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  * @wirq: Wake irq specific data
  16  *
  17  * Internal function to attach a dedicated wake-up interrupt as a wake IRQ.
  18  */
  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  */
  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  */
  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  */
 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 static int __dev_pm_set_dedicated_wake_irq(struct device *dev, int irq, unsigned int flag)
 146 {
 147         struct wake_irq *wirq;
 148         int err;
 149
 150         if (irq < 0)
 151                 return -EINVAL;
 152
 153         wirq = kzalloc(sizeof(*wirq), GFP_KERNEL);
 154         if (!wirq)
 155                 return -ENOMEM;
 156
 157         wirq->name = kasprintf(GFP_KERNEL, "%s:wakeup", dev_name(dev));
 158         if (!wirq->name) {
 159                 err = -ENOMEM;
 160                 goto err_free;
 161         }
 162
 163         wirq->dev = dev;
 164         wirq->irq = irq;
 165
 166         /* Prevent deferred spurious wakeirqs with disable_irq_nosync() */
 167         irq_set_status_flags(irq, IRQ_DISABLE_UNLAZY);
 168
 169         /*
 170          * Consumer device may need to power up and restore state
 171          * so we use a threaded irq.
 172          */
 173         err = request_threaded_irq(irq, NULL, handle_threaded_wake_irq,
 174                                    IRQF_ONESHOT | IRQF_NO_AUTOEN,
 175                                    wirq->name, wirq);
 176         if (err)
 177                 goto err_free_name;
 178
 179         err = dev_pm_attach_wake_irq(dev, wirq);
 180         if (err)
 181                 goto err_free_irq;
 182
 183         wirq->status = WAKE_IRQ_DEDICATED_ALLOCATED | flag;
 184
 185         return err;
 186
 187 err_free_irq:
 188         free_irq(irq, wirq);
 189 err_free_name:
 190         kfree(wirq->name);
 191 err_free:
 192         kfree(wirq);
 193
 194         return err;
 195 }
 196
 197 /**
 198  * dev_pm_set_dedicated_wake_irq - Request a dedicated wake-up interrupt
 199  * @dev: Device entry
 200  * @irq: Device wake-up interrupt
 201  *
 202  * Unless your hardware has separate wake-up interrupts in addition
 203  * to the device IO interrupts, you don't need this.
 204  *
 205  * Sets up a threaded interrupt handler for a device that has
 206  * a dedicated wake-up interrupt in addition to the device IO
 207  * interrupt.
 208  */
 209 int dev_pm_set_dedicated_wake_irq(struct device *dev, int irq)
 210 {
 211         return __dev_pm_set_dedicated_wake_irq(dev, irq, 0);
 212 }
 213 EXPORT_SYMBOL_GPL(dev_pm_set_dedicated_wake_irq);
 214
 215 /**
 216  * dev_pm_set_dedicated_wake_irq_reverse - Request a dedicated wake-up interrupt
 217  *                                         with reverse enable ordering
 218  * @dev: Device entry
 219  * @irq: Device wake-up interrupt
 220  *
 221  * Unless your hardware has separate wake-up interrupts in addition
 222  * to the device IO interrupts, you don't need this.
 223  *
 224  * Sets up a threaded interrupt handler for a device that has a dedicated
 225  * wake-up interrupt in addition to the device IO interrupt. It sets
 226  * the status of WAKE_IRQ_DEDICATED_REVERSE to tell rpm_suspend()
 227  * to enable dedicated wake-up interrupt after running the runtime suspend
 228  * callback for @dev.
 229  */
 230 int dev_pm_set_dedicated_wake_irq_reverse(struct device *dev, int irq)
 231 {
 232         return __dev_pm_set_dedicated_wake_irq(dev, irq, WAKE_IRQ_DEDICATED_REVERSE);
 233 }
 234 EXPORT_SYMBOL_GPL(dev_pm_set_dedicated_wake_irq_reverse);
 235
 236 /**
 237  * dev_pm_enable_wake_irq_check - Checks and enables wake-up interrupt
 238  * @dev: Device
 239  * @can_change_status: Can change wake-up interrupt status
 240  *
 241  * Enables wakeirq conditionally. We need to enable wake-up interrupt
 242  * lazily on the first rpm_suspend(). This is needed as the consumer device
 243  * starts in RPM_SUSPENDED state, and the first pm_runtime_get() would
 244  * otherwise try to disable already disabled wakeirq. The wake-up interrupt
 245  * starts disabled with IRQ_NOAUTOEN set.
 246  *
 247  * Should be only called from rpm_suspend() and rpm_resume() path.
