Split out power button code from switch.c

The power button code is platform-independent.  This change splits the
code out of the LM4 switch.c module so that a subseqent change to
STM32 platforms can start using it.

BUG=chrome-os-partner:18945
BRANCH=none
TEST=manual

1. Power+refresh+esc goes to recovery mode,
2. Press power button at recovery screen turns off.
3. With system off, power button turns system on.
4. Press power button for a second; screen locks.
5. Press power button while typing; blocks keystrokes while it's pressed.
6. Hold power button down for 8 sec; system forced to shutdown.
7. From EC console, with system on:
   hostevent clear
   hostevent -> event 0x04 is clear
   press power button
   hostevent -> event 0x04 is set
8. From EC console, with system off:
   powerbtn -> system turns on
   powerbtn 5000 -> system turns off, just like power button was held for 5 sec

Change-Id: If2a9b02514a201e1d03c857d128e2ccab51a16ef
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/49217
Reviewed-by: Bill Richardson <wfrichar@chromium.org>

13 files changed, 261 insertions, 175 deletions

diff --git a/board/link/board.c b/board/link/board.c
index ba1a26679d..28ff9b3a14 100644
--- a/board/link/board.c
+++ b/board/link/board.c
@@ -14,6 +14,7 @@
 #include "lid_switch.h"
 #include "lm4_adc.h"
 #include "peci.h"
+#include "power_button.h"
 #include "registers.h"
 #include "switch.h"
 #include "temp_sensor.h"
@@ -26,7 +27,7 @@
 const struct gpio_info gpio_list[GPIO_COUNT] = {
 	/* Inputs with interrupt handlers are first for efficiency */
 	{"POWER_BUTTON_L",       LM4_GPIO_K, (1<<7), GPIO_INT_BOTH,
-	 switch_interrupt},
+	 power_button_interrupt},
 	{"LID_OPEN",             LM4_GPIO_K, (1<<5), GPIO_INT_BOTH,
 	 lid_interrupt},
 	/* Other inputs */
diff --git a/board/link/board.h b/board/link/board.h
index e0c4170c9b..2cbd12d643 100644
--- a/board/link/board.h
+++ b/board/link/board.h
@@ -32,6 +32,7 @@
 #define CONFIG_ONEWIRE
 #define CONFIG_ONEWIRE_LED
 #define CONFIG_PECI
+#define CONFIG_POWER_BUTTON
 #define CONFIG_PWM
 #define CONFIG_TEMP_SENSOR
 #define CONFIG_TMP006
diff --git a/chip/lm4/switch.c b/chip/lm4/switch.c
index f323c81060..b461d1a63c 100644
--- a/chip/lm4/switch.c
+++ b/chip/lm4/switch.c
@@ -15,6 +15,7 @@
 #include "keyboard_protocol.h"
 #include "keyboard_scan.h"
 #include "lid_switch.h"
+#include "power_button.h"
 #include "pwm.h"
 #include "switch.h"
 #include "system.h"
@@ -43,7 +44,6 @@
  *     @S0   make code             break code
  */
 /* TODO: link to full power button / lid switch state machine description. */
-#define PWRBTN_DEBOUNCE_US (30 * MSEC)  /* Debounce time for power button */
 #define PWRBTN_DELAY_T0    (32 * MSEC)  /* 32ms (PCH requires >16ms) */
 #define PWRBTN_DELAY_T1    (4 * SECOND - PWRBTN_DELAY_T0)  /* 4 secs - t0 */
 /*
@@ -109,8 +109,6 @@ static uint64_t tnext_state;
 static uint64_t tdebounce_pwr;
 
 static uint8_t *memmap_switches;
-static int debounced_power_pressed;
-static int simulate_power_pressed;
 
 /**
  * Update status of non-debounced switches.
@@ -147,23 +145,6 @@ static void set_pwrbtn_to_pch(int high)
 	gpio_set_level(GPIO_PCH_PWRBTN_L, high);
 }
 
