mec1322: hibernate: Don't reconfigure all GPIOs

Configuring all GPIOs to INPUT / PULL_UP in hibernate is not a good
idea:

- INPUT / PULL_UP is not necessarially the lowest-power state (for
  example, if there is an onboard pull-down).
- Most GPIOs should already be in lowest-power state when we're in S5.
- For the few GPIOs that need to be in a different state for hibernate,
  we can use a board-level callback.

In addition, remove mec1322 code related to restoring from hibernate
state, since we always reset coming out of hibernate.

BUG=chrome-os-partner:49608
BRANCH=glados, strago
TEST=`hibernate` on chell console when in S5 and AC removed. Verify that
EC power is roughly equivalent to low-power idle power. Attach Zinger,
verify that device wakes and boots, and charges from charger.

Change-Id: Ib00ef035bec32cea3847eb38d743f5c0cec896ca
Signed-off-by: Shawn Nematbakhsh <shawnn@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/322937
Commit-Ready: Shawn N <shawnn@chromium.org>
Tested-by: Shawn N <shawnn@chromium.org>
Reviewed-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-by: Todd Broch <tbroch@chromium.org>

9 files changed, 50 insertions, 226 deletions

diff --git a/board/chell/board.c b/board/chell/board.c
index 27316719e0..b0e4ec2ac5 100644
--- a/board/chell/board.c
+++ b/board/chell/board.c
@@ -357,35 +357,17 @@ static void board_chipset_suspend(void)
 }
 DECLARE_HOOK(HOOK_CHIPSET_SUSPEND, board_chipset_suspend, HOOK_PRIO_DEFAULT);
 
-uint32_t board_get_gpio_hibernate_state(uint32_t port, uint32_t pin)
+void board_set_gpio_hibernate_state(void)
 {
-	int i;
-	const uint32_t out_low_gpios[][2] = {
-		/* Turn off LEDs in hibernate */
-		GPIO_TO_PORT_MASK_PAIR(GPIO_CHARGE_LED_1),
-		GPIO_TO_PORT_MASK_PAIR(GPIO_CHARGE_LED_2),
-		/*
-		 * Set PD wake low so that it toggles high to generate a wake
-		 * event once we leave hibernate.
-		 */
-		GPIO_TO_PORT_MASK_PAIR(GPIO_USB_PD_WAKE),
-		/* The GPIO to reset PMIC is active high */
-		GPIO_TO_PORT_MASK_PAIR(GPIO_PMIC_LDO_EN),
-		/* The GPIO to control RTCRST is active high. */
-		GPIO_TO_PORT_MASK_PAIR(GPIO_PCH_RTCRST),
-		/* Keep keyboard backlight off, GPIO34 pin is in PWM mode */
-		GPIO_TO_PORT_MASK_PAIR(GPIO_KEYBOARD_BACKLIGHT),
-		/* RSMRST to PCH should be low when rails are off */
-		GPIO_TO_PORT_MASK_PAIR(GPIO_PCH_RSMRST_L),
-	};
-
-	/* Some GPIOs should be driven low in hibernate */
-	for (i = 0; i < ARRAY_SIZE(out_low_gpios); ++i)
-		if (out_low_gpios[i][0] == port && out_low_gpios[i][1] == pin)
-			return GPIO_OUTPUT | GPIO_LOW;
-
-	/* Other GPIOs should be put in a low-power state */
-	return GPIO_INPUT | GPIO_PULL_UP;
+	/* Turn off LEDs in hibernate */
+	gpio_set_level(GPIO_CHARGE_LED_1, 0);
+	gpio_set_level(GPIO_CHARGE_LED_2, 0);
+
+	/*
+	 * Set PD wake low so that it toggles high to generate a wake
+	 * event once we leave hibernate.
+	 */
+	gpio_set_level(GPIO_USB_PD_WAKE, 0);
 }
 
 /* Make the pmic re-sequence the power rails under these conditions. */
diff --git a/board/glados/board.c b/board/glados/board.c
index 534a8086aa..eb39af9f4e 100644
--- a/board/glados/board.c
+++ b/board/glados/board.c
@@ -419,31 +419,17 @@ static void board_chipset_suspend(void)
 }
 DECLARE_HOOK(HOOK_CHIPSET_SUSPEND, board_chipset_suspend, HOOK_PRIO_DEFAULT);
 
