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authorZheng Bao <fishbaozi@gmail.com>2012-11-27 18:08:53 +0800
committerPatrick Georgi <patrick@georgi-clan.de>2012-11-27 11:03:52 +0100
commitb8117b062266eda6b8ac9a8b60881a99f0323a48 (patch)
treec89c3f217e8e6c93a468876600e2993fe5ae3af0
parent1a5301dd3373e7def334fc34787f79073f49029a (diff)
downloadcoreboot-b8117b062266eda6b8ac9a8b60881a99f0323a48.tar.xz
SPI/SST: Add OpCode Enable-Write-Status-Register (EWSR)
For SST chips, the Write-Status-Register instruction must be executed immediately after the execution of the Enable-Write-Status-Register instruction, instead of Write-Enable. Change-Id: I4b3473cd671829def3bd1641ececcf8d9dad4a56 Signed-off-by: Zheng Bao <zheng.bao@amd.com> Signed-off-by: zbao <fishbaozi@gmail.com> Reviewed-on: http://review.coreboot.org/1919 Tested-by: build bot (Jenkins) Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net> Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>
-rw-r--r--src/drivers/spi/sst.c12
1 files changed, 11 insertions, 1 deletions
diff --git a/src/drivers/spi/sst.c b/src/drivers/spi/sst.c
index 8245f726a7..ebeb441d1e 100644
--- a/src/drivers/spi/sst.c
+++ b/src/drivers/spi/sst.c
@@ -20,6 +20,7 @@
#define CMD_SST_WRDI 0x04 /* Write Disable */
#define CMD_SST_RDSR 0x05 /* Read Status Register */
#define CMD_SST_WRSR 0x01 /* Write Status Register */
+#define CMD_SST_EWSR 0x50 /* Enable Write Status Register */
#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 */
@@ -101,6 +102,15 @@ sst_enable_writing(struct spi_flash *flash)
}
static int
+sst_enable_writing_status(struct spi_flash *flash)
+{
+ int ret = spi_flash_cmd(flash->spi, CMD_SST_EWSR, NULL, 0);
+ if (ret)
+ printk(BIOS_WARNING, "SF: Enabling Write Status failed\n");
+ return ret;
+}
+
+static int
sst_disable_writing(struct spi_flash *flash)
{
int ret = spi_flash_cmd(flash->spi, CMD_SST_WRDI, NULL, 0);
@@ -212,7 +222,7 @@ sst_unlock(struct spi_flash *flash)
int ret;
u8 cmd, status;
- ret = sst_enable_writing(flash);
+ ret = sst_enable_writing_status(flash);
if (ret)
return ret;