]> pilppa.org Git - linux-2.6-omap-h63xx.git/blobdiff - drivers/mtd/nand/nand_base.c
[MTD] [NAND] nandsim: allow for 64-bit size
[linux-2.6-omap-h63xx.git] / drivers / mtd / nand / nand_base.c
index e29c1da7f56e82530a987beb96ab84a735a2b637..ba1bdf787323190377c20aa239317ee278769b5b 100644 (file)
@@ -89,7 +89,7 @@ static int nand_do_write_oob(struct mtd_info *mtd, loff_t to,
                             struct mtd_oob_ops *ops);
 
 /*
- * For devices which display every fart in the system on a seperate LED. Is
+ * For devices which display every fart in the system on a separate LED. Is
  * compiled away when LED support is disabled.
  */
 DEFINE_LED_TRIGGER(nand_led_trigger);
@@ -2229,6 +2229,7 @@ static struct nand_flash_dev *nand_get_flash_type(struct mtd_info *mtd,
 {
        struct nand_flash_dev *type = NULL;
        int i, dev_id, maf_idx;
+       int tmp_id, tmp_manf;
 
        /* Select the device */
        chip->select_chip(mtd, 0);
@@ -2240,6 +2241,26 @@ static struct nand_flash_dev *nand_get_flash_type(struct mtd_info *mtd,
        *maf_id = chip->read_byte(mtd);
        dev_id = chip->read_byte(mtd);
 
+       /* Try again to make sure, as some systems the bus-hold or other
+        * interface concerns can cause random data which looks like a
+        * possibly credible NAND flash to appear. If the two results do
+        * not match, ignore the device completely.
+        */
+
+       chip->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
+
+       /* Read manufacturer and device IDs */
+
+       tmp_manf = chip->read_byte(mtd);
+       tmp_id = chip->read_byte(mtd);
+
+       if (tmp_manf != *maf_id || tmp_id != dev_id) {
+               printk(KERN_INFO "%s: second ID read did not match "
+                      "%02x,%02x against %02x,%02x\n", __func__,
+                      *maf_id, dev_id, tmp_manf, tmp_id);
+               return ERR_PTR(-ENODEV);
+       }
+
        /* Lookup the flash id */
        for (i = 0; nand_flash_ids[i].name != NULL; i++) {
                if (dev_id == nand_flash_ids[i].id) {
@@ -2469,8 +2490,12 @@ int nand_scan_tail(struct mtd_info *mtd)
                        chip->ecc.write_oob = nand_write_oob_std;
 
        case NAND_ECC_HW_SYNDROME:
-               if (!chip->ecc.calculate || !chip->ecc.correct ||
-                   !chip->ecc.hwctl) {
+               if ((!chip->ecc.calculate || !chip->ecc.correct ||
+                    !chip->ecc.hwctl) &&
+                   (!chip->ecc.read_page ||
+                    chip->ecc.read_page == nand_read_page_hwecc ||
+                    !chip->ecc.write_page ||
+                    chip->ecc.write_page == nand_write_page_hwecc)) {
                        printk(KERN_WARNING "No ECC functions supplied, "
                               "Hardware ECC not possible\n");
                        BUG();