From a70aaa64da2205d32d1c9362d8f5d4be619cd58f Mon Sep 17 00:00:00 2001 From: Doug Anderson Date: Fri, 11 Jan 2013 17:03:50 +0000 Subject: [PATCH] mmc: dw_mmc: Add "disable-wp" device tree property The "disable-wp" property is used to specify that a given SD card slot doesn't have a concept of write protect. This eliminates the need for special case code for SD slots that should never be write protected (like a micro SD slot or a dev board). The dw_mmc driver is special in needing to specify "disable-wp" because the lack of a "wp-gpios" property means to use the special purpose write protect line. On some other mmc devices the lack of "wp-gpios" means that write protect should be disabled. Signed-off-by: Doug Anderson Acked-by: Seungwon Jeon Acked-by: Will Newton Acked-by: Olof Johansson Signed-off-by: Chris Ball --- .../devicetree/bindings/mmc/synopsis-dw-mshc.txt | 12 +++++-- drivers/mmc/host/dw_mmc.c | 41 +++++++++++++++++++++- include/linux/mmc/dw_mmc.h | 9 +++++ 3 files changed, 59 insertions(+), 3 deletions(-) diff --git a/Documentation/devicetree/bindings/mmc/synopsis-dw-mshc.txt b/Documentation/devicetree/bindings/mmc/synopsis-dw-mshc.txt index 06cd32d08..726fd21 100644 --- a/Documentation/devicetree/bindings/mmc/synopsis-dw-mshc.txt +++ b/Documentation/devicetree/bindings/mmc/synopsis-dw-mshc.txt @@ -26,8 +26,16 @@ Required Properties: * bus-width: as documented in mmc core bindings. * wp-gpios: specifies the write protect gpio line. The format of the - gpio specifier depends on the gpio controller. If the write-protect - line is not available, this property is optional. + gpio specifier depends on the gpio controller. If a GPIO is not used + for write-protect, this property is optional. + + * disable-wp: If the wp-gpios property isn't present then (by default) + we'd assume that the write protect is hooked up directly to the + controller's special purpose write protect line (accessible via + the WRTPRT register). However, it's possible that we simply don't + want write protect. In that case specify 'disable-wp'. + NOTE: This property is not required for slots known to always + connect to eMMC or SDIO cards. Optional properties: diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c index 323c502..90f7d99 100644 --- a/drivers/mmc/host/dw_mmc.c +++ b/drivers/mmc/host/dw_mmc.c @@ -74,6 +74,7 @@ struct idmac_desc { * struct dw_mci_slot - MMC slot state * @mmc: The mmc_host representing this slot. * @host: The MMC controller this slot is using. + * @quirks: Slot-level quirks (DW_MCI_SLOT_QUIRK_XXX) * @ctype: Card type for this slot. * @mrq: mmc_request currently being processed or waiting to be * processed, or NULL when the slot is idle. @@ -88,6 +89,8 @@ struct dw_mci_slot { struct mmc_host *mmc; struct dw_mci *host; + int quirks; + u32 ctype; struct mmc_request *mrq; @@ -825,7 +828,13 @@ static int dw_mci_get_ro(struct mmc_host *mmc) struct dw_mci_board *brd = slot->host->pdata; /* Use platform get_ro function, else try on board write protect */ - if (brd->quirks & DW_MCI_QUIRK_NO_WRITE_PROTECT) + + /* + * NOTE: DW_MCI_QUIRK_NO_WRITE_PROTECT will be removed in a future + * patch in the series once reference to it is removed. + */ + if ((brd->quirks & DW_MCI_QUIRK_NO_WRITE_PROTECT) || + (slot->quirks & DW_MCI_SLOT_QUIRK_NO_WRITE_PROTECT)) read_only = 0; else if (brd->get_ro) read_only = brd->get_ro(slot->id); @@ -1785,6 +1794,30 @@ static struct device_node *dw_mci_of_find_slot_node(struct device *dev, u8 slot) return NULL; } +static struct dw_mci_of_slot_quirks { + char *quirk; + int id; +} of_slot_quirks[] = { + { + .quirk = "disable-wp", + .id = DW_MCI_SLOT_QUIRK_NO_WRITE_PROTECT, + }, +}; + +static int dw_mci_of_get_slot_quirks(struct device *dev, u8 slot) +{ + struct device_node *np = dw_mci_of_find_slot_node(dev, slot); + int quirks = 0; + int idx; + + /* get quirks */ + for (idx = 0; idx < ARRAY_SIZE(of_slot_quirks); idx++) + if (of_get_property(np, of_slot_quirks[idx].quirk, NULL)) + quirks |= of_slot_quirks[idx].id; + + return quirks; +} + /* find out bus-width for a given slot */ static u32 dw_mci_of_get_bus_wd(struct device *dev, u8 slot) { @@ -1800,6 +1833,10 @@ static u32 dw_mci_of_get_bus_wd(struct device *dev, u8 slot) return bus_wd; } #else /* CONFIG_OF */ +static int dw_mci_of_get_slot_quirks(struct device *dev, u8 slot) +{ + return 0; +} static u32 dw_mci_of_get_bus_wd(struct device *dev, u8 slot) { return 1; @@ -1828,6 +1865,8 @@ static int dw_mci_init_slot(struct dw_mci *host, unsigned int id) slot->host = host; host->slot[id] = slot; + slot->quirks = dw_mci_of_get_slot_quirks(host->dev, slot->id); + mmc->ops = &dw_mci_ops; mmc->f_min = DIV_ROUND_UP(host->bus_hz, 510); mmc->f_max = host->bus_hz; diff --git a/include/linux/mmc/dw_mmc.h b/include/linux/mmc/dw_mmc.h index 34be4f4..de61de5 100644 --- a/include/linux/mmc/dw_mmc.h +++ b/include/linux/mmc/dw_mmc.h @@ -209,9 +209,18 @@ struct dw_mci_dma_ops { #define DW_MCI_QUIRK_HIGHSPEED BIT(2) /* Unreliable card detection */ #define DW_MCI_QUIRK_BROKEN_CARD_DETECTION BIT(3) + /* Write Protect detection not available */ +/* + * NOTE: DW_MCI_QUIRK_NO_WRITE_PROTECT will be removed in a future + * patch in the series once reference to it is removed. + */ #define DW_MCI_QUIRK_NO_WRITE_PROTECT BIT(4) +/* Slot level quirks */ +/* This slot has no write protect */ +#define DW_MCI_SLOT_QUIRK_NO_WRITE_PROTECT BIT(0) + struct dma_pdata; struct block_settings { -- 2.7.4