summaryrefslogtreecommitdiff
path: root/drivers/acpi/device_pm.c
blob: b4f03f91b0b04194e4e351b0ca5d8a2f002b3308 (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
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
/*
 * drivers/acpi/device_pm.c - ACPI device power management routines.
 *
 * Copyright (C) 2012, Intel Corp.
 * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2 as published
 *  by the Free Software Foundation.
 *
 *  This program is distributed in the hope that it will be useful, but
 *  WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 */

#include <linux/device.h>
#include <linux/export.h>
#include <linux/mutex.h>
#include <linux/pm_qos.h>
#include <linux/pm_runtime.h>

#include <acpi/acpi.h>
#include <acpi/acpi_bus.h>

static DEFINE_MUTEX(acpi_pm_notifier_lock);

/**
 * acpi_add_pm_notifier - Register PM notifier for given ACPI device.
 * @adev: ACPI device to add the notifier for.
 * @context: Context information to pass to the notifier routine.
 *
 * NOTE: @adev need not be a run-wake or wakeup device to be a valid source of
 * PM wakeup events.  For example, wakeup events may be generated for bridges
 * if one of the devices below the bridge is signaling wakeup, even if the
 * bridge itself doesn't have a wakeup GPE associated with it.
 */
acpi_status acpi_add_pm_notifier(struct acpi_device *adev,
				 acpi_notify_handler handler, void *context)
{
	acpi_status status = AE_ALREADY_EXISTS;

	mutex_lock(&acpi_pm_notifier_lock);

	if (adev->wakeup.flags.notifier_present)
		goto out;

	status = acpi_install_notify_handler(adev->handle,
					     ACPI_SYSTEM_NOTIFY,
					     handler, context);
	if (ACPI_FAILURE(status))
		goto out;

	adev->wakeup.flags.notifier_present = true;

 out:
	mutex_unlock(&acpi_pm_notifier_lock);
	return status;
}

/**
 * acpi_remove_pm_notifier - Unregister PM notifier from given ACPI device.
 * @adev: ACPI device to remove the notifier from.
 */
acpi_status acpi_remove_pm_notifier(struct acpi_device *adev,
				    acpi_notify_handler handler)
{
	acpi_status status = AE_BAD_PARAMETER;

	mutex_lock(&acpi_pm_notifier_lock);

	if (!adev->wakeup.flags.notifier_present)
		goto out;

	status = acpi_remove_notify_handler(adev->handle,
					    ACPI_SYSTEM_NOTIFY,
					    handler);
	if (ACPI_FAILURE(status))
		goto out;

	adev->wakeup.flags.notifier_present = false;

 out:
	mutex_unlock(&acpi_pm_notifier_lock);
	return status;
}

/**
 * acpi_device_power_state - Get preferred power state of ACPI device.
 * @dev: Device whose preferred target power state to return.
 * @adev: ACPI device node corresponding to @dev.
 * @target_state: System state to match the resultant device state.
 * @d_max_in: Deepest low-power state to take into consideration.
 * @d_min_p: Location to store the upper limit of the allowed states range.
 * Return value: Preferred power state of the device on success, -ENODEV
 * (if there's no 'struct acpi_device' for @dev) or -EINVAL on failure
 *
 * Find the lowest power (highest number) ACPI device power state that the
 * device can be in while the system is in the state represented by
 * @target_state.  If @d_min_p is set, the highest power (lowest number) device
 * power state that @dev can be in for the given system sleep state is stored
 * at the location pointed to by it.
 *
 * Callers must ensure that @dev and @adev are valid pointers and that @adev
 * actually corresponds to @dev before using this function.
 */
int acpi_device_power_state(struct device *dev, struct acpi_device *adev,
			    u32 target_state, int d_max_in, int *d_min_p)
{
	char acpi_method[] = "_SxD";
	unsigned long long d_min, d_max;
	bool wakeup = false;

	if (d_max_in < ACPI_STATE_D0 || d_max_in > ACPI_STATE_D3)
		return -EINVAL;

	if (d_max_in > ACPI_STATE_D3_HOT) {
		enum pm_qos_flags_status stat;

		stat = dev_pm_qos_flags(dev, PM_QOS_FLAG_NO_POWER_OFF);
		if (stat == PM_QOS_FLAGS_ALL)
			d_max_in = ACPI_STATE_D3_HOT;
	}

	acpi_method[2] = '0' + target_state;
	/*
	 * If the sleep state is S0, the lowest limit from ACPI is D3,
	 * but if the device has _S0W, we will use the value from _S0W
	 * as the lowest limit from ACPI.  Finally, we will constrain
	 * the lowest limit with the specified one.
	 */
	d_min = ACPI_STATE_D0;
	d_max = ACPI_STATE_D3;

