mb/google/sarien: Fix recovery mode detection

In order to support the physical recovery GPIO on sarien it needs
to enable the option VBOOT_PHYSICAL_REC_SWITCH and set the GPIO
number in the coreboot table appropriately so that depthcharge can
correctly determine the GPIO number.  The same is done for the
write protect GPIO in this table.

Additionally since we are reading a recovery request from H1 it
needs to cache the result since H1 will only return true on the
first request.  All subsequent queries to H1 will not indicate
recovery.  Add a CAR global here to keep track of the state and
only read it from H1 the first time.

BUG=b:121380403
TEST=test_that DUT firmware_DevMode

Change-Id: Ia816a2e285d3c2c3769b25fc5d20147abbc71421
Signed-off-by: Duncan Laurie <dlaurie@google.com>
Reviewed-on: https://review.coreboot.org/c/31043
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

2 files changed, 32 insertions, 8 deletions

diff --git a/src/mainboard/google/sarien/Kconfig b/src/mainboard/google/sarien/Kconfig
index ff2f678831..f93910fe4c 100644
--- a/src/mainboard/google/sarien/Kconfig
+++ b/src/mainboard/google/sarien/Kconfig
@@ -100,5 +100,6 @@ config VBOOT
 	select HAS_RECOVERY_MRC_CACHE
 	select MRC_CLEAR_NORMAL_CACHE_ON_RECOVERY_RETRAIN
 	select VBOOT_LID_SWITCH
+	select VBOOT_PHYSICAL_REC_SWITCH
 
 endif # BOARD_GOOGLE_BASEBOARD_SARIEN
diff --git a/src/mainboard/google/sarien/chromeos.c b/src/mainboard/google/sarien/chromeos.c
index 8b2090e5b0..0ea237a407 100644
--- a/src/mainboard/google/sarien/chromeos.c
+++ b/src/mainboard/google/sarien/chromeos.c
@@ -14,6 +14,7 @@
  */
 
 #include <arch/acpi.h>
+#include <arch/early_variables.h>
 #include <boot/coreboot_tables.h>
 #include <gpio.h>
 #include <soc/gpio.h>
@@ -21,12 +22,20 @@
 #include <vendorcode/google/chromeos/chromeos.h>
 #include <security/tpm/tss.h>
 
+enum rec_mode_state {
+	REC_MODE_UNINITIALIZED,
+	REC_MODE_NOT_REQUESTED,
+	REC_MODE_REQUESTED,
+};
+static enum rec_mode_state saved_rec_mode CAR_GLOBAL;
 
 void fill_lb_gpios(struct lb_gpios *gpios)
 {
 	struct lb_gpio chromeos_gpios[] = {
-		{-1, ACTIVE_HIGH, get_write_protect_state(), "write protect"},
-		{-1, ACTIVE_HIGH, get_recovery_mode_switch(), "recovery"},
+		{GPIO_PCH_WP, ACTIVE_HIGH, get_write_protect_state(),
+		 "write protect"},
+		{GPIO_REC_MODE, ACTIVE_LOW, get_recovery_mode_switch(),
+		 "recovery"},
 		{-1, ACTIVE_HIGH, get_lid_switch(), "lid"},
 		{-1, ACTIVE_HIGH, 0, "power"},
 		{-1, ACTIVE_HIGH, gfx_get_init_done(), "oprom"},
@@ -72,16 +81,30 @@ int get_write_protect_state(void)
 
 int get_recovery_mode_switch(void)
 {
-	uint8_t recovery_button_state;
-	int recovery_mode_switch = 0;
+	enum rec_mode_state state = car_get_var(saved_rec_mode);
+	uint8_t recovery_button_state = 0;
 
+	/* Check the global variable first. */
+	if (state == REC_MODE_NOT_REQUESTED)
+		return 0;
+	else if (state == REC_MODE_REQUESTED)
+		return 1;
+
+	state = REC_MODE_NOT_REQUESTED;
+
+	/* Read state from the GPIO controlled by servo. */
 	if (cros_get_gpio_value(CROS_GPIO_REC))
-		recovery_mode_switch = 1;
+		state = REC_MODE_REQUESTED;
+	/* Read one-time recovery request from cr50. */
 	else if (tlcl_cr50_get_recovery_button(&recovery_button_state)
-		== TPM_SUCCESS)
-		recovery_mode_switch = recovery_button_state;
+		 == TPM_SUCCESS)
+		state = recovery_button_state ?
+			REC_MODE_REQUESTED : REC_MODE_NOT_REQUESTED;
+
+	/* Store the state in case this is called again in verstage. */
+	car_set_var(saved_rec_mode, state);
 
-	return recovery_mode_switch;
+	return state == REC_MODE_REQUESTED;
 }
 
 int get_lid_switch(void)