soc/intel/alderlake: Add support to update descriptor at runtime
On nereid, we need to update the descriptor based on fw_config (see
the follow-up patch), so add support to update the descriptor at
runtime. This is a temporary workaround while we find a better solution.
This is basically adding back the configure_pmc_descriptor() function
removed in CB:63339, just making it generic and allowing it to update
multiple bytes at once.
BUG=b:226848617
TEST=With the following patch, Type-C and HDMI work on nereid.
Change-Id: I43c4d2888706561e42ff6b8ce0377eedbc38dbfe
Signed-off-by: Reka Norman <rekanorman@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/63365
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Eric Lai <eric_lai@quanta.corp-partner.google.com>
Reviewed-by: Sam McNally <sammc@google.com>
diff --git a/src/soc/intel/alderlake/Kconfig b/src/soc/intel/alderlake/Kconfig
index b2f90f8..d3c52944 100644
--- a/src/soc/intel/alderlake/Kconfig
+++ b/src/soc/intel/alderlake/Kconfig
@@ -112,6 +112,13 @@
select UDK_202005_BINDING
select USE_FSP_NOTIFY_PHASE_POST_PCI_ENUM
+config ALDERLAKE_CONFIGURE_DESCRIPTOR
+ bool
+ help
+ Select this if the descriptor needs to be updated at runtime. This
+ can only be done if the descriptor region is writable, and should only
+ be used as a temporary workaround.
+
config ALDERLAKE_CAR_ENHANCED_NEM
bool
default y if !INTEL_CAR_NEM
diff --git a/src/soc/intel/alderlake/Makefile.inc b/src/soc/intel/alderlake/Makefile.inc
index b3235cd..a03c42a 100644
--- a/src/soc/intel/alderlake/Makefile.inc
+++ b/src/soc/intel/alderlake/Makefile.inc
@@ -16,6 +16,7 @@
bootblock-y += espi.c
bootblock-y += gpio.c
bootblock-y += p2sb.c
+bootblock-$(CONFIG_ALDERLAKE_CONFIGURE_DESCRIPTOR) += bootblock/update_descriptor.c
romstage-y += espi.c
romstage-y += gpio.c
diff --git a/src/soc/intel/alderlake/bootblock/update_descriptor.c b/src/soc/intel/alderlake/bootblock/update_descriptor.c
new file mode 100644
index 0000000..436825d
--- /dev/null
+++ b/src/soc/intel/alderlake/bootblock/update_descriptor.c
@@ -0,0 +1,92 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#include <arch/cpu.h>
+#include <arch/mmio.h>
+#include <cf9_reset.h>
+#include <commonlib/region.h>
+#include <console/console.h>
+#include <cpu/intel/cpu_ids.h>
+#include <fmap.h>
+#include <intelblocks/pmclib.h>
+#include <soc/bootblock.h>
+#include <types.h>
+
+/* Flash Master 1 : HOST/BIOS */
+#define FLMSTR1 0x80
+
+/* Flash signature Offset */
+#define FLASH_SIGN_OFFSET 0x10
+#define FLMSTR_WR_SHIFT_V2 20
+#define FLASH_VAL_SIGN 0xFF0A55A
+
+/* It checks whether host (Flash Master 1) has write access to the Descriptor Region or not */
+static bool is_descriptor_writeable(uint8_t *desc)
+{
+ /* Check flash has valid signature */
+ if (read32((void *)(desc + FLASH_SIGN_OFFSET)) != FLASH_VAL_SIGN) {
+ printk(BIOS_ERR, "Flash Descriptor is not valid\n");
+ return 0;
+ }
+
+ /* Check host has write access to the Descriptor Region */
+ if (!((read32((void *)(desc + FLMSTR1)) >> FLMSTR_WR_SHIFT_V2) & BIT(0))) {
+ printk(BIOS_ERR, "Host doesn't have write access to Descriptor Region\n");
+ return 0;
+ }
+
+ return 1;
+}
+
+void configure_descriptor(struct descriptor_byte *bytes, size_t num)
+{
+ uint8_t si_desc_buf[CONFIG_SI_DESC_REGION_SZ];
+ struct region_device desc_rdev;
+ bool update_required = false;
+
+ if (fmap_locate_area_as_rdev_rw(CONFIG_SI_DESC_REGION, &desc_rdev) < 0) {
+ printk(BIOS_ERR, "Failed to locate %s in the FMAP\n", CONFIG_SI_DESC_REGION);
+ return;
+ }
+
+ if (rdev_readat(&desc_rdev, si_desc_buf, 0, CONFIG_SI_DESC_REGION_SZ) !=
+ CONFIG_SI_DESC_REGION_SZ) {
+ printk(BIOS_ERR, "Failed to read Descriptor Region from SPI Flash\n");
+ return;
+ }
+
+ if (!is_descriptor_writeable(si_desc_buf))
+ return;
+
+ for (size_t i = 0; i < num; i++) {
+ size_t offset = bytes[i].offset;
+ uint8_t desired_value = bytes[i].desired_value;
+ printk(BIOS_DEBUG, "Current value of Descriptor byte 0x%lx: 0x%x\n",
+ offset, si_desc_buf[offset]);
+ if (si_desc_buf[offset] != desired_value) {
+ update_required = true;
+ si_desc_buf[offset] = desired_value;
+ }
+ }
+
+ if (!update_required) {
+ printk(BIOS_DEBUG, "Update of Descriptor is not required!\n");
+ return;
+ }
+
+ if (rdev_eraseat(&desc_rdev, 0, CONFIG_SI_DESC_REGION_SZ) != CONFIG_SI_DESC_REGION_SZ) {
+ printk(BIOS_ERR, "Failed to erase Descriptor Region area\n");
+ return;
+ }
+
+ if (rdev_writeat(&desc_rdev, si_desc_buf, 0, CONFIG_SI_DESC_REGION_SZ)
+ != CONFIG_SI_DESC_REGION_SZ) {
+ printk(BIOS_ERR, "Failed to update Descriptor Region\n");
+ return;
+ }
+
+ printk(BIOS_DEBUG, "Update of Descriptor successful, trigger GLOBAL RESET\n");
+
+ pmc_global_reset_enable(true);
+ do_full_reset();
+ die("Failed to trigger GLOBAL RESET\n");
+}
diff --git a/src/soc/intel/alderlake/include/soc/bootblock.h b/src/soc/intel/alderlake/include/soc/bootblock.h
index ce2e42e..ba4d1c2 100644
--- a/src/soc/intel/alderlake/include/soc/bootblock.h
+++ b/src/soc/intel/alderlake/include/soc/bootblock.h
@@ -9,6 +9,11 @@
#error "Please select exactly one PCH type"
#endif
+struct descriptor_byte {
+ size_t offset;
+ uint8_t desired_value;
+};
+
/* Bootblock pre console init programming */
void bootblock_pch_early_init(void);
@@ -17,4 +22,6 @@
void pch_early_iorange_init(void);
void report_platform_info(void);
+void configure_descriptor(struct descriptor_byte *bytes, size_t num);
+
#endif