mtd: nand: omap: use DT specified bus-width only for scanning NAND device

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Gitweb:     http://git.infradead.org/?p=mtd-2.6.git;a=commit;h=f18befb57b0779094ac7658fa7be5cf559da835f
Commit:     f18befb57b0779094ac7658fa7be5cf559da835f
Parent:     633deb58e1ecc81486505fe9d3dc2aa3cfbca719
Author:     Pekon Gupta <pekon at ti.com>
AuthorDate: Thu Oct 24 18:20:20 2013 +0530
Committer:  Brian Norris <computersforpeace at gmail.com>
CommitDate: Wed Nov 6 23:33:08 2013 -0800

    mtd: nand: omap: use DT specified bus-width only for scanning NAND device
    
    This patch:
    - calls nand_scan_ident() using bus-width as passed by DT
    - removes double calls to nand_scan_ident(), in case first call fails
      then omap_nand_probe just returns error.
    
    Signed-off-by: Pekon Gupta <pekon at ti.com>
    Tested-by: Ezequiel Garcia <ezequiel.garcia at free-electrons.com>
    Signed-off-by: Brian Norris <computersforpeace at gmail.com>
---
 drivers/mtd/nand/omap2.c | 21 +++++++++------------
 1 file changed, 9 insertions(+), 12 deletions(-)

diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c
index 5596368..f464321 100644
--- a/drivers/mtd/nand/omap2.c
+++ b/drivers/mtd/nand/omap2.c
@@ -1856,7 +1856,6 @@ static int omap_nand_probe(struct platform_device *pdev)
 	mtd->name		= dev_name(&pdev->dev);
 	mtd->owner		= THIS_MODULE;
 	nand_chip		= &info->nand;
-	nand_chip->options	= pdata->devsize;
 	nand_chip->options	|= NAND_SKIP_BBTSCAN;
 #ifdef CONFIG_MTD_NAND_OMAP_BCH
 	info->of_node		= pdata->of_node;
@@ -1904,6 +1903,15 @@ static int omap_nand_probe(struct platform_device *pdev)
 		nand_chip->chip_delay = 50;
 	}
 
+	/* scan NAND device connected to chip controller */
+	nand_chip->options |= pdata->devsize & NAND_BUSWIDTH_16;
+	if (nand_scan_ident(mtd, 1, NULL)) {
+		pr_err("nand device scan failed, may be bus-width mismatch\n");
+		err = -ENXIO;
+		goto out_release_mem_region;
+	}
+
+	/* re-populate low-level callbacks based on xfer modes */
 	switch (pdata->xfer_type) {
 	case NAND_OMAP_PREFETCH_POLLED:
 		nand_chip->read_buf   = omap_read_buf_pref;
@@ -2011,17 +2019,6 @@ static int omap_nand_probe(struct platform_device *pdev)
 		}
 	}
 
-	/* DIP switches on some boards change between 8 and 16 bit
-	 * bus widths for flash.  Try the other width if the first try fails.
-	 */
-	if (nand_scan_ident(mtd, 1, NULL)) {
-		nand_chip->options ^= NAND_BUSWIDTH_16;
-		if (nand_scan_ident(mtd, 1, NULL)) {
-			err = -ENXIO;
-			goto out_release_mem_region;
-		}
-	}
-
 	/* rom code layout */
 	if (pdata->ecc_opt == OMAP_ECC_HAM1_CODE_HW) {