summaryrefslogtreecommitdiffstats
path: root/drivers/acpi/acpi_tad.c
blob: e99c4ed7e677885a520a0fdfc4a097b5aceda2c2 (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
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
// SPDX-License-Identifier: GPL-2.0
/*
 * ACPI Time and Alarm (TAD) Device Driver
 *
 * Copyright (C) 2018 Intel Corporation
 * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
 *
 * This driver is based on Section 9.18 of the ACPI 6.2 specification revision.
 *
 * It only supports the system wakeup capabilities of the TAD.
 *
 * Provided are sysfs attributes, available under the TAD platform device,
 * allowing user space to manage the AC and DC wakeup timers of the TAD:
 * set and read their values, set and check their expire timer wake policies,
 * check and clear their status and check the capabilities of the TAD reported
 * by AML.  The DC timer attributes are only present if the TAD supports a
 * separate DC alarm timer.
 *
 * The wakeup events handling and power management of the TAD is expected to
 * be taken care of by the ACPI PM domain attached to its platform device.
 */

#include <linux/acpi.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/suspend.h>

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Rafael J. Wysocki");

/* ACPI TAD capability flags (ACPI 6.2, Section 9.18.2) */
#define ACPI_TAD_AC_WAKE	BIT(0)
#define ACPI_TAD_DC_WAKE	BIT(1)
#define ACPI_TAD_RT		BIT(2)
#define ACPI_TAD_RT_IN_MS	BIT(3)
#define ACPI_TAD_S4_S5__GWS	BIT(4)
#define ACPI_TAD_AC_S4_WAKE	BIT(5)
#define ACPI_TAD_AC_S5_WAKE	BIT(6)
#define ACPI_TAD_DC_S4_WAKE	BIT(7)
#define ACPI_TAD_DC_S5_WAKE	BIT(8)

/* ACPI TAD alarm timer selection */
#define ACPI_TAD_AC_TIMER	(u32)0
#define ACPI_TAD_DC_TIMER	(u32)1

/* Special value for disabled timer or expired timer wake policy. */
#define ACPI_TAD_WAKE_DISABLED	(~(u32)0)

struct acpi_tad_driver_data {
	u32 capabilities;
};

static int acpi_tad_wake_set(struct device *dev, char *method, u32 timer_id,
			     u32 value)
{
	acpi_handle handle = ACPI_HANDLE(dev);
	union acpi_object args[] = {
		{ .type = ACPI_TYPE_INTEGER, },
		{ .type = ACPI_TYPE_INTEGER, },
	};
	struct acpi_object_list arg_list = {
		.pointer = args,
		.count = ARRAY_SIZE(args),
	};
	unsigned long long retval;
	acpi_status status;

	args[0].integer.value = timer_id;
	args[1].integer.value = value;

	pm_runtime_get_sync(dev);

	status = acpi_evaluate_integer(handle, method, &arg_list, &retval);

	pm_runtime_put_sync(dev);

	if (ACPI_FAILURE(status) || retval)
		return -EIO;

	return 0;
}

static int acpi_tad_wake_write(struct device *dev, const char *buf, char *method,
			       u32 timer_id, const char *specval)
{
	u32 value;

	if (sysfs_streq(buf, specval)) {
		value = ACPI_TAD_WAKE_DISABLED;
	} else {
		int ret = kstrtou32(buf, 0, &value);

		if (ret)
			return ret;

		if (value == ACPI_TAD_WAKE_DISABLED)
			return -EINVAL;
	}

	return acpi_tad_wake_set(dev, method, timer_id, value);
}

static ssize_t acpi_tad_wake_read(struct device *dev, char *buf, char *method,
				  u32 timer_id, const char *specval)
{
	acpi_handle handle = ACPI_HANDLE(dev);
	union acpi_object args[] = {
		{ .type = ACPI_TYPE_INTEGER, },
	};
	struct acpi_object_list arg_list = {
		.pointer = args,
		.count = ARRAY_SIZE(args),
	};
	unsigned long long retval;
	acpi_status status;

