Merge tag 'drm-misc-fixes-2018-09-19' of git://anongit.freedesktop.org/drm/drm-misc...
[linux-2.6-block.git] / drivers / acpi / acpi_tad.c
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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * ACPI Time and Alarm (TAD) Device Driver
4 *
5 * Copyright (C) 2018 Intel Corporation
6 * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
7 *
8 * This driver is based on Section 9.18 of the ACPI 6.2 specification revision.
9 *
10 * It only supports the system wakeup capabilities of the TAD.
11 *
12 * Provided are sysfs attributes, available under the TAD platform device,
13 * allowing user space to manage the AC and DC wakeup timers of the TAD:
14 * set and read their values, set and check their expire timer wake policies,
15 * check and clear their status and check the capabilities of the TAD reported
16 * by AML. The DC timer attributes are only present if the TAD supports a
17 * separate DC alarm timer.
18 *
19 * The wakeup events handling and power management of the TAD is expected to
20 * be taken care of by the ACPI PM domain attached to its platform device.
21 */
22
23#include <linux/acpi.h>
24#include <linux/kernel.h>
25#include <linux/module.h>
26#include <linux/platform_device.h>
27#include <linux/pm_runtime.h>
28#include <linux/suspend.h>
29
30MODULE_LICENSE("GPL v2");
31MODULE_AUTHOR("Rafael J. Wysocki");
32
33/* ACPI TAD capability flags (ACPI 6.2, Section 9.18.2) */
34#define ACPI_TAD_AC_WAKE BIT(0)
35#define ACPI_TAD_DC_WAKE BIT(1)
36#define ACPI_TAD_RT BIT(2)
37#define ACPI_TAD_RT_IN_MS BIT(3)
38#define ACPI_TAD_S4_S5__GWS BIT(4)
39#define ACPI_TAD_AC_S4_WAKE BIT(5)
40#define ACPI_TAD_AC_S5_WAKE BIT(6)
41#define ACPI_TAD_DC_S4_WAKE BIT(7)
42#define ACPI_TAD_DC_S5_WAKE BIT(8)
43
44/* ACPI TAD alarm timer selection */
45#define ACPI_TAD_AC_TIMER (u32)0
46#define ACPI_TAD_DC_TIMER (u32)1
47
48/* Special value for disabled timer or expired timer wake policy. */
49#define ACPI_TAD_WAKE_DISABLED (~(u32)0)
50
51struct acpi_tad_driver_data {
52 u32 capabilities;
53};
54
55static int acpi_tad_wake_set(struct device *dev, char *method, u32 timer_id,
56 u32 value)
57{
58 acpi_handle handle = ACPI_HANDLE(dev);
59 union acpi_object args[] = {
60 { .type = ACPI_TYPE_INTEGER, },
61 { .type = ACPI_TYPE_INTEGER, },
62 };
63 struct acpi_object_list arg_list = {
64 .pointer = args,
65 .count = ARRAY_SIZE(args),
66 };
67 unsigned long long retval;
68 acpi_status status;
69
70 args[0].integer.value = timer_id;
71 args[1].integer.value = value;
72
73 pm_runtime_get_sync(dev);
74
75 status = acpi_evaluate_integer(handle, method, &arg_list, &retval);
76
77 pm_runtime_put_sync(dev);
78
79 if (ACPI_FAILURE(status) || retval)
80 return -EIO;
81
82 return 0;
83}
84
85static int acpi_tad_wake_write(struct device *dev, const char *buf, char *method,
86 u32 timer_id, const char *specval)
87{
88 u32 value;
89
90 if (sysfs_streq(buf, specval)) {
91 value = ACPI_TAD_WAKE_DISABLED;
92 } else {
93 int ret = kstrtou32(buf, 0, &value);
94
95 if (ret)
96 return ret;
97
98 if (value == ACPI_TAD_WAKE_DISABLED)
99 return -EINVAL;
100 }
101
102 return acpi_tad_wake_set(dev, method, timer_id, value);
103}
104
105static ssize_t acpi_tad_wake_read(struct device *dev, char *buf, char *method,
106 u32 timer_id, const char *specval)
107{
