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
145 /**
146 * dev_pm_set_dedicated_wake_irq - Request a dedicated wake-up interrupt
147 * @dev: Device entry
148 * @irq: Device wake-up interrupt
149 *
150 * Unless your hardware has separate wake-up interrupts in addition
151 * to the device IO interrupts, you don't need this.
152 *
153 * Sets up a threaded interrupt handler for a device that has
154 * a dedicated wake-up interrupt in addition to the device IO
155 * interrupt.
156 *
157 * The interrupt starts disabled, and needs to be managed for
158 * the device by the bus code or the device driver using
159 * dev_pm_enable_wake_irq() and dev_pm_disable_wake_irq()
160 * functions.
161 */
dev_pm_set_dedicated_wake_irq(struct device * dev,int irq)162 int dev_pm_set_dedicated_wake_irq(struct device *dev, int irq)
163 {
164 struct wake_irq *wirq;
165 int err;
166
167 if (irq < 0)
168 return -EINVAL;
169
170 wirq = kzalloc(sizeof(*wirq), GFP_KERNEL);
171 if (!wirq)
172 return -ENOMEM;
173
174 wirq->name = kasprintf(GFP_KERNEL, "%s:wakeup", dev_name(dev));
175 if (!wirq->name) {
176 err = -ENOMEM;
177 goto err_free;
178 }
179
180 wirq->dev = dev;
181 wirq->irq = irq;
182
183 /* Prevent deferred spurious wakeirqs with disable_irq_nosync() */
184 irq_set_status_flags(irq, IRQ_DISABLE_UNLAZY);
185
186 /*
187 * Consumer device may need to power up and restore state
188 * so we use a threaded irq.
189 */
190 err = request_threaded_irq(irq, NULL, handle_threaded_wake_irq,
191 IRQF_ONESHOT | IRQF_NO_AUTOEN,
192 wirq->name, wirq);
193 if (err)
194 goto err_free_name;
195
196 err = dev_pm_attach_wake_irq(dev, wirq);
197 if (err)
198 goto err_free_irq;
199
200 wirq->status = WAKE_IRQ_DEDICATED_ALLOCATED;
201
202 return err;
203
204 err_free_irq:
205 free_irq(irq, wirq);
206 err_free_name:
207 kfree(wirq->name);
208 err_free:
209 kfree(wirq);
210
211 return err;
212 }
213 EXPORT_SYMBOL_GPL(dev_pm_set_dedicated_wake_irq);
214
215 /**
216 * dev_pm_enable_wake_irq - Enable device wake-up interrupt
217 * @dev: Device
218 *
219 * Optionally called from the bus code or the device driver for
220 * runtime_resume() to override the PM runtime core managed wake-up
221 * interrupt handling to enable the wake-up interrupt.
222 *
223 * Note that for runtime_suspend()) the wake-up interrupts
224 * should be unconditionally enabled unlike for suspend()
225 * that is conditional.
226 */
dev_pm_enable_wake_irq(struct device * dev)227 void dev_pm_enable_wake_irq(struct device *dev)
228 {
229 struct wake_irq *wirq = dev->power.wakeirq;
230
231 if (wirq && (wirq->status & WAKE_IRQ_DEDICATED_ALLOCATED))
232 enable_irq(wirq->irq);
233 }
234 EXPORT_SYMBOL_GPL(dev_pm_enable_wake_irq);
235
236 /**
237 * dev_pm_disable_wake_irq - Disable device wake-up interrupt
238 * @dev: Device
239 *
240 * Optionally called from the bus code or the device driver for
241 * runtime_suspend() to override the PM runtime core managed wake-up
242 * interrupt handling to disable the wake-up interrupt.
