ec: add nyan board

This is to add nyan board support:
  - new files in board/nyan folder, including battery.c
  - new common/chipset_tegra.c, which is mostly based on
    chipset_gaia.c
  - new include/tegra_power.h
  - modified build.mk and flash_ec for nyan

BUG=none
BRANCH=nyan
TEST=tested on Venice 2 board

Change-Id: I36895f34f2f4d144a9440aff358c8274797ebbd6
Signed-off-by: Yen Lin <yelin@nvidia.com>
Reviewed-on: https://chromium-review.googlesource.com/168078
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>
Reviewed-by: Randall Spangler <rspangler@chromium.org>

2 files changed, 603 insertions, 0 deletions

diff --git a/common/build.mk b/common/build.mk
index c3e2fcf453..02d841e9ee 100644
--- a/common/build.mk
+++ b/common/build.mk
@@ -25,6 +25,7 @@ common-$(CONFIG_CHARGER_BQ24738)+=charger_bq24738.o
 common-$(CONFIG_CHARGER_TPS65090)+=pmu_tps65090_charger.o
 common-$(CONFIG_CHIPSET_BAYTRAIL)+=chipset_baytrail.o
 common-$(CONFIG_CHIPSET_GAIA)+=chipset_gaia.o
+common-$(CONFIG_CHIPSET_TEGRA)+=chipset_tegra.o
 common-$(CONFIG_CHIPSET_HASWELL)+=chipset_haswell.o
 common-$(CONFIG_CHIPSET_IVYBRIDGE)+=chipset_ivybridge.o
 common-$(CONFIG_CHIPSET_X86)+=chipset_x86_common.o
diff --git a/common/chipset_tegra.c b/common/chipset_tegra.c
new file mode 100644
index 0000000000..7032f969cb
--- /dev/null
+++ b/common/chipset_tegra.c
@@ -0,0 +1,602 @@
+/* Copyright (c) 2013 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.
+ */
+
+/*
+ * TEGRA SoC power sequencing module for Chrome EC
+ *
+ * This implements the following features:
+ *
+ * - Cold reset powers on the AP
+ *
+ *  When powered off:
+ *  - Press pwron turns on the AP
+ *  - Hold pwron turns on the AP, and then 9s later turns it off and leaves
+ *    it off until pwron is released and pressed again
+ *
+ *  When powered on:
+ *  - The PMIC PWRON signal is released <= 1 second after the power button is
+ *    released
+ *  - Holding pwron for 9s powers off the AP
+ *  - Pressing and releasing pwron within that 9s is ignored
+ *  - If XPSHOLD is dropped by the AP, then we power the AP off
+ */
+
+#include "clock.h"
+#include "chipset.h"  /* This module implements chipset functions too */
+#include "common.h"
+#include "console.h"
+#include "tegra_power.h"
+#include "gpio.h"
+#include "hooks.h"
+#include "lid_switch.h"
+#include "keyboard_scan.h"
+#include "power_led.h"
+#include "pmu_tpschrome.h"
+#include "system.h"
+#include "task.h"
+#include "timer.h"
+#include "util.h"
+
+/* Console output macros */
+#define CPUTS(outstr) cputs(CC_CHIPSET, outstr)
+#define CPRINTF(format, args...) cprintf(CC_CHIPSET, format, ## args)
+
+/* Long power key press to force shutdown */
+#define DELAY_FORCE_SHUTDOWN  (9 * SECOND)
+
+/*
+ * If the power key 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 XPSHOLD == 0).
+ */
+#define DELAY_SHUTDOWN_ON_POWER_HOLD	(9 * SECOND)
+
+/* Maximum delay after power button press before we deassert GPIO_PMIC_PWRON */
+#define DELAY_RELEASE_PWRON   SECOND /* 1s */
+
+/* debounce time to prevent accidental power-on after keyboard power off */
+#define KB_PWR_ON_DEBOUNCE    250    /* 250us */
+
+/*
+ * nyan's GPIO_SOC1V8_XPSHOLD will go low for ~20ms after initial high.
+ * XPSHOLD_DEBOUNCE is used to wait this long, then check the signal again.
+ */
+#define XPSHOLD_DEBOUNCE      (30 * 1000)  /* 30 ms */
+
+/* Application processor power state */
+static int ap_on;
+static int ap_suspended;
+
+/* simulated event state */
+static int force_signal = -1;
+static int force_value;
+
+/* 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;
+
+/**
+ * Wait for GPIO "signal" to reach level "value".
+ * Returns EC_ERROR_TIMEOUT if timeout before reaching the desired state.