	args[0].integer.value = timer_id;

	pm_runtime_get_sync(dev);

	status = acpi_evaluate_integer(handle, method, &arg_list, &retval);

	pm_runtime_put_sync(dev);

	if (ACPI_FAILURE(status))
		return -EIO;

	if ((u32)retval == ACPI_TAD_WAKE_DISABLED)
		return sprintf(buf, "%s\n", specval);

	return sprintf(buf, "%u\n", (u32)retval);
}

static const char *alarm_specval = "disabled";

static int acpi_tad_alarm_write(struct device *dev, const char *buf,
				u32 timer_id)
{
	return acpi_tad_wake_write(dev, buf, "_STV", timer_id, alarm_specval);
}

static ssize_t acpi_tad_alarm_read(struct device *dev, char *buf, u32 timer_id)
{
	return acpi_tad_wake_read(dev, buf, "_TIV", timer_id, alarm_specval);
}

static const char *policy_specval = "never";

static int acpi_tad_policy_write(struct device *dev, const char *buf,
				 u32 timer_id)
{
	return acpi_tad_wake_write(dev, buf, "_STP", timer_id, policy_specval);
}

static ssize_t acpi_tad_policy_read(struct device *dev, char *buf, u32 timer_id)
{
	return acpi_tad_wake_read(dev, buf, "_TIP", timer_id, policy_specval);
}

static int acpi_tad_clear_status(struct device *dev, u32 timer_id)
{
	acpi_handle handle = ACPI_HANDLE(dev);
	union acpi_object args[] = {
		{ .type = ACPI_TYPE_INTEGER, },
	};
	struct acpi_object_list arg_list = {
		.pointer = args,
		.count = ARRAY_SIZE(args),
	};
	unsigned long long retval;
	acpi_status status;

	args[0].integer.value = timer_id;

	pm_runtime_get_sync(dev);

	status = acpi_evaluate_integer(handle, "_CWS", &arg_list, &retval);

	pm_runtime_put_sync(dev);

	if (ACPI_FAILURE(status) || retval)
		return -EIO;

	return 0;
}

static int acpi_tad_status_write(struct device *dev, const char *buf, u32 timer_id)
{
	int ret, value;

	ret = kstrtoint(buf, 0, &value);
	if (ret)
		return ret;

	if (value)
		return -EINVAL;

	return acpi_tad_clear_status(dev, timer_id);
}

static ssize_t acpi_tad_status_read(struct device *dev, char *buf, u32 timer_id)
{
	acpi_handle handle = ACPI_HANDLE(dev);
	union acpi_object args[] = {
		{ .type = ACPI_TYPE_INTEGER, },
	};
	struct acpi_object_list arg_list = {
		.pointer = args,
		.count = ARRAY_SIZE(args),
	};
	unsigned long long retval;
	acpi_status status;

	args[0].integer.value = timer_id;

	pm_runtime_get_sync(dev);

	status = acpi_evaluate_integer(handle, "_GWS", &arg_list, &retval);

	pm_runtime_put_sync(dev);

	if (ACPI_FAILURE(status))
		return -EIO;

	return sprintf(buf, "0x%02X\n", (u32)retval);
}

static ssize_t caps_show(struct device *dev, struct device_attribute *attr,
			 char *buf)
{
	struct acpi_tad_driver_data *dd = dev_get_drvdata(dev);

	return sprintf(buf, "0x%02X\n", dd->capabilities);
}

static DEVICE_ATTR_RO(caps);

static ssize_t ac_alarm_store(struct device *dev, struct device_attribute *attr,
			      const char *buf, size_t count)
{
	int ret = acpi_tad_alarm_write(dev, buf, ACPI_TAD_AC_TIMER);