-/**
- * Get raw power button signal state.
- *
- * @return 1 if power button is pressed, 0 if not pressed.
- */
-static int raw_power_button_pressed(void)
-{
-	if (simulate_power_pressed)
-		return 1;
-
-	/* Ignore power button if lid is closed */
-	if (!lid_is_open())
-		return 0;
-
-	return gpio_get_level(GPIO_POWER_BUTTON_L) ? 0 : 1;
-}
-
 static void update_backlight(void)
 {
 	/* Only enable the backlight if the lid is open */
@@ -181,20 +162,10 @@ static void update_backlight(void)
  */
 static void power_button_pressed(uint64_t tnow)
 {
-	if (debounced_power_pressed == 1) {
-		CPRINTF("[%T PB already pressed]\n");
-		return;
-	}
-
 	CPRINTF("[%T PB pressed]\n");
-	debounced_power_pressed = 1;
 	pwrbtn_state = PWRBTN_STATE_PRESSED;
 	tnext_state = tnow;
 	*memmap_switches |= EC_SWITCH_POWER_BUTTON_PRESSED;
-#ifdef HAS_TASK_KEYPROTO
-	keyboard_set_power_button(1);
-#endif
-	host_set_single_event(EC_HOST_EVENT_POWER_BUTTON);
 }
 
 /**
@@ -202,52 +173,10 @@ static void power_button_pressed(uint64_t tnow)
  */
 static void power_button_released(uint64_t tnow)
 {
-	if (debounced_power_pressed == 0) {
-		CPRINTF("[%T PB already released]\n");
-		return;
-	}
-
 	CPRINTF("[%T PB released]\n");
-	debounced_power_pressed = 0;
 	pwrbtn_state = PWRBTN_STATE_RELEASED;
 	tnext_state = tnow;
 	*memmap_switches &= ~EC_SWITCH_POWER_BUTTON_PRESSED;
-#ifdef HAS_TASK_KEYPROTO
-	keyboard_set_power_button(0);
-#endif
-}
-
-/**
- * Handle debounced power button changing state.
- */
-static void power_button_changed(uint64_t tnow)
-{
-	if (pwrbtn_state == PWRBTN_STATE_BOOT_KB_RESET ||
-	    pwrbtn_state == PWRBTN_STATE_INIT_ON ||
-	    pwrbtn_state == PWRBTN_STATE_LID_OPEN ||
-	    pwrbtn_state == PWRBTN_STATE_WAS_OFF) {
-		/* Ignore all power button changes during an initial pulse */
-		CPRINTF("[%T PB ignoring change]\n");
-		return;
-	}
-
-	if (raw_power_button_pressed()) {
-		/* Power button pressed */
-		power_button_pressed(tnow);
-	} else {
-		/* Power button released */
-		if (pwrbtn_state == PWRBTN_STATE_EAT_RELEASE) {
-			/*
-			 * Ignore the first power button release if we already
-			 * told the PCH the power button was released.
-			 */
-			CPRINTF("[%T PB ignoring release]\n");
-			pwrbtn_state = PWRBTN_STATE_IDLE;
-			return;
-		}
-
-		power_button_released(tnow);
-	}
 }
 
 /**
@@ -257,16 +186,13 @@ static void set_initial_pwrbtn_state(void)
 {
 	uint32_t reset_flags = system_get_reset_flags();
 