+ *
+ * @param signal	Signal to watch
+ * @param value		Value to watch for
+ * @param timeout	Timeout in microseconds from now, or -1 to wait forever
+ * @return 0 if signal did change to required value, EC_ERROR_TIMEOUT if we
+ * timed out first.
+ */
+static int wait_in_signal(enum gpio_signal signal, int value, int timeout)
+{
+	timestamp_t deadline;
+	timestamp_t now = get_time();
+
+	deadline.val = now.val + timeout;
+
+	while (((force_signal != signal) || (force_value != value)) &&
+			gpio_get_level(signal) != value) {
+		now = get_time();
+		if (timeout < 0) {
+			task_wait_event(-1);
+		} else if (timestamp_expired(deadline, &now) ||
+				(task_wait_event(deadline.val - now.val) ==
+					TASK_EVENT_TIMER)) {
+			CPRINTF("[%T power timeout waiting for GPIO %d/%s]\n",
+				signal, gpio_get_name(signal));
+			return EC_ERROR_TIMEOUT;
+		}
+	}
+
+	return EC_SUCCESS;
+}
+
+/**
+ * Set the PMIC PWROK signal.
+ *
+ * @param asserted	Assert (=1) or deassert (=0) the signal.  This is the
+ *			logical level of the pin, not the physical level.
+ */
+static void set_pmic_pwrok(int asserted)
+{
+	/* Signal is active-low */
+	gpio_set_level(GPIO_PMIC_PWRON_L, asserted ? 0 : 1);
+}
+
+/**
+ * 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 XPSHOLD.
+ *
+ * @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_request is POWER_REQ_OFF, simulate the requst as power
+	 * button is pressed. This will casue GPIO_PMIC_PWRON_L to be driven
+	 * low (by set_pmic_pwrok(1)) until PMIC automatically turns off power.
+	 * (PMIC turns off power if GPIO_PMIC_PWRON_L is low for >=9 seconds.)
+	 */
+	if (gpio_get_level(GPIO_KB_PWR_ON_L) == 0) {
+		udelay(KB_PWR_ON_DEBOUNCE);
+		if (gpio_get_level(GPIO_KB_PWR_ON_L) == 0)
+			pressed = 1;
+	} else if (power_request == POWER_REQ_OFF) {
+		pressed = 1;
+		power_request = POWER_REQ_NONE;
+	}
+
+#ifdef HAS_TASK_KEYSCAN
+	/* Dis/Enable keyboard scanning when the power button state changes */
+	if (!pressed || pressed != power_button_was_pressed)
+		keyboard_scan_enable(!pressed);
+#endif
+
+	now = get_time();
+	if (pressed) {
+		set_pmic_pwrok(1);
+
+		if (!power_button_was_pressed) {
+			power_off_deadline.val = now.val + DELAY_FORCE_SHUTDOWN;
+			CPRINTF("[%T power waiting for long press %u]\n",
+				power_off_deadline.le.lo);
+		} else if (timestamp_expired(power_off_deadline, &now)) {
+			power_off_deadline.val = 0;
+			CPRINTF("[%T power off after long press now=%u, %u]\n",
+				now.le.lo, power_off_deadline.le.lo);
+			return 2;
+		}
+	} else if (power_button_was_pressed) {
+		CPRINTF("[%T power off cancel]\n");
+		set_pmic_pwrok(0);
+	}
+
+	power_button_was_pressed = pressed;
+
+	/* XPSHOLD released by AP : shutdown immediately */
+	if (gpio_get_level(GPIO_SOC1V8_XPSHOLD) == 0)
+		return 3;
+
+	return 0;
+}
+
+/**
+ * Deferred handling for suspend events
+ *
+ * The suspend event needs to be able to call the suspend and resume hooks.
+ * This cannot be done from interrupt level, since the handlers from those
+ * hooks may need to use mutexes or other functionality not present at
+ * interrupt level.  Use a deferred function instead.
+ *
+ * Deferred functions are called from the hook task and not the chipset task,
+ * so that's a slight deviation from the spec in hooks.h, but a minor one.