-uint32_t board_get_gpio_hibernate_state(uint32_t port, uint32_t pin)
+void board_set_gpio_hibernate_state(void)
 {
-	int i;
-	const uint32_t out_low_gpios[][2] = {
-		/* Turn off LEDs in hibernate */
-		GPIO_TO_PORT_MASK_PAIR(GPIO_CHARGE_LED_1),
-		GPIO_TO_PORT_MASK_PAIR(GPIO_CHARGE_LED_2),
-		/*
-		 * Set PD wake low so that it toggles high to generate a wake
-		 * event once we leave hibernate.
-		 */
-		GPIO_TO_PORT_MASK_PAIR(GPIO_USB_PD_WAKE),
-		/* The GPIO to control RTCRST is active high. */
-		GPIO_TO_PORT_MASK_PAIR(GPIO_PCH_RTCRST),
-		/* RSMRST to PCH should be low when rails are off */
-		GPIO_TO_PORT_MASK_PAIR(GPIO_PCH_RSMRST_L),
-	};
-
-	/* LED GPIOs should be driven low to turn off LEDs */
-	for (i = 0; i < ARRAY_SIZE(out_low_gpios); ++i)
-		if (out_low_gpios[i][0] == port && out_low_gpios[i][1] == pin)
-			return GPIO_OUTPUT | GPIO_LOW;
-
-	/* Other GPIOs should be put in a low-power state */
-	return GPIO_INPUT | GPIO_PULL_UP;
+	/* Turn off LEDs in hibernate */
+	gpio_set_level(GPIO_CHARGE_LED_1, 0);
+	gpio_set_level(GPIO_CHARGE_LED_2, 0);
+
+	/*
+	 * Set PD wake low so that it toggles high to generate a wake
+	 * event once we leave hibernate.
+	 */
+	gpio_set_level(GPIO_USB_PD_WAKE, 0);
 }
 
 /* Any glados boards post version 2 should have ROP_LDO_EN stuffed. */
diff --git a/board/wheatley/board.c b/board/wheatley/board.c
index 143642c3e0..8fcd142efa 100644
--- a/board/wheatley/board.c
+++ b/board/wheatley/board.c
@@ -379,7 +379,7 @@ static void board_chipset_suspend(void)
 }
 DECLARE_HOOK(HOOK_CHIPSET_SUSPEND, board_chipset_suspend, HOOK_PRIO_DEFAULT);
 
-void board_set_gpio_state_hibernate(void)
+void board_set_gpio_hibernate_state(void)
 {
 	int i;
 	const uint32_t hibernate_pins[][2] = {
diff --git a/chip/mec1322/registers.h b/chip/mec1322/registers.h
index be2d5f4a90..b7a814cd8c 100644
--- a/chip/mec1322/registers.h
+++ b/chip/mec1322/registers.h
@@ -65,7 +65,6 @@
 #define MEC1322_EC_WDT_CNT     REG32(MEC1322_EC_BASE + 0x28)
 #define MEC1322_EC_ADC_VREF_PD REG32(MEC1322_EC_BASE + 0x38)
 
-
 /* Interrupt aggregator */
 #define MEC1322_INT_BASE       0x4000c000
 #define MEC1322_INTx_BASE(x)   (MEC1322_INT_BASE + ((x) - 8) * 0x14)
@@ -498,11 +497,4 @@ typedef volatile struct mec1322_dma_regs mec1322_dma_regs_t;
 extern const enum gpio_signal hibernate_wake_pins[];
 extern const int hibernate_wake_pins_used;
 
-/*
- * Optional board-level function to get hibernate GPIO state.
- * Returns desired GPIO state in hibernate, or 0 to skip reconfiguration.
- */
-uint32_t board_get_gpio_hibernate_state(uint32_t port, uint32_t pin)
-	__attribute__((weak));
-
 #endif /* __CROS_EC_REGISTERS_H */
diff --git a/chip/mec1322/system.c b/chip/mec1322/system.c
index d97f5b0c4e..967d8eb03b 100644
--- a/chip/mec1322/system.c
+++ b/chip/mec1322/system.c
@@ -186,101 +186,9 @@ uint32_t system_get_scratchpad(void)
 	return MEC1322_VBAT_RAM(HIBDATA_INDEX_SCRATCHPAD);
 }
 
