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authorChen Gong <g.chen@freescale.com>2008-11-26 10:23:57 +0000
committerDavid Woodhouse <David.Woodhouse@intel.com>2008-11-26 10:24:27 +0000
commit7854643a91eade84112dca9768eeb8d32463d101 (patch)
tree4d905d09f1e4c37929f50f612f8b12e7ea0f6496 /drivers/mtd
parent9168ab861ae3eb8942da61d884a5c1980ba98a5f (diff)
[MTD] m25p80: chip erase != block erase != sector erase
This fixes broken terminology added in the "m25p80.c erase enhance" patch, which added a chip erase command but called it "block erase". There are already two block erase commands; blocks are 4KiB or 32KiB. There's also a sector erase (usually 64 KiB). Chip erase typically covers Megabytes. OPCODE_BE ==> OPCODE_CHIP_ERASE erase_block ==> erase_chip [dbrownell@users.sourceforge.net: update sector erase comments too ] Signed-off-by: Chen Gong <clumsycg@gmail.com> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Diffstat (limited to 'drivers/mtd')
-rw-r--r--drivers/mtd/devices/m25p80.c23
1 files changed, 13 insertions, 10 deletions
diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c
index 6188fd4ddcc..6659b2275c0 100644
--- a/drivers/mtd/devices/m25p80.c
+++ b/drivers/mtd/devices/m25p80.c
@@ -37,9 +37,9 @@
#define OPCODE_NORM_READ 0x03 /* Read data bytes (low frequency) */
#define OPCODE_FAST_READ 0x0b /* Read data bytes (high frequency) */
#define OPCODE_PP 0x02 /* Page program (up to 256 bytes) */
-#define OPCODE_BE_4K 0x20 /* Erase 4KiB block */
+#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_CHIP_ERASE 0xc7 /* Erase whole flash chip */
#define OPCODE_SE 0xd8 /* Sector erase (usually 64KiB) */
#define OPCODE_RDID 0x9f /* Read JEDEC ID */
@@ -167,7 +167,7 @@ static int wait_till_ready(struct m25p *flash)
*
* Returns 0 if successful, non-zero otherwise.
*/
-static int erase_block(struct m25p *flash)
+static int erase_chip(struct m25p *flash)
{
DEBUG(MTD_DEBUG_LEVEL3, "%s: %s %dKiB\n",
flash->spi->dev.bus_id, __func__,
@@ -181,7 +181,7 @@ static int erase_block(struct m25p *flash)
write_enable(flash);
/* Set up command buffer. */
- flash->command[0] = OPCODE_BE;
+ flash->command[0] = OPCODE_CHIP_ERASE;
spi_write(flash->spi, flash->command, 1);
@@ -250,15 +250,18 @@ static int m25p80_erase(struct mtd_info *mtd, struct erase_info *instr)
mutex_lock(&flash->lock);
- /* REVISIT in some cases we could speed up erasing large regions
- * by using OPCODE_SE instead of OPCODE_BE_4K
- */
-
- /* now erase those sectors */
- if (len == flash->mtd.size && erase_block(flash)) {
+ /* whole-chip erase? */
+ if (len == flash->mtd.size && erase_chip(flash)) {
instr->state = MTD_ERASE_FAILED;
mutex_unlock(&flash->lock);
return -EIO;
+
+ /* REVISIT in some cases we could speed up erasing large regions
+ * by using OPCODE_SE instead of OPCODE_BE_4K. We may have set up
+ * to use "small sector erase", but that's not always optimal.
+ */
+
+ /* "sector"-at-a-time erase */
} else {
while (len) {
if (erase_sector(flash, addr)) {