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 /** 199 * dev_pm_set_dedicated_wake_irq - Request a dedicated wake-up interrupt 200 * @dev: Device entry 201 * @irq: Device wake-up interrupt 202 * 203 * Unless your hardware has separate wake-up interrupts in addition 204 * to the device IO interrupts, you don't need this. 205 * 206 * Sets up a threaded interrupt handler for a device that has 207 * a dedicated wake-up interrupt in addition to the device IO 208 * interrupt. 209 * 210 * The interrupt starts disabled, and needs to be managed for 211 * the device by the bus code or the device driver using 212 * dev_pm_enable_wake_irq*() and dev_pm_disable_wake_irq*() 213 * functions. 214 */ 215 int dev_pm_set_dedicated_wake_irq(struct device *dev, int irq) 216 { 217 return __dev_pm_set_dedicated_wake_irq(dev, irq, 0); 218 } 219 EXPORT_SYMBOL_GPL(dev_pm_set_dedicated_wake_irq); 220 221 /** 222 * dev_pm_set_dedicated_wake_irq_reverse - Request a dedicated wake-up interrupt 223 * with reverse enable ordering 224 * @dev: Device entry 225 * @irq: Device wake-up interrupt 226 * 227 * Unless your hardware has separate wake-up interrupts in addition 228 * to the device IO interrupts, you don't need this. 229 * 230 * Sets up a threaded interrupt handler for a device that has a dedicated 231 * wake-up interrupt in addition to the device IO interrupt. It sets 232 * the status of WAKE_IRQ_DEDICATED_REVERSE to tell rpm_suspend() 233 * to enable dedicated wake-up interrupt after running the runtime suspend 234 * callback for @dev. 235 * 236 * The interrupt starts disabled, and needs to be managed for 237 * the device by the bus code or the device driver using 238 * dev_pm_enable_wake_irq*() and dev_pm_disable_wake_irq*() 239 * functions. 240 */ 241 int dev_pm_set_dedicated_wake_irq_reverse(struct device *dev, int irq) 242 { 243 return __dev_pm_set_dedicated_wake_irq(dev, irq, WAKE_IRQ_DEDICATED_REVERSE); 244 } 245 EXPORT_SYMBOL_GPL(dev_pm_set_dedicated_wake_irq_reverse); 246 247 /** 248 * dev_pm_enable_wake_irq - Enable device wake-up interrupt 249 * @dev: Device 250 * 251 * Optionally called from the bus code or the device driver for 252 * runtime_resume() to override the PM runtime core managed wake-up 253 * interrupt handling to enable the wake-up interrupt. 254 * 255 * Note that for runtime_suspend()) the wake-up interrupts 256 * should be unconditionally enabled unlike for suspend() 257 * that is conditional. 258 */ 259 void dev_pm_enable_wake_irq(struct device *dev) 260 { 261 struct wake_irq *wirq = dev->power.wakeirq; 262 263 if (wirq && (wirq->status & WAKE_IRQ_DEDICATED_ALLOCATED)) 264 enable_irq(wirq->irq); 265 } 266 EXPORT_SYMBOL_GPL(dev_pm_enable_wake_irq); 267 268 /** 269 * dev_pm_disable_wake_irq - Disable device wake-up interrupt 270 * @dev: Device 271 * 272 * Optionally called from the bus code or the device driver for 273 * runtime_suspend() to override the PM runtime core managed wake-up 274 * interrupt handling to disable the wake-up interrupt. 