-/* Returns desired GPIO state in hibernate, or 0 to skip reconfiguration */
-static uint32_t system_get_gpio_hibernate_state(uint32_t port, uint32_t pin)
-{
-	int i;
-	const int skip[][2] = {
-		/*
-		 * Leave USB-C charging enabled in hibernate, in order to
-		 * allow wake-on-plug. 5V enable must be pulled low.
-		 */
-#ifdef CONFIG_USB_PD_PORT_COUNT
-#if CONFIG_USB_PD_PORT_COUNT > 0
-		GPIO_TO_PORT_MASK_PAIR(GPIO_USB_C0_5V_EN),
-		GPIO_TO_PORT_MASK_PAIR(GPIO_USB_C0_CHARGE_EN_L),
-#endif
-#if CONFIG_USB_PD_PORT_COUNT > 1
-		GPIO_TO_PORT_MASK_PAIR(GPIO_USB_C1_5V_EN),
-		GPIO_TO_PORT_MASK_PAIR(GPIO_USB_C1_CHARGE_EN_L),
-#endif
-#endif /* CONFIG_USB_PD_PORT_COUNT */
-
-		/*
-		 * MEC1322 datasheet, sec. 20.6: VCC1_RST# cannot be used
-		 * as a GPIO pin.
-		 */
-		{13, 1},
-		/* GPIO 205 doesn't exist. */
-		{20, 5},
-	};
-
-	for (i = 0; i < ARRAY_SIZE(skip); ++i)
-		if (port == skip[i][0] && pin == skip[i][1])
-			return 0;
-
-	if (board_get_gpio_hibernate_state)
-		return board_get_gpio_hibernate_state(port, pin);
-	else
-		return GPIO_INPUT | GPIO_PULL_UP;
-}
-
-static void system_set_gpio_power(int enabled, uint32_t *backup_gpio_ctl)
-{
-	int i, j;
-	uint32_t port, flags;
-
-	const int pins[][2] = {
-				{0, 7}, {1, 7}, {2, 7}, {3, 6}, {4, 7}, {5, 7},
-				{6, 7}, {10, 7}, {11, 7}, {12, 7}, {13, 6},
-				{14, 7}, {15, 7}, {16, 5}, {20, 6}, {21, 1}
-	};
-
-	for (i = 0; i < ARRAY_SIZE(pins); ++i) {
-		port = pins[i][0];
-		for (j = 0; j <= pins[i][1]; ++j) {
-			flags = system_get_gpio_hibernate_state(port, j);
-			if (flags == 0)
-				continue;
-
-			if (enabled) {
-				MEC1322_GPIO_CTL(port, j) =
-					backup_gpio_ctl[i * 8 + j];
-			} else {
-				if (backup_gpio_ctl != NULL)
-					backup_gpio_ctl[i * 8 + j] =
-						MEC1322_GPIO_CTL(port, j);
-				gpio_set_flags_by_mask(port, 1 << j, flags);
-				gpio_set_alternate_function(port, 1 << j, -1);
-			}
-		}
-	}
-
-#ifdef CONFIG_USB_PD_PORT_COUNT
-	if (!enabled) {
-		/*
-		 * Leave USB-C charging enabled in hibernate, in order to
-		 * allow wake-on-plug. 5V enable must be pulled low.
-		 */
-#if CONFIG_USB_PD_PORT_COUNT > 0
-		gpio_set_flags(GPIO_USB_C0_5V_EN, GPIO_PULL_DOWN | GPIO_INPUT);
-		gpio_set_level(GPIO_USB_C0_CHARGE_EN_L, 0);
-#endif
-#if CONFIG_USB_PD_PORT_COUNT > 1
-		gpio_set_flags(GPIO_USB_C1_5V_EN, GPIO_PULL_DOWN | GPIO_INPUT);
-		gpio_set_level(GPIO_USB_C1_CHARGE_EN_L, 0);
-#endif
-	}
-#endif /* CONFIG_USB_PD_PORT_COUNT */
-}
-
 void system_hibernate(uint32_t seconds, uint32_t microseconds)
 {
 	int i;
-	uint32_t int_status[16];
-	uint32_t int_block_status;
-	uint32_t nvic_status[3];
-	char *backup_gpio_ctl;
 
