[PATCH] mmc: dw_mmc: use the use_hold_reg bit in CMD register

[Jaehoon Chung <jh80.chung@samsung.com>]

This patch is added the use_hold_reg bit in CMD register.

In 2.40a, bit[29] of CMD register is used the use_hold_reg.
Some SoC is affected by this bit.
(This bit means whether use hold register when send data and cmd.
 And related with cclk_in_drv phase)
if set IMPLEMENT_HOLD_REG in HCON register, i think fine that set this
bit by default.

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
---
 drivers/mmc/host/dw_mmc.c  |    9 +++++++++
 drivers/mmc/host/dw_mmc.h  |    1 +
 include/linux/mmc/dw_mmc.h |    1 +
 3 files changed, 11 insertions(+), 0 deletions(-)

diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index 0ed1d28..544a616 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -276,6 +276,13 @@ static void dw_mci_start_command(struct dw_mci *host,
 	mci_writel(host, CMDARG, cmd->arg);
 	wmb();

+	/*
+	 * If use HOLD register,
+	 * CMD and DATA sent to card through HOLD register.
+	 */
+	if (host->use_hold_reg)
+		cmd_flags |= SDMMC_CMD_USE_HOLD_REG;
+
 	mci_writel(host, CMD, cmd_flags | SDMMC_CMD_START);
 }

@@ -1886,6 +1893,8 @@ static int dw_mci_probe(struct platform_device *pdev)
 		host->data_shift = 2;
 	}

+	host->use_hold_reg = (mci_readl(host, HCON) >> 22) & 0x1;
+
 	/* Reset all blocks */
 	if (!mci_wait_reset(&pdev->dev, host)) {
 		ret = -ENODEV;
diff --git a/drivers/mmc/host/dw_mmc.h b/drivers/mmc/host/dw_mmc.h
index bfa3c1c..8c4edca 100644
--- a/drivers/mmc/host/dw_mmc.h
+++ b/drivers/mmc/host/dw_mmc.h
@@ -102,6 +102,7 @@
 #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 6b46819..d6d1515 100644
--- a/include/linux/mmc/dw_mmc.h
+++ b/include/linux/mmc/dw_mmc.h
@@ -147,6 +147,7 @@ struct dw_mci {
 	u32			current_speed;
 	u32			num_slots;
 	u32			fifoth_val;
+	bool			use_hold_reg;
 	struct platform_device	*pdev;
 	struct dw_mci_board	*pdata;
 	struct dw_mci_slot	*slot[MAX_MCI_SLOTS];