soc/intel/skylake: Fix SPI WP disable status check

Use SPI write protect disable bit from BIOS_CONTROL register
to check write protect status.

Change-Id: Ie79fb4e3e92a4ae777c5d501abbb44a732a9862a
Signed-off-by: Ravi Sarawadi <ravishankar.sarawadi@intel.com>
Reviewed-on: https://review.coreboot.org/21449
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

2 files changed, 26 insertions, 1 deletions

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 078e0ae1f1..87cafb976e 100644
--- a/src/soc/intel/common/block/fast_spi/fast_spi.c
+++ b/src/soc/intel/common/block/fast_spi/fast_spi.c
@@ -274,3 +274,21 @@ void fast_spi_early_init(uintptr_t spi_base_address)
 	/* Initialize SPI to allow BIOS to write/erase on flash. */
 	fast_spi_init();
 }
+
+/* Read SPI Write Protect disable status. */
+bool fast_spi_wpd_status(void)
+{
+	return pci_read_config16(PCH_DEV_SPI, SPIBAR_BIOS_CONTROL) &
+		SPIBAR_BIOS_CONTROL_WPD;
+}
+
+/* Enable SPI Write Protect. */
+void fast_spi_enable_wp(void)
+{
+	device_t dev = PCH_DEV_SPI;
+	uint8_t bios_cntl;
+
+	bios_cntl = pci_read_config8(dev, SPIBAR_BIOS_CONTROL);
+	bios_cntl &= ~SPIBAR_BIOS_CONTROL_WPD;
+	pci_write_config8(dev, SPIBAR_BIOS_CONTROL, bios_cntl);
+}
diff --git a/src/soc/intel/common/block/include/intelblocks/fast_spi.h b/src/soc/intel/common/block/include/intelblocks/fast_spi.h
index 086143bc5f..6499ca5f5c 100644
--- a/src/soc/intel/common/block/include/intelblocks/fast_spi.h
+++ b/src/soc/intel/common/block/include/intelblocks/fast_spi.h
@@ -74,11 +74,18 @@ void fast_spi_cache_bios_region(void);
  * Caching.
  */
 void fast_spi_early_init(uintptr_t spi_base_address);
-
 /*
  * Fast SPI flash controller structure to allow SoCs to define bus-controller
  * mapping.
  */
 extern const struct spi_ctrlr fast_spi_flash_ctrlr;
+/*
+ * Read SPI Write protect disable bit.
+ */
+bool fast_spi_wpd_status(void);
+/*
+ * Enable SPI Write protect.
+ */
+void fast_spi_enable_wp(void);
 
 #endif	/* SOC_INTEL_COMMON_BLOCK_FAST_SPI_H */