3 files changed, 55 insertions, 0 deletions
diff --git a/src/drivers/intel/fsp2_0/Kconfig.debug_blob b/src/drivers/intel/fsp2_0/Kconfig.debug_blob
index 14f502c4d6..e9e6053c64 100644
--- a/src/drivers/intel/fsp2_0/Kconfig.debug_blob
+++ b/src/drivers/intel/fsp2_0/Kconfig.debug_blob
@@ -45,4 +45,21 @@ config DISPLAY_FSP_VERSION_INFO_2
 	  Select this option to display Firmware version information
 	  using new header 'FirmwareVersionInfo.h'.
 
+config HAVE_GPIO_SNAPSHOT_VERIFY_SUPPORT
+	bool
+	default n
+	help
+	  Select this option if platform provides support for GPIO
+	  config snapshot and verify callbacks: `gpio_snapshot()`
+	  and `gpio_verify_snapshot()`
+
+config CHECK_GPIO_CONFIG_CHANGES
+	bool "Check GPIO config changes across calls to FSP-S"
+	depends on HAVE_GPIO_SNAPSHOT_VERIFY_SUPPORT
+	help
+	  Select this option to identify if any GPIOs are re-configured
+	  by FSP-S differently than the mainboard configuration. This
+	  requires platform support to snapshot and verify that config
+	  matches snapshot.
+
 endif # PLATFORM_USES_FSP2_0
diff --git a/src/drivers/intel/fsp2_0/debug.c b/src/drivers/intel/fsp2_0/debug.c
index 3d66587eb9..323c799987 100644
--- a/src/drivers/intel/fsp2_0/debug.c
+++ b/src/drivers/intel/fsp2_0/debug.c
@@ -11,6 +11,27 @@ asmlinkage size_t fsp_write_line(uint8_t *buffer, size_t number_of_bytes)
 	return number_of_bytes;
 }
 
+enum fsp_call_phase {
+	BEFORE_FSP_CALL,
+	AFTER_FSP_CALL,
+};
+
+static void fsp_gpio_config_check(enum fsp_call_phase phase, const char *call_str)
+{
+	switch (phase) {
+	case BEFORE_FSP_CALL:
+		printk(BIOS_SPEW, "Snapshot all GPIOs before %s.\n", call_str);
+		gpio_snapshot();
+		break;
+	case AFTER_FSP_CALL:
+		printk(BIOS_SPEW, "Verify GPIO snapshot after %s...", call_str);
+		printk(BIOS_SPEW, "%zd changes detected!\n", gpio_verify_snapshot());
+		break;
+	default:
+		break;
+	}
+}
+
 /*-----------
  * MemoryInit
  *-----------
@@ -62,6 +83,9 @@ void fsp_debug_before_silicon_init(fsp_silicon_init_fn silicon_init,
 	const FSPS_UPD *fsps_old_upd,
 	const FSPS_UPD *fsps_new_upd)
 {
+	if (CONFIG(CHECK_GPIO_CONFIG_CHANGES))
+		fsp_gpio_config_check(BEFORE_FSP_CALL, "FSP Silicon Init");
+
 	display_mtrrs();
 
 	/* Display the UPD values */
@@ -77,6 +101,9 @@ void fsp_debug_before_silicon_init(fsp_silicon_init_fn silicon_init,
 
 void fsp_debug_after_silicon_init(uint32_t status)
 {
+	if (CONFIG(CHECK_GPIO_CONFIG_CHANGES))
+		fsp_gpio_config_check(AFTER_FSP_CALL, "FSP Silicon Init");
+
 	if (CONFIG(DISPLAY_FSP_CALLS_AND_STATUS))
 		printk(BIOS_SPEW, "FspSiliconInit returned 0x%08x\n", status);
 
@@ -94,6 +121,9 @@ void fsp_debug_after_silicon_init(uint32_t status)
 void fsp_before_debug_notify(fsp_notify_fn notify,
 	const struct fsp_notify_params *notify_params)
 {
+	if (CONFIG(CHECK_GPIO_CONFIG_CHANGES))
+		fsp_gpio_config_check(BEFORE_FSP_CALL, "FSP Notify");
+
 	/* Display the call to FspNotify */
 	if (!CONFIG(DISPLAY_FSP_CALLS_AND_STATUS))
 		return;
@@ -105,6 +135,9 @@ void fsp_before_debug_notify(fsp_notify_fn notify,
 
 void fsp_debug_after_notify(uint32_t status)
 {
+	if (CONFIG(CHECK_GPIO_CONFIG_CHANGES))
+		fsp_gpio_config_check(AFTER_FSP_CALL, "FSP Notify");
+
 	if (CONFIG(DISPLAY_FSP_CALLS_AND_STATUS))
 		printk(BIOS_SPEW, "FspNotify returned 0x%08x\n", status);
 
diff --git a/src/drivers/intel/fsp2_0/include/fsp/debug.h b/src/drivers/intel/fsp2_0/include/fsp/debug.h
index e3d19180f0..be7dd3a1a8 100644
--- a/src/drivers/intel/fsp2_0/include/fsp/debug.h
+++ b/src/drivers/intel/fsp2_0/include/fsp/debug.h
@@ -57,4 +57,9 @@ void fsp_print_guid_extension_hob(const struct hob_header *hob);
  */
 asmlinkage size_t fsp_write_line(uint8_t *buffer, size_t number_of_bytes);
 
+/* Callback to snapshot all GPIO configurations. */
+void gpio_snapshot(void);
+/* Callback to verify that current GPIO configuration matches the saved snapshot */
+size_t gpio_verify_snapshot(void);
+
 #endif /* _FSP2_0_DEBUG_H_ */