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>

1 files changed, 135 insertions, 0 deletions

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);
+