summaryrefslogtreecommitdiff
path: root/common/power_button.c
blob: 1ac389349279aac16a71c5e3a702ea1600c0624f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
/* Copyright 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 "button.h"
#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 "system.h"
#include "task.h"
#include "timer.h"
#include "util.h"

/* Console output macros */
#define CPUTS(outstr) cputs(CC_SWITCH, outstr)
#define CPRINTS(format, args...) cprints(CC_SWITCH, format, ## args)

/* By default the power button is active low */
#ifndef CONFIG_POWER_BUTTON_FLAGS
#define CONFIG_POWER_BUTTON_FLAGS 0
#endif

static int debounced_power_pressed;	/* Debounced power button state */
static int simulate_power_pressed;
static volatile int power_button_is_stable = 1;

static const struct button_config power_button = {
	.name = "power button",
	.gpio = GPIO_POWER_BUTTON_L,
	.debounce_us = BUTTON_DEBOUNCE_US,
	.flags = CONFIG_POWER_BUTTON_FLAGS,
};

int power_button_signal_asserted(void)
{
	return !!(gpio_get_level(power_button.gpio)
		== (power_button.flags & BUTTON_FLAG_ACTIVE_HIGH) ? 1 : 0);
}

/**
 * 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;

#ifndef CONFIG_POWER_BUTTON_IGNORE_LID
	/*
	 * Always indicate power button released if the lid is closed.
	 * This prevents waking the system if the device is squashed enough to
	 * press the power button through the closed lid.
	 */
	if (!lid_is_open())
		return 0;
#endif

	return power_button_signal_asserted();
}

int power_button_is_pressed(void)
{
	return debounced_power_pressed;
}

int power_button_wait_for_release(int timeout_us)
{
	timestamp_t deadline;
	timestamp_t now = get_time();

	deadline.val = now.val + timeout_us;

	while (!power_button_is_stable || power_button_is_pressed()) {
		now = get_time();
		if (timeout_us >= 0 && timestamp_expired(deadline, &now)) {
			CPRINTS("%s not released in time", power_button.name);
			return EC_ERROR_TIMEOUT;
		}
		/*
		 * We use task_wait_event() instead of usleep() here. It will
		 * be woken up immediately if the power button is debouned and
		 * changed. However, it is not guaranteed, like the cases that
		 * the power button is debounced but not changed, or the power
		 * button has not been debounced.
		 */
		task_wait_event(MIN(power_button.debounce_us,
				    deadline.val - now.val));
	}

	CPRINTS("%s released in time", power_button.name);
	return EC_SUCCESS;
}

/**
 * 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(power_button.gpio);
}
DECLARE_HOOK(HOOK_INIT, power_button_init, HOOK_PRIO_INIT_POWER_BUTTON);

#ifdef CONFIG_POWER_BUTTON_INIT_IDLE
/*
 * Set/clear AP_IDLE flag. It's set when the system gracefully shuts down and
 * it's cleared when the system boots up. The result is the system tries to
 * go back to the previous state upon AC plug-in. If the system uncleanly
 * shuts down, it boots immediately. If the system shuts down gracefully,
 * it'll stay at S5 and wait for power button press.
 */
static void pb_chipset_startup(void)
{
	chip_save_reset_flags(chip_read_reset_flags() & ~EC_RESET_FLAG_AP_IDLE);
	system_clear_reset_flags(EC_RESET_FLAG_AP_IDLE);
	CPRINTS("Cleared AP_IDLE flag");
}
DECLARE_HOOK(HOOK_CHIPSET_STARTUP, pb_chipset_startup, HOOK_PRIO_DEFAULT);

static void pb_chipset_shutdown(void)
{
	chip_save_reset_flags(chip_read_reset_flags() | EC_RESET_FLAG_AP_IDLE);
	system_set_reset_flags(EC_RESET_FLAG_AP_IDLE);
	CPRINTS("Saved AP_IDLE flag");
}
DECLARE_HOOK(HOOK_CHIPSET_SHUTDOWN, pb_chipset_shutdown,
	     /*
	      * Slightly higher than handle_pending_reboot because
	      * it may clear AP_IDLE flag.
	      */
	     HOOK_PRIO_DEFAULT - 1);
#endif

/**
 * Handle debounced power button changing state.
 */
static void power_button_change_deferred(void)
{
	const int new_pressed = raw_power_button_pressed();

	/* Re-enable keyboard scanning if power button is no longer pressed */
	if (!new_pressed)
		keyboard_scan_enable(1, KB_SCAN_DISABLE_POWER_BUTTON);

	/* If power button hasn't changed state, nothing to do */
	if (new_pressed == debounced_power_pressed) {
		power_button_is_stable = 1;
		return;
	}

	debounced_power_pressed = new_pressed;
	power_button_is_stable = 1;

	CPRINTS("%s %s",
		power_button.name, new_pressed ? "pressed" : "released");

	/* 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, KB_SCAN_DISABLE_POWER_BUTTON);

	/* Reset power button debounce time */
	power_button_is_stable = 0;
	hook_call_deferred(&power_button_change_deferred_data,
			   power_button.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 %s press.\n", ms, power_button.name);
	simulate_power_pressed = 1;
	power_button_is_stable = 0;
	hook_call_deferred(&power_button_change_deferred_data, 0);

	if (ms > 0)
		msleep(ms);

	ccprintf("Simulating %s release.\n", power_button.name);
	simulate_power_pressed = 0;
	power_button_is_stable = 0;
	hook_call_deferred(&power_button_change_deferred_data, 0);

	return EC_SUCCESS;
}
DECLARE_CONSOLE_COMMAND(powerbtn, command_powerbtn,
			"[msec]",
			"Simulate power button press");