 #ifdef CONFIG_HOSTCMD_PD
 	/* Inform the PD MCU that we are going to hibernate. */
@@ -293,18 +201,14 @@ void system_hibernate(uint32_t seconds, uint32_t microseconds)
 
 	/* Disable interrupts */
 	interrupt_disable();
-	for (i = 0; i < 3; ++i)
-		nvic_status[i] = CPU_NVIC_EN(i);
 	for (i = 0; i <= 92; ++i) {
 		task_disable_irq(i);
 		task_clear_pending_irq(i);
 	}
 
-	for (i = 8; i <= 23; ++i) {
-		int_status[i - 8] = MEC1322_INT_ENABLE(i);
+	for (i = 8; i <= 23; ++i)
 		MEC1322_INT_DISABLE(i) = 0xffffffff;
-	}
-	int_block_status = MEC1322_INT_BLK_EN;
+
 	MEC1322_INT_BLK_DIS |= 0xffff00;
 
 	/* Power down ADC VREF */
@@ -345,12 +249,24 @@ void system_hibernate(uint32_t seconds, uint32_t microseconds)
 	MEC1322_PCR_SYS_SLP_CTL = (MEC1322_PCR_SYS_SLP_CTL & ~0x7) | 0x2;
 	CPU_SCB_SYSCTRL |= 0x4;
 
-	/* Attempt to backup GPIO states if we need to restore them on wake. */
-#ifndef CONFIG_HIBERNATE_RESET_ON_WAKE
-	if (shared_mem_acquire(512, &backup_gpio_ctl) != EC_SUCCESS)
+	/* Setup GPIOs for hibernate */
+	if (board_set_gpio_hibernate_state)
+		board_set_gpio_hibernate_state();
+
+#ifdef CONFIG_USB_PD_PORT_COUNT
+	/*
+	 * Leave USB-C charging enabled in hibernate, in order to
+	 * allow wake-on-plug. 5V enable must be pulled low.
+	 */
+#if CONFIG_USB_PD_PORT_COUNT > 0
+	gpio_set_flags(GPIO_USB_C0_5V_EN, GPIO_PULL_DOWN | GPIO_INPUT);
+	gpio_set_level(GPIO_USB_C0_CHARGE_EN_L, 0);
 #endif
-		backup_gpio_ctl = NULL;
-	system_set_gpio_power(0, (uint32_t *)backup_gpio_ctl);
+#if CONFIG_USB_PD_PORT_COUNT > 1
+	gpio_set_flags(GPIO_USB_C1_5V_EN, GPIO_PULL_DOWN | GPIO_INPUT);
+	gpio_set_level(GPIO_USB_C1_CHARGE_EN_L, 0);
+#endif
+#endif /* CONFIG_USB_PD_PORT_COUNT */
 
 	if (hibernate_wake_pins_used > 0) {
 		for (i = 0; i < hibernate_wake_pins_used; ++i) {
@@ -393,55 +309,12 @@ void system_hibernate(uint32_t seconds, uint32_t microseconds)
 	/* Use 48MHz clock to speed through wake-up */
 	MEC1322_PCR_PROC_CLK_CTL = 1;
 
-	/* If we didn't back up GPIO status, just reboot. */
-	if (backup_gpio_ctl == NULL)
-		_system_reset(0, 1);
-
-	system_set_gpio_power(1, (uint32_t *)backup_gpio_ctl);
-	shared_mem_release(backup_gpio_ctl);
+	/* Reboot */
+	_system_reset(0, 1);
 
