[PATCH] mmc: dw_mmc: add support for use_hold_reg

[<dinguyen@altera.com>]

From: Dinh Nguyen <dinguyen@altera.com>

Add code to read value of the use_hold_reg in the cmd register so that
the cmdflags can be correct.

Signed-off-by: Dinh Nguyen <dinguyen@altera.com>
---
 drivers/mmc/host/dw_mmc.c  |    6 ++++++
 drivers/mmc/host/dw_mmc.h  |    1 +
 include/linux/mmc/dw_mmc.h |    3 +++
 3 files changed, 10 insertions(+)

diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index 323c502..490490b 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -265,6 +265,9 @@ static u32 dw_mci_prepare_command(struct mmc_host *mmc, struct mmc_command *cmd)
 	if (drv_data && drv_data->prepare_command)
 		drv_data->prepare_command(slot->host, &cmdr);
 
+	if (slot->host->use_hold_reg)
+		cmdr |= SDMMC_CMD_USE_HOLD_REG;
+
 	return cmdr;
 }
 
@@ -2183,6 +2186,9 @@ int dw_mci_probe(struct dw_mci *host)
 		host->data_shift = 2;
 	}
 
+	/* Get the USE_HOLD_REG */
+	host->use_hold_reg = mci_readl(host, CMD) & SDMMC_CMD_USE_HOLD_REG;
+
 	/* Reset all blocks */
 	if (!mci_wait_reset(host->dev, host))
 		return -ENODEV;
diff --git a/drivers/mmc/host/dw_mmc.h b/drivers/mmc/host/dw_mmc.h
index 53b8fd9..6172900 100644
--- a/drivers/mmc/host/dw_mmc.h
+++ b/drivers/mmc/host/dw_mmc.h
@@ -111,6 +111,7 @@
 #define SDMMC_INT_ERROR			0xbfc2
 /* Command register defines */
 #define SDMMC_CMD_START			BIT(31)
+#define SDMMC_CMD_USE_HOLD_REG		BIT(29)
 #define SDMMC_CMD_CCS_EXP		BIT(23)
 #define SDMMC_CMD_CEATA_RD		BIT(22)
 #define SDMMC_CMD_UPD_CLK		BIT(21)
diff --git a/include/linux/mmc/dw_mmc.h b/include/linux/mmc/dw_mmc.h
index 34be4f4..36cab8a 100644
--- a/include/linux/mmc/dw_mmc.h
+++ b/include/linux/mmc/dw_mmc.h
@@ -187,6 +187,9 @@ struct dw_mci {
 	struct regulator	*vmmc;	/* Power regulator */
 	unsigned long		irq_flags; /* IRQ flags */
 	int			irq;
+
+	/* Set to one for SDR12 and SDR25 */
+	unsigned int use_hold_reg;
 };
 
 /* DMA ops for Internal/External DMAC interface */
-- 
1.7.9.5