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 = 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}
104EXPORT_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 */
124static 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
145static 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
187err_free_irq:
188	free_irq(irq, wirq);
189err_free_name:
190	kfree(wirq->name);
191err_free:
192	kfree(wirq);
193
194	return err;
195}
196
197/**
198 * dev_pm_set_dedicated_wake_irq - Request a dedicated wake-up interrupt
199 * @dev: Device entry
200 * @irq: Device wake-up interrupt
201 *
202 * Unless your hardware has separate wake-up interrupts in addition
203 * to the device IO interrupts, you don't need this.
204 *
205 * Sets up a threaded interrupt handler for a device that has
206 * a dedicated wake-up interrupt in addition to the device IO
207 * interrupt.
208 */
209int dev_pm_set_dedicated_wake_irq(struct device *dev, int irq)
210{
211	return __dev_pm_set_dedicated_wake_irq(dev, irq, 0);
212}
213EXPORT_SYMBOL_GPL(dev_pm_set_dedicated_wake_irq);
214
215/**
216 * dev_pm_set_dedicated_wake_irq_reverse - Request a dedicated wake-up interrupt
217 *                                         with reverse enable ordering
218 * @dev: Device entry
219 * @irq: Device wake-up interrupt
220 *
221 * Unless your hardware has separate wake-up interrupts in addition
222 * to the device IO interrupts, you don't need this.
223 *
224 * Sets up a threaded interrupt handler for a device that has a dedicated
225 * wake-up interrupt in addition to the device IO interrupt. It sets
226 * the status of WAKE_IRQ_DEDICATED_REVERSE to tell rpm_suspend()
227 * to enable dedicated wake-up interrupt after running the runtime suspend
228 * callback for @dev.
229 */
230int dev_pm_set_dedicated_wake_irq_reverse(struct device *dev, int irq)
231{
232	return __dev_pm_set_dedicated_wake_irq(dev, irq, WAKE_IRQ_DEDICATED_REVERSE);
233}
234EXPORT_SYMBOL_GPL(dev_pm_set_dedicated_wake_irq_reverse);
235
236/**
237 * dev_pm_enable_wake_irq_check - Checks and enables wake-up interrupt
238 * @dev: Device
239 * @can_change_status: Can change wake-up interrupt status
240 *
241 * Enables wakeirq conditionally. We need to enable wake-up interrupt
242 * lazily on the first rpm_suspend(). This is needed as the consumer device
243 * starts in RPM_SUSPENDED state, and the first pm_runtime_get() would
244 * otherwise try to disable already disabled wakeirq. The wake-up interrupt
245 * starts disabled with IRQ_NOAUTOEN set.
246 *
247 * Should be only called from rpm_suspend() and rpm_resume() path.
248 * Caller must hold &dev->power.lock to change wirq->status
249 */
250void dev_pm_enable_wake_irq_check(struct device *dev,
251				  bool can_change_status)
252{
253	struct wake_irq *wirq = dev->power.wakeirq;
254
255	if (!wirq || !(wirq->status & WAKE_IRQ_DEDICATED_MASK))
256		return;
257
258	if (likely(wirq->status & WAKE_IRQ_DEDICATED_MANAGED)) {
259		goto enable;
260	} else if (can_change_status) {
261		wirq->status |= WAKE_IRQ_DEDICATED_MANAGED;
262		goto enable;
263	}
264
265	return;
266
267enable:
268	if (!can_change_status || !(wirq->status & WAKE_IRQ_DEDICATED_REVERSE)) {
269		enable_irq(wirq->irq);
270		wirq->status |= WAKE_IRQ_DEDICATED_ENABLED;
271	}
272}
273
274/**
275 * dev_pm_disable_wake_irq_check - Checks and disables wake-up interrupt
276 * @dev: Device
277 * @cond_disable: if set, also check WAKE_IRQ_DEDICATED_REVERSE
278 *
279 * Disables wake-up interrupt conditionally based on status.
280 * Should be only called from rpm_suspend() and rpm_resume() path.
281 */
282void dev_pm_disable_wake_irq_check(struct device *dev, bool cond_disable)
283{
284	struct wake_irq *wirq = dev->power.wakeirq;
285
286	if (!wirq || !(wirq->status & WAKE_IRQ_DEDICATED_MASK))
287		return;
288
289	if (cond_disable && (wirq->status & WAKE_IRQ_DEDICATED_REVERSE))
290		return;
291
292	if (wirq->status & WAKE_IRQ_DEDICATED_MANAGED) {
293		wirq->status &= ~WAKE_IRQ_DEDICATED_ENABLED;
294		disable_irq_nosync(wirq->irq);
295	}
296}
297
298/**
299 * dev_pm_enable_wake_irq_complete - enable wake IRQ not enabled before
300 * @dev: Device using the wake IRQ
301 *
302 * Enable wake IRQ conditionally based on status, mainly used if want to
303 * enable wake IRQ after running ->runtime_suspend() which depends on
304 * WAKE_IRQ_DEDICATED_REVERSE.
305 *
306 * Should be only called from rpm_suspend() path.
307 */
308void dev_pm_enable_wake_irq_complete(struct device *dev)
309{
310	struct wake_irq *wirq = dev->power.wakeirq;
311
312	if (!wirq || !(wirq->status & WAKE_IRQ_DEDICATED_MASK))
313		return;
314
315	if (wirq->status & WAKE_IRQ_DEDICATED_MANAGED &&
316	    wirq->status & WAKE_IRQ_DEDICATED_REVERSE) {
317		enable_irq(wirq->irq);
318		wirq->status |= WAKE_IRQ_DEDICATED_ENABLED;
319	}
320}
321
322/**
323 * dev_pm_arm_wake_irq - Arm device wake-up
324 * @wirq: Device wake-up interrupt
325 *
326 * Sets up the wake-up event conditionally based on the
327 * device_may_wake().
328 */
329void dev_pm_arm_wake_irq(struct wake_irq *wirq)
330{
331	if (!wirq)
332		return;
333
334	if (device_may_wakeup(wirq->dev)) {
335		if (wirq->status & WAKE_IRQ_DEDICATED_ALLOCATED &&
336		    !(wirq->status & WAKE_IRQ_DEDICATED_ENABLED))
337			enable_irq(wirq->irq);
338
339		enable_irq_wake(wirq->irq);
340	}
341}
342
343/**
344 * dev_pm_disarm_wake_irq - Disarm device wake-up
345 * @wirq: Device wake-up interrupt
346 *
347 * Clears up the wake-up event conditionally based on the
348 * device_may_wake().
349 */
350void dev_pm_disarm_wake_irq(struct wake_irq *wirq)
351{
352	if (!wirq)
353		return;
354
355	if (device_may_wakeup(wirq->dev)) {
356		disable_irq_wake(wirq->irq);
357
358		if (wirq->status & WAKE_IRQ_DEDICATED_ALLOCATED &&
359		    !(wirq->status & WAKE_IRQ_DEDICATED_ENABLED))
360			disable_irq_nosync(wirq->irq);
361	}
362}
363