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authorBin Meng <bmeng.cn@gmail.com>2017-07-23 14:44:37 (GMT)
committerJagan Teki <jagan@amarulasolutions.com>2017-08-16 12:51:50 (GMT)
commit294f2050c438d1e4ab39fd040d394927772048f2 (patch)
tree35acc30c4fc837d434bec4f4af040c5493967f03 /drivers
parent8fc2faefdd8bd950fa6ef615ab63f8ec3b6de7e5 (diff)
downloadu-boot-294f2050c438d1e4ab39fd040d394927772048f2.tar.xz
sf: Preserve QE bit when clearing BP# bits for Macronix flash
On some flash (like Macronix), QE (quad enable) bit is in the same status register as BP# bits, and we need preserve its original value during a reboot cycle as this is required by some platforms (like Intel ICH SPI controller working under descriptor mode). Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Simon Glass <sjg@chromium.org> Reviewed-by: Jagan Teki <jagan@openedev.com> [Refined code for readability] Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/mtd/spi/spi_flash.c22
1 files changed, 18 insertions, 4 deletions
diff --git a/drivers/mtd/spi/spi_flash.c b/drivers/mtd/spi/spi_flash.c
index 0034a28..34f6888 100644
--- a/drivers/mtd/spi/spi_flash.c
+++ b/drivers/mtd/spi/spi_flash.c
@@ -947,11 +947,25 @@ int spi_flash_scan(struct spi_flash *flash)
if (IS_ERR_OR_NULL(info))
return -ENOENT;
- /* Flash powers up read-only, so clear BP# bits */
+ /*
+ * Flash powers up read-only, so clear BP# bits.
+ *
+ * Note on some flash (like Macronix), QE (quad enable) bit is in the
+ * same status register as BP# bits, and we need preserve its original
+ * value during a reboot cycle as this is required by some platforms
+ * (like Intel ICH SPI controller working under descriptor mode).
+ */
if (JEDEC_MFR(info) == SPI_FLASH_CFI_MFR_ATMEL ||
- JEDEC_MFR(info) == SPI_FLASH_CFI_MFR_MACRONIX ||
- JEDEC_MFR(info) == SPI_FLASH_CFI_MFR_SST)
- write_sr(flash, 0);
+ (JEDEC_MFR(info) == SPI_FLASH_CFI_MFR_SST) ||
+ (JEDEC_MFR(info) == SPI_FLASH_CFI_MFR_MACRONIX)) {
+ u8 sr = 0;
+
+ if (JEDEC_MFR(info) == SPI_FLASH_CFI_MFR_MACRONIX) {
+ read_sr(flash, &sr);
+ sr &= STATUS_QEB_MXIC;
+ }
+ write_sr(flash, sr);
+ }
flash->name = info->name;
flash->memory_map = spi->memory_map;