-	/* Set debounced power button state to initial button state */
-	debounced_power_pressed = raw_power_button_pressed();
-
 	if (system_jumped_to_this_image() &&
 	    chipset_in_state(CHIPSET_STATE_ON)) {
 		/*
 		 * Jumped to this image while the chipset was already on, so
 		 * simply reflect the actual power button state.
 		 */
-		if (debounced_power_pressed) {
+		if (power_button_is_pressed()) {
 			*memmap_switches |= EC_SWITCH_POWER_BUTTON_PRESSED;
 			CPRINTF("[%T PB init-jumped-held]\n");
 			set_pwrbtn_to_pch(0);
@@ -288,7 +214,7 @@ static void set_initial_pwrbtn_state(void)
 		 */
 		CPRINTF("[%T PB init-off]\n");
 		set_pwrbtn_to_pch(1);
-		if (debounced_power_pressed)
+		if (power_button_is_pressed())
 			pwrbtn_state = PWRBTN_STATE_EAT_RELEASE;
 		else
 			pwrbtn_state = PWRBTN_STATE_IDLE;
@@ -386,7 +312,7 @@ static void state_machine(uint64_t tnow)
 		set_pwrbtn_to_pch(0);
 		tnext_state = get_time().val + PWRBTN_INITIAL_US;
 
-		if (debounced_power_pressed) {
+		if (power_button_is_pressed()) {
 			*memmap_switches |= EC_SWITCH_POWER_BUTTON_PRESSED;
 
 			if (system_get_reset_flags() & RESET_FLAG_RESET_PIN)
@@ -405,7 +331,7 @@ static void state_machine(uint64_t tnow)
 		 * recovery combination doesn't cause the chipset to shut back
 		 * down. */
 		set_pwrbtn_to_pch(1);
-		if (raw_power_button_pressed())
+		if (power_button_is_pressed())
 			pwrbtn_state = PWRBTN_STATE_EAT_RELEASE;
 		else
 			pwrbtn_state = PWRBTN_STATE_IDLE;
@@ -413,7 +339,7 @@ static void state_machine(uint64_t tnow)
 	case PWRBTN_STATE_WAS_OFF:
 		/* Done stretching initial power button signal, so show the
 		 * true power button state to the PCH. */
-		if (raw_power_button_pressed()) {
+		if (power_button_is_pressed()) {
 			/* User is still holding the power button */
 			pwrbtn_state = PWRBTN_STATE_HELD;
 		} else {
@@ -437,22 +363,6 @@ void switch_task(void)
 	while (1) {
 		t = get_time().val;
 
-		/* Handle debounce timeout for power button */
-		if (tdebounce_pwr && t >= tdebounce_pwr) {
-			tdebounce_pwr = 0;
-
-			/*
-			 * Re-enable keyboard scanning if the power button is
-			 * no longer pressed.
-			 */
-			if (!raw_power_button_pressed())
-				keyboard_scan_enable(1);
-
-			if (raw_power_button_pressed() !=
-			    debounced_power_pressed)
-				power_button_changed(t);
-		}
-
 		/* Handle non-debounced switches */
 		update_other_switches();
 
@@ -537,22 +447,47 @@ static void switch_lid_change(void)
 }
 DECLARE_HOOK(HOOK_LID_CHANGE, switch_lid_change, HOOK_PRIO_DEFAULT);
 
-void switch_interrupt(enum gpio_signal signal)
+/**
+ * Handle debounced power button changing state.
+ */
+static void power_button_changed(void)
 {
-	/* Reset debounce time for the changed signal */
-	switch (signal) {
-	case GPIO_POWER_BUTTON_L:
-		/* Reset power button debounce time */
-		tdebounce_pwr = get_time().val + PWRBTN_DEBOUNCE_US;
-		if (raw_power_button_pressed()) {
+	if (pwrbtn_state == PWRBTN_STATE_BOOT_KB_RESET ||
+	    pwrbtn_state == PWRBTN_STATE_INIT_ON ||
+	    pwrbtn_state == PWRBTN_STATE_LID_OPEN ||
+	    pwrbtn_state == PWRBTN_STATE_WAS_OFF) {
+		/* Ignore all power button changes during an initial pulse */
+		CPRINTF("[%T PB ignoring change]\n");
+		return;
+	}
+
+	if (power_button_is_pressed()) {
+		/* Power button pressed */
+		power_button_pressed(get_time().val);
+	} else {
+		/* Power button released */
+		if (pwrbtn_state == PWRBTN_STATE_EAT_RELEASE) {
 			/*
-			 * Disable the matrix scan as soon as possible to
-			 * reduce the risk of false-reboot triggered by those
-			 * keys on the same column with refresh key.
+			 * Ignore the first power button release if we already
+			 * told the PCH the power button was released.
 			 */
-			keyboard_scan_enable(0);
+			CPRINTF("[%T PB ignoring release]\n");
+			pwrbtn_state = PWRBTN_STATE_IDLE;
+			return;
 		}
-		break;
+
+		power_button_released(get_time().val);
+	}
+
+	/* Wake the switch task */
+	task_wake(TASK_ID_SWITCH);
+}
+DECLARE_HOOK(HOOK_POWER_BUTTON_CHANGE, power_button_changed, HOOK_PRIO_DEFAULT);
+
+void switch_interrupt(enum gpio_signal signal)
+{
+	/* Reset debounce time for the changed signal */
+	switch (signal) {
 	case GPIO_PCH_BKLTEN:
 		update_backlight();
 		break;
@@ -574,39 +509,6 @@ void switch_interrupt(enum gpio_signal signal)
 	task_wake(TASK_ID_SWITCH);
 }
 
