1 // SPDX-License-Identifier: GPL-2.0
2 /* Device wakeirq helper functions */
3 #include <linux/device.h>
4 #include <linux/interrupt.h>
5 #include <linux/irq.h>
6 #include <linux/slab.h>
7 #include <linux/pm_runtime.h>
8 #include <linux/pm_wakeirq.h>
9
10 #include "power.h"
11
12 /**
13 * dev_pm_attach_wake_irq - Attach device interrupt as a wake IRQ
14 * @dev: Device entry
15 * @wirq: Wake irq specific data
16 *
17 * Internal function to attach a dedicated wake-up interrupt as a wake IRQ.
18 */
dev_pm_attach_wake_irq(struct device * dev,struct wake_irq * wirq)19 static int dev_pm_attach_wake_irq(struct device *dev, struct wake_irq *wirq)
20 {
21 unsigned long flags;
22
23 if (!dev || !wirq)
24 return -EINVAL;
25
26 spin_lock_irqsave(&dev->power.lock, flags);
27 if (dev_WARN_ONCE(dev, dev->power.wakeirq,
28 "wake irq already initialized\n")) {
29 spin_unlock_irqrestore(&dev->power.lock, flags);
30 return -EEXIST;
31 }
32
33 dev->power.wakeirq = wirq;
34 device_wakeup_attach_irq(dev, wirq);
35
36 spin_unlock_irqrestore(&dev->power.lock, flags);
37 return 0;
38 }
39
40 /**
41 * dev_pm_set_wake_irq - Attach device IO interrupt as wake IRQ
42 * @dev: Device entry
43 * @irq: Device IO interrupt
44 *
45 * Attach a device IO interrupt as a wake IRQ. The wake IRQ gets
46 * automatically configured for wake-up from suspend based
47 * on the device specific sysfs wakeup entry. Typically called
48 * during driver probe after calling device_init_wakeup().
49 */
dev_pm_set_wake_irq(struct device * dev,int irq)50 int dev_pm_set_wake_irq(struct device *dev, int irq)
51 {
52 struct wake_irq *wirq;
53 int err;
54
55 if (irq < 0)
56 return -EINVAL;
57
58 wirq = kzalloc(sizeof(*wirq), GFP_KERNEL);
59 if (!wirq)
60 return -ENOMEM;
61
62 wirq->dev = dev;
63 wirq->irq = irq;
64
65 err = dev_pm_attach_wake_irq(dev, wirq);
66 if (err)
67 kfree(wirq);
68
69 return err;
70 }
71 EXPORT_SYMBOL_GPL(dev_pm_set_wake_irq);
72
73 /**
74 * dev_pm_clear_wake_irq - Detach a device IO interrupt wake IRQ
75 * @dev: Device entry
76 *
77 * Detach a device wake IRQ and free resources.
78 *
79 * Note that it's OK for drivers to call this without calling
80 * dev_pm_set_wake_irq() as all the driver instances may not have
81 * a wake IRQ configured. This avoid adding wake IRQ specific
82 * checks into the drivers.
83 */
dev_pm_clear_wake_irq(struct device * dev)84 void dev_pm_clear_wake_irq(struct device *dev)
85 {
86 struct wake_irq *wirq = dev->power.wakeirq;
87 unsigned long flags;
88
89 if (!wirq)
90 return;
91
92 spin_lock_irqsave(&dev->power.lock, flags);
93 device_wakeup_detach_irq(dev);
94 dev->power.wakeirq = NULL;
95 spin_unlock_irqrestore(&dev->power.lock, flags);
96
97 if (wirq->status & WAKE_IRQ_DEDICATED_ALLOCATED) {
98 free_irq(wirq->irq, wirq);
99 wirq->status &= ~WAKE_IRQ_DEDICATED_MASK;
100 }
101 kfree(wirq->name);
102 kfree(wirq);
103 }
104 EXPORT_SYMBOL_GPL(dev_pm_clear_wake_irq);
105
106 /**
107 * handle_threaded_wake_irq - Handler for dedicated wake-up interrupts
108 * @irq: Device specific dedicated wake-up interrupt
109 * @_wirq: Wake IRQ data
110 *
111 * Some devices have a separate wake-up interrupt in addition to the
112 * device IO interrupt. The wake-up interrupt signals that a device
113 * should be woken up from it's idle state. This handler uses device
114 * specific pm_runtime functions to wake the device, and then it's
115 * up to the device to do whatever it needs to. Note that as the
116 * device may need to restore context and start up regulators, we
117 * use a threaded IRQ.
