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4990d4fe TL |
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 | */ | |
32 | static int dev_pm_attach_wake_irq(struct device *dev, int irq, | |
33 | struct wake_irq *wirq) | |
34 | { | |
35 | unsigned long flags; | |
36 | int err; | |
37 | ||
38 | if (!dev || !wirq) | |
39 | return -EINVAL; | |
40 | ||
41 | spin_lock_irqsave(&dev->power.lock, flags); | |
42 | if (dev_WARN_ONCE(dev, dev->power.wakeirq, | |
43 | "wake irq already initialized\n")) { | |
44 | spin_unlock_irqrestore(&dev->power.lock, flags); | |
45 | return -EEXIST; | |
46 | } | |
47 | ||
4990d4fe | 48 | err = device_wakeup_attach_irq(dev, wirq); |
6d3dab7d RW |
49 | if (!err) |
50 | dev->power.wakeirq = wirq; | |
4990d4fe | 51 | |
6d3dab7d RW |
52 | spin_unlock_irqrestore(&dev->power.lock, flags); |
53 | return err; | |
4990d4fe TL |
54 | } |
55 | ||
56 | /** | |
57 | * dev_pm_set_wake_irq - Attach device IO interrupt as wake IRQ | |
58 | * @dev: Device entry | |
59 | * @irq: Device IO interrupt | |
60 | * | |
61 | * Attach a device IO interrupt as a wake IRQ. The wake IRQ gets | |
62 | * automatically configured for wake-up from suspend based | |
63 | * on the device specific sysfs wakeup entry. Typically called | |
64 | * during driver probe after calling device_init_wakeup(). | |
65 | */ | |
66 | int dev_pm_set_wake_irq(struct device *dev, int irq) | |
67 | { | |
68 | struct wake_irq *wirq; | |
69 | int err; | |
70 | ||
71 | wirq = kzalloc(sizeof(*wirq), GFP_KERNEL); | |
72 | if (!wirq) | |
73 | return -ENOMEM; | |
74 | ||
75 | wirq->dev = dev; | |
76 | wirq->irq = irq; | |
77 | ||
78 | err = dev_pm_attach_wake_irq(dev, irq, wirq); | |
79 | if (err) | |
80 | kfree(wirq); | |
81 | ||
82 | return err; | |
83 | } | |
84 | EXPORT_SYMBOL_GPL(dev_pm_set_wake_irq); | |
85 | ||
86 | /** | |
87 | * dev_pm_clear_wake_irq - Detach a device IO interrupt wake IRQ | |
88 | * @dev: Device entry | |
89 | * | |
90 | * Detach a device wake IRQ and free resources. | |
91 | * | |
92 | * Note that it's OK for drivers to call this without calling | |
93 | * dev_pm_set_wake_irq() as all the driver instances may not have | |
94 | * a wake IRQ configured. This avoid adding wake IRQ specific | |
95 | * checks into the drivers. | |
96 | */ | |
97 | void dev_pm_clear_wake_irq(struct device *dev) | |
98 | { | |
99 | struct wake_irq *wirq = dev->power.wakeirq; | |
100 | unsigned long flags; | |
101 | ||
102 | if (!wirq) | |
103 | return; | |
104 | ||
105 | spin_lock_irqsave(&dev->power.lock, flags); | |
6d3dab7d | 106 | device_wakeup_detach_irq(dev); |
4990d4fe TL |
107 | dev->power.wakeirq = NULL; |
108 | spin_unlock_irqrestore(&dev->power.lock, flags); | |
109 | ||
4990d4fe TL |
110 | if (wirq->dedicated_irq) |
111 | free_irq(wirq->irq, wirq); | |
112 | kfree(wirq); | |
113 | } | |
114 | EXPORT_SYMBOL_GPL(dev_pm_clear_wake_irq); | |
115 | ||
116 | /** | |
117 | * handle_threaded_wake_irq - Handler for dedicated wake-up interrupts | |
118 | * @irq: Device specific dedicated wake-up interrupt | |
119 | * @_wirq: Wake IRQ data | |
120 | * | |
121 | * Some devices have a separate wake-up interrupt in addition to the | |
122 | * device IO interrupt. The wake-up interrupt signals that a device | |
123 | * should be woken up from it's idle state. This handler uses device | |
124 | * specific pm_runtime functions to wake the device, and then it's | |
125 | * up to the device to do whatever it needs to. Note that as the | |
126 | * device may need to restore context and start up regulators, we | |
127 | * use a threaded IRQ. | |
128 | * | |
129 | * Also note that we are not resending the lost device interrupts. | |
130 | * We assume that the wake-up interrupt just needs to wake-up the | |
131 | * device, and then device's pm_runtime_resume() can deal with the | |
132 | * situation. | |
133 | */ | |
134 | static irqreturn_t handle_threaded_wake_irq(int irq, void *_wirq) | |
135 | { | |
136 | struct wake_irq *wirq = _wirq; | |
137 | int res; | |
138 | ||
139 | /* We don't want RPM_ASYNC or RPM_NOWAIT here */ | |
140 | res = pm_runtime_resume(wirq->dev); | |
141 | if (res < 0) | |
142 | dev_warn(wirq->dev, | |