-/*****************************************************************************/
-/* Console commands */
-
-static int command_powerbtn(int argc, char **argv)
-{
-	int ms = PWRBTN_INITIAL_US / MSEC;  /* Press duration in ms */
-	char *e;
-
-	if (argc > 1) {
-		ms = strtoi(argv[1], &e, 0);
-		if (*e)
-			return EC_ERROR_PARAM1;
-	}
-
-	ccprintf("Simulating %d ms power button press.\n", ms);
-	simulate_power_pressed = 1;
-	tdebounce_pwr = get_time().val + PWRBTN_DEBOUNCE_US;
-	task_wake(TASK_ID_SWITCH);
-
-	msleep(ms);
-
-	ccprintf("Simulating power button release.\n");
-	simulate_power_pressed = 0;
-	tdebounce_pwr = get_time().val + PWRBTN_DEBOUNCE_US;
-	task_wake(TASK_ID_SWITCH);
-
-	return EC_SUCCESS;
-}
-DECLARE_CONSOLE_COMMAND(powerbtn, command_powerbtn,
-			"[msec]",
-			"Simulate power button press",
-			NULL);
-
 static int command_mmapinfo(int argc, char **argv)
 {
 	uint8_t *memmap_switches = host_get_memmap(EC_MEMMAP_SWITCHES);
diff --git a/common/build.mk b/common/build.mk
index 3eb16d01a9..9b3297c7bf 100644
--- a/common/build.mk
+++ b/common/build.mk
@@ -30,6 +30,7 @@ common-$(CONFIG_LID_SWITCH)+=lid_switch.o
 common-$(CONFIG_LP5562)+=lp5562.o lp5562_battery_led.o
 common-$(CONFIG_LPC)+=port80.o
 common-$(CONFIG_ONEWIRE_LED)+=onewire_led.o
+common-$(CONFIG_POWER_BUTTON)+=power_button.o
 common-$(CONFIG_PSTORE)+=pstore_commands.o
 common-$(CONFIG_SMART_BATTERY)+=smart_battery.o smart_battery_stub.o
 common-$(HAS_TASK_CHIPSET)+=chipset.o
diff --git a/common/hooks.c b/common/hooks.c
index 3597a77ea8..d239e3abc2 100644
--- a/common/hooks.c
+++ b/common/hooks.c
@@ -42,6 +42,7 @@ static const struct hook_ptrs hook_list[] = {
 	{__hooks_chipset_shutdown, __hooks_chipset_shutdown_end},
 	{__hooks_ac_change, __hooks_ac_change_end},
 	{__hooks_lid_change, __hooks_lid_change_end},
+	{__hooks_pwrbtn_change, __hooks_pwrbtn_change_end},
 	{__hooks_tick, __hooks_tick_end},
 	{__hooks_second, __hooks_second_end},
 };
diff --git a/common/keyboard_8042.c b/common/keyboard_8042.c
index a65c935558..8e2646cb4a 100644
--- a/common/keyboard_8042.c
+++ b/common/keyboard_8042.c
@@ -15,6 +15,7 @@
 #include "keyboard_protocol.h"
 #include "lightbar.h"
 #include "lpc.h"
+#include "power_button.h"
 #include "queue.h"
 #include "registers.h"
 #include "shared_mem.h"
@@ -831,34 +832,6 @@ static void keyboard_special(uint16_t k)
 	}
 }
 
