mtd: nand: denali: max_banks calculation changed in revision 5.1

Read Denali hardware revision number and use it to
calculate max_banks,  The encoding of max_banks changed
in Denali revision 5.1.

Signed-off-by: Graham Moore <grmoore@opensource.altera.com>
[Brian: parentheses around macro arg]
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

2 files changed, 12 insertions, 1 deletions

diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
index 7b6186ffe3ac..43c0771c587c 100644
--- a/drivers/mtd/nand/denali.c
+++ b/drivers/mtd/nand/denali.c
@@ -458,8 +458,17 @@ 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));
 
-        denali->max_banks = 2 << (features & FEATURES__N_BANKS);
+        if (revision < REVISION_5_1)
+                denali->max_banks = 2 << (features & FEATURES__N_BANKS);
+        else
+                denali->max_banks = 1 << (features & FEATURES__N_BANKS);
 }
 
 static void detect_partition_feature(struct denali_nand_info *denali)
diff --git a/drivers/mtd/nand/denali.h b/drivers/mtd/nand/denali.h
index 145bf88930e8..4b12cd302819 100644
--- a/drivers/mtd/nand/denali.h
+++ b/drivers/mtd/nand/denali.h
@@ -178,6 +178,8 @@
 
 #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