wakeirq.c

  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(&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 */
 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(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;
 87	unsigned long flags;
 88
 89	spin_lock_irqsave(&dev->power.lock, flags);
 90	wirq = dev->power.wakeirq;
 91	if (!wirq) {
 92		spin_unlock_irqrestore(&dev->power.lock, flags);
 93		return;
 94	}
 95
 96	device_wakeup_detach_irq(dev);
 97	dev->power.wakeirq = NULL;
 98	spin_unlock_irqrestore(&dev->power.lock, flags);
 99
100	if (wirq->status & WAKE_IRQ_DEDICATED_ALLOCATED) {
101		free_irq(wirq->irq, wirq);
102		wirq->status &= ~WAKE_IRQ_DEDICATED_MASK;
103	}
104	kfree(wirq->name);
105	kfree(wirq);
106}
107EXPORT_SYMBOL_GPL(dev_pm_clear_wake_irq);
108
109static void devm_pm_clear_wake_irq(void *dev)
110{
111	dev_pm_clear_wake_irq(dev);
112}
113
114/**
115 * devm_pm_set_wake_irq - device-managed variant of dev_pm_set_wake_irq
116 * @dev: Device entry
117 * @irq: Device IO interrupt
118 *
119 *
120 * Attach a device IO interrupt as a wake IRQ, same with dev_pm_set_wake_irq,
121 * but the device will be auto clear wake capability on driver detach.
122 */
123int devm_pm_set_wake_irq(struct device *dev, int irq)
124{
125	int ret;
126
127	ret = dev_pm_set_wake_irq(dev, irq);
128	if (ret)
129		return ret;
130
131	return devm_add_action_or_reset(dev, devm_pm_clear_wake_irq, dev);
132}
133EXPORT_SYMBOL_GPL(devm_pm_set_wake_irq);
134
135/**
136 * handle_threaded_wake_irq - Handler for dedicated wake-up interrupts
137 * @irq: Device specific dedicated wake-up interrupt
138 * @_wirq: Wake IRQ data
139 *
140 * Some devices have a separate wake-up interrupt in addition to the
141 * device IO interrupt. The wake-up interrupt signals that a device
142 * should be woken up from it's idle state. This handler uses device
143 * specific pm_runtime functions to wake the device, and then it's
144 * up to the device to do whatever it needs to. Note that as the
145 * device may need to restore context and start up regulators, we
146 * use a threaded IRQ.
147 *
148 * Also note that we are not resending the lost device interrupts.
149 * We assume that the wake-up interrupt just needs to wake-up the
150 * device, and then device's pm_runtime_resume() can deal with the
151 * situation.
152 */
153static irqreturn_t handle_threaded_wake_irq(int irq, void *_wirq)
154{
155	struct wake_irq *wirq = _wirq;
156	int res;
157
158	/* Maybe abort suspend? */
159	if (irqd_is_wakeup_set(irq_get_irq_data(irq))) {
160		pm_wakeup_event(wirq->dev, 0);
161
162		return IRQ_HANDLED;
163	}
164
165	/* We don't want RPM_ASYNC or RPM_NOWAIT here */
166	res = pm_runtime_resume(wirq->dev);
167	if (res < 0)
168		dev_warn(wirq->dev,
169			 "wake IRQ with no resume: %i\n", res);
170
171	return IRQ_HANDLED;
172}
173
174static int __dev_pm_set_dedicated_wake_irq(struct device *dev, int irq, unsigned int flag)
175{
176	struct wake_irq *wirq;
177	int err;
178
179	if (irq < 0)
180		return -EINVAL;
181
182	wirq = kzalloc(sizeof(*wirq), GFP_KERNEL);
183	if (!wirq)
184		return -ENOMEM;
185
186	wirq->name = kasprintf(GFP_KERNEL, "%s:wakeup", dev_name(dev));
187	if (!wirq->name) {
188		err = -ENOMEM;
189		goto err_free;
190	}
191
192	wirq->dev = dev;
193	wirq->irq = irq;
194
195	/* Prevent deferred spurious wakeirqs with disable_irq_nosync() */
196	irq_set_status_flags(irq, IRQ_DISABLE_UNLAZY);
197
198	/*
199	 * Consumer device may need to power up and restore state
200	 * so we use a threaded irq.
