[MTD] m25p80.c erase enhance

This patch adds an erase_block command to enhance erase operation

Signed-off-by: Chen Gong <g.chen@freescale.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c
index b35c3333e210b61878493d3fd052e1228b38d6db..8fbd1b57f60658370dbb6235e082c15189f4bb45 100644 (file)
--- a/drivers/mtd/devices/m25p80.c
+++ b/drivers/mtd/devices/m25p80.c
@@ -39,6 +39,7 @@
 #define        OPCODE_PP               0x02    /* Page program (up to 256 bytes) */
 #define        OPCODE_BE_4K            0x20    /* Erase 4KiB block */
 #define        OPCODE_BE_32K           0x52    /* Erase 32KiB block */
+#define        OPCODE_BE               0xc7    /* Erase whole flash block */
 #define        OPCODE_SE               0xd8    /* Sector erase (usually 64KiB) */
 #define        OPCODE_RDID             0x9f    /* Read JEDEC ID */
 
@@ -161,6 +162,31 @@ static int wait_till_ready(struct m25p *flash)
        return 1;
 }
 
+/*
+ * Erase the whole flash memory
+ *
+ * Returns 0 if successful, non-zero otherwise.
+ */
+static int erase_block(struct m25p *flash)
+{
+       DEBUG(MTD_DEBUG_LEVEL3, "%s: %s %dKiB\n",
+                       flash->spi->dev.bus_id, __func__,
+                       flash->mtd.size / 1024);
+
+       /* Wait until finished previous write command. */
+       if (wait_till_ready(flash))
+               return 1;
+
+       /* Send write enable, then erase commands. */
+       write_enable(flash);
+
+       /* Set up command buffer. */
+       flash->command[0] = OPCODE_BE;
+
+       spi_write(flash->spi, flash->command, 1);
+
+       return 0;
+}
 
 /*
  * Erase one sector of flash memory at offset ``offset'' which is any
@@ -229,15 +255,21 @@ static int m25p80_erase(struct mtd_info *mtd, struct erase_info *instr)
         */
 
        /* now erase those sectors */
-       while (len) {
-               if (erase_sector(flash, addr)) {
-                       instr->state = MTD_ERASE_FAILED;
-                       mutex_unlock(&flash->lock);
-                       return -EIO;
-               }
+       if (len == flash->mtd.size && erase_block(flash)) {
+               instr->state = MTD_ERASE_FAILED;
+               mutex_unlock(&flash->lock);
+               return -EIO;
+       } else {
+               while (len) {
+                       if (erase_sector(flash, addr)) {
+                               instr->state = MTD_ERASE_FAILED;
+                               mutex_unlock(&flash->lock);
+                               return -EIO;
+                       }
 
-               addr += mtd->erasesize;
-               len -= mtd->erasesize;
+                       addr += mtd->erasesize;
+                       len -= mtd->erasesize;
+               }
        }
 
        mutex_unlock(&flash->lock);