[PATCH v3 01/20] mtd: nand: qcom: program NAND_DEV_CMD_VLD register

[Abhishek Sahu <absahu@codeaurora.org>]

The NAND page read fails without complete boot chain since
NAND_DEV_CMD_VLD value is not proper. The default power on reset
value for this register is

    0xe - ERASE_START_VALID | WRITE_START_VALID | READ_STOP_VALID

The READ_START_VALID should be enabled for sending PAGE_READ
command. READ_STOP_VALID should be cleared since normal NAND
page read does not require READ_STOP command.

Fixes: c76b78d8ec05a ("mtd: nand: Qualcomm NAND controller driver")
Cc: stable@vger.kernel.org
Reviewed-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
---
 drivers/mtd/nand/qcom_nandc.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/nand/qcom_nandc.c b/drivers/mtd/nand/qcom_nandc.c
index 0289f09..7406019 100644
--- a/drivers/mtd/nand/qcom_nandc.c
+++ b/drivers/mtd/nand/qcom_nandc.c
@@ -110,6 +110,10 @@
 
 /* NAND_DEV_CMD_VLD bits */
 #define	READ_START_VLD			0
+#define	READ_STOP_VALID			1
+#define	WRITE_START_VALID		2
+#define	ERASE_START_VALID		3
+#define	SEQ_READ_START_VLD		4
 
 /* NAND_EBI2_ECC_BUF_CFG bits */
 #define	NUM_STEPS			0
@@ -148,6 +152,12 @@
 #define	FETCH_ID			0xb
 #define	RESET_DEVICE			0xd
 
+/* Default Value for NAND_DEV_CMD_VLD */
+#define NAND_DEV_CMD_VLD_VAL		(BIT(READ_START_VLD)	| \
+					 BIT(WRITE_START_VALID)	| \
+					 BIT(ERASE_START_VALID)	| \
+					 BIT(SEQ_READ_START_VLD))
+
 /*
  * the NAND controller performs reads/writes with ECC in 516 byte chunks.
  * the driver calls the chunks 'step' or 'codeword' interchangeably
@@ -1995,13 +2005,14 @@ static int qcom_nandc_setup(struct qcom_nand_controller *nandc)
 {
 	/* kill onenand */
 	nandc_write(nandc, SFLASHC_BURST_CFG, 0);
+	nandc_write(nandc, NAND_DEV_CMD_VLD, NAND_DEV_CMD_VLD_VAL);
 
 	/* enable ADM DMA */
 	nandc_write(nandc, NAND_FLASH_CHIP_SELECT, DM_EN);
 
 	/* save the original values of these registers */
 	nandc->cmd1 = nandc_read(nandc, NAND_DEV_CMD1);
-	nandc->vld = nandc_read(nandc, NAND_DEV_CMD_VLD);
+	nandc->vld = NAND_DEV_CMD_VLD_VAL;
 
 	return 0;
 }
-- 
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