Patchwork [U-Boot] driver/mtd/ifc: Read Status while programming NAND flash

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Submitter Prabhakar Kushwaha
Date Oct. 3, 2013, 6:05 a.m.
Message ID <1380780335-6570-1-git-send-email-prabhakar@freescale.com>
Download mbox | patch
Permalink /patch/280223/
State Accepted
Delegated to: Scott Wood
Headers show

Comments

Prabhakar Kushwaha - Oct. 3, 2013, 6:05 a.m.
as per controller description,
  "While programming a NAND flash, status read should never skipped.
   Because it may happen that a new command is issued to the NAND Flash,
   even when the device has not yet finished processing the previous request.
   This may result in unpredictable behaviour."

IFC controller never polls for R/B signal after command send. It just return
control to software. This behaviour may not occur with NAND flash access.
because new commands are sent after polling R/B signal. But it may happen
in scenario where GPCM-ASIC and NAND flash device are working simultaneously.

Update the controller driver to take care of this requirement

Signed-off-by: Prabhakar Kushwaha <prabhakar@freescale.com>
---
 drivers/mtd/nand/fsl_ifc_nand.c |   21 ++++++++++++++++-----
 1 file changed, 16 insertions(+), 5 deletions(-)

Patch

diff --git a/drivers/mtd/nand/fsl_ifc_nand.c b/drivers/mtd/nand/fsl_ifc_nand.c
index cfed549..49b63af 100644
--- a/drivers/mtd/nand/fsl_ifc_nand.c
+++ b/drivers/mtd/nand/fsl_ifc_nand.c
@@ -491,20 +491,27 @@  static void fsl_ifc_cmdfunc(struct mtd_info *mtd, unsigned int command,
 		if (mtd->writesize > 512) {
 			nand_fcr0 =
 				(NAND_CMD_SEQIN << IFC_NAND_FCR0_CMD0_SHIFT) |
-				(NAND_CMD_PAGEPROG << IFC_NAND_FCR0_CMD1_SHIFT);
+				(NAND_CMD_STATUS << IFC_NAND_FCR0_CMD1_SHIFT) |
+				(NAND_CMD_PAGEPROG << IFC_NAND_FCR0_CMD2_SHIFT);
 
 			out_be32(&ifc->ifc_nand.nand_fir0,
 				 (IFC_FIR_OP_CW0 << IFC_NAND_FIR0_OP0_SHIFT) |
 				 (IFC_FIR_OP_CA0 << IFC_NAND_FIR0_OP1_SHIFT) |
 				 (IFC_FIR_OP_RA0 << IFC_NAND_FIR0_OP2_SHIFT) |
 				 (IFC_FIR_OP_WBCD  << IFC_NAND_FIR0_OP3_SHIFT) |
-				 (IFC_FIR_OP_CW1 << IFC_NAND_FIR0_OP4_SHIFT));
-			out_be32(&ifc->ifc_nand.nand_fir1, 0);
+				 (IFC_FIR_OP_CMD2 << IFC_NAND_FIR0_OP4_SHIFT));
+			out_be32(&ifc->ifc_nand.nand_fir1,
+				 (IFC_FIR_OP_CW1 << IFC_NAND_FIR1_OP5_SHIFT) |
+				 (IFC_FIR_OP_RDSTAT <<
+					IFC_NAND_FIR1_OP6_SHIFT) |
+				 (IFC_FIR_OP_NOP << IFC_NAND_FIR1_OP7_SHIFT));
 		} else {
 			nand_fcr0 = ((NAND_CMD_PAGEPROG <<
 					IFC_NAND_FCR0_CMD1_SHIFT) |
 				    (NAND_CMD_SEQIN <<
-					IFC_NAND_FCR0_CMD2_SHIFT));
+					IFC_NAND_FCR0_CMD2_SHIFT) |
+				    (NAND_CMD_STATUS <<
+					IFC_NAND_FCR0_CMD3_SHIFT));
 
 			out_be32(&ifc->ifc_nand.nand_fir0,
 				 (IFC_FIR_OP_CW0 << IFC_NAND_FIR0_OP0_SHIFT) |
@@ -513,7 +520,11 @@  static void fsl_ifc_cmdfunc(struct mtd_info *mtd, unsigned int command,
 				 (IFC_FIR_OP_RA0 << IFC_NAND_FIR0_OP3_SHIFT) |
 				 (IFC_FIR_OP_WBCD << IFC_NAND_FIR0_OP4_SHIFT));
 			out_be32(&ifc->ifc_nand.nand_fir1,
-				 (IFC_FIR_OP_CW1 << IFC_NAND_FIR1_OP5_SHIFT));
+				 (IFC_FIR_OP_CMD1 << IFC_NAND_FIR1_OP5_SHIFT) |
+				 (IFC_FIR_OP_CW3 << IFC_NAND_FIR1_OP6_SHIFT) |
+				 (IFC_FIR_OP_RDSTAT <<
+					IFC_NAND_FIR1_OP7_SHIFT) |
+				 (IFC_FIR_OP_NOP << IFC_NAND_FIR1_OP8_SHIFT));
 
 			if (column >= mtd->writesize)
 				nand_fcr0 |=