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