118 *
119 * Also note that we are not resending the lost device interrupts.
120 * We assume that the wake-up interrupt just needs to wake-up the
121 * device, and then device's pm_runtime_resume() can deal with the
122 * situation.
123 */
handle_threaded_wake_irq(int irq,void * _wirq)124 static irqreturn_t handle_threaded_wake_irq(int irq, void *_wirq)
125 {
126 struct wake_irq *wirq = _wirq;
127 int res;
128
129 /* Maybe abort suspend? */
130 if (irqd_is_wakeup_set(irq_get_irq_data(irq))) {
131 pm_wakeup_event(wirq->dev, 0);
132
133 return IRQ_HANDLED;
134 }
135
136 /* We don't want RPM_ASYNC or RPM_NOWAIT here */
137 res = pm_runtime_resume(wirq->dev);
138 if (res < 0)
139 dev_warn(wirq->dev,
140 "wake IRQ with no resume: %i\n", res);
141
142 return IRQ_HANDLED;
143 }
144
__dev_pm_set_dedicated_wake_irq(struct device * dev,int irq,unsigned int flag)145 static int __dev_pm_set_dedicated_wake_irq(struct device *dev, int irq, unsigned int flag)
146 {
147 struct wake_irq *wirq;
148 int err;
149
150 if (irq < 0)
151 return -EINVAL;
152
153 wirq = kzalloc(sizeof(*wirq), GFP_KERNEL);
154 if (!wirq)
155 return -ENOMEM;
156
157 wirq->name = kasprintf(GFP_KERNEL, "%s:wakeup", dev_name(dev));
158 if (!wirq->name) {
159 err = -ENOMEM;
160 goto err_free;
161 }
162
163 wirq->dev = dev;
164 wirq->irq = irq;
165
166 /* Prevent deferred spurious wakeirqs with disable_irq_nosync() */
167 irq_set_status_flags(irq, IRQ_DISABLE_UNLAZY);
168
169 /*
170 * Consumer device may need to power up and restore state
171 * so we use a threaded irq.
172 */
173 err = request_threaded_irq(irq, NULL, handle_threaded_wake_irq,
174 IRQF_ONESHOT | IRQF_NO_AUTOEN,
175 wirq->name, wirq);
176 if (err)
177 goto err_free_name;
178
179 err = dev_pm_attach_wake_irq(dev, wirq);
180 if (err)
181 goto err_free_irq;
182
183 wirq->status = WAKE_IRQ_DEDICATED_ALLOCATED | flag;
184
185 return err;
186
187 err_free_irq:
188 free_irq(irq, wirq);
189 err_free_name:
190 kfree(wirq->name);
191 err_free:
192 kfree(wirq);
193
194 return err;
195 }
196
197
198 /**
199 * dev_pm_set_dedicated_wake_irq - Request a dedicated wake-up interrupt
200 * @dev: Device entry
201 * @irq: Device wake-up interrupt
202 *
203 * Unless your hardware has separate wake-up interrupts in addition
204 * to the device IO interrupts, you don't need this.
205 *
206 * Sets up a threaded interrupt handler for a device that has
207 * a dedicated wake-up interrupt in addition to the device IO
208 * interrupt.
209 *
210 * The interrupt starts disabled, and needs to be managed for
211 * the device by the bus code or the device driver using
212 * dev_pm_enable_wake_irq*() and dev_pm_disable_wake_irq*()
213 * functions.
