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mmc: dw_mmc: Add "disable-wp" device tree property

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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 <dianders@chromium.org>
Acked-by: Seungwon Jeon <tgih.jun@samsung.com>
Acked-by: Will Newton <will.newton@imgtec.com>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Chris Ball <cjb@laptop.org>
This commit is contained in:
Doug Anderson
2013-01-11 17:03:50 +00:00
committed by Chris Ball
parent c148e9ff4b
commit a70aaa64da
3 changed files with 59 additions and 3 deletions
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41
drivers/mmc/host/dw_mmc.c
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@@ -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;