	/*
	 * If present, _SxD methods return the minimum D-state (highest power
	 * state) we can use for the corresponding S-states.  Otherwise, the
	 * minimum D-state is D0 (ACPI 3.x).
	 *
	 * NOTE: We rely on acpi_evaluate_integer() not clobbering the integer
	 * provided -- that's our fault recovery, we ignore retval.
	 */
	if (target_state > ACPI_STATE_S0) {
		acpi_evaluate_integer(adev->handle, acpi_method, NULL, &d_min);
		wakeup = device_may_wakeup(dev) && adev->wakeup.flags.valid
			&& adev->wakeup.sleep_state >= target_state;
	} else if (dev_pm_qos_flags(dev, PM_QOS_FLAG_REMOTE_WAKEUP) !=
			PM_QOS_FLAGS_NONE) {
		wakeup = adev->wakeup.flags.valid;
	}

	/*
	 * If _PRW says we can wake up the system from the target sleep state,
	 * the D-state returned by _SxD is sufficient for that (we assume a
	 * wakeup-aware driver if wake is set).  Still, if _SxW exists
	 * (ACPI 3.x), it should return the maximum (lowest power) D-state that
	 * can wake the system.  _S0W may be valid, too.
	 */
	if (wakeup) {
		acpi_status status;

		acpi_method[3] = 'W';
		status = acpi_evaluate_integer(adev->handle, acpi_method, NULL,
						&d_max);
		if (ACPI_FAILURE(status)) {
			if (target_state != ACPI_STATE_S0 ||
			    status != AE_NOT_FOUND)
				d_max = d_min;
		} else if (d_max < d_min) {
			/* Warn the user of the broken DSDT */
			printk(KERN_WARNING "ACPI: Wrong value from %s\n",
				acpi_method);
			/* Sanitize it */
			d_min = d_max;
		}
	}

	if (d_max_in < d_min)
		return -EINVAL;
	if (d_min_p)
		*d_min_p = d_min;
	/* constrain d_max with specified lowest limit (max number) */
	if (d_max > d_max_in) {
		for (d_max = d_max_in; d_max > d_min; d_max--) {
			if (adev->power.states[d_max].flags.valid)
				break;
		}
	}
	return d_max;
}
EXPORT_SYMBOL_GPL(acpi_device_power_state);

#ifdef CONFIG_PM_RUNTIME
/**
 * __acpi_device_run_wake - Enable/disable runtime remote wakeup for device.
 * @adev: ACPI device to enable/disable the remote wakeup for.
 * @enable: Whether to enable or disable the wakeup functionality.
 *
 * Enable/disable the GPE associated with @adev so that it can generate
 * wakeup signals for the device in response to external (remote) events and
 * enable/disable device wakeup power.
 *
 * Callers must ensure that @adev is a valid ACPI device node before executing
 * this function.
 */
int __acpi_device_run_wake(struct acpi_device *adev, bool enable)
{
	struct acpi_device_wakeup *wakeup = &adev->wakeup;

	if (enable) {
		acpi_status res;
		int error;

		error = acpi_enable_wakeup_device_power(adev, ACPI_STATE_S0);
		if (error)
			return error;

		res = acpi_enable_gpe(wakeup->gpe_device, wakeup->gpe_number);
		if (ACPI_FAILURE(res)) {
			acpi_disable_wakeup_device_power(adev);
			return -EIO;
		}
	} else {
		acpi_disable_gpe(wakeup->gpe_device, wakeup->gpe_number);
		acpi_disable_wakeup_device_power(adev);
	}
	return 0;
}

/**
 * acpi_pm_device_run_wake - Enable/disable remote wakeup for given device.
 * @dev: Device to enable/disable the platform to wake up.
 * @enable: Whether to enable or disable the wakeup functionality.
 */
int acpi_pm_device_run_wake(struct device *phys_dev, bool enable)
{
	struct acpi_device *adev;
	acpi_handle handle;

	if (!device_run_wake(phys_dev))
		return -EINVAL;

	handle = DEVICE_ACPI_HANDLE(phys_dev);
	if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &adev))) {
		dev_dbg(phys_dev, "ACPI handle without context in %s!\n",
			__func__);
		return -ENODEV;
	}

	return __acpi_device_run_wake(adev, enable);
}
EXPORT_SYMBOL(acpi_pm_device_run_wake);
#endif /* CONFIG_PM_RUNTIME */

 #ifdef CONFIG_PM_SLEEP
/**
 * __acpi_device_sleep_wake - Enable or disable device to wake up the system.
 * @dev: Device to enable/desible to wake up the system.
 * @target_state: System state the device is supposed to wake up from.
 * @enable: Whether to enable or disable @dev to wake up the system.
 */
int __acpi_device_sleep_wake(struct acpi_device *adev, u32 target_state,
			     bool enable)
{
	return enable ?
		acpi_enable_wakeup_device_power(adev, target_state) :
		acpi_disable_wakeup_device_power(adev);
}
#endif /* CONFIG_PM_SLEEP */