cheza: Add SDM845 power sequence for rev-0 board

This is the power sequence for rev-0 board. Confirmed the behavior of
reprogramming the PMIC registers to enable the instant reset and
shutdown.

BRANCH=none
BUG=b:74395451
TEST=make buildall -j
TEST=Tried the following cases:
* Cold reset:
  $ dut-control cold_reset:on sleep:0.2 cold_reset:off
  Result: G3 -> S0
* Long power press to shutdown:
  $ dut-control pwr_button:press sleep:8.2 pwr_button:release
  Result: S0 -> S5 -> G3
* Long power press to power-on but then shutdown:
  $ dut-control pwr_button:press sleep:8.2 pwr_button:release
  Result: G3 -> S0 -> S5 -> G3
* Short power press to power-on:
  $ dut-control pwr_button:press sleep:0.2 pwr_button:release
  Result: G3 -> S0
* Console command: apreset
  Result: S0 -> S5 -> S0
* Console command: power off
  Result: S0 -> S5 -> G3
* Console command: power on
  Result: G3 -> S0
* Console command: apshutdown
  Result: S0 -> S5 -> G3
* Lid open to power-on:
  $ dut-control lid_open:no sleep:0.2 lid_open:yes
  Result: G3 -> S0

Change-Id: Ia9d44b1dccac66b5b580c08c6c1697ef5989b923
Signed-off-by: Wai-Hong Tam <waihong@google.com>
Signed-off-by: Alexandru M Stan <amstan@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/969702

1 files changed, 640 insertions, 0 deletions

diff --git a/power/sdm845.c b/power/sdm845.c
new file mode 100644
index 0000000000..4e96c1385e
--- /dev/null
+++ b/power/sdm845.c
@@ -0,0 +1,640 @@
+/* Copyright 2018 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.
+ */
+
+/*
+ * SDM845 SoC power sequencing module for Chrome EC
+ *
+ * This implements the following features:
+ *
+ * - Cold reset powers on the AP
+ *
+ *  When powered off:
+ *  - Press power button turns on the AP
+ *  - Hold power button turns on the AP, and then 8s later turns it off and
+ *    leaves it off until pwron is released and pressed again
+ *  - Lid open turns on the AP
+ *
+ *  When powered on:
+ *  - Holding power button for 8s powers off the AP
+ *  - Pressing and releasing pwron within that 8s is ignored
+ *  - If POWER_GOOD is dropped by the AP, then we power the AP off
+ */
+
+#include "chipset.h"
+#include "common.h"
+#include "gpio.h"
+#include "hooks.h"
+#include "lid_switch.h"
+#include "power.h"
+#include "power_button.h"
+#include "system.h"
+#include "task.h"
+#include "util.h"
+
+#define CPRINTS(format, args...) cprints(CC_CHIPSET, format, ## args)
+
+/* Masks for power signals */
+#define IN_POWER_GOOD POWER_SIGNAL_MASK(SDM845_POWER_GOOD)
+
+/* Long power key press to force shutdown */
+#define DELAY_FORCE_SHUTDOWN		(8 * SECOND)
+
+/*
+ * If the power button is pressed to turn on, then held for this long, we
+ * power off.
+ *
+ * Normal case: User releases power button and chipset_task() goes
+ *    into the inner loop, waiting for next event to occur (power button
+ *    press or POWER_GOOD == 0).
+ */
+#define DELAY_SHUTDOWN_ON_POWER_HOLD	(8 * SECOND)
+
+/*
+ * After trigger PMIC power-on, how long it triggers AP to turn on.
+ * Obversed that the worst case is ~150ms. Pick a safe vale.
+ */
+#define PMIC_POWER_AP_RESPONSE_TIMEOUT	(350 * MSEC)
+
+/* Wait for polling the AP on signal */
+#define PMIC_POWER_AP_WAIT		(1 * MSEC)
+
+/* Delay between power-on the system and power-on the PMIC */
+#define SYSTEM_POWER_ON_DELAY		(10 * MSEC)
+
+/* Delay between power-off the system and all things (PMIC/AP) expected off */
+#define SYSTEM_POWER_OFF_DELAY		(350 * MSEC)
+
+/* TODO(crosbug.com/p/25047): move to HOOK_POWER_BUTTON_CHANGE */
+/* 1 if the power button was pressed last time we checked */
+static char power_button_was_pressed;
+
+/* 1 if lid-open event has been detected */
+static char lid_opened;
+
+/* Time where we will power off, if power button still held down */
+static timestamp_t power_off_deadline;
+
+/* Force AP power on (used for recovery keypress) */
+static int auto_power_on;
+
+enum power_request_t {
+	POWER_REQ_NONE,
+	POWER_REQ_OFF,
+	POWER_REQ_ON,
+
+	POWER_REQ_COUNT,
+};
+
+static enum power_request_t power_request;
+
+/**
+ * Return values for check_for_power_off_event().
