Implement cold reboot

The verified boot spec requires that firmware cold (not warm) reboots so
that TPM gets reseted.

BUG=chrome-os-partner:3574
TEST=manual

1. Run load_fw twice, and verify that SetupTPM failed in the second run
------------------------------------------------------------
CrOS> cros load_fw 0x0 0x01000000 0x00400000 0x10000000
...
DEBUG: TPM: SetupTPM(r0, d0)
...
DEBUG: TPM: SetupTPM() succeeded
...
CrOS> cros load_fw 0x0 0x01000000 0x00400000 0x10000000
...
DEBUG: TPM: SetupTPM(r0, d0)
...
DEBUG: Unable to setup TPM and read stored versions.
------------------------------------------------------------

2. Run load_fw twice and a reset in between, and results the same
------------------------------------------------------------
CrOS> cros load_fw 0x0 0x01000000 0x00400000 0x10000000
...
CrOS> reset
...
CrOS> cros load_fw 0x0 0x01000000 0x00400000 0x10000000
------------------------------------------------------------

3. Run load_fw twice and a "cros cold_reboot" in between, and verify
   that SetupTPM succeeds in both runs
------------------------------------------------------------
CrOS> cros load_fw 0x0 0x01000000 0x00400000 0x10000000
...
CrOS> cros cold_reboot
...
CrOS> cros load_fw 0x0 0x01000000 0x00400000 0x10000000
------------------------------------------------------------

Cherry-pick: bbb6ba7
Change-Id: Ie74bb214c80714d1814b4ae295c4780aa2bc7ddc
Reviewed-on: http://gerrit.chromium.org/gerrit/756
Tested-by: Che-Liang Chiou <clchiou@chromium.org>
Reviewed-by: Rong Chang <rongchang@chromium.org>

2 files changed, 57 insertions, 0 deletions

diff --git a/board/nvidia/chromeos/Makefile b/board/nvidia/chromeos/Makefile
index b1d3bd1b70..7b1d1cdc6c 100644
--- a/board/nvidia/chromeos/Makefile
+++ b/board/nvidia/chromeos/Makefile
@@ -39,6 +39,7 @@ include $(TOPDIR)/config.mk
 LIB	= $(obj)libchromeos_hardware_interface.a
 
 COBJS-$(CONFIG_CHROMEOS) += gpio.o
+COBJS-$(CONFIG_CHROMEOS) += power_management.o
 
 COBJS	:= $(COBJS-y)
 OBJS	:= $(addprefix $(obj),$(COBJS))
diff --git a/board/nvidia/chromeos/power_management.c b/board/nvidia/chromeos/power_management.c
new file mode 100644
index 0000000000..118f5df600
--- /dev/null
+++ b/board/nvidia/chromeos/power_management.c
@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") version 2 as published by the Free
+ * Software Foundation.
+ */
+
+/* Implementation of per-board power management function */
+
+#include <common.h>
+#include <i2c.h>
+
+#include <chromeos/power_management.h>
+
+#define PREFIX "cold_reboot: "
+
+#define PMIC_I2C_BUS		0x00
+#define PMIC_I2C_DEVICE_ADDRESS	0x34
+#define TPS6586X_SUPPLYENE	0x14
+
+/* This function never returns */
+void cold_reboot(void)
+{
+	uint8_t byte;
+
+	if (i2c_set_bus_num(PMIC_I2C_BUS)) {
+		debug(PREFIX "i2c_set_bus_num fail\n");
+		goto FATAL;
+	}
+
+	if (i2c_read(PMIC_I2C_DEVICE_ADDRESS, TPS6586X_SUPPLYENE, 1,
+				&byte, sizeof(byte))) {
+		debug(PREFIX "i2c_read fail\n");
+		goto FATAL;
+	}
+
+	/* Set TPS6586X_SUPPLYENE bit0 to 1 */
+	byte |= 1;
+
+	if (i2c_write(PMIC_I2C_DEVICE_ADDRESS, TPS6586X_SUPPLYENE, 1,
+				&byte, sizeof(byte))) {
+		debug(PREFIX "i2c_write fail\n");
+		goto FATAL;
+	}
+
+	/* The PMIC will reboot the whole system after 10 ms */
+	udelay(100);
+
+FATAL:
+	/* The final solution of doing a cold reboot */
+	printf("Please press cold reboot button\n");
+	while (1);
+}