[PATCH] Enable sector erase function for selected ST M50 chips.

[Stefan Tauner]

Affected chips: M50FLW040A, M50FLW040B, M50FLW080A, M50FLW080B.

Signed-off-by: Stefan Tauner <[e-mail]>
---
 flashchips.c |  8 ++++----
 stm50.c      | 24 ++++++++++++++++++------
 2 files changed, 22 insertions(+), 10 deletions(-)

diff --git a/flashchips.c b/flashchips.c
index b83f32c..9c688e6 100644
--- a/flashchips.c
+++ b/flashchips.c
@@ -10766,7 +10766,7 @@ const struct flashchip flashchips[] = {
 					{4 * 1024, 16}, /* sector */
 					{4 * 1024, 16}, /* sector */
 				},
-				.block_erase = NULL,
+				.block_erase = erase_sector_stm50,
 			}, {
 				.eraseblocks = { {64 * 1024, 8}, },
 				.block_erase = erase_block_82802ab,
@@ -10799,7 +10799,7 @@ const struct flashchip flashchips[] = {
 					{64 * 1024, 5}, /* block */
 					{4 * 1024, 16}, /* sector */
 				},
-				.block_erase = NULL,
+				.block_erase = erase_sector_stm50,
 			}, {
 				.eraseblocks = { {64 * 1024, 8}, },
 				.block_erase = erase_block_82802ab,
@@ -10832,7 +10832,7 @@ const struct flashchip flashchips[] = {
 					{4 * 1024, 16}, /* sector */
 					{4 * 1024, 16}, /* sector */
 				},
-				.block_erase = NULL,
+				.block_erase = erase_sector_stm50,
 			}, {
 				.eraseblocks = { {64 * 1024, 16}, },
 				.block_erase = erase_block_82802ab,
@@ -10865,7 +10865,7 @@ const struct flashchip flashchips[] = {
 					{64 * 1024, 13}, /* block */
 					{4 * 1024, 16}, /* sector */
 				},
-				.block_erase = NULL,
+				.block_erase = erase_sector_stm50,
 			}, {
 				.eraseblocks = { {64 * 1024, 16}, },
 				.block_erase = erase_block_82802ab,
diff --git a/stm50.c b/stm50.c
index f6c30a9..7e77e09 100644
--- a/stm50.c
+++ b/stm50.c
@@ -83,10 +83,9 @@ int unlock_stm50_uniform(struct flashctx *flash)
 	return 0;
 }
 
-/* This function is unused. */
-int erase_sector_stm50(struct flashctx *flash, unsigned int sector, unsigned int sectorsize)
+static int stm50_erase_sector(struct flashctx *flash, unsigned int addr)
 {
-	chipaddr bios = flash->virtual_memory + sector;
+	chipaddr bios = flash->virtual_memory + addr;
 
 	// clear status register
 	chip_writeb(flash, 0x50, bios);
@@ -95,8 +94,21 @@ int erase_sector_stm50(struct flashctx *flash, unsigned int sector, unsigned int
 	chip_writeb(flash, 0xd0, bios);
 	programmer_delay(10);
 
-	wait_82802ab(flash);
+	uint8_t status = wait_82802ab(flash);
+	print_status_82802ab(status);
 
-	/* FIXME: Check the status register for errors. */
-	return 0;
+	return status == 0x80;
+}
+
+/* Some ST M50* chips do support erasing of sectors. This function will derive the erase function to use from
+ * the length of the of the block. For calls that apparently do not address a sector (but a block) we just call
+ * the block erase function instead. FIXME: This duplicates the behavior of the remaining erasers for blocks and
+ * might be fixed when flashrom supports multiple functions per eraser or erasers that do erase parts of the
+ * chip only. */
+int erase_sector_stm50(struct flashctx *flash, unsigned int addr, unsigned int len)
+{
+	if (len == 4096)
+		return stm50_erase_sector(flash, addr);
+	else
+		return erase_block_82802ab(flash, addr, len);
 }
-- 
Kind regards, Stefan Tauner