/* Copyright 2015 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.
 */

/* Skylake IMVP8 / ROP PMIC chipset power control module for Chrome EC */

#include "chipset.h"
#include "console.h"
#include "gpio.h"
#include "hooks.h"
#include "intel_x86.h"
#include "lpc.h"
#include "power_button.h"
#include "skylake.h"
#include "system.h"
#include "timer.h"

/* Console output macros */
#define CPRINTS(format, args...) cprints(CC_CHIPSET, format, ## args)

static int forcing_shutdown;  /* Forced shutdown in progress? */


void chipset_force_shutdown(void)
{
	CPRINTS("%s()", __func__);

	/*
	 * Force off. Sending a reset command to the PMIC will power off
	 * the EC, so simulate a long power button press instead. This
	 * condition will reset once the state machine transitions to G3.
	 * Consider reducing the latency here by changing the power off
	 * hold time on the PMIC.
	 */
	if (!chipset_in_state(CHIPSET_STATE_HARD_OFF)) {
		forcing_shutdown = 1;
		power_button_pch_press();
	}
}

__attribute__((weak)) void chipset_set_pmic_slp_sus_l(int level)
{
	gpio_set_level(GPIO_PMIC_SLP_SUS_L, level);
}

enum power_state chipset_force_g3(void)
{
	CPRINTS("Forcing fake G3.");

	chipset_set_pmic_slp_sus_l(0);

	return POWER_G3;
}

void chipset_reset(int cold_reset)
{
	CPRINTS("%s(%d)", __func__, cold_reset);

	if (cold_reset) {
		if (gpio_get_level(GPIO_SYS_RESET_L) == 0)
			return;
		gpio_set_level(GPIO_SYS_RESET_L, 0);
		/* Debounce time for SYS_RESET_L is 16 ms */
		udelay(20 * MSEC);
		gpio_set_level(GPIO_SYS_RESET_L, 1);
	} else {
		/*
		 * Send a RCIN_PCH_RCIN_L
		 * assert INIT# to the CPU without dropping power or asserting
		 * PLTRST# to reset the rest of the system.
		 */

		/* Pulse must be at least 16 PCI clocks long = 500 ns */
#ifdef CONFIG_ESPI_VW_SIGNALS
		lpc_host_reset();
#else
		gpio_set_level(GPIO_PCH_RCIN_L, 0);
		udelay(10);
		gpio_set_level(GPIO_PCH_RCIN_L, 1);
#endif
	}
}

static void handle_slp_sus(enum power_state state)
{
	/* If we're down or going down don't do anythin with SLP_SUS_L. */
	if (state == POWER_G3 || state == POWER_S5G3)
		return;

	/* Always mimic PCH SLP_SUS request for all other states. */
	chipset_set_pmic_slp_sus_l(gpio_get_level(GPIO_PCH_SLP_SUS_L));
}

void chipset_handle_espi_reset_assert(void)
{
	/*
	 * If eSPI_Reset# pin is asserted without SLP_SUS# being asserted, then
	 * it means that there is an unexpected power loss (global reset
	 * event). In this case, check if shutdown was being forced by pressing
	 * power button. If yes, release power button.
	 */
	if ((power_get_signals() & IN_PCH_SLP_SUS_DEASSERTED) &&
		forcing_shutdown) {
		power_button_pch_release();
		forcing_shutdown = 0;
	}
}

enum power_state power_handle_state(enum power_state state)
{
	enum power_state new_state;

	/* Process RSMRST_L state changes. */
	common_intel_x86_handle_rsmrst(state);

	if (state == POWER_S5 && forcing_shutdown) {
		power_button_pch_release();
		forcing_shutdown = 0;
	}

	new_state = common_intel_x86_power_handle_state(state);

	/* Process SLP_SUS_L state changes after a new state is decided. */
	handle_slp_sus(new_state);

	return new_state;
}

/* Workaround for flags getting lost with power cycle */
__attribute__((weak)) int board_has_working_reset_flags(void)
{
	return 1;
}

#ifdef CONFIG_CHIPSET_HAS_PLATFORM_PMIC_RESET
static void chipset_handle_reboot(void)
{
	int flags;

	if (system_jumped_to_this_image())
		return;

	/* Interrogate current reset flags from previous reboot. */
	flags = system_get_reset_flags();

	/*
	 * Do not make PMIC re-sequence the power rails if the following reset
	 * conditions are not met.
	 */
	if (!(flags &
		(RESET_FLAG_WATCHDOG | RESET_FLAG_SOFT | RESET_FLAG_HARD)))
		return;

	/* Preserve AP off request. */
	if (flags & RESET_FLAG_AP_OFF) {
		/* Do not issue PMIC reset if board cannot save reset flags */
		if (!board_has_working_reset_flags()) {
			ccprintf("Skip PMIC reset due to board issue.\n");
			cflush();
			return;
		}
		chip_save_reset_flags(RESET_FLAG_AP_OFF);
	}

	ccprintf("Restarting system with PMIC.\n");
	/* Flush console */
	cflush();

	/* Bring down all rails but RTC rail (including EC power). */
	gpio_set_level(GPIO_EC_PLATFORM_RST, 1);
	while (1)
		; /* wait here */
}
DECLARE_HOOK(HOOK_INIT, chipset_handle_reboot, HOOK_PRIO_FIRST);
#endif