+ */
+enum power_off_event_t {
+	POWER_OFF_CANCEL,
+	POWER_OFF_BY_POWER_BUTTON_PRESSED,
+	POWER_OFF_BY_LONG_PRESS,
+	POWER_OFF_BY_POWER_GOOD_LOST,
+	POWER_OFF_BY_POWER_REQ,
+
+	POWER_OFF_EVENT_COUNT,
+};
+
+/**
+ * Return values for check_for_power_on_event().
+ */
+enum power_on_event_t {
+	POWER_ON_CANCEL,
+	POWER_ON_BY_IN_POWER_GOOD,
+	POWER_ON_BY_AUTO_POWER_ON,
+	POWER_ON_BY_LID_OPEN,
+	POWER_ON_BY_POWER_BUTTON_PRESSED,
+	POWER_ON_BY_POWER_REQ_NONE,
+
+	POWER_ON_EVENT_COUNT,
+};
+
+static void sdm845_lid_event(void)
+{
+	/* Power task only cares about lid-open events */
+	if (!lid_is_open())
+		return;
+
+	lid_opened = 1;
+	task_wake(TASK_ID_CHIPSET);
+}
+DECLARE_HOOK(HOOK_LID_CHANGE, sdm845_lid_event, HOOK_PRIO_DEFAULT);
+
+static void powerbtn_sdm845_changed(void)
+{
+	task_wake(TASK_ID_CHIPSET);
+}
+DECLARE_HOOK(HOOK_POWER_BUTTON_CHANGE, powerbtn_sdm845_changed,
+	     HOOK_PRIO_DEFAULT);
+
+/**
+ * Set the state of the system power signals.
+ *
+ * The system power signals are the enable pins of SwitchCap and VBOB.
+ * They control the power of the set of PMIC chips and the AP.
+ *
+ * @param enable	1 to enable or 0 to disable
+ */
+static void set_system_power(int enable)
+{
+	CPRINTS("set_system_power(%d)", enable);
+	gpio_set_level(GPIO_SWITCHCAP_ON_L, enable);
+	gpio_set_level(GPIO_VBOB_EN, enable);
+}
+
+/**
+ * Get the state of the system power signals.
+ *
+ * @return 1 if the system is powered, 0 if not
+ */
+static int is_system_powered(void)
+{
+	return gpio_get_level(GPIO_SWITCHCAP_ON_L);
+}
+
+/**
+ * Get the PMIC/AP power signal.
+ *
+ * We treat the PMIC chips and the AP as a whole here. Don't deal with
+ * the individual chip.
+ *
+ * @return 1 if the PMIC/AP is powered, 0 if not
+ */
+static int is_pmic_pwron(void)
+{
+	/* Use PS_HOLD to indicate PMIC/AP is on/off */
+	return gpio_get_level(GPIO_PS_HOLD);
+}
+
+/**
+ * Wait the PMIC/AP power-on state.
+ *
+ * @param enable	1 to wait the PMIC/AP on.
+			0 to wait the PMIC/AP off.
+ */
+static void wait_pmic_pwron(int enable)
+{
+	timestamp_t poll_deadline;
+
+	/* Check the AP power status */
+	if (enable == is_pmic_pwron())
+		return;
+
+	poll_deadline = get_time();
+	poll_deadline.val += PMIC_POWER_AP_RESPONSE_TIMEOUT;
+	while (enable != is_pmic_pwron() &&
+	       get_time().val < poll_deadline.val) {
+		usleep(PMIC_POWER_AP_WAIT);
+	}
+
+	/* Check the timeout case */
+	if (enable != is_pmic_pwron()) {
+		if (enable)
+			CPRINTS("AP POWER NOT READY!");
+		else
+			CPRINTS("AP POWER STILL UP!");
+	}
+}
+
+/**
+ * Set the PMIC/AP power-on state.
+ *
+ * It triggers the PMIC/AP power-on and power-off sequence.
+ *
+ * @param enable	1 to power the PMIC/AP on.
+			0 to power the PMIC/AP off.