108 acpi_handle handle = ACPI_HANDLE(dev);
109 union acpi_object args[] = {
110 { .type = ACPI_TYPE_INTEGER, },
111 };
112 struct acpi_object_list arg_list = {
113 .pointer = args,
114 .count = ARRAY_SIZE(args),
115 };
116 unsigned long long retval;
117 acpi_status status;
118
119 args[0].integer.value = timer_id;
120
121 pm_runtime_get_sync(dev);
122
123 status = acpi_evaluate_integer(handle, method, &arg_list, &retval);
124
125 pm_runtime_put_sync(dev);
126
127 if (ACPI_FAILURE(status))
128 return -EIO;
129
130 if ((u32)retval == ACPI_TAD_WAKE_DISABLED)
131 return sprintf(buf, "%s\n", specval);
132
133 return sprintf(buf, "%u\n", (u32)retval);
134}
135
136static const char *alarm_specval = "disabled";
137
138static int acpi_tad_alarm_write(struct device *dev, const char *buf,
139 u32 timer_id)
140{
141 return acpi_tad_wake_write(dev, buf, "_STV", timer_id, alarm_specval);
142}
143
144static ssize_t acpi_tad_alarm_read(struct device *dev, char *buf, u32 timer_id)
145{
146 return acpi_tad_wake_read(dev, buf, "_TIV", timer_id, alarm_specval);
147}
148
149static const char *policy_specval = "never";
150
151static int acpi_tad_policy_write(struct device *dev, const char *buf,
152 u32 timer_id)
153{
154 return acpi_tad_wake_write(dev, buf, "_STP", timer_id, policy_specval);
155}
156
157static ssize_t acpi_tad_policy_read(struct device *dev, char *buf, u32 timer_id)
158{
159 return acpi_tad_wake_read(dev, buf, "_TIP", timer_id, policy_specval);
160}
161
162static int acpi_tad_clear_status(struct device *dev, u32 timer_id)
163{
164 acpi_handle handle = ACPI_HANDLE(dev);
165 union acpi_object args[] = {
166 { .type = ACPI_TYPE_INTEGER, },
167 };
168 struct acpi_object_list arg_list = {
169 .pointer = args,
170 .count = ARRAY_SIZE(args),
171 };
172 unsigned long long retval;
173 acpi_status status;
174
175 args[0].integer.value = timer_id;
176
177 pm_runtime_get_sync(dev);
178
179 status = acpi_evaluate_integer(handle, "_CWS", &arg_list, &retval);
180
181 pm_runtime_put_sync(dev);
182
183 if (ACPI_FAILURE(status) || retval)
184 return -EIO;
185
186 return 0;
187}
188
189static int acpi_tad_status_write(struct device *dev, const char *buf, u32 timer_id)
190{
191 int ret, value;
192
193 ret = kstrtoint(buf, 0, &value);
194 if (ret)
195 return ret;
196
197 if (value)
198 return -EINVAL;
199
200 return acpi_tad_clear_status(dev, timer_id);
201}
202
203static ssize_t acpi_tad_status_read(struct device *dev, char *buf, u32 timer_id)
204{
205 acpi_handle handle = ACPI_HANDLE(dev);
206 union acpi_object args[] = {
207 { .type = ACPI_TYPE_INTEGER, },
208 };
209 struct acpi_object_list arg_list = {
210 .pointer = args,
211 .count = ARRAY_SIZE(args),
212 };
213 unsigned long long retval;
214 acpi_status status;
215
216 args[0].integer.value = timer_id;
217
218 pm_runtime_get_sync(dev);
219
220 status = acpi_evaluate_integer(handle, "_GWS", &arg_list, &retval);
221
222 pm_runtime_put_sync(dev);
223
224 if (ACPI_FAILURE(status))
225 return -EIO;
226
227 return sprintf(buf, "0x%02X\n", (u32)retval);
228}
229
230static ssize_t caps_show(struct device *dev, struct device_attribute *attr,
231 char *buf)
232{
233 struct acpi_tad_driver_data *dd = dev_get_drvdata(dev);
234
235 return sprintf(buf, "0x%02X\n", dd->capabilities);
236}
237
238static DEVICE_ATTR_RO(caps);
239
240static ssize_t ac_alarm_store(struct device *dev, struct device_attribute *attr,
