Autodetection of NAND device bus-width was added in generic NAND driver as
part of following commit
        commit 64b37b2a63eb2f80b65c7185f0013f8ffc637ae3
        Author:     Matthieu CASTET <matthieu.cas...@parrot.com>
        AuthorDate: 2012-11-06
        mtd: nand: add NAND_BUSWIDTH_AUTO to autodetect bus width
This patch enables this feature for OMAP2 NAND driver

Signed-off-by: Pekon Gupta <pe...@ti.com>
---
 drivers/mtd/nand/omap2.c | 29 ++++++++++++++++-------------
 1 file changed, 16 insertions(+), 13 deletions(-)

diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c
index 5596368..57a3f51 100644
--- a/drivers/mtd/nand/omap2.c
+++ b/drivers/mtd/nand/omap2.c
@@ -1856,8 +1856,7 @@ 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;
+       nand_chip->options      |= NAND_SKIP_BBTSCAN | NAND_BUSWIDTH_AUTO;
 #ifdef CONFIG_MTD_NAND_OMAP_BCH
        info->of_node           = pdata->of_node;
 #endif
@@ -1904,6 +1903,21 @@ static int omap_nand_probe(struct platform_device *pdev)
                nand_chip->chip_delay = 50;
        }
 
+       /* scan for NAND device connected to chip controller */
+       if (nand_scan_ident(mtd, 1, NULL)) {
+               err = -ENXIO;
+               goto out_release_mem_region;
+       }
+       if ((nand_chip->options & NAND_BUSWIDTH_16) !=
+                       (pdata->devsize & NAND_BUSWIDTH_16)) {
+               pr_err("%s: detected %s device but driver configured for %s\n",
+                       DRIVER_NAME,
+                       (nand_chip->options & NAND_BUSWIDTH_16) ? "x16" : "x8",
+                       (pdata->devsize & NAND_BUSWIDTH_16) ? "x16" : "x8");
+               err = -EINVAL;
+               goto out_release_mem_region;
+       }
+
        switch (pdata->xfer_type) {
        case NAND_OMAP_PREFETCH_POLLED:
                nand_chip->read_buf   = omap_read_buf_pref;
@@ -2011,17 +2025,6 @@ 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) {
 
-- 
1.8.1

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