+ */
+static void set_pmic_pwron(int enable)
+{
+	CPRINTS("set_pmic_pwron(%d)", enable);
+
+	/* Check the PMIC/AP power state */
+	if (enable == is_pmic_pwron())
+		return;
+
+	/*
+	 * Power-on sequence:
+	 * 1. Hold down PMIC_KPD_PWR_ODL, which is a power-on trigger
+	 * 2. PM845 pulls up AP_RST_L signal to power-on SDM845
+	 * 3. SDM845 pulls up PS_HOLD signal
+	 * 4. Wait for PS_HOLD up
+	 * 5. Release PMIC_KPD_PWR_ODL
+	 *
+	 * Power-off sequence:
+	 * 1. Hold down PMIC_KPD_PWR_ODL and SYS_RST_L, which is a power-off
+	 *    trigger (requiring reprogramming PMIC registers to make
+	 *    PMIC_KPD_PWR_ODL + SYS_RST_L as a shutdown trigger)
+	 * 2. PM845 pulls down AP_RST_L signal to power-off SDM845 (requreing
+	 *    reprogramming PMIC to set the stage-1 and stage-2 reset timers to
+	 *    0 such that the pull down happens just after the deboucing time
+	 *    of the trigger, like 2ms)
+	 * 3. SDM845 pulls down PS_HOLD signal
+	 * 4. Wait for PS_HOLD down
+	 * 5. Release PMIC_KPD_PWR_ODL and SYS_RST_L
+	 *
+	 * If the above PMIC registers not programmed or programmed wrong, it
+	 * falls back to the next functions, which cuts off the system power.
+	 */
+
+	gpio_set_level(GPIO_PMIC_KPD_PWR_ODL, 0);
+	if (!enable)
+		gpio_set_level(GPIO_SYS_RST_L, 0);
+	wait_pmic_pwron(enable);
+	gpio_set_level(GPIO_PMIC_KPD_PWR_ODL, 1);
+	if (!enable)
+		gpio_set_level(GPIO_SYS_RST_L, 1);
+}
+
+enum power_state power_chipset_init(void)
+{
+	int init_power_state;
+	uint32_t reset_flags = system_get_reset_flags();
+
+	/*
+	 * Force the AP shutdown unless we are doing SYSJUMP. Otherwise,
+	 * the AP could stay in strange state.
+	 */
+	if (!(reset_flags & RESET_FLAG_SYSJUMP)) {
+		CPRINTS("not sysjump; forcing system shutdown");
+		set_system_power(0);
+		init_power_state = POWER_G3;
+	} else {
+		/* In the SYSJUMP case, we check if the AP is on */
+		if (power_get_signals() & IN_POWER_GOOD) {
+			CPRINTS("SOC ON");
+			init_power_state = POWER_S0;
+		} else {
+			CPRINTS("SOC OFF");
+			init_power_state = POWER_G3;
+		}
+	}
+
+	/* Leave power off only if requested by reset flags */
+	if (!(reset_flags & RESET_FLAG_AP_OFF) &&
+	    !(reset_flags & RESET_FLAG_SYSJUMP)) {
+		CPRINTS("auto_power_on set due to reset_flag 0x%x",
+			system_get_reset_flags());
+		auto_power_on = 1;
+	}
+
+	/*
+	 * TODO(crosbug.com/p/28289): Wait battery stable.
+	 * Some batteries use clock stretching feature, which requires
+	 * more time to be stable.
+	 */
+
+	return init_power_state;
+}
+
+/*****************************************************************************/
+
+/**
+ * Power off the AP
+ */
+static void power_off(void)
+{
+	/* Check the power off status */
+	if (!is_system_powered())
+		return;
+
+	/* Call hooks before we drop power rails */
+	hook_notify(HOOK_CHIPSET_SHUTDOWN);
+
+	/* Do a graceful way to shutdown PMIC/AP first */
+	set_pmic_pwron(0);
+
+	/* Force to switch off all rails */
+	set_system_power(0);
+
+	/* Wait longer to ensure the PMIC/AP totally off */
+	usleep(SYSTEM_POWER_OFF_DELAY);
+
+	lid_opened = 0;
+	enable_sleep(SLEEP_MASK_AP_RUN);
+	CPRINTS("power shutdown complete");
+}
+
+/**
+ * Power on the AP
+ */
+static void power_on(void)
+{
+	/*
+	 * When power_on() is called, we are at S5S3. Initialize components
+	 * to ready state before AP is up.
+	 */
+	hook_notify(HOOK_CHIPSET_PRE_INIT);
+
+	set_system_power(1);
+	usleep(SYSTEM_POWER_ON_DELAY);
+	set_pmic_pwron(1);
+
+	disable_sleep(SLEEP_MASK_AP_RUN);
+
+	CPRINTS("AP running ...");
+}
+
+/**
+ * Check if there has been a power-on event
+ *
+ * This checks all power-on event signals and returns non-zero if any have been
+ * triggered (with debounce taken into account).
