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 */
19static 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(lock: &dev->power.lock, flags);
30 return -EEXIST;
31 }
32
33 dev->power.wakeirq = wirq;
34 device_wakeup_attach_irq(dev, wakeirq: wirq);
35
36 spin_unlock_irqrestore(lock: &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 */
50int 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(objp: wirq);
68
69 return err;
70}
71EXPORT_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 */
84void 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(lock: &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(objp: wirq->name);
102 kfree(objp: wirq);
103}
104EXPORT_SYMBOL_GPL(dev_pm_clear_wake_irq);
105
106static void devm_pm_clear_wake_irq(void *dev)
107{
108 dev_pm_clear_wake_irq(dev);
109}
110
111/**
112 * devm_pm_set_wake_irq - device-managed variant of dev_pm_set_wake_irq
113 * @dev: Device entry
114 * @irq: Device IO interrupt
115 *
116 *
117 * Attach a device IO interrupt as a wake IRQ, same with dev_pm_set_wake_irq,
118 * but the device will be auto clear wake capability on driver detach.
119 */
120int devm_pm_set_wake_irq(struct device *dev, int irq)
121{
122 int ret;
123
124 ret = dev_pm_set_wake_irq(dev, irq);
125 if (ret)
126 return ret;
127
128 return devm_add_action_or_reset(dev, devm_pm_clear_wake_irq, dev);
129}
130EXPORT_SYMBOL_GPL(devm_pm_set_wake_irq);
131
132/**
133 * handle_threaded_wake_irq - Handler for dedicated wake-up interrupts
134 * @irq: Device specific dedicated wake-up interrupt
135 * @_wirq: Wake IRQ data
136 *
137 * Some devices have a separate wake-up interrupt in addition to the
138 * device IO interrupt. The wake-up interrupt signals that a device
139 * should be woken up from it's idle state. This handler uses device
140 * specific pm_runtime functions to wake the device, and then it's
141 * up to the device to do whatever it needs to. Note that as the
142 * device may need to restore context and start up regulators, we
143 * use a threaded IRQ.
144 *
145 * Also note that we are not resending the lost device interrupts.
146 * We assume that the wake-up interrupt just needs to wake-up the
147 * device, and then device's pm_runtime_resume() can deal with the
148 * situation.
149 */
150static irqreturn_t handle_threaded_wake_irq(int irq, void *_wirq)
151{
152 struct wake_irq *wirq = _wirq;
153 int res;
154
155 /* Maybe abort suspend? */
156 if (irqd_is_wakeup_set(d: irq_get_irq_data(irq))) {
157 pm_wakeup_event(dev: wirq->dev, msec: 0);
158
159 return IRQ_HANDLED;
160 }
161
162 /* We don't want RPM_ASYNC or RPM_NOWAIT here */
163 res = pm_runtime_resume(dev: wirq->dev);
164 if (res < 0)
165 dev_warn(wirq->dev,
166 "wake IRQ with no resume: %i\n", res);
167
168 return IRQ_HANDLED;
169}
170
171static int __dev_pm_set_dedicated_wake_irq(struct device *dev, int irq, unsigned int flag)
172{
173 struct wake_irq *wirq;
174 int err;
175
176 if (irq < 0)
177 return -EINVAL;
178
179 wirq = kzalloc(sizeof(*wirq), GFP_KERNEL);
180 if (!wirq)
181 return -ENOMEM;
182
183 wirq->name = kasprintf(GFP_KERNEL, fmt: "%s:wakeup", dev_name(dev));
184 if (!wirq->name) {
185 err = -ENOMEM;
186 goto err_free;
187 }
188
189 wirq->dev = dev;
190 wirq->irq = irq;
191
192 /* Prevent deferred spurious wakeirqs with disable_irq_nosync() */
193 irq_set_status_flags(irq, set: IRQ_DISABLE_UNLAZY);
194
195 /*
196 * Consumer device may need to power up and restore state
197 * so we use a threaded irq.