241 const char *buf, size_t count)
242{
243 int ret = acpi_tad_alarm_write(dev, buf, ACPI_TAD_AC_TIMER);
244
245 return ret ? ret : count;
246}
247
248static ssize_t ac_alarm_show(struct device *dev, struct device_attribute *attr,
249 char *buf)
250{
251 return acpi_tad_alarm_read(dev, buf, ACPI_TAD_AC_TIMER);
252}
253
254static DEVICE_ATTR(ac_alarm, S_IRUSR | S_IWUSR, ac_alarm_show, ac_alarm_store);
255
256static ssize_t ac_policy_store(struct device *dev, struct device_attribute *attr,
257 const char *buf, size_t count)
258{
259 int ret = acpi_tad_policy_write(dev, buf, ACPI_TAD_AC_TIMER);
260
261 return ret ? ret : count;
262}
263
264static ssize_t ac_policy_show(struct device *dev, struct device_attribute *attr,
265 char *buf)
266{
267 return acpi_tad_policy_read(dev, buf, ACPI_TAD_AC_TIMER);
268}
269
270static DEVICE_ATTR(ac_policy, S_IRUSR | S_IWUSR, ac_policy_show, ac_policy_store);
271
272static ssize_t ac_status_store(struct device *dev, struct device_attribute *attr,
273 const char *buf, size_t count)
274{
275 int ret = acpi_tad_status_write(dev, buf, ACPI_TAD_AC_TIMER);
276
277 return ret ? ret : count;
278}
279
280static ssize_t ac_status_show(struct device *dev, struct device_attribute *attr,
281 char *buf)
282{
283 return acpi_tad_status_read(dev, buf, ACPI_TAD_AC_TIMER);
284}
285
286static DEVICE_ATTR(ac_status, S_IRUSR | S_IWUSR, ac_status_show, ac_status_store);
287
288static struct attribute *acpi_tad_attrs[] = {
289 &dev_attr_caps.attr,
290 &dev_attr_ac_alarm.attr,
291 &dev_attr_ac_policy.attr,
292 &dev_attr_ac_status.attr,
293 NULL,
294};
295static const struct attribute_group acpi_tad_attr_group = {
296 .attrs = acpi_tad_attrs,
297};
298
299static ssize_t dc_alarm_store(struct device *dev, struct device_attribute *attr,
300 const char *buf, size_t count)
301{
302 int ret = acpi_tad_alarm_write(dev, buf, ACPI_TAD_DC_TIMER);
303
304 return ret ? ret : count;
305}
306
307static ssize_t dc_alarm_show(struct device *dev, struct device_attribute *attr,
308 char *buf)
309{
310 return acpi_tad_alarm_read(dev, buf, ACPI_TAD_DC_TIMER);
311}
312
313static DEVICE_ATTR(dc_alarm, S_IRUSR | S_IWUSR, dc_alarm_show, dc_alarm_store);
314
315static ssize_t dc_policy_store(struct device *dev, struct device_attribute *attr,
316 const char *buf, size_t count)
317{
318 int ret = acpi_tad_policy_write(dev, buf, ACPI_TAD_DC_TIMER);
319
320 return ret ? ret : count;
321}
322
323static ssize_t dc_policy_show(struct device *dev, struct device_attribute *attr,
324 char *buf)
325{
326 return acpi_tad_policy_read(dev, buf, ACPI_TAD_DC_TIMER);
327}
328
329static DEVICE_ATTR(dc_policy, S_IRUSR | S_IWUSR, dc_policy_show, dc_policy_store);
330
331static ssize_t dc_status_store(struct device *dev, struct device_attribute *attr,
332 const char *buf, size_t count)
333{
334 int ret = acpi_tad_status_write(dev, buf, ACPI_TAD_DC_TIMER);
335
336 return ret ? ret : count;
337}
338
339static ssize_t dc_status_show(struct device *dev, struct device_attribute *attr,
340 char *buf)
341{
342 return acpi_tad_status_read(dev, buf, ACPI_TAD_DC_TIMER);
343}
344
345static DEVICE_ATTR(dc_status, S_IRUSR | S_IWUSR, dc_status_show, dc_status_store);
346
347static struct attribute *acpi_tad_dc_attrs[] = {
348 &dev_attr_dc_alarm.attr,
349 &dev_attr_dc_policy.attr,