+ *
+ * @return non-zero if there has been a power-on event, 0 if not.
+ */
+static int check_for_power_on_event(void)
+{
+	int ap_off_flag;
+
+	ap_off_flag = system_get_reset_flags() & RESET_FLAG_AP_OFF;
+	system_clear_reset_flags(RESET_FLAG_AP_OFF);
+	/* check if system is already ON */
+	if (power_get_signals() & IN_POWER_GOOD) {
+		if (ap_off_flag) {
+			CPRINTS("system is on, but RESET_FLAG_AP_OFF is on");
+			return POWER_ON_CANCEL;
+		}
+		CPRINTS("system is on, thus clear auto_power_on");
+		/* no need to arrange another power on */
+		auto_power_on = 0;
+		return POWER_ON_BY_IN_POWER_GOOD;
+	}
+	if (ap_off_flag) {
+		CPRINTS("RESET_FLAG_AP_OFF is on");
+		power_off();
+		return POWER_ON_CANCEL;
+	}
+
+	CPRINTS("POWER_GOOD is not asserted");
+
+	/* power on requested at EC startup for recovery */
+	if (auto_power_on) {
+		auto_power_on = 0;
+		return POWER_ON_BY_AUTO_POWER_ON;
+	}
+
+	/* Check lid open */
+	if (lid_opened) {
+		lid_opened = 0;
+		return POWER_ON_BY_LID_OPEN;
+	}
+
+	/* check for power button press */
+	if (power_button_is_pressed())
+		return POWER_ON_BY_POWER_BUTTON_PRESSED;
+
+	if (power_request == POWER_REQ_ON) {
+		power_request = POWER_REQ_NONE;
+		return POWER_ON_BY_POWER_REQ_NONE;
+	}
+
+	return POWER_OFF_CANCEL;
+}
+
+/**
+ * Check for some event triggering the shutdown.
+ *
+ * It can be either a long power button press or a shutdown triggered from the
+ * AP and detected by reading POWER_GOOD.
+ *
+ * @return non-zero if a shutdown should happen, 0 if not
+ */
+static int check_for_power_off_event(void)
+{
+	timestamp_t now;
+	int pressed = 0;
+
+	/*
+	 * Check for power button press.
+	 */
+	if (power_button_is_pressed()) {
+		pressed = POWER_OFF_BY_POWER_BUTTON_PRESSED;
+	} else if (power_request == POWER_REQ_OFF) {
+		power_request = POWER_REQ_NONE;
+		/* return non-zero for shudown down */
+		return POWER_OFF_BY_POWER_REQ;
+	}
+
+	now = get_time();
+	if (pressed) {
+		if (!power_button_was_pressed) {
+			power_off_deadline.val = now.val + DELAY_FORCE_SHUTDOWN;
+			CPRINTS("power waiting for long press %u",
+				power_off_deadline.le.lo);
+			/* Ensure we will wake up to check the power key */
+			timer_arm(power_off_deadline, TASK_ID_CHIPSET);
+		} else if (timestamp_expired(power_off_deadline, &now)) {
+			power_off_deadline.val = 0;
+			CPRINTS("power off after long press now=%u, %u",
+				now.le.lo, power_off_deadline.le.lo);
+			return POWER_OFF_BY_LONG_PRESS;
+		}
+	} else if (power_button_was_pressed) {
+		CPRINTS("power off cancel");
+		timer_cancel(TASK_ID_CHIPSET);
+	}
+
+	power_button_was_pressed = pressed;
+
+	/* POWER_GOOD released by AP : shutdown immediately */
+	if (!power_has_signals(IN_POWER_GOOD)) {
+		if (power_button_was_pressed)
+			timer_cancel(TASK_ID_CHIPSET);
+
+		CPRINTS("POWER_GOOD is lost");
+		return POWER_OFF_BY_POWER_GOOD_LOST;
+	}
+
+	return POWER_OFF_CANCEL;
+}
+
+/*****************************************************************************/
+/* Chipset interface */
+
+void chipset_force_shutdown(void)
+{
+	CPRINTS("EC triggered shutdown");
+	power_off();
+
+	/* Clean-up internal variable */
+	power_request = POWER_REQ_NONE;
+}
+
+void chipset_reset(void)
+{
+	/*
+	 * Before we can reprogram the PMIC to make the PMIC RESIN_N pin as
+	 * reset pin and zero-latency. We do cold reset instead.
