system: Add wait-ext option to ec reboot command

EC_IN_RW signal is used to determine if the switch to dev mode can be
safely made. However, EC_IN_RW needs the EC_RST_L line driven low in
order to be reset. In faft tests that utilize crosEcSoftrecPower
method, EC_RST_L is not being driven by servo to fix other test
failures related to keeping EC and AC reboots in sync.

This CL adds a new argument 'wait-ext' to the EC reboot command.
When this option is used, instead of the EC generating a reset via
it's system watchdog, it will wait 10 seconds for EC_RST_L to be
driven.

BUG=b:64603944
BRANCH=coral
CQ-DEPEND=I086687c3dd7591460099267880d56ab8265d2e4b
TEST=Ran "/usr/bin/test_that --board=coral <ip addr> firmware_DevMode"
mutliple times and verified that it passes. Previoulsy, this test
always fails when the EC is in RW before it starts. Also tested
platform_ServoPowerStateController_USBPluggedin and verified it passed.

Change-Id: I614f9156066d5719601ee43e29c7a064f9bba6e2
Signed-off-by: Scott Collyer <scollyer@google.com>
Reviewed-on: https://chromium-review.googlesource.com/737524
Commit-Ready: Scott Collyer <scollyer@chromium.org>
Tested-by: Scott Collyer <scollyer@chromium.org>
Reviewed-by: Randall Spangler <rspangler@chromium.org>

3 files changed, 53 insertions, 16 deletions

diff --git a/chip/npcx/system.c b/chip/npcx/system.c
index 51c7c6e74a..96879b40e4 100644
--- a/chip/npcx/system.c
+++ b/chip/npcx/system.c
@@ -21,6 +21,7 @@
 #include "task.h"
 #include "timer.h"
 #include "util.h"
+#include "watchdog.h"
 
 /* Delay after writing TTC for value to latch */
 #define MTC_TTC_LOAD_DELAY_US 250
@@ -702,28 +703,28 @@ void system_pre_init(void)
 
 void system_reset(int flags)
 {
-	uint32_t save_flags = 0;
+	uint32_t save_flags;
 
 	/* Disable interrupts to avoid task swaps during reboot */
 	interrupt_disable();
 
-	/* Save current reset reasons if necessary */
-	if (flags & SYSTEM_RESET_PRESERVE_FLAGS)
-		save_flags = system_get_reset_flags() | RESET_FLAG_PRESERVED;
-
-	/* Add in AP off flag into saved flags. */
-	if (flags & SYSTEM_RESET_LEAVE_AP_OFF)
-		save_flags |= RESET_FLAG_AP_OFF;
-
-	/* Save reset flag */
-	if (flags & SYSTEM_RESET_HARD)
-		save_flags |= RESET_FLAG_HARD;
-	else
-		save_flags |= RESET_FLAG_SOFT;
+	/*  Get flags to be saved in BBRAM */
+	system_encode_save_flags(flags, &save_flags);
 
 	/* Store flags to battery backed RAM. */
 	chip_save_reset_flags(save_flags);
 
+	/* If WAIT_EXT is set, then allow 10 seconds for external reset */
+	if (flags & SYSTEM_RESET_WAIT_EXT) {
+		int i;
+
+		/* Wait 10 seconds for external reset */
+		for (i = 0; i < 1000; i++) {
+			watchdog_reload();
+			udelay(10000);
+		}
+	}
+
 	/* Ask the watchdog to trigger a hard reboot */
 	system_watchdog_reset();
 
diff --git a/common/system.c b/common/system.c
index 741cec71f1..928fb1d21a 100644
--- a/common/system.c
+++ b/common/system.c
@@ -226,6 +226,25 @@ test_mockable uintptr_t system_usable_ram_end(void)
 	return (uintptr_t)jdata - jdata->jump_tag_total;
 }
 
+void system_encode_save_flags(int reset_flags, uint32_t *save_flags)
+{
+	*save_flags = 0;
+
+	/* Save current reset reasons if necessary */
+	if (reset_flags & SYSTEM_RESET_PRESERVE_FLAGS)
+		*save_flags = system_get_reset_flags() | RESET_FLAG_PRESERVED;
+
+	/* Add in AP off flag into saved flags. */
+	if (reset_flags & SYSTEM_RESET_LEAVE_AP_OFF)
+		*save_flags |= RESET_FLAG_AP_OFF;
+
+	/* Save reset flag */
+	if (reset_flags & (SYSTEM_RESET_HARD | SYSTEM_RESET_WAIT_EXT))
+		*save_flags |= RESET_FLAG_HARD;
+	else
+		*save_flags |= RESET_FLAG_SOFT;
+}
+
 uint32_t system_get_reset_flags(void)
 {
 	return reset_flags;
@@ -1135,20 +1154,25 @@ static int command_reboot(int argc, char **argv)
 			return EC_SUCCESS;
 		} else if (!strcasecmp(argv[i], "preserve")) {
 			flags |= SYSTEM_RESET_PRESERVE_FLAGS;
+		} else if (!strcasecmp(argv[i], "wait-ext")) {
+			flags |= SYSTEM_RESET_WAIT_EXT;
 		} else
 			return EC_ERROR_PARAM1 + i - 1;
 	}
 
 	if (flags & SYSTEM_RESET_HARD)
 		ccputs("Hard-");
-	ccputs("Rebooting!\n\n\n");
+	if (flags & SYSTEM_RESET_WAIT_EXT)
+		ccputs("Waiting for ext reset!\n\n\n");
+	else
+		ccputs("Rebooting!\n\n\n");
 	cflush();
 
 	system_reset(flags);
 	return EC_SUCCESS;
 }
 DECLARE_CONSOLE_COMMAND(reboot, command_reboot,
-			"[hard|soft] [preserve] [ap-off] [cancel]",
+			"[hard|soft] [preserve] [ap-off] [wait-ext] [cancel]",
 			"Reboot the EC");
 
 #ifdef CONFIG_CMD_SYSLOCK
diff --git a/include/system.h b/include/system.h
index 5587446ff9..f0f934ccf4 100644
--- a/include/system.h
+++ b/include/system.h
@@ -68,6 +68,14 @@ void system_pre_init(void);
 void system_common_pre_init(void);
 
 /**
+ * Set up flags that should be saved to battery backed RAM.
+ *
+ * @param reset_flags - flags passed into system_reset
+ * @param *save_flags - flags to be saved in battery backed RAM
+ */
+void system_encode_save_flags(int reset_flags, uint32_t *save_flags);
+
+/**
  * Get the reset flags.
  *
  * @return Reset flags (RESET_FLAG_*), or 0 if the cause is unknown.
@@ -261,6 +269,10 @@ const char *system_get_build_info(void);
  * Indicate that this was a manually triggered reset.
  */
 #define SYSTEM_RESET_MANUALLY_TRIGGERED (1 << 3)
+/*
+ * Wait for reset pin to be driven, rather that resetting ourselves.
+ */
+#define SYSTEM_RESET_WAIT_EXT           (1 << 4)
 
 /**
  * Reset the system.