 248  * Caller must hold &dev->power.lock to change wirq->status
 249  */
 250 void dev_pm_enable_wake_irq_check(struct device *dev,
 251                                   bool can_change_status)
 252 {
 253         struct wake_irq *wirq = dev->power.wakeirq;
 254
 255         if (!wirq || !(wirq->status & WAKE_IRQ_DEDICATED_MASK))
 256                 return;
 257
 258         if (likely(wirq->status & WAKE_IRQ_DEDICATED_MANAGED)) {
 259                 goto enable;
 260         } else if (can_change_status) {
 261                 wirq->status |= WAKE_IRQ_DEDICATED_MANAGED;
 262                 goto enable;
 263         }
 264
 265         return;
 266
 267 enable:
 268         if (!can_change_status || !(wirq->status & WAKE_IRQ_DEDICATED_REVERSE)) {
 269                 enable_irq(wirq->irq);
 270                 wirq->status |= WAKE_IRQ_DEDICATED_ENABLED;
 271         }
 272 }
 273
 274 /**
 275  * dev_pm_disable_wake_irq_check - Checks and disables wake-up interrupt
 276  * @dev: Device
 277  * @cond_disable: if set, also check WAKE_IRQ_DEDICATED_REVERSE
 278  *
 279  * Disables wake-up interrupt conditionally based on status.
 280  * Should be only called from rpm_suspend() and rpm_resume() path.
 281  */
 282 void dev_pm_disable_wake_irq_check(struct device *dev, bool cond_disable)
 283 {
 284         struct wake_irq *wirq = dev->power.wakeirq;
 285
 286         if (!wirq || !(wirq->status & WAKE_IRQ_DEDICATED_MASK))
 287                 return;
 288
 289         if (cond_disable && (wirq->status & WAKE_IRQ_DEDICATED_REVERSE))
 290                 return;
 291
 292         if (wirq->status & WAKE_IRQ_DEDICATED_MANAGED) {
 293                 wirq->status &= ~WAKE_IRQ_DEDICATED_ENABLED;
 294                 disable_irq_nosync(wirq->irq);
 295         }
 296 }
 297
 298 /**
 299  * dev_pm_enable_wake_irq_complete - enable wake IRQ not enabled before
 300  * @dev: Device using the wake IRQ
 301  *
 302  * Enable wake IRQ conditionally based on status, mainly used if want to
 303  * enable wake IRQ after running ->runtime_suspend() which depends on
 304  * WAKE_IRQ_DEDICATED_REVERSE.
 305  *
 306  * Should be only called from rpm_suspend() path.
 307  */
 308 void dev_pm_enable_wake_irq_complete(struct device *dev)
 309 {
 310         struct wake_irq *wirq = dev->power.wakeirq;
 311
 312         if (!wirq || !(wirq->status & WAKE_IRQ_DEDICATED_MASK))
 313                 return;
 314
 315         if (wirq->status & WAKE_IRQ_DEDICATED_MANAGED &&
 316             wirq->status & WAKE_IRQ_DEDICATED_REVERSE) {
 317                 enable_irq(wirq->irq);
 318                 wirq->status |= WAKE_IRQ_DEDICATED_ENABLED;
 319         }
 320 }
 321
 322 /**
 323  * dev_pm_arm_wake_irq - Arm device wake-up
 324  * @wirq: Device wake-up interrupt
 325  *
 326  * Sets up the wake-up event conditionally based on the
 327  * device_may_wake().
 328  */
 329 void dev_pm_arm_wake_irq(struct wake_irq *wirq)
 330 {
 331         if (!wirq)
 332                 return;
 333
 334         if (device_may_wakeup(wirq->dev)) {
 335                 if (wirq->status & WAKE_IRQ_DEDICATED_ALLOCATED &&
 336                     !(wirq->status & WAKE_IRQ_DEDICATED_ENABLED))
 337                         enable_irq(wirq->irq);
 338
 339                 enable_irq_wake(wirq->irq);
 340         }
 341 }
 342
 343 /**
 344  * dev_pm_disarm_wake_irq - Disarm device wake-up
 345  * @wirq: Device wake-up interrupt
 346  *
 347  * Clears up the wake-up event conditionally based on the
 348  * device_may_wake().
 349  */
 350 void dev_pm_disarm_wake_irq(struct wake_irq *wirq)
 351 {
 352         if (!wirq)
 353                 return;
 354
 355         if (device_may_wakeup(wirq->dev)) {
 356                 disable_irq_wake(wirq->irq);
 357
 358                 if (wirq->status & WAKE_IRQ_DEDICATED_ALLOCATED &&
 359                     !(wirq->status & WAKE_IRQ_DEDICATED_ENABLED))
 360                         disable_irq_nosync(wirq->irq);
 361         }
 362 }