3 files changed, 18 insertions, 13 deletions

diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
index 417a8950cf49..16634df2e39a 100644
--- a/drivers/mtd/nand/denali.c
+++ b/drivers/mtd/nand/denali.c
@@ -419,17 +419,12 @@ static void find_valid_banks(struct denali_nand_info *denali)
 static void detect_max_banks(struct denali_nand_info *denali)
 {
         uint32_t features = ioread32(denali->flash_reg + FEATURES);
-        /*
-         * Read the revision register, so we can calculate the max_banks
-         * properly: the encoding changed from rev 5.0 to 5.1
-         */
-        u32 revision = MAKE_COMPARABLE_REVISION(
-                                ioread32(denali->flash_reg + REVISION));
 
-        if (revision < REVISION_5_1)
-                denali->max_banks = 2 << (features & FEATURES__N_BANKS);
-        else
-                denali->max_banks = 1 << (features & FEATURES__N_BANKS);
+        denali->max_banks = 1 << (features & FEATURES__N_BANKS);
+
+        /* the encoding changed from rev 5.0 to 5.1 */
+        if (denali->revision < 0x0501)
+                denali->max_banks <<= 1;
 }
 
 static uint16_t denali_nand_timing_set(struct denali_nand_info *denali)
@@ -1320,6 +1315,14 @@ static void denali_cmdfunc(struct mtd_info *mtd, unsigned int cmd, int col,
 static void denali_hw_init(struct denali_nand_info *denali)
 {
         /*
+         * The REVISION register may not be reliable.  Platforms are allowed to
+         * override it.
+         */
+        if (!denali->revision)
+                denali->revision =
+                                swab16(ioread32(denali->flash_reg + REVISION));
+
+        /*
          * tell driver how many bit controller will skip before
          * writing ECC code in OOB, this register may be already
          * set by firmware. So we read this value out.
diff --git a/drivers/mtd/nand/denali.h b/drivers/mtd/nand/denali.h
index 1f413d05a010..ec004850652a 100644
--- a/drivers/mtd/nand/denali.h
+++ b/drivers/mtd/nand/denali.h
@@ -179,8 +179,6 @@
 
 #define REVISION                                0x370
 #define     REVISION__VALUE                             0xffff
-#define MAKE_COMPARABLE_REVISION(x)             swab16((x) & REVISION__VALUE)
-#define REVISION_5_1                            0x00000501
 
 #define ONFI_DEVICE_FEATURES                    0x380
 #define     ONFI_DEVICE_FEATURES__VALUE                 0x003f
@@ -343,6 +341,7 @@ struct denali_nand_info {
         int devnum;     /* represent how many nands connected */
         int bbtskipbytes;
         int max_banks;
+        unsigned int revision;
         unsigned int caps;
 };
 
diff --git a/drivers/mtd/nand/denali_dt.c b/drivers/mtd/nand/denali_dt.c
index ada38636122c..df9ef36cc2ce 100644
--- a/drivers/mtd/nand/denali_dt.c
+++ b/drivers/mtd/nand/denali_dt.c
@@ -30,6 +30,7 @@ struct denali_dt {
 };
 
 struct denali_dt_data {
+        unsigned int revision;
         unsigned int caps;
 };
 
@@ -60,8 +61,10 @@ static int denali_dt_probe(struct platform_device *pdev)
         denali = &dt->denali;
 
         data = of_device_get_match_data(&pdev->dev);
-        if (data)
+        if (data) {
+                denali->revision = data->revision;
                 denali->caps = data->caps;
+        }
 
         denali->platform = DT;
         denali->dev = &pdev->dev;