198 */
199 err = request_threaded_irq(irq, NULL, thread_fn: handle_threaded_wake_irq,
200 IRQF_ONESHOT | IRQF_NO_AUTOEN,
201 name: wirq->name, dev: wirq);
202 if (err)
203 goto err_free_name;
204
205 err = dev_pm_attach_wake_irq(dev, wirq);
206 if (err)
207 goto err_free_irq;
208
209 wirq->status = WAKE_IRQ_DEDICATED_ALLOCATED | flag;
210
211 return err;
212
213err_free_irq:
214 free_irq(irq, wirq);
215err_free_name:
216 kfree(objp: wirq->name);
217err_free:
218 kfree(objp: wirq);
219
220 return err;
221}
222
223/**
224 * dev_pm_set_dedicated_wake_irq - Request a dedicated wake-up interrupt
225 * @dev: Device entry
226 * @irq: Device wake-up interrupt
227 *
228 * Unless your hardware has separate wake-up interrupts in addition
229 * to the device IO interrupts, you don't need this.
230 *
231 * Sets up a threaded interrupt handler for a device that has
232 * a dedicated wake-up interrupt in addition to the device IO
233 * interrupt.
234 */
235int dev_pm_set_dedicated_wake_irq(struct device *dev, int irq)
236{
237 return __dev_pm_set_dedicated_wake_irq(dev, irq, flag: 0);
238}
239EXPORT_SYMBOL_GPL(dev_pm_set_dedicated_wake_irq);
240
241/**
242 * dev_pm_set_dedicated_wake_irq_reverse - Request a dedicated wake-up interrupt
243 * with reverse enable ordering
244 * @dev: Device entry
245 * @irq: Device wake-up interrupt
246 *
247 * Unless your hardware has separate wake-up interrupts in addition
248 * to the device IO interrupts, you don't need this.
249 *
250 * Sets up a threaded interrupt handler for a device that has a dedicated
251 * wake-up interrupt in addition to the device IO interrupt. It sets
252 * the status of WAKE_IRQ_DEDICATED_REVERSE to tell rpm_suspend()
253 * to enable dedicated wake-up interrupt after running the runtime suspend
254 * callback for @dev.
255 */
256int dev_pm_set_dedicated_wake_irq_reverse(struct device *dev, int irq)
257{
258 return __dev_pm_set_dedicated_wake_irq(dev, irq, WAKE_IRQ_DEDICATED_REVERSE);
259}
260EXPORT_SYMBOL_GPL(dev_pm_set_dedicated_wake_irq_reverse);
261
262/**
263 * dev_pm_enable_wake_irq_check - Checks and enables wake-up interrupt
264 * @dev: Device
265 * @can_change_status: Can change wake-up interrupt status
266 *
267 * Enables wakeirq conditionally. We need to enable wake-up interrupt
268 * lazily on the first rpm_suspend(). This is needed as the consumer device
269 * starts in RPM_SUSPENDED state, and the first pm_runtime_get() would
270 * otherwise try to disable already disabled wakeirq. The wake-up interrupt
271 * starts disabled with IRQ_NOAUTOEN set.
272 *
273 * Should be only called from rpm_suspend() and rpm_resume() path.
274 * Caller must hold &dev->power.lock to change wirq->status
275 */
276void dev_pm_enable_wake_irq_check(struct device *dev,
277 bool can_change_status)
278{
279 struct wake_irq *wirq = dev->power.wakeirq;
280
281 if (!wirq || !(wirq->status & WAKE_IRQ_DEDICATED_MASK))
282 return;
283
284 if (likely(wirq->status & WAKE_IRQ_DEDICATED_MANAGED)) {
285 goto enable;
286 } else if (can_change_status) {
287 wirq->status |= WAKE_IRQ_DEDICATED_MANAGED;
288 goto enable;
289 }
290
291 return;
292
293enable:
294 if (!can_change_status || !(wirq->status & WAKE_IRQ_DEDICATED_REVERSE)) {
295 enable_irq(irq: wirq->irq);
296 wirq->status |= WAKE_IRQ_DEDICATED_ENABLED;
297 }
298}
299
300/**
301 * dev_pm_disable_wake_irq_check - Checks and disables wake-up interrupt
302 * @dev: Device
303 * @cond_disable: if set, also check WAKE_IRQ_DEDICATED_REVERSE
304 *
305 * Disables wake-up interrupt conditionally based on status.
