drivers/base/power/wakeirq.c

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