	return ret ? ret : count;
}

static ssize_t ac_alarm_show(struct device *dev, struct device_attribute *attr,
			     char *buf)
{
	return acpi_tad_alarm_read(dev, buf, ACPI_TAD_AC_TIMER);
}

static DEVICE_ATTR(ac_alarm, S_IRUSR | S_IWUSR, ac_alarm_show, ac_alarm_store);

static ssize_t ac_policy_store(struct device *dev, struct device_attribute *attr,
			       const char *buf, size_t count)
{
	int ret = acpi_tad_policy_write(dev, buf, ACPI_TAD_AC_TIMER);

	return ret ? ret : count;
}

static ssize_t ac_policy_show(struct device *dev, struct device_attribute *attr,
			      char *buf)
{
	return acpi_tad_policy_read(dev, buf, ACPI_TAD_AC_TIMER);
}

static DEVICE_ATTR(ac_policy, S_IRUSR | S_IWUSR, ac_policy_show, ac_policy_store);

static ssize_t ac_status_store(struct device *dev, struct device_attribute *attr,
			       const char *buf, size_t count)
{
	int ret = acpi_tad_status_write(dev, buf, ACPI_TAD_AC_TIMER);

	return ret ? ret : count;
}

static ssize_t ac_status_show(struct device *dev, struct device_attribute *attr,
			      char *buf)
{
	return acpi_tad_status_read(dev, buf, ACPI_TAD_AC_TIMER);
}

static DEVICE_ATTR(ac_status, S_IRUSR | S_IWUSR, ac_status_show, ac_status_store);

static struct attribute *acpi_tad_attrs[] = {
	&dev_attr_caps.attr,
	&dev_attr_ac_alarm.attr,
	&dev_attr_ac_policy.attr,
	&dev_attr_ac_status.attr,
	NULL,
};
static const struct attribute_group acpi_tad_attr_group = {
	.attrs	= acpi_tad_attrs,
};

static ssize_t dc_alarm_store(struct device *dev, struct device_attribute *attr,
			      const char *buf, size_t count)
{
	int ret = acpi_tad_alarm_write(dev, buf, ACPI_TAD_DC_TIMER);

	return ret ? ret : count;
}

static ssize_t dc_alarm_show(struct device *dev, struct device_attribute *attr,
			     char *buf)
{
	return acpi_tad_alarm_read(dev, buf, ACPI_TAD_DC_TIMER);
}

static DEVICE_ATTR(dc_alarm, S_IRUSR | S_IWUSR, dc_alarm_show, dc_alarm_store);

static ssize_t dc_policy_store(struct device *dev, struct device_attribute *attr,
			       const char *buf, size_t count)
{
	int ret = acpi_tad_policy_write(dev, buf, ACPI_TAD_DC_TIMER);

	return ret ? ret : count;
}

static ssize_t dc_policy_show(struct device *dev, struct device_attribute *attr,
			      char *buf)
{
	return acpi_tad_policy_read(dev, buf, ACPI_TAD_DC_TIMER);
}

static DEVICE_ATTR(dc_policy, S_IRUSR | S_IWUSR, dc_policy_show, dc_policy_store);

static ssize_t dc_status_store(struct device *dev, struct device_attribute *attr,
			       const char *buf, size_t count)
{
	int ret = acpi_tad_status_write(dev, buf, ACPI_TAD_DC_TIMER);

	return ret ? ret : count;
}

static ssize_t dc_status_show(struct device *dev, struct device_attribute *attr,
			      char *buf)
{
	return acpi_tad_status_read(dev, buf, ACPI_TAD_DC_TIMER);
}

static DEVICE_ATTR(dc_status, S_IRUSR | S_IWUSR, dc_status_show, dc_status_store);

static struct attribute *acpi_tad_dc_attrs[] = {
	&dev_attr_dc_alarm.attr,
	&dev_attr_dc_policy.attr,
	&dev_attr_dc_status.attr,
	NULL,
};
static const struct attribute_group acpi_tad_dc_attr_group = {
	.attrs	= acpi_tad_dc_attrs,
};

