mtd: nand: rearrange ONFI revision checking, add ONFI 2.3

In checking for the ONFI revision, the first conditional (for checking
"unsupported" ONFI) seems unnecessary.  All ONFI revisions should be
backwards-compatible; even if this is not the case on some newer ONFI
revision, it should simply fail the second version-checking if-else block
(i.e., the bit-fields for 1.0, 2.0, etc. would not be set to 1). Thus, we
move our "unsupported" condition after having checked each bit field.

Also, it's simple enough to add a condition for ONFI revision 2.3. Note
that this does *NOT* mean we handle all new features of ONFI versions
above 1.0.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Acked-by: Florian Fainelli <ffainelli@freebox.fr>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 12 insertions, 8 deletions

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index c52ded31a12e..5dd7ae4e4b23 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -2865,20 +2865,24 @@ static int nand_flash_detect_onfi(struct mtd_info *mtd, struct nand_chip *chip,
 
         /* check version */
         val = le16_to_cpu(p->revision);
-        if (val == 1 || val > (1 << 4)) {
-                printk(KERN_INFO "%s: unsupported ONFI version: %d\n",
-                                                                __func__, val);
-                return 0;
-        }
-
-        if (val & (1 << 4))
+        if (val & (1 << 5))
+                chip->onfi_version = 23;
+        else if (val & (1 << 4))
                 chip->onfi_version = 22;
         else if (val & (1 << 3))
                 chip->onfi_version = 21;
         else if (val & (1 << 2))
                 chip->onfi_version = 20;
-        else
+        else if (val & (1 << 1))
                 chip->onfi_version = 10;
+        else
+                chip->onfi_version = 0;
+
+        if (!chip->onfi_version) {
+                printk(KERN_INFO "%s: unsupported ONFI version: %d\n",
+                                                                __func__, val);
+                return 0;
+        }
 
         sanitize_string(p->manufacturer, sizeof(p->manufacturer));
         sanitize_string(p->model, sizeof(p->model));