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	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
 48	err = device_wakeup_attach_irq(dev, wirq);
 49	if (!err)
 50		dev->power.wakeirq = wirq;
 51
 52	spin_unlock_irqrestore(&dev->power.lock, flags);
 53	return err;
 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 */
 66int dev_pm_set_wake_irq(struct device *dev, int irq)
 67{
 68	struct wake_irq *wirq;
 69	int err;
 70
 71	if (irq < 0)
 72		return -EINVAL;
 73
 74	wirq = kzalloc(sizeof(*wirq), GFP_KERNEL);
 75	if (!wirq)
 76		return -ENOMEM;
 77
 78	wirq->dev = dev;
 79	wirq->irq = irq;
 80
 81	err = dev_pm_attach_wake_irq(dev, irq, wirq);
 82	if (err)
 83		kfree(wirq);
 84
 85	return err;
 86}
 87EXPORT_SYMBOL_GPL(dev_pm_set_wake_irq);
 88
 89/**
 90 * dev_pm_clear_wake_irq - Detach a device IO interrupt wake IRQ
 91 * @dev: Device entry
 92 *
 93 * Detach a device wake IRQ and free resources.
 94 *
 95 * Note that it's OK for drivers to call this without calling
 96 * dev_pm_set_wake_irq() as all the driver instances may not have
 97 * a wake IRQ configured. This avoid adding wake IRQ specific
 98 * checks into the drivers.
 99 */
100void dev_pm_clear_wake_irq(struct device *dev)
101{
102	struct wake_irq *wirq = dev->power.wakeirq;
103	unsigned long flags;
104
105	if (!wirq)
106		return;
107
108	spin_lock_irqsave(&dev->power.lock, flags);
109	device_wakeup_detach_irq(dev);
110	dev->power.wakeirq = NULL;
111	spin_unlock_irqrestore(&dev->power.lock, flags);
112
113	if (wirq->dedicated_irq)
114		free_irq(wirq->irq, wirq);
115	kfree(wirq);
116}
117EXPORT_SYMBOL_GPL(dev_pm_clear_wake_irq);
118
119/**
120 * handle_threaded_wake_irq - Handler for dedicated wake-up interrupts
121 * @irq: Device specific dedicated wake-up interrupt
122 * @_wirq: Wake IRQ data
123 *
124 * Some devices have a separate wake-up interrupt in addition to the
125 * device IO interrupt. The wake-up interrupt signals that a device
126 * should be woken up from it's idle state. This handler uses device
127 * specific pm_runtime functions to wake the device, and then it's
128 * up to the device to do whatever it needs to. Note that as the
129 * device may need to restore context and start up regulators, we
130 * use a threaded IRQ.
131 *
132 * Also note that we are not resending the lost device interrupts.
133 * We assume that the wake-up interrupt just needs to wake-up the
134 * device, and then device's pm_runtime_resume() can deal with the
135 * situation.
136 */
137static irqreturn_t handle_threaded_wake_irq(int irq, void *_wirq)
138{
139	struct wake_irq *wirq = _wirq;
140	int res;
141
142	/* We don't want RPM_ASYNC or RPM_NOWAIT here */
143	res = pm_runtime_resume(wirq->dev);
144	if (res < 0)
145		dev_warn(wirq->dev,
146			 "wake IRQ with no resume: %i\n", res);
147
148	return IRQ_HANDLED;
149}
150
151/**
152 * dev_pm_set_dedicated_wake_irq - Request a dedicated wake-up interrupt
153 * @dev: Device entry
154 * @irq: Device wake-up interrupt
155 *
156 * Unless your hardware has separate wake-up interrupts in addition
157 * to the device IO interrupts, you don't need this.
158 *
159 * Sets up a threaded interrupt handler for a device that has
160 * a dedicated wake-up interrupt in addition to the device IO
161 * interrupt.
162 *
163 * The interrupt starts disabled, and needs to be managed for
164 * the device by the bus code or the device driver using
165 * dev_pm_enable_wake_irq() and dev_pm_disable_wake_irq()
166 * functions.
167 */
168int dev_pm_set_dedicated_wake_irq(struct device *dev, int irq)
169{
170	struct wake_irq *wirq;
171	int err;
172
173	if (irq < 0)
174		return -EINVAL;
175
176	wirq = kzalloc(sizeof(*wirq), GFP_KERNEL);
177	if (!wirq)
178		return -ENOMEM;
179
180	wirq->dev = dev;
181	wirq->irq = irq;
182	wirq->dedicated_irq = true;
183	irq_set_status_flags(irq, IRQ_NOAUTOEN);
184
185	/*
186	 * Consumer device may need to power up and restore state
187	 * so we use a threaded irq.
188	 */
189	err = request_threaded_irq(irq, NULL, handle_threaded_wake_irq,
190				   IRQF_ONESHOT, dev_name(dev), wirq);
191	if (err)
192		goto err_free;
193
194	err = dev_pm_attach_wake_irq(dev, irq, wirq);
195	if (err)
196		goto err_free_irq;
197
198	return err;
199
200err_free_irq:
201	free_irq(irq, wirq);
202err_free:
203	kfree(wirq);
204
205	return err;
206}
207EXPORT_SYMBOL_GPL(dev_pm_set_dedicated_wake_irq);
208
209/**
210 * dev_pm_enable_wake_irq - Enable device wake-up interrupt
211 * @dev: Device
212 *
213 * Called from the bus code or the device driver for
214 * runtime_suspend() to enable the wake-up interrupt while
215 * the device is running.
216 *
217 * Note that for runtime_suspend()) the wake-up interrupts
218 * should be unconditionally enabled unlike for suspend()
219 * that is conditional.
220 */
221void dev_pm_enable_wake_irq(struct device *dev)
222{
223	struct wake_irq *wirq = dev->power.wakeirq;
224
225	if (wirq && wirq->dedicated_irq)
226		enable_irq(wirq->irq);
227}
228EXPORT_SYMBOL_GPL(dev_pm_enable_wake_irq);
229
230/**
231 * dev_pm_disable_wake_irq - Disable device wake-up interrupt
232 * @dev: Device
233 *
234 * Called from the bus code or the device driver for
235 * runtime_resume() to disable the wake-up interrupt while
236 * the device is running.
237 */
238void dev_pm_disable_wake_irq(struct device *dev)
239{
240	struct wake_irq *wirq = dev->power.wakeirq;
241
242	if (wirq && wirq->dedicated_irq)
243		disable_irq_nosync(wirq->irq);
244}
245EXPORT_SYMBOL_GPL(dev_pm_disable_wake_irq);
246
247/**
248 * dev_pm_arm_wake_irq - Arm device wake-up
249 * @wirq: Device wake-up interrupt
250 *
251 * Sets up the wake-up event conditionally based on the
252 * device_may_wake().
253 */
254void dev_pm_arm_wake_irq(struct wake_irq *wirq)
255{
256	if (!wirq)
257		return;
258
259	if (device_may_wakeup(wirq->dev))
260		enable_irq_wake(wirq->irq);
261}
262
263/**
264 * dev_pm_disarm_wake_irq - Disarm device wake-up
265 * @wirq: Device wake-up interrupt
266 *
267 * Clears up the wake-up event conditionally based on the
268 * device_may_wake().
269 */
270void dev_pm_disarm_wake_irq(struct wake_irq *wirq)
271{
272	if (!wirq)
273		return;
274
275	if (device_may_wakeup(wirq->dev))
276		disable_irq_wake(wirq->irq);
277}