-
-void keyboard_set_power_button(int pressed)
-{
-	enum scancode_set_list code_set;
-	uint8_t code[2][2][3] = {
-		{  /* set 1 */
-			{0xe0, 0xde},        /* break */
-			{0xe0, 0x5e},        /* make */
-		}, {  /* set 2 */
-			{0xe0, 0xf0, 0x37},  /* break */
-			{0xe0, 0x37},        /* make */
-		}
-	};
-
-	power_button_pressed = pressed;
-
-	/* Only send the scan code if main chipset is fully awake */
-	if (!chipset_in_state(CHIPSET_STATE_ON))
-		return;
-
-	code_set = acting_code_set(scancode_set);
-	if (keystroke_enabled) {
-		i8042_send_to_host(
-			 (code_set == SCANCODE_SET_2 && !pressed) ? 3 : 2,
-			 code[code_set - SCANCODE_SET_1][pressed]);
-	}
-}
-
 void keyboard_protocol_task(void)
 {
 	int wait = -1;
@@ -1097,3 +1070,36 @@ static void keyboard_restore_state(void)
 	}
 }
 DECLARE_HOOK(HOOK_INIT, keyboard_restore_state, HOOK_PRIO_DEFAULT);
+
+/**
+ * Handle power button changing state.
+ */
+static void keyboard_power_button(void)
+{
+	enum scancode_set_list code_set;
+	uint8_t code[2][2][3] = {
+		{  /* set 1 */
+			{0xe0, 0xde},        /* break */
+			{0xe0, 0x5e},        /* make */
+		}, {  /* set 2 */
+			{0xe0, 0xf0, 0x37},  /* break */
+			{0xe0, 0x37},        /* make */
+		}
+	};
+
+	power_button_pressed = power_button_is_pressed();
+
+	/*
+	 * Only send the scan code if main chipset is fully awake and
+	 * keystrokes are enabled.
+	 */
+	if (!chipset_in_state(CHIPSET_STATE_ON) || !keystroke_enabled)
+		return;
+
+	code_set = acting_code_set(scancode_set);
+	i8042_send_to_host(
+		(code_set == SCANCODE_SET_2 && !power_button_pressed) ? 3 : 2,
+		code[code_set - SCANCODE_SET_1][power_button_pressed]);
+}
+DECLARE_HOOK(HOOK_POWER_BUTTON_CHANGE, keyboard_power_button,
+	     HOOK_PRIO_DEFAULT);
diff --git a/common/lid_switch.c b/common/lid_switch.c
index 0f83f7c318..8e1e1bf082 100644
--- a/common/lid_switch.c
+++ b/common/lid_switch.c
@@ -10,6 +10,7 @@
 #include "gpio.h"
 #include "hooks.h"
 #include "host_command.h"
+#include "lid_switch.h"
 #include "timer.h"
 #include "util.h"
 
