ARM: OMAP2+: nand: bch capability check

Capability of bch schemes could be discovered using soc
revision checks. If soc revision indicates that selected
ecc scheme is not supported bail out.

Signed-off-by: Afzal Mohammed <afzal@ti.com>

1 files changed, 24 insertions, 0 deletions

diff --git a/arch/arm/mach-omap2/gpmc-nand.c b/arch/arm/mach-omap2/gpmc-nand.c
index abdb78a95a94..e89a36c8143b 100644
--- a/arch/arm/mach-omap2/gpmc-nand.c
+++ b/arch/arm/mach-omap2/gpmc-nand.c
@@ -90,6 +90,27 @@ static int omap2_nand_gpmc_retime(
         return 0;
 }
 
+static bool __init gpmc_hwecc_bch_capable(enum omap_ecc ecc_opt)
+{
+        /* support only OMAP3 class */
+        if (!cpu_is_omap34xx()) {
+                pr_err("BCH ecc is not supported on this CPU\n");
+                return 0;
+        }
+
+        /*
+         * For now, assume 4-bit mode is only supported on OMAP3630 ES1.x, x>=1.
+         * Other chips may be added if confirmed to work.
+         */
+        if ((ecc_opt == OMAP_ECC_BCH4_CODE_HW) &&
+            (!cpu_is_omap3630() || (GET_OMAP_REVISION() == 0))) {
+                pr_err("BCH 4-bit mode is not supported on this CPU\n");
+                return 0;
+        }
+
+        return 1;
+}
+
 int __init gpmc_nand_init(struct omap_nand_platform_data *gpmc_nand_data,
                           struct gpmc_timings *gpmc_t)
 {
@@ -128,6 +149,9 @@ int __init gpmc_nand_init(struct omap_nand_platform_data *gpmc_nand_data,
 
         gpmc_update_nand_reg(&gpmc_nand_data->reg, gpmc_nand_data->cs);
 
+        if (!gpmc_hwecc_bch_capable(gpmc_nand_data->ecc_opt))
+                return -EINVAL;
+
         err = platform_device_register(&gpmc_nand_device);
         if (err < 0) {
                 dev_err(dev, "Unable to register NAND device\n");