214 */
dev_pm_set_dedicated_wake_irq(struct device * dev,int irq)215 int dev_pm_set_dedicated_wake_irq(struct device *dev, int irq)
216 {
217 return __dev_pm_set_dedicated_wake_irq(dev, irq, 0);
218 }
219 EXPORT_SYMBOL_GPL(dev_pm_set_dedicated_wake_irq);
220
221 /**
222 * dev_pm_set_dedicated_wake_irq_reverse - Request a dedicated wake-up interrupt
223 * with reverse enable ordering
224 * @dev: Device entry
225 * @irq: Device wake-up interrupt
226 *
227 * Unless your hardware has separate wake-up interrupts in addition
228 * to the device IO interrupts, you don't need this.
229 *
230 * Sets up a threaded interrupt handler for a device that has a dedicated
231 * wake-up interrupt in addition to the device IO interrupt. It sets
232 * the status of WAKE_IRQ_DEDICATED_REVERSE to tell rpm_suspend()
233 * to enable dedicated wake-up interrupt after running the runtime suspend
234 * callback for @dev.
235 *
236 * The interrupt starts disabled, and needs to be managed for
237 * the device by the bus code or the device driver using
238 * dev_pm_enable_wake_irq*() and dev_pm_disable_wake_irq*()
239 * functions.
240 */
dev_pm_set_dedicated_wake_irq_reverse(struct device * dev,int irq)241 int dev_pm_set_dedicated_wake_irq_reverse(struct device *dev, int irq)
242 {
243 return __dev_pm_set_dedicated_wake_irq(dev, irq, WAKE_IRQ_DEDICATED_REVERSE);
244 }
245 EXPORT_SYMBOL_GPL(dev_pm_set_dedicated_wake_irq_reverse);
246
247 /**
248 * dev_pm_enable_wake_irq - Enable device wake-up interrupt
249 * @dev: Device
250 *
251 * Optionally called from the bus code or the device driver for
252 * runtime_resume() to override the PM runtime core managed wake-up
253 * interrupt handling to enable the wake-up interrupt.
254 *
255 * Note that for runtime_suspend()) the wake-up interrupts
256 * should be unconditionally enabled unlike for suspend()
257 * that is conditional.
258 */
dev_pm_enable_wake_irq(struct device * dev)259 void dev_pm_enable_wake_irq(struct device *dev)
260 {
261 struct wake_irq *wirq = dev->power.wakeirq;
262
263 if (wirq && (wirq->status & WAKE_IRQ_DEDICATED_ALLOCATED))
264 enable_irq(wirq->irq);
265 }
266 EXPORT_SYMBOL_GPL(dev_pm_enable_wake_irq);
267
268 /**
269 * dev_pm_disable_wake_irq - Disable device wake-up interrupt
270 * @dev: Device
271 *
272 * Optionally called from the bus code or the device driver for
273 * runtime_suspend() to override the PM runtime core managed wake-up
274 * interrupt handling to disable the wake-up interrupt.
275 */
dev_pm_disable_wake_irq(struct device * dev)276 void dev_pm_disable_wake_irq(struct device *dev)
277 {
278 struct wake_irq *wirq = dev->power.wakeirq;
279
280 if (wirq && (wirq->status & WAKE_IRQ_DEDICATED_ALLOCATED))
281 disable_irq_nosync(wirq->irq);
282 }
283 EXPORT_SYMBOL_GPL(dev_pm_disable_wake_irq);
284
285 /**
286 * dev_pm_enable_wake_irq_check - Checks and enables wake-up interrupt
287 * @dev: Device
288 * @can_change_status: Can change wake-up interrupt status
289 *
290 * Enables wakeirq conditionally. We need to enable wake-up interrupt
291 * lazily on the first rpm_suspend(). This is needed as the consumer device
292 * starts in RPM_SUSPENDED state, and the first pm_runtime_get() would
293 * otherwise try to disable already disabled wakeirq. The wake-up interrupt
294 * starts disabled with IRQ_NOAUTOEN set.
295 *
296 * Should be only called from rpm_suspend() and rpm_resume() path.
