From 55a6ceb2d5b845f198bcd76aa18910e05a47d0c2 Mon Sep 17 00:00:00 2001 From: Doug Anderson Date: Fri, 11 Jan 2013 17:03:53 +0000 Subject: [PATCH] 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: Doug Anderson Acked-by: Seungwon Jeon Acked-by: Olof Johansson Signed-off-by: Chris Ball --- drivers/mmc/host/dw_mmc.c | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c index 90f7d99..df62079 100644 --- a/drivers/mmc/host/dw_mmc.c +++ b/drivers/mmc/host/dw_mmc.c @@ -34,6 +34,7 @@ #include #include #include +#include #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) -- 2.7.4