NAND: rearrange ONFI revision checking, add ONFI 2.3

This patch sync with Brian's patch on Linux in nand_flash_detect_onfi()

	commit b7b1a29d94c17e4341856381bccb4d17495bea60
	Author: Brian Norris <computersforpeace@gmail.com>
	Date:   Sun Dec 12 00:23:33 2010 -0800

	    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>
Signed-off-by: Florian Fainelli <florian@openwrt.org>

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 3cb92c19c2be441fd66551a291ce68a91b650da1..52f8575aac67f0e1933dabb4c0ce4e304ef26618 100644 (file)
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -2461,20 +2461,24 @@ static int nand_flash_detect_onfi(struct mtd_info *mtd,
 
        /* 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;
+       }
 
        if (!mtd->name)
                mtd->name = p->model;