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Commit 55a6ceb2 authored by Doug Anderson's avatar Doug Anderson Committed by Chris Ball
Browse files

mmc: dw_mmc: Handle wp-gpios from device tree 



On some SoCs (like exynos5250) you need to use an external GPIO for
write protect.  Add support for wp-gpios to the core dw_mmc driver
since it could be useful across multiple SoCs.

With this change I am able to make use of the write protect for the
external SD slot on exynos5250-snow.

Signed-off-by: default avatarDoug Anderson <dianders@chromium.org>
Acked-by: default avatarSeungwon Jeon <tgih.jun@samsung.com>
Acked-by: default avatarOlof Johansson <olof@lixom.net>
Signed-off-by: default avatarChris Ball <cjb@laptop.org>
parent 07b24041

drivers/mmc/host/dw_mmc.c

+34 −0
Original line number Diff line number Diff line
@@ -34,6 +34,7 @@ 
#include <linux/regulator/consumer.h>

#include <linux/workqueue.h>

#include <linux/of.h>

#include <linux/of_gpio.h>



#include "dw_mmc.h"
@@ -75,6 +76,7 @@ struct idmac_desc { 
 * @mmc: The mmc_host representing this slot.

 * @host: The MMC controller this slot is using.

 * @quirks: Slot-level quirks (DW_MCI_SLOT_QUIRK_XXX)

 * @wp_gpio: If gpio_is_valid() we'll use this to read write protect.

 * @ctype: Card type for this slot.

 * @mrq: mmc_request currently being processed or waiting to be

 *	processed, or NULL when the slot is idle.
@@ -90,6 +92,7 @@ struct dw_mci_slot { 
	struct dw_mci		*host;



	int			quirks;

	int			wp_gpio;



	u32			ctype;
@@ -838,6 +841,8 @@ static int dw_mci_get_ro(struct mmc_host *mmc) 
		read_only = 0;

	else if (brd->get_ro)

		read_only = brd->get_ro(slot->id);

	else if (gpio_is_valid(slot->wp_gpio))

		read_only = gpio_get_value(slot->wp_gpio);

	else

		read_only =

			mci_readl(slot->host, WRTPRT) & (1 << slot->id) ? 1 : 0;
@@ -1832,6 +1837,29 @@ static u32 dw_mci_of_get_bus_wd(struct device *dev, u8 slot) 
			       " as 1\n");

	return bus_wd;

}



/* find the write protect gpio for a given slot; or -1 if none specified */

static int dw_mci_of_get_wp_gpio(struct device *dev, u8 slot)

{

	struct device_node *np = dw_mci_of_find_slot_node(dev, slot);

	int gpio;



	if (!np)

		return -EINVAL;



	gpio = of_get_named_gpio(np, "wp-gpios", 0);



	/* Having a missing entry is valid; return silently */

	if (!gpio_is_valid(gpio))

		return -EINVAL;



	if (devm_gpio_request(dev, gpio, "dw-mci-wp")) {

		dev_warn(dev, "gpio [%d] request failed\n", gpio);

		return -EINVAL;

	}



	return gpio;

}

#else /* CONFIG_OF */

static int dw_mci_of_get_slot_quirks(struct device *dev, u8 slot)

{
@@ -1845,6 +1873,10 @@ static struct device_node *dw_mci_of_find_slot_node(struct device *dev, u8 slot) 
{

	return NULL;

}

static int dw_mci_of_get_wp_gpio(struct device *dev, u8 slot)

{

	return -EINVAL;

}

#endif /* CONFIG_OF */



static int dw_mci_init_slot(struct dw_mci *host, unsigned int id)
@@ -1962,6 +1994,8 @@ static int dw_mci_init_slot(struct dw_mci *host, unsigned int id) 
	else

		clear_bit(DW_MMC_CARD_PRESENT, &slot->flags);



	slot->wp_gpio = dw_mci_of_get_wp_gpio(host->dev, slot->id);



	mmc_add_host(mmc);



#if defined(CONFIG_DEBUG_FS)