drivers/spi/sst: remove unnecessary byte programming

The SST25VF064C supports page programming mode like other spi flash
parts in that there isn't an offset requirement. Remove this
check and single byte program because CMD_SST_BP (0x2) is the
same as page programming command. Lastly, for clariy purposes provide
a CMD_SST_PP to explicitly indicate page programming despite the
values (0x2) being the same as byte programming for the other parts.

Change-Id: I84eea0b044ccac6c6f26ea4cb42f4c13cf8f5173
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/37959
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Marshall Dawson <marshalldawson3rd@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

1 files changed, 2 insertions, 20 deletions

diff --git a/src/drivers/spi/sst.c b/src/drivers/spi/sst.c
index 6223cf98da..499db3550b 100644
--- a/src/drivers/spi/sst.c
+++ b/src/drivers/spi/sst.c
@@ -32,6 +32,7 @@
 #define CMD_SST_READ		0x03	/* Read Data Bytes */
 #define CMD_SST_FAST_READ	0x0b	/* Read Data Bytes at Higher Speed */
 #define CMD_SST_BP		0x02	/* Byte Program */
+#define CMD_SST_PP		0x02	/* Page Program */
 #define CMD_SST_AAI_WP		0xAD	/* Auto Address Increment Word Program */
 #define CMD_SST_SE		0x20	/* Sector Erase */
 
@@ -197,30 +198,12 @@ static int sst_write_256(const struct spi_flash *flash, u32 offset, size_t len,
 
 	page_size = 256;
 
-	/* If the data is not word aligned, write out leading single byte */
-	actual = offset % 2;
-	if (actual) {
-		ret = sst_byte_write(flash, offset, buf);
-		if (ret)
-			goto done;
-	}
-	offset += actual;
-
-	ret = sst_enable_writing(flash);
-	if (ret)
-		goto done;
-
-	cmd[0] = CMD_SST_AAI_WP;
-	cmd[1] = offset >> 16;
-	cmd[2] = offset >> 8;
-	cmd[3] = offset;
-
 	for (actual = 0; actual < len; actual += chunk_len) {
 		byte_addr = offset % page_size;
 		chunk_len = MIN(len - actual, page_size - byte_addr);
 		chunk_len = spi_crop_chunk(&flash->spi, sizeof(cmd), chunk_len);
 
-		cmd[0] = CMD_SST_BP;
+		cmd[0] = CMD_SST_PP;
 		cmd[1] = (offset >> 16) & 0xff;
 		cmd[2] = (offset >> 8) & 0xff;
 		cmd[3] = offset & 0xff;
@@ -251,7 +234,6 @@ static int sst_write_256(const struct spi_flash *flash, u32 offset, size_t len,
 		offset += chunk_len;
 	}
 
-done:
 #if CONFIG(DEBUG_SPI_FLASH)
 	printk(BIOS_SPEW, "SF: SST: program %s %zu bytes @ 0x%lx\n",
 	      ret ? "failure" : "success", len, (unsigned long)offset - actual);