static int acpi_tad_disable_timer(struct device *dev, u32 timer_id)
{
	return acpi_tad_wake_set(dev, "_STV", timer_id, ACPI_TAD_WAKE_DISABLED);
}

static int acpi_tad_remove(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct acpi_tad_driver_data *dd = dev_get_drvdata(dev);

	device_init_wakeup(dev, false);

	pm_runtime_get_sync(dev);

	if (dd->capabilities & ACPI_TAD_DC_WAKE)
		sysfs_remove_group(&dev->kobj, &acpi_tad_dc_attr_group);

	sysfs_remove_group(&dev->kobj, &acpi_tad_attr_group);

	acpi_tad_disable_timer(dev, ACPI_TAD_AC_TIMER);
	acpi_tad_clear_status(dev, ACPI_TAD_AC_TIMER);
	if (dd->capabilities & ACPI_TAD_DC_WAKE) {
		acpi_tad_disable_timer(dev, ACPI_TAD_DC_TIMER);
		acpi_tad_clear_status(dev, ACPI_TAD_DC_TIMER);
	}

	pm_runtime_put_sync(dev);
	pm_runtime_disable(dev);
	return 0;
}

static int acpi_tad_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	acpi_handle handle = ACPI_HANDLE(dev);
	struct acpi_tad_driver_data *dd;
	acpi_status status;
	unsigned long long caps;
	int ret;

	/*
	 * Initialization failure messages are mostly about firmware issues, so
	 * print them at the "info" level.
	 */
	status = acpi_evaluate_integer(handle, "_GCP", NULL, &caps);
	if (ACPI_FAILURE(status)) {
		dev_info(dev, "Unable to get capabilities\n");
		return -ENODEV;
	}

	if (!(caps & ACPI_TAD_AC_WAKE)) {
		dev_info(dev, "Unsupported capabilities\n");
		return -ENODEV;
	}

	if (!acpi_has_method(handle, "_PRW")) {
		dev_info(dev, "Missing _PRW\n");
		return -ENODEV;
	}

	dd = devm_kzalloc(dev, sizeof(*dd), GFP_KERNEL);
	if (!dd)
		return -ENOMEM;

	dd->capabilities = caps;
	dev_set_drvdata(dev, dd);

	/*
	 * Assume that the ACPI PM domain has been attached to the device and
	 * simply enable system wakeup and runtime PM and put the device into
	 * runtime suspend.  Everything else should be taken care of by the ACPI
	 * PM domain callbacks.
	 */
	device_init_wakeup(dev, true);
	dev_pm_set_driver_flags(dev, DPM_FLAG_SMART_SUSPEND |
				     DPM_FLAG_LEAVE_SUSPENDED);
	/*
	 * The platform bus type layer tells the ACPI PM domain powers up the
	 * device, so set the runtime PM status of it to "active".
	 */
	pm_runtime_set_active(dev);
	pm_runtime_enable(dev);
	pm_runtime_suspend(dev);

	ret = sysfs_create_group(&dev->kobj, &acpi_tad_attr_group);
	if (ret)
		goto fail;

	if (caps & ACPI_TAD_DC_WAKE) {
		ret = sysfs_create_group(&dev->kobj, &acpi_tad_dc_attr_group);
		if (ret)
			goto fail;
	}

	return 0;

fail:
	acpi_tad_remove(pdev);
	return ret;
}

static const struct acpi_device_id acpi_tad_ids[] = {
	{"ACPI000E", 0},
	{}
};

static struct platform_driver acpi_tad_driver = {
	.driver = {
		.name = "acpi-tad",
		.acpi_match_table = acpi_tad_ids,
	},
	.probe = acpi_tad_probe,
	.remove = acpi_tad_remove,
};
MODULE_DEVICE_TABLE(acpi, acpi_tad_ids);

module_platform_driver(acpi_tad_driver);
OpenPOWER on IntegriCloud