306 * Should be only called from rpm_suspend() and rpm_resume() path.
307 */
308void dev_pm_disable_wake_irq_check(struct device *dev, bool cond_disable)
309{
310 struct wake_irq *wirq = dev->power.wakeirq;
311
312 if (!wirq || !(wirq->status & WAKE_IRQ_DEDICATED_MASK))
313 return;
314
315 if (cond_disable && (wirq->status & WAKE_IRQ_DEDICATED_REVERSE))
316 return;
317
318 if (wirq->status & WAKE_IRQ_DEDICATED_MANAGED) {
319 wirq->status &= ~WAKE_IRQ_DEDICATED_ENABLED;
320 disable_irq_nosync(irq: wirq->irq);
321 }
322}
323
324/**
325 * dev_pm_enable_wake_irq_complete - enable wake IRQ not enabled before
326 * @dev: Device using the wake IRQ
327 *
328 * Enable wake IRQ conditionally based on status, mainly used if want to
329 * enable wake IRQ after running ->runtime_suspend() which depends on
330 * WAKE_IRQ_DEDICATED_REVERSE.
331 *
332 * Should be only called from rpm_suspend() path.
333 */
334void dev_pm_enable_wake_irq_complete(struct device *dev)
335{
336 struct wake_irq *wirq = dev->power.wakeirq;
337
338 if (!wirq || !(wirq->status & WAKE_IRQ_DEDICATED_MASK))
339 return;
340
341 if (wirq->status & WAKE_IRQ_DEDICATED_MANAGED &&
342 wirq->status & WAKE_IRQ_DEDICATED_REVERSE) {
343 enable_irq(irq: wirq->irq);
344 wirq->status |= WAKE_IRQ_DEDICATED_ENABLED;
345 }
346}
347
348/**
349 * dev_pm_arm_wake_irq - Arm device wake-up
350 * @wirq: Device wake-up interrupt
351 *
352 * Sets up the wake-up event conditionally based on the
353 * device_may_wake().
354 */
355void dev_pm_arm_wake_irq(struct wake_irq *wirq)
356{
357 if (!wirq)
358 return;
359
360 if (device_may_wakeup(dev: wirq->dev)) {
361 if (wirq->status & WAKE_IRQ_DEDICATED_ALLOCATED &&
362 !(wirq->status & WAKE_IRQ_DEDICATED_ENABLED))
363 enable_irq(irq: wirq->irq);
364
365 enable_irq_wake(irq: wirq->irq);
366 }
367}
368
369/**
370 * dev_pm_disarm_wake_irq - Disarm device wake-up
371 * @wirq: Device wake-up interrupt
372 *
373 * Clears up the wake-up event conditionally based on the
374 * device_may_wake().
375 */
376void dev_pm_disarm_wake_irq(struct wake_irq *wirq)
377{
378 if (!wirq)
379 return;
380
381 if (device_may_wakeup(dev: wirq->dev)) {
382 disable_irq_wake(irq: wirq->irq);
383
384 if (wirq->status & WAKE_IRQ_DEDICATED_ALLOCATED &&
385 !(wirq->status & WAKE_IRQ_DEDICATED_ENABLED))
386 disable_irq_nosync(irq: wirq->irq);
387 }
388}
389

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source code of linux/drivers/base/power/wakeirq.c