diff --git a/common/power_button.c b/common/power_button.c
new file mode 100644
index 0000000000..c26fb8d5d4
--- /dev/null
+++ b/common/power_button.c
@@ -0,0 +1,135 @@
+/* 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.
+ */
+
+/* Power button module for Chrome EC */
+
+#include "common.h"
+#include "console.h"
+#include "gpio.h"
+#include "hooks.h"
+#include "host_command.h"
+#include "keyboard_scan.h"
+#include "lid_switch.h"
+#include "power_button.h"
+#include "timer.h"
+#include "util.h"
+
+/* Console output macros */
+#define CPUTS(outstr) cputs(CC_SWITCH, outstr)
+#define CPRINTF(format, args...) cprintf(CC_SWITCH, format, ## args)
+
+#define PWRBTN_DEBOUNCE_US (30 * MSEC)  /* Debounce time for power button */
+
+static int debounced_power_pressed;	/* Debounced power button state */
+static int simulate_power_pressed;
+
+/**
+ * Get raw power button signal state.
+ *
+ * @return 1 if power button is pressed, 0 if not pressed.
+ */
+static int raw_power_button_pressed(void)
+{
+	if (simulate_power_pressed)
+		return 1;
+
+	/* Ignore power button if lid is closed */
+	if (!lid_is_open())
+		return 0;
+
+	return gpio_get_level(GPIO_POWER_BUTTON_L) ? 0 : 1;
+}
+
+int power_button_is_pressed(void)
+{
+	return debounced_power_pressed;
+}
+
+/**
+ * Handle power button initialization.
+ */
+static void power_button_init(void)
+{
+	if (raw_power_button_pressed())
+		debounced_power_pressed = 1;
+
+	/* Enable interrupts, now that we've initialized */
+	gpio_enable_interrupt(GPIO_POWER_BUTTON_L);
+}
+DECLARE_HOOK(HOOK_INIT, power_button_init, HOOK_PRIO_INIT_POWER_BUTTON);
+
+/**
+ * Handle debounced power button changing state.
+ */
+static void power_button_change_deferred(void)
+{
+	const int new_pressed = raw_power_button_pressed();
+
+	/* If power button hasn't changed state, nothing to do */
+	if (new_pressed == debounced_power_pressed)
+		return;
+
+	debounced_power_pressed = new_pressed;
+
+	CPRINTF("[%T power button %s]\n", new_pressed ? "pressed" : "released");
+
+	/* Re-enable keyboard scanning if power button is no longer pressed */
+	if (!new_pressed)
+		keyboard_scan_enable(1);
+
+	/* Call hooks */
+	hook_notify(HOOK_POWER_BUTTON_CHANGE);
+
+	/* Notify host if power button has been pressed */
+	if (new_pressed)
+		host_set_single_event(EC_HOST_EVENT_POWER_BUTTON);
+}
+DECLARE_DEFERRED(power_button_change_deferred);
+
+void power_button_interrupt(enum gpio_signal signal)
+{
+	/*
+	 * If power button is pressed, disable the matrix scan as soon as
+	 * possible to reduce the risk of false-reboot triggered by those keys
+	 * on the same column with refresh key.
+	 */
+	if (raw_power_button_pressed())
+		keyboard_scan_enable(0);
+
+	/* Reset power button debounce time */
+	hook_call_deferred(power_button_change_deferred, PWRBTN_DEBOUNCE_US);
+}
+
+/*****************************************************************************/
+/* Console commands */
+
+static int command_powerbtn(int argc, char **argv)
+{
+	int ms = 200;  /* Press duration in ms */
+	char *e;
+
+	if (argc > 1) {
+		ms = strtoi(argv[1], &e, 0);
+		if (*e)
+			return EC_ERROR_PARAM1;
+	}
+
+	ccprintf("Simulating %d ms power button press.\n", ms);
+	simulate_power_pressed = 1;
+	hook_call_deferred(power_button_change_deferred, 0);
+
+	msleep(ms);
+
+	ccprintf("Simulating power button release.\n");
+	simulate_power_pressed = 0;
+	hook_call_deferred(power_button_change_deferred, 0);
+
+	return EC_SUCCESS;
+}
+DECLARE_CONSOLE_COMMAND(powerbtn, command_powerbtn,
+			"[msec]",
+			"Simulate power button press",
+			NULL);
+
diff --git a/core/cortex-m/ec.lds.S b/core/cortex-m/ec.lds.S
index 339ee4f435..9a8f09c9ba 100644
--- a/core/cortex-m/ec.lds.S
+++ b/core/cortex-m/ec.lds.S
@@ -96,6 +96,10 @@ SECTIONS
         *(.rodata.HOOK_LID_CHANGE)
         __hooks_lid_change_end = .;
 
