From 77334d49842f82497dbbcbd0da43bb134016198e Mon Sep 17 00:00:00 2001 From: Subrata Banik Date: Mon, 18 Apr 2022 11:30:38 +0530 Subject: [PATCH] soc/intel/cmn/lpc: Add APIs to enable/disable LPC write protect (WP) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This patch implements two APIs to perform LPC/eSPI write protect enable/ disable operation using PCI configuration space register 0xDC (BIOS Controller). BUG=b:211954778 TEST=Able to build and boot google/redrix to OS. Signed-off-by: Subrata Banik Change-Id: I8ce831218025a1d682ea2ad6be76901b0345b362 Reviewed-on: https://review.coreboot.org/c/coreboot/+/63687 Tested-by: build bot (Jenkins) Reviewed-by: Lean Sheng Tan --- .../block/include/intelblocks/lpc_lib.h | 4 +++ src/soc/intel/common/block/lpc/lpc_def.h | 1 + src/soc/intel/common/block/lpc/lpc_lib.c | 25 +++++++++++++++++++ 3 files changed, 30 insertions(+) diff --git a/src/soc/intel/common/block/include/intelblocks/lpc_lib.h b/src/soc/intel/common/block/include/intelblocks/lpc_lib.h index 3590852034..7d033677aa 100644 --- a/src/soc/intel/common/block/include/intelblocks/lpc_lib.h +++ b/src/soc/intel/common/block/include/intelblocks/lpc_lib.h @@ -99,4 +99,8 @@ unsigned long southbridge_write_acpi_tables(const struct device *device, unsigned long current, struct acpi_rsdp *rsdp); const uint8_t *lpc_get_pic_pirq_routing(size_t *num); +/* Enable LPC Write Protect. */ +void lpc_enable_wp(void); +/* Disable LPC Write Protect. */ +void lpc_disable_wp(void); #endif /* _SOC_COMMON_BLOCK_LPC_LIB_H_ */ diff --git a/src/soc/intel/common/block/lpc/lpc_def.h b/src/soc/intel/common/block/lpc/lpc_def.h index ab9f2018c5..47697ca087 100644 --- a/src/soc/intel/common/block/lpc/lpc_def.h +++ b/src/soc/intel/common/block/lpc/lpc_def.h @@ -26,6 +26,7 @@ #define LPC_BIOS_CNTL 0xdc #define LPC_BC_BILD (1 << 7) /* BILD */ #define LPC_BC_LE (1 << 1) /* LE */ +#define LPC_BC_WPD (1 << 0) /* WPD */ #define LPC_BC_EISS (1 << 5) /* EISS */ #define LPC_PCCTL 0xE0 /* PCI Clock Control */ #define LPC_PCCTL_CLKRUN_EN (1 << 0) diff --git a/src/soc/intel/common/block/lpc/lpc_lib.c b/src/soc/intel/common/block/lpc/lpc_lib.c index 654dcea224..cdaeae15c3 100644 --- a/src/soc/intel/common/block/lpc/lpc_lib.c +++ b/src/soc/intel/common/block/lpc/lpc_lib.c @@ -195,6 +195,31 @@ void lpc_set_eiss(void) lpc_set_bios_control_reg(LPC_BC_EISS); } +static void lpc_configure_write_protect(bool status) +{ + const pci_devfn_t dev = PCH_DEV_LPC; + uint8_t bios_cntl; + + bios_cntl = pci_read_config8(dev, LPC_BIOS_CNTL); + if (status) + bios_cntl &= ~LPC_BC_WPD; + else + bios_cntl |= LPC_BC_WPD; + pci_write_config8(dev, LPC_BIOS_CNTL, bios_cntl); +} + +/* Enable LPC Write Protect. */ +void lpc_enable_wp(void) +{ + lpc_configure_write_protect(true); +} + +/* Disable LPC Write Protect. */ +void lpc_disable_wp(void) +{ + lpc_configure_write_protect(false); +} + /* * Set LPC Serial IRQ mode. */