201	 */
202	err = request_threaded_irq(irq, NULL, handle_threaded_wake_irq,
203				   IRQF_ONESHOT | IRQF_NO_AUTOEN,
204				   wirq->name, wirq);
205	if (err)
206		goto err_free_name;
207
208	err = dev_pm_attach_wake_irq(dev, wirq);
209	if (err)
210		goto err_free_irq;
211
212	wirq->status = WAKE_IRQ_DEDICATED_ALLOCATED | flag;
213
214	return err;
215
216err_free_irq:
217	free_irq(irq, wirq);
218err_free_name:
219	kfree(wirq->name);
220err_free:
221	kfree(wirq);
222
223	return err;
224}
225
226/**
227 * dev_pm_set_dedicated_wake_irq - Request a dedicated wake-up interrupt
228 * @dev: Device entry
229 * @irq: Device wake-up interrupt
230 *
231 * Unless your hardware has separate wake-up interrupts in addition
232 * to the device IO interrupts, you don't need this.
233 *
234 * Sets up a threaded interrupt handler for a device that has
235 * a dedicated wake-up interrupt in addition to the device IO
236 * interrupt.
237 */
238int dev_pm_set_dedicated_wake_irq(struct device *dev, int irq)
239{
240	return __dev_pm_set_dedicated_wake_irq(dev, irq, 0);
241}
242EXPORT_SYMBOL_GPL(dev_pm_set_dedicated_wake_irq);
243
244/**
245 * dev_pm_set_dedicated_wake_irq_reverse - Request a dedicated wake-up interrupt
246 *                                         with reverse enable ordering
247 * @dev: Device entry
248 * @irq: Device wake-up interrupt
249 *
250 * Unless your hardware has separate wake-up interrupts in addition
251 * to the device IO interrupts, you don't need this.
252 *
253 * Sets up a threaded interrupt handler for a device that has a dedicated
254 * wake-up interrupt in addition to the device IO interrupt. It sets
255 * the status of WAKE_IRQ_DEDICATED_REVERSE to tell rpm_suspend()
256 * to enable dedicated wake-up interrupt after running the runtime suspend
257 * callback for @dev.
258 */
259int dev_pm_set_dedicated_wake_irq_reverse(struct device *dev, int irq)
260{
261	return __dev_pm_set_dedicated_wake_irq(dev, irq, WAKE_IRQ_DEDICATED_REVERSE);
262}
263EXPORT_SYMBOL_GPL(dev_pm_set_dedicated_wake_irq_reverse);
264
265/**
266 * dev_pm_enable_wake_irq_check - Checks and enables wake-up interrupt
267 * @dev: Device
268 * @can_change_status: Can change wake-up interrupt status
269 *
270 * Enables wakeirq conditionally. We need to enable wake-up interrupt
271 * lazily on the first rpm_suspend(). This is needed as the consumer device
272 * starts in RPM_SUSPENDED state, and the first pm_runtime_get() would
273 * otherwise try to disable already disabled wakeirq. The wake-up interrupt
274 * starts disabled with IRQ_NOAUTOEN set.
275 *
276 * Should be only called from rpm_suspend() and rpm_resume() path.