+        __hooks_pwrbtn_change = .;
+        *(.rodata.HOOK_POWER_BUTTON_CHANGE)
+        __hooks_pwrbtn_change_end = .;
+
         __hooks_tick = .;
         *(.rodata.HOOK_TICK)
         __hooks_tick_end = .;
diff --git a/core/cortex-m/link_defs.h b/core/cortex-m/link_defs.h
index f78a7c46c4..6681d6b371 100644
--- a/core/cortex-m/link_defs.h
+++ b/core/cortex-m/link_defs.h
@@ -38,6 +38,8 @@ extern const struct hook_data __hooks_ac_change[];
 extern const struct hook_data __hooks_ac_change_end[];
 extern const struct hook_data __hooks_lid_change[];
 extern const struct hook_data __hooks_lid_change_end[];
+extern const struct hook_data __hooks_pwrbtn_change[];
+extern const struct hook_data __hooks_pwrbtn_change_end[];
 extern const struct hook_data __hooks_tick[];
 extern const struct hook_data __hooks_tick_end[];
 extern const struct hook_data __hooks_second[];
diff --git a/include/hooks.h b/include/hooks.h
index 084e9bb36b..59f982eaee 100644
--- a/include/hooks.h
+++ b/include/hooks.h
@@ -25,6 +25,8 @@ enum hook_priority {
 	HOOK_PRIO_INIT_CHIPSET = HOOK_PRIO_FIRST + 2,
 	/* Lid switch inits before power button */
 	HOOK_PRIO_INIT_LID = HOOK_PRIO_FIRST + 3,
+	/* Power button inits before chipset and switch */
+	HOOK_PRIO_INIT_POWER_BUTTON = HOOK_PRIO_FIRST + 4,
 };
 
 enum hook_type {
@@ -106,6 +108,14 @@ enum hook_type {
 	HOOK_LID_CHANGE,
 
 	/*
+	 * Power button pressed or released.  Based on debounced power button
+	 * state, not raw GPIO input.
+	 *
+	 * Hook routines are called from the chipset task.
+	 */
+	HOOK_POWER_BUTTON_CHANGE,
+
+	/*
 	 * Periodic tick, every HOOK_TICK_INTERVAL.
 	 *
 	 * Hook routines will be called from the TICK task.
diff --git a/include/keyboard_8042.h b/include/keyboard_8042.h
index a0d3389d11..b0a247893f 100644
--- a/include/keyboard_8042.h
+++ b/include/keyboard_8042.h
@@ -27,9 +27,4 @@ void keyboard_host_write(int data, int is_cmd);
  */
 void keyboard_state_changed(int row, int col, int is_pressed);
 
-/**
- * Send make/break code of power button to host.
- */
-void keyboard_set_power_button(int pressed);
-
 #endif  /* __CROS_EC_KEYBOARD_8042_H */
diff --git a/include/power_button.h b/include/power_button.h
new file mode 100644
index 0000000000..f3da24da9b
--- /dev/null
+++ b/include/power_button.h
@@ -0,0 +1,27 @@
+/* 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.
+ */
+
+/* Power button API for Chrome EC */
+
+#ifndef __CROS_EC_POWER_BUTTON_H
+#define __CROS_EC_POWER_BUTTON_H
+
+#include "common.h"
+
+/**
+ * Return non-zero if power button is pressed.
+ *
+ * Uses the debounced button state, not the raw signal from the GPIO.
+ */
+int power_button_is_pressed(void);
+
+/**
+ * Interrupt handler for power button.
+ *
+ * @param signal	Signal which triggered the interrupt.
+ */
+void power_button_interrupt(enum gpio_signal signal);
+
+#endif  /* __CROS_EC_POWER_BUTTON_H */