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authorChen Gong <g.chen@freescale.com>2008-11-26 05:23:57 -0500
committerDavid Woodhouse <David.Woodhouse@intel.com>2008-11-26 05:24:27 -0500
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 6188fd4ddcc0..6659b2275c0c 100644
--- a/drivers/mtd/devices/m25p80.c
+++ b/drivers/mtd/devices/m25p80.c
@@ -37,9 +37,9 @@
37#define OPCODE_NORM_READ 0x03 /* Read data bytes (low frequency) */ 37#define OPCODE_NORM_READ 0x03 /* Read data bytes (low frequency) */
38#define OPCODE_FAST_READ 0x0b /* Read data bytes (high frequency) */ 38#define OPCODE_FAST_READ 0x0b /* Read data bytes (high frequency) */
39#define OPCODE_PP 0x02 /* Page program (up to 256 bytes) */ 39#define OPCODE_PP 0x02 /* Page program (up to 256 bytes) */
40#define OPCODE_BE_4K 0x20 /* Erase 4KiB block */ 40#define OPCODE_BE_4K 0x20 /* Erase 4KiB block */
41#define OPCODE_BE_32K 0x52 /* Erase 32KiB block */ 41#define OPCODE_BE_32K 0x52 /* Erase 32KiB block */
42#define OPCODE_BE 0xc7 /* Erase whole flash block */ 42#define OPCODE_CHIP_ERASE 0xc7 /* Erase whole flash chip */
43#define OPCODE_SE 0xd8 /* Sector erase (usually 64KiB) */ 43#define OPCODE_SE 0xd8 /* Sector erase (usually 64KiB) */
44#define OPCODE_RDID 0x9f /* Read JEDEC ID */ 44#define OPCODE_RDID 0x9f /* Read JEDEC ID */
45 45
@@ -167,7 +167,7 @@ static int wait_till_ready(struct m25p *flash)
167 * 167 *
168 * Returns 0 if successful, non-zero otherwise. 168 * Returns 0 if successful, non-zero otherwise.
169 */ 169 */
170static int erase_block(struct m25p *flash) 170static int erase_chip(struct m25p *flash)
171{ 171{
172 DEBUG(MTD_DEBUG_LEVEL3, "%s: %s %dKiB\n", 172 DEBUG(MTD_DEBUG_LEVEL3, "%s: %s %dKiB\n",
173 flash->spi->dev.bus_id, __func__, 173 flash->spi->dev.bus_id, __func__,
@@ -181,7 +181,7 @@ static int erase_block(struct m25p *flash)
181 write_enable(flash); 181 write_enable(flash);
182 182
183 /* Set up command buffer. */ 183 /* Set up command buffer. */
184 flash->command[0] = OPCODE_BE; 184 flash->command[0] = OPCODE_CHIP_ERASE;
185 185
186 spi_write(flash->spi, flash->command, 1); 186 spi_write(flash->spi, flash->command, 1);
187 187
@@ -250,15 +250,18 @@ static int m25p80_erase(struct mtd_info *mtd, struct erase_info *instr)
250 250
251 mutex_lock(&flash->lock); 251 mutex_lock(&flash->lock);
252 252
253 /* REVISIT in some cases we could speed up erasing large regions 253 /* whole-chip erase? */
254 * by using OPCODE_SE instead of OPCODE_BE_4K 254 if (len == flash->mtd.size && erase_chip(flash)) {
255 */
256
257 /* now erase those sectors */
258 if (len == flash->mtd.size && erase_block(flash)) {
259 instr->state = MTD_ERASE_FAILED; 255 instr->state = MTD_ERASE_FAILED;
260 mutex_unlock(&flash->lock); 256 mutex_unlock(&flash->lock);
261 return -EIO; 257 return -EIO;
258
259 /* REVISIT in some cases we could speed up erasing large regions
260 * by using OPCODE_SE instead of OPCODE_BE_4K. We may have set up
261 * to use "small sector erase", but that's not always optimal.
262 */
263
264 /* "sector"-at-a-time erase */
262 } else { 265 } else {
263 while (len) { 266 while (len) {
264 if (erase_sector(flash, addr)) { 267 if (erase_sector(flash, addr)) {