Commit 5aa7dad3 authored by Guennadi Liakhovetski's avatar Guennadi Liakhovetski Committed by Chris Ball
Browse files

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: default avatarGuennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: default avatarChris Ball <cjb@laptop.org>
parent a7d1a1eb

drivers/mmc/core/slot-gpio.c

+51 −1
Original line number Diff line number Diff line
@@ -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;

include/linux/mmc/slot-gpio.h

+4 −0
Original line number Diff line number Diff line
@@ -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);