+	 */
+	CPRINTS("EC triggered cold reboot");
+	power_off();
+
+	/* Issue a request to initiate a power-on sequence */
+	power_request = POWER_REQ_ON;
+	task_wake(TASK_ID_CHIPSET);
+}
+
+/**
+ * Power handler for steady states
+ *
+ * @param state		Current power state
+ * @return Updated power state
+ */
+enum power_state power_handle_state(enum power_state state)
+{
+	int value;
+	static int boot_from_g3;
+
+	switch (state) {
+	case POWER_G3:
+		boot_from_g3 = check_for_power_on_event();
+		if (boot_from_g3)
+			return POWER_G3S5;
+		break;
+
+	case POWER_G3S5:
+		return POWER_S5;
+
+	case POWER_S5:
+		if (boot_from_g3) {
+			value = boot_from_g3;
+			boot_from_g3 = 0;
+		} else {
+			value = check_for_power_on_event();
+		}
+
+		if (value) {
+			CPRINTS("power on %d", value);
+			return POWER_S5S3;
+		}
+		break;
+
+	case POWER_S5S3:
+		power_on();
+		if (power_wait_signals(IN_POWER_GOOD) == EC_SUCCESS) {
+			CPRINTS("POWER_GOOD seen");
+			if (power_button_wait_for_release(
+					DELAY_SHUTDOWN_ON_POWER_HOLD) ==
+					EC_SUCCESS) {
+				power_button_was_pressed = 0;
+
+				/* Call hooks now that AP is running */
+				hook_notify(HOOK_CHIPSET_STARTUP);
+
+				return POWER_S3;
+			}
+			CPRINTS("long-press button, shutdown");
+			power_off();
+			/*
+			 * Since the AP may be up already, return S0S3
+			 * state to go through the suspend hook.
+			 */
+			return POWER_S0S3;
+		}
+		CPRINTS("POWER_GOOD not seen in time");
+		set_system_power(0);
+		return POWER_S5;
+
+	case POWER_S3:
+		if (!(power_get_signals() & IN_POWER_GOOD))
+			return POWER_S3S5;
+
+		/* Go to S3S0 directly, as don't know if it is in suspend */
+		return POWER_S3S0;
+
+	case POWER_S3S0:
+		hook_notify(HOOK_CHIPSET_RESUME);
+		return POWER_S0;
+
+	case POWER_S0:
+		value = check_for_power_off_event();
+		if (value) {
+			CPRINTS("power off %d", value);
+			power_off();
+			return POWER_S0S3;
+		}
+		break;
+
+	case POWER_S0S3:
+		/*
+		 * If the power button is pressing, we need cancel the long
+		 * press timer, otherwise EC will crash.
+		 */
+		if (power_button_was_pressed)
+			timer_cancel(TASK_ID_CHIPSET);
+
+		/* Call hooks here since we don't know it prior to AP suspend */
+		hook_notify(HOOK_CHIPSET_SUSPEND);
+		return POWER_S3;
+
+	case POWER_S3S5:
+		power_button_wait_for_release(-1);
+		power_button_was_pressed = 0;
+		return POWER_S5;
+
+	case POWER_S5G3:
+		return POWER_G3;
+	}
+
+	return state;
+}
+
+/*****************************************************************************/
+/* Console debug command */
+
+static const char *power_req_name[POWER_REQ_COUNT] = {
+	"none",
+	"off",
+	"on",
+};
+
+/* Power states that we can report */
+enum power_state_t {
+	PSTATE_UNKNOWN,
+	PSTATE_OFF,
+	PSTATE_ON,
+	PSTATE_COUNT,
+};
+
+static const char * const state_name[] = {
+	"unknown",
+	"off",
+	"on",
+};
+
+static int command_power(int argc, char **argv)
+{
+	int v;
+
+	if (argc < 2) {
+		enum power_state_t state;
+
+		state = PSTATE_UNKNOWN;
+		if (chipset_in_state(CHIPSET_STATE_ANY_OFF))
+			state = PSTATE_OFF;
+		if (chipset_in_state(CHIPSET_STATE_ON))
+			state = PSTATE_ON;
+		ccprintf("%s\n", state_name[state]);
+
+		return EC_SUCCESS;
+	}
+
+	if (!parse_bool(argv[1], &v))
+		return EC_ERROR_PARAM1;
+
+	power_request = v ? POWER_REQ_ON : POWER_REQ_OFF;
+	ccprintf("Requesting power %s\n", power_req_name[power_request]);
+	task_wake(TASK_ID_CHIPSET);
+
+	return EC_SUCCESS;
+}
+DECLARE_CONSOLE_COMMAND(power, command_power,
+			"on/off",
+			"Turn AP power on/off");