diff options
| author | Bin Meng <bmeng.cn@gmail.com> | 2017-07-23 07:44:37 -0700 |
|---|---|---|
| committer | Jagan Teki <jagan@amarulasolutions.com> | 2017-08-16 18:21:50 +0530 |
| commit | 294f2050c438d1e4ab39fd040d394927772048f2 (patch) | |
| tree | 35acc30c4fc837d434bec4f4af040c5493967f03 | |
| parent | 8fc2faefdd8bd950fa6ef615ab63f8ec3b6de7e5 (diff) | |
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>
| -rw-r--r-- | drivers/mtd/spi/spi_flash.c | 22 |
1 files changed, 18 insertions, 4 deletions
diff --git a/drivers/mtd/spi/spi_flash.c b/drivers/mtd/spi/spi_flash.c index 0034a28d5f..34f68881ed 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; |