243 */
dev_pm_disable_wake_irq(struct device * dev)244 void dev_pm_disable_wake_irq(struct device *dev)
245 {
246 struct wake_irq *wirq = dev->power.wakeirq;
247
248 if (wirq && (wirq->status & WAKE_IRQ_DEDICATED_ALLOCATED))
249 disable_irq_nosync(wirq->irq);
250 }
251 EXPORT_SYMBOL_GPL(dev_pm_disable_wake_irq);
252
253 /**
254 * dev_pm_enable_wake_irq_check - Checks and enables wake-up interrupt
255 * @dev: Device
256 * @can_change_status: Can change wake-up interrupt status
257 *
258 * Enables wakeirq conditionally. We need to enable wake-up interrupt
259 * lazily on the first rpm_suspend(). This is needed as the consumer device
260 * starts in RPM_SUSPENDED state, and the the first pm_runtime_get() would
261 * otherwise try to disable already disabled wakeirq. The wake-up interrupt
262 * starts disabled with IRQ_NOAUTOEN set.
263 *
264 * Should be only called from rpm_suspend() and rpm_resume() path.
265 * Caller must hold &dev->power.lock to change wirq->status
266 */
dev_pm_enable_wake_irq_check(struct device * dev,bool can_change_status)267 void dev_pm_enable_wake_irq_check(struct device *dev,
268 bool can_change_status)
269 {
270 struct wake_irq *wirq = dev->power.wakeirq;
271
272 if (!wirq || !(wirq->status & WAKE_IRQ_DEDICATED_MASK))
273 return;
274
275 if (likely(wirq->status & WAKE_IRQ_DEDICATED_MANAGED)) {
276 goto enable;
277 } else if (can_change_status) {
278 wirq->status |= WAKE_IRQ_DEDICATED_MANAGED;
279 goto enable;
280 }
281
282 return;
283
284 enable:
285 enable_irq(wirq->irq);
286 }
287
288 /**
289 * dev_pm_disable_wake_irq_check - Checks and disables wake-up interrupt
290 * @dev: Device
291 *
292 * Disables wake-up interrupt conditionally based on status.
293 * Should be only called from rpm_suspend() and rpm_resume() path.
294 */
dev_pm_disable_wake_irq_check(struct device * dev)295 void dev_pm_disable_wake_irq_check(struct device *dev)
296 {
297 struct wake_irq *wirq = dev->power.wakeirq;
298
299 if (!wirq || !(wirq->status & WAKE_IRQ_DEDICATED_MASK))
300 return;
301
302 if (wirq->status & WAKE_IRQ_DEDICATED_MANAGED)
303 disable_irq_nosync(wirq->irq);
304 }
305
306 /**
307 * dev_pm_arm_wake_irq - Arm device wake-up
308 * @wirq: Device wake-up interrupt
309 *
310 * Sets up the wake-up event conditionally based on the
311 * device_may_wake().
312 */
dev_pm_arm_wake_irq(struct wake_irq * wirq)313 void dev_pm_arm_wake_irq(struct wake_irq *wirq)
314 {
315 if (!wirq)
316 return;
317
318 if (device_may_wakeup(wirq->dev)) {
319 if (wirq->status & WAKE_IRQ_DEDICATED_ALLOCATED &&
320 !pm_runtime_status_suspended(wirq->dev))
321 enable_irq(wirq->irq);
322
323 enable_irq_wake(wirq->irq);
324 }
325 }
326
327 /**
328 * dev_pm_disarm_wake_irq - Disarm device wake-up
329 * @wirq: Device wake-up interrupt
330 *
331 * Clears up the wake-up event conditionally based on the
332 * device_may_wake().
333 */
dev_pm_disarm_wake_irq(struct wake_irq * wirq)334 void dev_pm_disarm_wake_irq(struct wake_irq *wirq)
335 {
336 if (!wirq)
337 return;
338
339 if (device_may_wakeup(wirq->dev)) {
340 disable_irq_wake(wirq->irq);
341
342 if (wirq->status & WAKE_IRQ_DEDICATED_ALLOCATED &&
343 !pm_runtime_status_suspended(wirq->dev))
344 disable_irq_nosync(wirq->irq);
345 }
346 }
347
