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 diand...@chromium.org
Acked-by: Seungwon Jeon tgih@samsung.com
---
Changes in v4:
- Added a comment about the fact that a future patch will remove the
controller-level quirk; the comments and quirk will be removed in
the future change mmc: dw_mmc: Remove
DW_MCI_QUIRK_NO_WRITE_PROTECT. I split the patch up this way to
preserve bisectability and also to keep changes logically separated.
I will squash if desired.
Changes in v3:
- New for this version of the patch series. Chose disable-wp rather
than the discussed broken-internal-wp since it mapped more cleanly
to an existing quirk (and the only reason to specify that the
internal wp is broken is if you're disabling the write protect
anyway).
.../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