+ */
+static void tegra_suspend_deferred(void)
+{
+	int new_ap_suspended;
+
+	if (!ap_on) /* power on/off : not a real suspend / resume */
+		return;
+
+	new_ap_suspended = !gpio_get_level(GPIO_SUSPEND_L);
+
+	/* We never want to call two suspend or two resumes in a row */
+	if (ap_suspended == new_ap_suspended)
+		return;
+
+	ap_suspended = new_ap_suspended;
+
+	if (ap_suspended) {
+		if (lid_is_open())
+			powerled_set_state(POWERLED_STATE_SUSPEND);
+		else
+			powerled_set_state(POWERLED_STATE_OFF);
+		/* Call hooks here since we don't know it prior to AP suspend */
+		hook_notify(HOOK_CHIPSET_SUSPEND);
+	} else {
+		powerled_set_state(POWERLED_STATE_ON);
+		hook_notify(HOOK_CHIPSET_RESUME);
+	}
+}
+DECLARE_DEFERRED(tegra_suspend_deferred);
+
+void tegra_suspend_event(enum gpio_signal signal)
+{
+	hook_call_deferred(tegra_suspend_deferred, 0);
+}
+
+void tegra_power_event(enum gpio_signal signal)
+{
+	/* Wake up the task */
+	task_wake(TASK_ID_CHIPSET);
+}
+
+static void tegra_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, tegra_lid_event, HOOK_PRIO_DEFAULT);
+
+static int tegra_power_init(void)
+{
+	/* Enable interrupts for our GPIOs */
+	gpio_enable_interrupt(GPIO_KB_PWR_ON_L);
+	gpio_enable_interrupt(GPIO_SOC1V8_XPSHOLD);
+	gpio_enable_interrupt(GPIO_SUSPEND_L);
+
+	/* Leave power off only if requested by reset flags */
+	if (!(system_get_reset_flags() & RESET_FLAG_AP_OFF)) {
+		CPRINTF("[%T auto_power_on is set due to reset_flag 0x%x]\n",
+			system_get_reset_flags());
+		auto_power_on = 1;
+	}
+
+	return EC_SUCCESS;
+}
+
+/*****************************************************************************/
+/* Chipset interface */
+
+int chipset_in_state(int state_mask)
+{
+	/* If AP is off, match any off state for now */
+	if ((state_mask & CHIPSET_STATE_ANY_OFF) && !ap_on)
+		return 1;
+
+	/* If AP is on, match on state */
+	if ((state_mask & CHIPSET_STATE_ON) && ap_on && !ap_suspended)
+		return 1;
+
+	/* if AP is suspended, match on state */
+	if ((state_mask & CHIPSET_STATE_SUSPEND) && ap_on && ap_suspended)
+		return 1;
+
+	/* In any other case, we don't have a match */
+	return 0;
+}
+
+void chipset_exit_hard_off(void)
+{
+	/* TODO: implement, if/when we take the AP down to a hard-off state */
+}
+
+void chipset_reset(int is_cold)
+{
+	/* TODO: implement cold reset.  For now, all resets are warm resets. */
+	CPRINTF("[%T EC triggered warm reboot]\n");
+
+	/*
+	 * This is a hack to do an AP warm reboot while still preserving RAM
+	 * contents. This is useful for looking at kernel log message contents
+	 * from previous boot in cases where the AP/OS is hard hung.
+	 */
+	power_request = POWER_REQ_ON;
+	task_wake(TASK_ID_CHIPSET);
+}
+
+void chipset_force_shutdown(void)
+{
+	set_pmic_pwrok(0);
+}
+
+/*****************************************************************************/
+
+/**
+ * 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)
+{
+	/* check if system is already ON */
+	if (gpio_get_level(GPIO_SOC1V8_XPSHOLD)) {
+		CPRINTF("[%T system is on, thus clear auto_power_on]\n");
+		auto_power_on = 0;  /* no need to arrange another power on */
+		return 1;
+	}
+
+	/* power on requested at EC startup for recovery */
+	if (auto_power_on) {
+		auto_power_on = 0;
+		return 2;
+	}
+
+	/* Check lid open */
+	if (lid_opened) {
+		lid_opened = 0;
+		return 3;
+	}
+
+	/* check for power button press */
+	if (gpio_get_level(GPIO_KB_PWR_ON_L) == 0) {
+		udelay(KB_PWR_ON_DEBOUNCE);
+		if (gpio_get_level(GPIO_KB_PWR_ON_L) == 0)
+			return 4;
+	}
+
+	if (power_request == POWER_REQ_ON) {
+		power_request = POWER_REQ_NONE;
+		return 5;
+	}
+
+	return 0;
+}
+
+/**
+ * Power on the AP
+ *
+ * @return 0 if ok, -1 on error (PP1800_LDO2 failed to come on)
+ */
+static int power_on(void)
+{
+	gpio_set_level(GPIO_AP_RESET_L, 1);
+	set_pmic_pwrok(1);
+
+	if (gpio_get_level(GPIO_SOC1V8_XPSHOLD) == 0)
+		/* Initialize non-AP components */
+		hook_notify(HOOK_CHIPSET_PRE_INIT);