350 &dev_attr_dc_status.attr,
351 NULL,
352};
353static const struct attribute_group acpi_tad_dc_attr_group = {
354 .attrs = acpi_tad_dc_attrs,
355};
356
357static int acpi_tad_disable_timer(struct device *dev, u32 timer_id)
358{
359 return acpi_tad_wake_set(dev, "_STV", timer_id, ACPI_TAD_WAKE_DISABLED);
360}
361
362static int acpi_tad_remove(struct platform_device *pdev)
363{
364 struct device *dev = &pdev->dev;
365 struct acpi_tad_driver_data *dd = dev_get_drvdata(dev);
366
367 device_init_wakeup(dev, false);
368
369 pm_runtime_get_sync(dev);
370
371 if (dd->capabilities & ACPI_TAD_DC_WAKE)
372 sysfs_remove_group(&dev->kobj, &acpi_tad_dc_attr_group);
373
374 sysfs_remove_group(&dev->kobj, &acpi_tad_attr_group);
375
376 acpi_tad_disable_timer(dev, ACPI_TAD_AC_TIMER);
377 acpi_tad_clear_status(dev, ACPI_TAD_AC_TIMER);
378 if (dd->capabilities & ACPI_TAD_DC_WAKE) {
379 acpi_tad_disable_timer(dev, ACPI_TAD_DC_TIMER);
380 acpi_tad_clear_status(dev, ACPI_TAD_DC_TIMER);
381 }
382
383 pm_runtime_put_sync(dev);
384 pm_runtime_disable(dev);
385 return 0;
386}
387
388static int acpi_tad_probe(struct platform_device *pdev)
389{
390 struct device *dev = &pdev->dev;
391 acpi_handle handle = ACPI_HANDLE(dev);
392 struct acpi_tad_driver_data *dd;
393 acpi_status status;
394 unsigned long long caps;
395 int ret;
396
397 /*
398 * Initialization failure messages are mostly about firmware issues, so
399 * print them at the "info" level.
400 */
401 status = acpi_evaluate_integer(handle, "_GCP", NULL, &caps);
402 if (ACPI_FAILURE(status)) {
403 dev_info(dev, "Unable to get capabilities\n");
404 return -ENODEV;
405 }
406
407 if (!(caps & ACPI_TAD_AC_WAKE)) {
408 dev_info(dev, "Unsupported capabilities\n");
409 return -ENODEV;
410 }
411
412 if (!acpi_has_method(handle, "_PRW")) {
413 dev_info(dev, "Missing _PRW\n");
414 return -ENODEV;
415 }
416
417 dd = devm_kzalloc(dev, sizeof(*dd), GFP_KERNEL);
418 if (!dd)
419 return -ENOMEM;
420
421 dd->capabilities = caps;
422 dev_set_drvdata(dev, dd);
423
424 /*
425 * Assume that the ACPI PM domain has been attached to the device and
426 * simply enable system wakeup and runtime PM and put the device into
427 * runtime suspend. Everything else should be taken care of by the ACPI
428 * PM domain callbacks.
429 */
430 device_init_wakeup(dev, true);
431 dev_pm_set_driver_flags(dev, DPM_FLAG_SMART_SUSPEND |
432 DPM_FLAG_LEAVE_SUSPENDED);
433 /*
434 * The platform bus type layer tells the ACPI PM domain powers up the
435 * device, so set the runtime PM status of it to "active".
436 */
437 pm_runtime_set_active(dev);
438 pm_runtime_enable(dev);
439 pm_runtime_suspend(dev);
440
441 ret = sysfs_create_group(&dev->kobj, &acpi_tad_attr_group);
442 if (ret)
443 goto fail;
444
445 if (caps & ACPI_TAD_DC_WAKE) {
446 ret = sysfs_create_group(&dev->kobj, &acpi_tad_dc_attr_group);
447 if (ret)
448 goto fail;
449 }
450
451 return 0;
452
453fail:
454 acpi_tad_remove(pdev);
455 return ret;
456}
457
458static const struct acpi_device_id acpi_tad_ids[] = {
459 {"ACPI000E", 0},
460 {}
461};
462
463static struct platform_driver acpi_tad_driver = {
464 .driver = {
465 .name = "acpi-tad",
466 .acpi_match_table = acpi_tad_ids,
467 },
468 .probe = acpi_tad_probe,
469 .remove = acpi_tad_remove,
470};
471MODULE_DEVICE_TABLE(acpi, acpi_tad_ids);
472
473module_platform_driver(acpi_tad_driver);