297 * Caller must hold &dev->power.lock to change wirq->status
298 */
dev_pm_enable_wake_irq_check(struct device * dev,bool can_change_status)299 void dev_pm_enable_wake_irq_check(struct device *dev,
300 bool can_change_status)
301 {
302 struct wake_irq *wirq = dev->power.wakeirq;
303
304 if (!wirq || !(wirq->status & WAKE_IRQ_DEDICATED_MASK))
305 return;
306
307 if (likely(wirq->status & WAKE_IRQ_DEDICATED_MANAGED)) {
308 goto enable;
309 } else if (can_change_status) {
310 wirq->status |= WAKE_IRQ_DEDICATED_MANAGED;
311 goto enable;
312 }
313
314 return;
315
316 enable:
317 if (!can_change_status || !(wirq->status & WAKE_IRQ_DEDICATED_REVERSE))
318 enable_irq(wirq->irq);
319 }
320
321 /**
322 * dev_pm_disable_wake_irq_check - Checks and disables wake-up interrupt
323 * @dev: Device
324 * @cond_disable: if set, also check WAKE_IRQ_DEDICATED_REVERSE
325 *
326 * Disables wake-up interrupt conditionally based on status.
327 * Should be only called from rpm_suspend() and rpm_resume() path.
328 */
dev_pm_disable_wake_irq_check(struct device * dev,bool cond_disable)329 void dev_pm_disable_wake_irq_check(struct device *dev, bool cond_disable)
330 {
331 struct wake_irq *wirq = dev->power.wakeirq;
332
333 if (!wirq || !(wirq->status & WAKE_IRQ_DEDICATED_MASK))
334 return;
335
336 if (cond_disable && (wirq->status & WAKE_IRQ_DEDICATED_REVERSE))
337 return;
338
339 if (wirq->status & WAKE_IRQ_DEDICATED_MANAGED)
340 disable_irq_nosync(wirq->irq);
341 }
342
343 /**
344 * dev_pm_enable_wake_irq_complete - enable wake IRQ not enabled before
345 * @dev: Device using the wake IRQ
346 *
347 * Enable wake IRQ conditionally based on status, mainly used if want to
348 * enable wake IRQ after running ->runtime_suspend() which depends on
349 * WAKE_IRQ_DEDICATED_REVERSE.
350 *
351 * Should be only called from rpm_suspend() path.
352 */
dev_pm_enable_wake_irq_complete(struct device * dev)353 void dev_pm_enable_wake_irq_complete(struct device *dev)
354 {
355 struct wake_irq *wirq = dev->power.wakeirq;
356
357 if (!wirq || !(wirq->status & WAKE_IRQ_DEDICATED_MASK))
358 return;
359
360 if (wirq->status & WAKE_IRQ_DEDICATED_MANAGED &&
361 wirq->status & WAKE_IRQ_DEDICATED_REVERSE)
362 enable_irq(wirq->irq);
363 }
364
365 /**
366 * dev_pm_arm_wake_irq - Arm device wake-up
367 * @wirq: Device wake-up interrupt
368 *
369 * Sets up the wake-up event conditionally based on the
370 * device_may_wake().
371 */
dev_pm_arm_wake_irq(struct wake_irq * wirq)372 void dev_pm_arm_wake_irq(struct wake_irq *wirq)
373 {
374 if (!wirq)
375 return;
376
377 if (device_may_wakeup(wirq->dev)) {
378 if (wirq->status & WAKE_IRQ_DEDICATED_ALLOCATED &&
379 !pm_runtime_status_suspended(wirq->dev))
380 enable_irq(wirq->irq);
381
382 enable_irq_wake(wirq->irq);
383 }
384 }
385
386 /**
387 * dev_pm_disarm_wake_irq - Disarm device wake-up
388 * @wirq: Device wake-up interrupt
389 *
390 * Clears up the wake-up event conditionally based on the
391 * device_may_wake().
392 */
dev_pm_disarm_wake_irq(struct wake_irq * wirq)393 void dev_pm_disarm_wake_irq(struct wake_irq *wirq)
394 {
395 if (!wirq)
396 return;
397
398 if (device_may_wakeup(wirq->dev)) {
399 disable_irq_wake(wirq->irq);
400
401 if (wirq->status & WAKE_IRQ_DEDICATED_ALLOCATED &&
402 !pm_runtime_status_suspended(wirq->dev))
403 disable_irq_nosync(wirq->irq);
404 }
405 }
406