intel/common/block/fast_spi: Add config option to disable write status
Chrome OS systems rely on the write status register to enable/disable
flash write protection and disabling this opcode breaks the ability
to enable or disable write protection with flashrom.
Add a configure option for this feature that will disable the opcode
for Write Status commands unless CONFIG_CHROMEOS is enabled.
Tested to ensure that a default build without CONFIG_CHROMEOS has this
option enabled while a build with CONFIG_CHROMEOS does not. Also
ensured that when this option is disabled (for Chrome OS) then flashrom
can be used with the --wp-enable and --wp-disable commands, depending
on the state of the external write protect pin.
Change-Id: Ia2ef3c3b1e10fba2c437e083f3537022f1fce84a
Signed-off-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-on: https://review.coreboot.org/21021
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: Subrata Banik <subrata.banik@intel.com>
diff --git a/src/soc/intel/common/block/fast_spi/Kconfig b/src/soc/intel/common/block/fast_spi/Kconfig
index 87edb92..4bd1f59 100644
--- a/src/soc/intel/common/block/fast_spi/Kconfig
+++ b/src/soc/intel/common/block/fast_spi/Kconfig
@@ -2,3 +2,11 @@
bool
help
Intel Processor common FAST_SPI support
+
+config FAST_SPI_DISABLE_WRITE_STATUS
+ bool "Disable write status SPI opcode"
+ depends on SOC_INTEL_COMMON_BLOCK_FAST_SPI
+ default n if CHROMEOS
+ default y
+ help
+ Disable the write status SPI opcode in Intel Fast SPI block.
diff --git a/src/soc/intel/common/block/fast_spi/fast_spi.c b/src/soc/intel/common/block/fast_spi/fast_spi.c
index fe0217a..f7ef685 100644
--- a/src/soc/intel/common/block/fast_spi/fast_spi.c
+++ b/src/soc/intel/common/block/fast_spi/fast_spi.c
@@ -144,7 +144,10 @@
void fast_spi_lock_bar(void)
{
void *spibar = fast_spi_get_bar();
- const uint16_t hsfs = SPIBAR_HSFSTS_FLOCKDN | SPIBAR_HSFSTS_WRSDIS;
+ uint16_t hsfs = SPIBAR_HSFSTS_FLOCKDN;
+
+ if (IS_ENABLED(CONFIG_FAST_SPI_DISABLE_WRITE_STATUS))
+ hsfs |= SPIBAR_HSFSTS_WRSDIS;
write16(spibar + SPIBAR_HSFSTS_CTL, hsfs);
}