gpio.c
@@ -18,7 +18,9 @@
 #include <linux/slab.h>
 
 struct mmc_gpio {
+       int ro_gpio;
        int cd_gpio;
+       char *ro_label;
        char cd_label[0];
 };
 
@@ -43,11 +45,14 @@ static int mmc_gpio_alloc(struct mmc_host *host)
                 * before device_add(), i.e., between mmc_alloc_host() and
                 * mmc_add_host()
                 */
-               ctx = devm_kzalloc(&host->class_dev, sizeof(*ctx) + len,
+               ctx = devm_kzalloc(&host->class_dev, sizeof(*ctx) + 2 * len,
                                   GFP_KERNEL);
                if (ctx) {
+                       ctx->ro_label = ctx->cd_label + len;
                        snprintf(ctx->cd_label, len, "%s cd", dev_name(host->parent));
+                       snprintf(ctx->ro_label, len, "%s ro", dev_name(host->parent));
                        ctx->cd_gpio = -EINVAL;
+                       ctx->ro_gpio = -EINVAL;
                        host->slot.handler_priv = ctx;
                }
        }
@@ -57,6 +62,18 @@ static int mmc_gpio_alloc(struct mmc_host *host)
        return ctx ? 0 : -ENOMEM;
 }
 
+int mmc_gpio_get_ro(struct mmc_host *host)
+{
+       struct mmc_gpio *ctx = host->slot.handler_priv;
+
+       if (!ctx || !gpio_is_valid(ctx->ro_gpio))
+               return -ENOSYS;
+
+       return !gpio_get_value_cansleep(ctx->ro_gpio) ^
+               !!(host->caps2 & MMC_CAP2_RO_ACTIVE_HIGH);
+}
+EXPORT_SYMBOL(mmc_gpio_get_ro);
+
 int mmc_gpio_get_cd(struct mmc_host *host)
 {
        struct mmc_gpio *ctx = host->slot.handler_priv;
@@ -69,6 +86,24 @@ int mmc_gpio_get_cd(struct mmc_host *host)
 }
 EXPORT_SYMBOL(mmc_gpio_get_cd);
 
+int mmc_gpio_request_ro(struct mmc_host *host, unsigned int gpio)
+{
+       struct mmc_gpio *ctx;
+       int ret;
+
+       if (!gpio_is_valid(gpio))
+               return -EINVAL;
+
+       ret = mmc_gpio_alloc(host);
+       if (ret < 0)
+               return ret;
+
+       ctx = host->slot.handler_priv;
+
+       return gpio_request_one(gpio, GPIOF_DIR_IN, ctx->ro_label);
+}
+EXPORT_SYMBOL(mmc_gpio_request_ro);
+
 int mmc_gpio_request_cd(struct mmc_host *host, unsigned int gpio)
 {
        struct mmc_gpio *ctx;
@@ -117,6 +152,21 @@ int mmc_gpio_request_cd(struct mmc_host *host, unsigned int gpio)
 }
 EXPORT_SYMBOL(mmc_gpio_request_cd);
 
+void mmc_gpio_free_ro(struct mmc_host *host)
+{
+       struct mmc_gpio *ctx = host->slot.handler_priv;
+       int gpio;
+
+       if (!ctx || !gpio_is_valid(ctx->ro_gpio))
+               return;
+
+       gpio = ctx->ro_gpio;
+       ctx->ro_gpio = -EINVAL;
+
+       gpio_free(gpio);
+}
+EXPORT_SYMBOL(mmc_gpio_free_ro);
+
 void mmc_gpio_free_cd(struct mmc_host *host)
 {
        struct mmc_gpio *ctx = host->slot.handler_priv;

diff --git a/include/linux/mmc/slot-gpio.h b/include/linux/mmc/slot-gpio.h
index 1a977d7ba3ba21c967e1935eead7bd1ebeee3c36..7d88d27bfafaf9a337dc201bc8b3296b59fdb6d1 100644 (file)
--- a/include/linux/mmc/slot-gpio.h
+++ b/include/linux/mmc/slot-gpio.h
@@ -13,6 +13,10 @@
 
 struct mmc_host;
 
+int mmc_gpio_get_ro(struct mmc_host *host);
+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);
 void mmc_gpio_free_cd(struct mmc_host *host);