275 */ 276 void dev_pm_disable_wake_irq(struct device *dev) 277 { 278 struct wake_irq *wirq = dev->power.wakeirq; 279 280 if (wirq && (wirq->status & WAKE_IRQ_DEDICATED_ALLOCATED)) 281 disable_irq_nosync(wirq->irq); 282 } 283 EXPORT_SYMBOL_GPL(dev_pm_disable_wake_irq); 284 285 /** 286 * dev_pm_enable_wake_irq_check - Checks and enables wake-up interrupt 287 * @dev: Device 288 * @can_change_status: Can change wake-up interrupt status 289 * 290 * Enables wakeirq conditionally. We need to enable wake-up interrupt 291 * lazily on the first rpm_suspend(). This is needed as the consumer device 292 * starts in RPM_SUSPENDED state, and the first pm_runtime_get() would 293 * otherwise try to disable already disabled wakeirq. The wake-up interrupt 294 * starts disabled with IRQ_NOAUTOEN set. 295 * 296 * Should be only called from rpm_suspend() and rpm_resume() path. 297 * Caller must hold &dev->power.lock to change wirq->status 298 */ 299 void dev_pm_enable_wake_irq_check(struct device *dev, 300 bool can_change_status) 301 { 302 struct wake_irq *wirq = dev->power.wakeirq; 303 304 if (!wirq || !(wirq->status & WAKE_IRQ_DEDICATED_MASK)) 305 return; 306 307 if (likely(wirq->status & WAKE_IRQ_DEDICATED_MANAGED)) { 308 goto enable; 309 } else if (can_change_status) { 310 wirq->status |= WAKE_IRQ_DEDICATED_MANAGED; 311 goto enable; 312 } 313 314 return; 315 316 enable: 317 if (!can_change_status || !(wirq->status & WAKE_IRQ_DEDICATED_REVERSE)) 318 enable_irq(wirq->irq); 319 } 320 321 /** 322 * dev_pm_disable_wake_irq_check - Checks and disables wake-up interrupt 323 * @dev: Device 324 * @cond_disable: if set, also check WAKE_IRQ_DEDICATED_REVERSE 325 * 326 * Disables wake-up interrupt conditionally based on status. 327 * Should be only called from rpm_suspend() and rpm_resume() path. 328 */ 329 void dev_pm_disable_wake_irq_check(struct device *dev, bool cond_disable) 330 { 331 struct wake_irq *wirq = dev->power.wakeirq; 332 333 if (!wirq || !(wirq->status & WAKE_IRQ_DEDICATED_MASK)) 334 return; 335 336 if (cond_disable && (wirq->status & WAKE_IRQ_DEDICATED_REVERSE)) 337 return; 338 339 if (wirq->status & WAKE_IRQ_DEDICATED_MANAGED) 340 disable_irq_nosync(wirq->irq); 341 } 342 343 /** 344 * dev_pm_enable_wake_irq_complete - enable wake IRQ not enabled before 345 * @dev: Device using the wake IRQ 346 * 347 * Enable wake IRQ conditionally based on status, mainly used if want to 348 * enable wake IRQ after running ->runtime_suspend() which depends on 349 * WAKE_IRQ_DEDICATED_REVERSE. 350 * 351 * Should be only called from rpm_suspend() path. 352 */ 353 void dev_pm_enable_wake_irq_complete(struct device *dev) 354 { 355 struct wake_irq *wirq = dev->power.wakeirq; 356 357 if (!wirq || !(wirq->status & WAKE_IRQ_DEDICATED_MASK)) 358 return; 359 360 if (wirq->status & WAKE_IRQ_DEDICATED_MANAGED && 361 wirq->status & WAKE_IRQ_DEDICATED_REVERSE) 362 enable_irq(wirq->irq); 363 } 364 365 /** 366 * dev_pm_arm_wake_irq - Arm device wake-up 367 * @wirq: Device wake-up interrupt 368 * 369 * Sets up the wake-up event conditionally based on the 370 * device_may_wake(). 371 */ 372 void dev_pm_arm_wake_irq(struct wake_irq *wirq) 373 { 374 if (!wirq) 375 return; 376 377 if (device_may_wakeup(wirq->dev)) { 378 if (wirq->status & WAKE_IRQ_DEDICATED_ALLOCATED && 379 !pm_runtime_status_suspended(wirq->dev)) 380 enable_irq(wirq->irq); 381 382 enable_irq_wake(wirq->irq); 383 } 384 } 385 386 /** 387 * dev_pm_disarm_wake_irq - Disarm device wake-up 388 * @wirq: Device wake-up interrupt 389 * 390 * Clears up the wake-up event conditionally based on the 391 * device_may_wake(). 392 */ 393 void dev_pm_disarm_wake_irq(struct wake_irq *wirq) 394 { 395 if (!wirq) 396 return; 397 398 if (device_may_wakeup(wirq->dev)) { 399 disable_irq_wake(wirq->irq); 400 401 if (wirq->status & WAKE_IRQ_DEDICATED_ALLOCATED && 402 !pm_runtime_status_suspended(wirq->dev)) 403 disable_irq_nosync(wirq->irq); 404 } 405 } 406