143 | "wake IRQ with no resume: %i\n", res); | |
144 | ||
145 | return IRQ_HANDLED; | |
146 | } | |
147 | ||
148 | /** | |
149 | * dev_pm_set_dedicated_wake_irq - Request a dedicated wake-up interrupt | |
150 | * @dev: Device entry | |
151 | * @irq: Device wake-up interrupt | |
152 | * | |
153 | * Unless your hardware has separate wake-up interrupts in addition | |
154 | * to the device IO interrupts, you don't need this. | |
155 | * | |
156 | * Sets up a threaded interrupt handler for a device that has | |
157 | * a dedicated wake-up interrupt in addition to the device IO | |
158 | * interrupt. | |
159 | * | |
160 | * The interrupt starts disabled, and needs to be managed for | |
161 | * the device by the bus code or the device driver using | |
162 | * dev_pm_enable_wake_irq() and dev_pm_disable_wake_irq() | |
163 | * functions. | |
164 | */ | |
165 | int dev_pm_set_dedicated_wake_irq(struct device *dev, int irq) | |
166 | { | |
167 | struct wake_irq *wirq; | |
168 | int err; | |
169 | ||
170 | wirq = kzalloc(sizeof(*wirq), GFP_KERNEL); | |
171 | if (!wirq) | |
172 | return -ENOMEM; | |
173 | ||
174 | wirq->dev = dev; | |
175 | wirq->irq = irq; | |
176 | wirq->dedicated_irq = true; | |
177 | irq_set_status_flags(irq, IRQ_NOAUTOEN); | |
178 | ||
179 | /* | |
180 | * Consumer device may need to power up and restore state | |
181 | * so we use a threaded irq. | |
182 | */ | |
183 | err = request_threaded_irq(irq, NULL, handle_threaded_wake_irq, | |
184 | IRQF_ONESHOT, dev_name(dev), wirq); | |
185 | if (err) | |
186 | goto err_free; | |
187 | ||
188 | err = dev_pm_attach_wake_irq(dev, irq, wirq); | |
189 | if (err) | |
190 | goto err_free_irq; | |
191 | ||
192 | return err; | |
193 | ||
194 | err_free_irq: | |
195 | free_irq(irq, wirq); | |
196 | err_free: | |
197 | kfree(wirq); | |
198 | ||
199 | return err; | |
200 | } | |
201 | EXPORT_SYMBOL_GPL(dev_pm_set_dedicated_wake_irq); | |
202 | ||
203 | /** | |
204 | * dev_pm_enable_wake_irq - Enable device wake-up interrupt | |
205 | * @dev: Device | |
206 | * | |
207 | * Called from the bus code or the device driver for | |
208 | * runtime_suspend() to enable the wake-up interrupt while | |
209 | * the device is running. | |
210 | * | |
211 | * Note that for runtime_suspend()) the wake-up interrupts | |
212 | * should be unconditionally enabled unlike for suspend() | |
213 | * that is conditional. | |
214 | */ | |
215 | void dev_pm_enable_wake_irq(struct device *dev) | |
216 | { | |
217 | struct wake_irq *wirq = dev->power.wakeirq; | |
218 | ||
219 | if (wirq && wirq->dedicated_irq) | |
220 | enable_irq(wirq->irq); | |
221 | } | |
222 | EXPORT_SYMBOL_GPL(dev_pm_enable_wake_irq); | |
223 | ||
224 | /** | |
225 | * dev_pm_disable_wake_irq - Disable device wake-up interrupt | |
226 | * @dev: Device | |
227 | * | |
228 | * Called from the bus code or the device driver for | |
229 | * runtime_resume() to disable the wake-up interrupt while | |
230 | * the device is running. | |
231 | */ | |
232 | void dev_pm_disable_wake_irq(struct device *dev) | |
233 | { | |
234 | struct wake_irq *wirq = dev->power.wakeirq; | |
235 | ||
236 | if (wirq && wirq->dedicated_irq) | |
237 | disable_irq_nosync(wirq->irq); | |
238 | } | |
239 | EXPORT_SYMBOL_GPL(dev_pm_disable_wake_irq); | |
240 | ||
241 | /** | |
242 | * dev_pm_arm_wake_irq - Arm device wake-up | |
243 | * @wirq: Device wake-up interrupt | |
244 | * | |
245 | * Sets up the wake-up event conditionally based on the | |
246 | * device_may_wake(). | |
247 | */ | |
248 | void dev_pm_arm_wake_irq(struct wake_irq *wirq) | |
249 | { | |
250 | if (!wirq) | |
251 | return; | |
252 | ||
253 | if (device_may_wakeup(wirq->dev)) | |
254 | enable_irq_wake(wirq->irq); | |
255 | } | |
256 | ||
257 | /** | |
258 | * dev_pm_disarm_wake_irq - Disarm device wake-up | |
259 | * @wirq: Device wake-up interrupt | |
260 | * | |
261 | * Clears up the wake-up event conditionally based on the | |
262 | * device_may_wake(). | |
263 | */ | |
264 | void dev_pm_disarm_wake_irq(struct wake_irq *wirq) | |
265 | { | |
266 | if (!wirq) | |
267 | return; | |
268 | ||
269 | if (device_may_wakeup(wirq->dev)) | |
270 | disable_irq_wake(wirq->irq); | |
271 | } |