+
+	ap_on = 1;
+	disable_sleep(SLEEP_MASK_AP_RUN);
+	powerled_set_state(POWERLED_STATE_ON);
+
+	/* Call hooks now that AP is running */
+	hook_notify(HOOK_CHIPSET_STARTUP);
+
+	CPRINTF("[%T AP running ...]\n");
+	return 0;
+}
+
+/**
+ * Wait for the power button to be released
+ *
+ * @return 0 if ok, -1 if power button failed to release
+ */
+static int wait_for_power_button_release(unsigned int timeout_us)
+{
+	/* wait for Power button release */
+	wait_in_signal(GPIO_KB_PWR_ON_L, 1, timeout_us);
+
+	udelay(KB_PWR_ON_DEBOUNCE);
+	if (gpio_get_level(GPIO_KB_PWR_ON_L) == 0) {
+		CPRINTF("[%T power button not released in time]\n");
+		return -1;
+	}
+	CPRINTF("[%T power button released]\n");
+	return 0;
+}
+
+/**
+ * Wait for the XPSHOLD signal from the AP to be asserted within timeout_us
+ * and if asserted clear the PMIC_PWRON signal
+ *
+ * @return 0 if ok, -1 if power button failed to release
+ */
+static int react_to_xpshold(unsigned int timeout_us)
+{
+	/* wait for Power button release */
+	wait_in_signal(GPIO_SOC1V8_XPSHOLD, 1, timeout_us);
+
+#ifdef BOARD_nyan
+	/*
+	 * nyan's GPIO_SOC1V8_XPSHOLD will go low for about 20ms after initial
+	 * high. Wait XPSHOLD_DEBOUNCE time, then check the signal again.
+	 */
+	udelay(XPSHOLD_DEBOUNCE);
+#endif
+
+	if (gpio_get_level(GPIO_SOC1V8_XPSHOLD) == 0) {
+		CPRINTF("[%T XPSHOLD not seen in time]\n");
+		return -1;
+	}
+
+	CPRINTF("[%T XPSHOLD seen]\n");
+	return 0;
+}
+
+/**
+ * Power off the AP
+ */
+static void power_off(void)
+{
+	/* Call hooks before we drop power rails */
+	hook_notify(HOOK_CHIPSET_SHUTDOWN);
+	/* switch off all rails */
+	chipset_force_shutdown();
+	ap_on = 0;
+	ap_suspended = 0;
+	lid_opened = 0;
+	enable_sleep(SLEEP_MASK_AP_RUN);
+	powerled_set_state(POWERLED_STATE_OFF);
+	CPRINTF("[%T power shutdown complete]\n");
+}
+
+/*
+ * Calculates the delay in microseconds to the next time we have to check
+ * for a power event,
+ *
+  *@return delay to next check, or -1 if no future check is needed
+ */
+static int next_pwr_event(void)
+{
+	if (!power_off_deadline.val)
+		return -1;
+
+	return power_off_deadline.val - get_time().val;
+}
+
+/*****************************************************************************/
+static int wait_for_power_on(void)
+{
+	int value;
+	while (1) {
+		value = check_for_power_on_event();
+		if (!value) {
+			task_wait_event(-1);
+			continue;
+		}
+
+#ifdef HAS_TASK_CHARGER
+		/*
+		 * If the system is already on (value == 1), the kernel
+		 * would handle low power condition and we should not
+		 * shutdown the system from EC.
+		 */
+		if (value != 1 && charge_keep_power_off()) {
+			CPRINTF("[%T power on ignored due to low battery]\n");
+			continue;
+		}
+#endif
+
+		CPRINTF("[%T power on %d]\n", value);
+		return value;
+	}
+}
+
+void chipset_task(void)
+{
+	int value;
+
+	tegra_power_init();
+	ap_on = 0;
+
+	while (1) {
+		/* Wait until we need to power on, then power on */
+		wait_for_power_on();
+
+		if (!power_on()) {
+			int continue_power = 0;
+
+			if (!react_to_xpshold(DELAY_RELEASE_PWRON)) {
+				/* AP looks good */
+				if (!wait_for_power_button_release(
+					DELAY_SHUTDOWN_ON_POWER_HOLD))
+					continue_power = 1;
+			}
+			set_pmic_pwrok(0);
+			if (continue_power) {
+				power_button_was_pressed = 0;
+				while (!(value = check_for_power_off_event()))
+					task_wait_event(next_pwr_event());
+				CPRINTF("[%T power ending loop %d]\n", value);
+			}
+		}
+		power_off();
+		wait_for_power_button_release(-1);
+	}
+}
+
+/*****************************************************************************/
+/* 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_SUSPEND,
+	PSTATE_ON,
+
+	PSTATE_COUNT,
+};
+
+static const char * const state_name[] = {
+	"unknown",
+	"off",
+	"suspend",
+	"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_SUSPEND))
+			state = PSTATE_SUSPEND;
+		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",
+			NULL);