277 * Caller must hold &dev->power.lock to change wirq->status
278 */
279void dev_pm_enable_wake_irq_check(struct device *dev,
280				  bool can_change_status)
281{
282	struct wake_irq *wirq = dev->power.wakeirq;
283
284	if (!wirq || !(wirq->status & WAKE_IRQ_DEDICATED_MASK))
285		return;
286
287	if (likely(wirq->status & WAKE_IRQ_DEDICATED_MANAGED)) {
288		goto enable;
289	} else if (can_change_status) {
290		wirq->status |= WAKE_IRQ_DEDICATED_MANAGED;
291		goto enable;
292	}
293
294	return;
295
296enable:
297	if (!can_change_status || !(wirq->status & WAKE_IRQ_DEDICATED_REVERSE)) {
298		enable_irq(wirq->irq);
299		wirq->status |= WAKE_IRQ_DEDICATED_ENABLED;
300	}
301}
302
303/**
304 * dev_pm_disable_wake_irq_check - Checks and disables wake-up interrupt
305 * @dev: Device
306 * @cond_disable: if set, also check WAKE_IRQ_DEDICATED_REVERSE
307 *
308 * Disables wake-up interrupt conditionally based on status.
309 * Should be only called from rpm_suspend() and rpm_resume() path.
310 */
311void dev_pm_disable_wake_irq_check(struct device *dev, bool cond_disable)
312{
313	struct wake_irq *wirq = dev->power.wakeirq;
314
315	if (!wirq || !(wirq->status & WAKE_IRQ_DEDICATED_MASK))
316		return;
317
318	if (cond_disable && (wirq->status & WAKE_IRQ_DEDICATED_REVERSE))
319		return;
320
321	if (wirq->status & WAKE_IRQ_DEDICATED_MANAGED) {
322		wirq->status &= ~WAKE_IRQ_DEDICATED_ENABLED;
323		disable_irq_nosync(wirq->irq);
324	}
325}
326
327/**
328 * dev_pm_enable_wake_irq_complete - enable wake IRQ not enabled before
329 * @dev: Device using the wake IRQ
330 *
331 * Enable wake IRQ conditionally based on status, mainly used if want to
332 * enable wake IRQ after running ->runtime_suspend() which depends on
333 * WAKE_IRQ_DEDICATED_REVERSE.
334 *
335 * Should be only called from rpm_suspend() path.
336 */
337void dev_pm_enable_wake_irq_complete(struct device *dev)
338{
339	struct wake_irq *wirq = dev->power.wakeirq;
340
341	if (!wirq || !(wirq->status & WAKE_IRQ_DEDICATED_MASK))
342		return;
343
344	if (wirq->status & WAKE_IRQ_DEDICATED_MANAGED &&
345	    wirq->status & WAKE_IRQ_DEDICATED_REVERSE) {
346		enable_irq(wirq->irq);
347		wirq->status |= WAKE_IRQ_DEDICATED_ENABLED;
348	}
349}
350
351/**
352 * dev_pm_arm_wake_irq - Arm device wake-up
353 * @wirq: Device wake-up interrupt
354 *
355 * Sets up the wake-up event conditionally based on the
356 * device_may_wake().
357 */
358void dev_pm_arm_wake_irq(struct wake_irq *wirq)
359{
360	if (!wirq)
361		return;
362
363	if (device_may_wakeup(wirq->dev)) {
364		if (wirq->status & WAKE_IRQ_DEDICATED_ALLOCATED &&
365		    !(wirq->status & WAKE_IRQ_DEDICATED_ENABLED))
366			enable_irq(wirq->irq);
367
368		enable_irq_wake(wirq->irq);
369	}
370}
371
372/**
373 * dev_pm_disarm_wake_irq - Disarm device wake-up
374 * @wirq: Device wake-up interrupt
375 *
376 * Clears up the wake-up event conditionally based on the
377 * device_may_wake().
378 */
379void dev_pm_disarm_wake_irq(struct wake_irq *wirq)
380{
381	if (!wirq)
382		return;
383
384	if (device_may_wakeup(wirq->dev)) {
385		disable_irq_wake(wirq->irq);
386
387		if (wirq->status & WAKE_IRQ_DEDICATED_ALLOCATED &&
388		    !(wirq->status & WAKE_IRQ_DEDICATED_ENABLED))
389			disable_irq_nosync(wirq->irq);
390	}
391}