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

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Gitweb:     http://git.infradead.org/?p=mtd-2.6.git;a=commit;h=b7b1a29d94c17e4341856381bccb4d17495bea60
Commit:     b7b1a29d94c17e4341856381bccb4d17495bea60
Parent:     0b524fb9314dc852d6a029296545ddbb17709a8b
Author:     Brian Norris <computersforpeace at gmail.com>
AuthorDate: Sun Dec 12 00:23:33 2010 -0800
Committer:  David Woodhouse <David.Woodhouse at intel.com>
CommitDate: Thu Jan 6 15:19:20 2011 +0000

    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 at gmail.com>
    Acked-by: Florian Fainelli <ffainelli at freebox.fr>
    Signed-off-by: David Woodhouse <David.Woodhouse at intel.com>
---
 drivers/mtd/nand/nand_base.c |   20 ++++++++++++--------
 1 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index c52ded3..5dd7ae4 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));