mtd: bcm47xxsflash: implement erasing support

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 41 insertions, 2 deletions

diff --git a/drivers/mtd/devices/bcm47xxsflash.c b/drivers/mtd/devices/bcm47xxsflash.c
index e9e38877a571..534cb741b107 100644
--- a/drivers/mtd/devices/bcm47xxsflash.c
+++ b/drivers/mtd/devices/bcm47xxsflash.c
@@ -64,6 +64,42 @@ static int bcm47xxsflash_poll(struct bcm47xxsflash *b47s, int timeout)
  * MTD ops
  **************************************************/
 
+static int bcm47xxsflash_erase(struct mtd_info *mtd, struct erase_info *erase)
+{
+        struct bcm47xxsflash *b47s = mtd->priv;
+        int err;
+
+        switch (b47s->type) {
+        case BCM47XXSFLASH_TYPE_ST:
+                bcm47xxsflash_cmd(b47s, OPCODE_ST_WREN);
+                b47s->cc_write(b47s, BCMA_CC_FLASHADDR, erase->addr);
+                /* Newer flashes have "sub-sectors" which can be erased
+                 * independently with a new command: ST_SSE. The ST_SE command
+                 * erases 64KB just as before.
+                 */
+                if (b47s->blocksize < (64 * 1024))
+                        bcm47xxsflash_cmd(b47s, OPCODE_ST_SSE);
+                else
+                        bcm47xxsflash_cmd(b47s, OPCODE_ST_SE);
+                break;
+        case BCM47XXSFLASH_TYPE_ATMEL:
+                b47s->cc_write(b47s, BCMA_CC_FLASHADDR, erase->addr << 1);
+                bcm47xxsflash_cmd(b47s, OPCODE_AT_PAGE_ERASE);
+                break;
+        }
+
+        err = bcm47xxsflash_poll(b47s, HZ);
+        if (err)
+                erase->state = MTD_ERASE_FAILED;
+        else
+                erase->state = MTD_ERASE_DONE;
+
+        if (erase->callback)
+                erase->callback(erase);
+
+        return err;
+}
+
 static int bcm47xxsflash_read(struct mtd_info *mtd, loff_t from, size_t len,
                               size_t *retlen, u_char *buf)
 {
@@ -88,12 +124,15 @@ static void bcm47xxsflash_fill_mtd(struct bcm47xxsflash *b47s)
         mtd->name = "bcm47xxsflash";
         mtd->owner = THIS_MODULE;
         mtd->type = MTD_ROM;
-        mtd->size = b47s->size;
-        mtd->_read = bcm47xxsflash_read;
 
         /* TODO: implement writing support and verify/change following code */
         mtd->flags = MTD_CAP_ROM;
+        mtd->size = b47s->size;
+        mtd->erasesize = b47s->blocksize;
         mtd->writebufsize = mtd->writesize = 1;
+
+        mtd->_erase = bcm47xxsflash_erase;
+        mtd->_read = bcm47xxsflash_read;
 }
 
 /**************************************************