[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>

1 files changed, 40 insertions, 8 deletions

diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c
index b35c3333e210..8fbd1b57f606 100644
--- 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);