-	/* Enable blocks */
-	MEC1322_PCR_SLOW_CLK_CTL |= 0x1e0;
-	MEC1322_PCR_CHIP_SLP_EN &= ~0x3;
-	MEC1322_PCR_EC_SLP_EN &= MEC1322_PCR_EC_SLP_EN_WAKE;
-	MEC1322_PCR_HOST_SLP_EN &= MEC1322_PCR_HOST_SLP_EN_WAKE;
-	MEC1322_PCR_EC_SLP_EN2 &= MEC1322_PCR_EC_SLP_EN2_WAKE;
-
-	/* Enable timer */
-	MEC1322_TMR32_CTL(0) |= 1;
-	MEC1322_TMR32_CTL(1) |= 1;
-	MEC1322_TMR16_CTL(0) |= 1;
-
-	/* Enable watchdog */
-	MEC1322_WDG_CTL |= 1;
-
-	/* Enable 32KHz clock */
-	MEC1322_VBAT_CE |= 0x2;
-
-	/* Enable JTAG */
-	MEC1322_EC_JTAG_EN |= 1;
-
-	/* Enable UART */
-	MEC1322_LPC_ACT |= 1;
-	MEC1322_UART_ACT |= 1;
-
-	/* Deassert nSIO_RESET */
-	MEC1322_PCR_PWR_RST_CTL &= ~1;
-
-	/* Enable ADC */
-	MEC1322_EC_ADC_VREF_PD &= ~1;
-	MEC1322_ADC_CTRL |= 1 << 0;
-
-	/* Restore interrupts */
-	for (i = 8; i <= 23; ++i)
-		MEC1322_INT_ENABLE(i) = int_status[i - 8];
-	MEC1322_INT_BLK_EN = int_block_status;
-
-	for (i = 0; i < 3; ++i)
-		CPU_NVIC_EN(i) = nvic_status[i];
-
-	/* Restore processor clock */
-	MEC1322_PCR_PROC_CLK_CTL = 4;
+	/* We should never get here. */
+	while (1)
+		;
 }
 
 void htimer_interrupt(void)
diff --git a/chip/npcx/registers.h b/chip/npcx/registers.h
index 35fb568080..abb8936c04 100644
--- a/chip/npcx/registers.h
+++ b/chip/npcx/registers.h
@@ -1400,10 +1400,4 @@ static inline void npcx_gpio2uart(void)
 extern const enum gpio_signal hibernate_wake_pins[];
 extern const int hibernate_wake_pins_used;
 
-/*
- * Optional board-level function to set GPIOs state in hibernate.
- */
-void board_set_gpio_state_hibernate(void)
-	__attribute__((weak));
-
 #endif /* __CROS_EC_REGISTERS_H */
diff --git a/chip/npcx/system.c b/chip/npcx/system.c
index 5abd5ff04e..dd44fce62d 100644
--- a/chip/npcx/system.c
+++ b/chip/npcx/system.c
@@ -353,8 +353,8 @@ void system_set_gpios_and_wakeup_inputs_hibernate(void)
 #endif /* CONFIG_USB_PD_PORT_COUNT */
 
 	/* board-level function to set GPIOs state in hibernate */
-	if (board_set_gpio_state_hibernate)
-		return board_set_gpio_state_hibernate();
+	if (board_set_gpio_hibernate_state)
+		return board_set_gpio_hibernate_state();
 }
 
 /**
diff --git a/include/config.h b/include/config.h
index 23aeb306ef..942608e6e4 100644
--- a/include/config.h
+++ b/include/config.h
@@ -1088,12 +1088,6 @@
 #undef CONFIG_HIBERNATE_BATT_PCT
 #undef CONFIG_HIBERNATE_BATT_SEC
 
-/*
- * Perform a system reset on wake from hibernate. This is the default behavior,
- * and the only chip-supported behavior for certain ECs.
- */
-#define CONFIG_HIBERNATE_RESET_ON_WAKE
-
 /* For ECs with multiple wakeup pins, define enabled wakeup pins */
 #undef CONFIG_HIBERNATE_WAKEUP_PINS
 
diff --git a/include/gpio.h b/include/gpio.h
index 060ef97c33..8c7e420cd9 100644
--- a/include/gpio.h
+++ b/include/gpio.h
@@ -252,4 +252,7 @@ void gpio_set_alternate_function(uint32_t port, uint32_t mask, int func);
  */
 void gpio_enable_clocks(void);
 
+/* Optional board-level function to set hibernate GPIO states. */
+void board_set_gpio_hibernate_state(void) __attribute__((weak));
+
 #endif  /* __CROS_EC_GPIO_H */