[PATCH v2 4/6] mmc: dw_mmc: add quirk to indicate missing write protect line

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If the write protect pad of the controller is not connected to the write
protect pin of the slot, the driver should be notified of this condition
so that incorrect check for write protection by reading the WRTORT
register can avoided. The get_ro platform callback can be used for in
such cases, but with device tree support enabled, such platform callbacks
cannot be supported.

Add a new quirk for notifying the driver about the missing write protect
line so the driver can assume that the card write protection is disabled.

Signed-off-by: Thomas Abraham <thomas.abraham@xxxxxxxxxx>
Acked-by: Will Newton <will.newton@xxxxxxxxxx>
 drivers/mmc/host/dw_mmc.c  |    4 +++-
 include/linux/mmc/dw_mmc.h |    3 ++-
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index eb5fa59..c862b7f 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -812,7 +812,9 @@ 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->get_ro)
+	if (brd->quirks & DW_MCI_QUIRK_NO_WRITE_PROTECT)
+		read_only = 0;
+	else if (brd->get_ro)
 		read_only = brd->get_ro(slot->id);
 		read_only =
diff --git a/include/linux/mmc/dw_mmc.h b/include/linux/mmc/dw_mmc.h
index 787ad56..b72e4aa 100644
--- a/include/linux/mmc/dw_mmc.h
+++ b/include/linux/mmc/dw_mmc.h
@@ -205,7 +205,8 @@ struct dw_mci_dma_ops {
 /* Unreliable card detection */
+/* Write Protect detection not available */
 struct dma_pdata;

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