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; 87 unsigned long flags; 88 89 spin_lock_irqsave(&dev->power.lock, flags); 90 wirq = dev->power.wakeirq; 91 if (!wirq) { 92 spin_unlock_irqrestore(&dev->power.lock, flags); 93 return; 94 } 95 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 static void devm_pm_clear_wake_irq(void *dev) 110 { 111 dev_pm_clear_wake_irq(dev); 112 } 113 114 /** 115 * devm_pm_set_wake_irq - device-managed variant of dev_pm_set_wake_irq 116 * @dev: Device entry 117 * @irq: Device IO interrupt 118 * 119 * 120 * Attach a device IO interrupt as a wake IRQ, same with dev_pm_set_wake_irq, 121 * but the device will be auto clear wake capability on driver detach. 122 */ 123 int devm_pm_set_wake_irq(struct device *dev, int irq) 124 { 125 int ret; 126 127 ret = dev_pm_set_wake_irq(dev, irq); 128 if (ret) 129 return ret; 130 131 return devm_add_action_or_reset(dev, devm_pm_clear_wake_irq, dev); 132 } 133 EXPORT_SYMBOL_GPL(devm_pm_set_wake_irq); 134 135 /** 136 * handle_threaded_wake_irq - Handler for dedicated wake-up interrupts 137 * @irq: Device specific dedicated wake-up interrupt 138 * @_wirq: Wake IRQ data 139 * 140 * Some devices have a separate wake-up interrupt in addition to the 141 * device IO interrupt. The wake-up interrupt signals that a device 142 * should be woken up from it's idle state. This handler uses device 143 * specific pm_runtime functions to wake the device, and then it's 144 * up to the device to do whatever it needs to. Note that as the 145 * device may need to restore context and start up regulators, we 146 * use a threaded IRQ. 147 * 148 * Also note that we are not resending the lost device interrupts. 149 * We assume that the wake-up interrupt just needs to wake-up the 150 * device, and then device's pm_runtime_resume() can deal with the 151 * situation. 152 */ 153 static irqreturn_t handle_threaded_wake_irq(int irq, void *_wirq) 154 { 155 struct wake_irq *wirq = _wirq; 156 int res; 157 158 /* Maybe abort suspend? */ 159 if (irqd_is_wakeup_set(irq_get_irq_data(irq))) { 160 pm_wakeup_event(wirq->dev, 0); 161 162 return IRQ_HANDLED; 163 } 164 165 /* We don't want RPM_ASYNC or RPM_NOWAIT here */ 166 res = pm_runtime_resume(wirq->dev); 167 if (res < 0) 168 dev_warn(wirq->dev, 169 "wake IRQ with no resume: %i\n", res); 170 171 return IRQ_HANDLED; 172 } 173 174 static int __dev_pm_set_dedicated_wake_irq(struct device *dev, int irq, unsigned int flag) 175 { 176 struct wake_irq *wirq; 177 int err; 178 179 if (irq < 0) 180 return -EINVAL; 181 182 wirq = kzalloc(sizeof(*wirq), GFP_KERNEL); 183 if (!wirq) 184 return -ENOMEM; 185 186 wirq->name = kasprintf(GFP_KERNEL, "%s:wakeup", dev_name(dev)); 187 if (!wirq->name) { 188 err = -ENOMEM; 189 goto err_free; 190 } 191 192 wirq->dev = dev; 193 wirq->irq = irq; 194 195 /* Prevent deferred spurious wakeirqs with disable_irq_nosync() */ 196 irq_set_status_flags(irq, IRQ_DISABLE_UNLAZY); 197 198 /* 199 * Consumer device may need to power up and restore state 200 * so we use a threaded irq. 201 */ 202 err = request_threaded_irq(irq, NULL, handle_threaded_wake_irq, 203 IRQF_ONESHOT | IRQF_NO_AUTOEN, 204 wirq->name, wirq); 205 if (err) 206 goto err_free_name; 207 208 err = dev_pm_attach_wake_irq(dev, wirq); 209 if (err) 210 goto err_free_irq; 211 212 wirq->status = WAKE_IRQ_DEDICATED_ALLOCATED | flag; 213 214 return err; 215 216 err_free_irq: 217 free_irq(irq, wirq); 218 err_free_name: 219 kfree(wirq->name); 220 err_free: 221 kfree(wirq); 222 223 return err; 224 } 225 226 /** 227 * dev_pm_set_dedicated_wake_irq - Request a dedicated wake-up interrupt 228 * @dev: Device entry 229 * @irq: Device wake-up interrupt 230 * 231 * Unless your hardware has separate wake-up interrupts in addition 232 * to the device IO interrupts, you don't need this. 233 * 234 * Sets up a threaded interrupt handler for a device that has 235 * a dedicated wake-up interrupt in addition to the device IO 236 * interrupt. 237 */ 238 int dev_pm_set_dedicated_wake_irq(struct device *dev, int irq) 239 { 240 return __dev_pm_set_dedicated_wake_irq(dev, irq, 0); 241 } 242 EXPORT_SYMBOL_GPL(dev_pm_set_dedicated_wake_irq); 243 244 /** 245 * dev_pm_set_dedicated_wake_irq_reverse - Request a dedicated wake-up interrupt 246 * with reverse enable ordering 247 * @dev: Device entry 248 * @irq: Device wake-up interrupt 249 * 250 * Unless your hardware has separate wake-up interrupts in addition 251 * to the device IO interrupts, you don't need this. 252 * 253 * Sets up a threaded interrupt handler for a device that has a dedicated 254 * wake-up interrupt in addition to the device IO interrupt. It sets 255 * the status of WAKE_IRQ_DEDICATED_REVERSE to tell rpm_suspend() 256 * to enable dedicated wake-up interrupt after running the runtime suspend 257 * callback for @dev. 258 */ 259 int dev_pm_set_dedicated_wake_irq_reverse(struct device *dev, int irq) 260 { 261 return __dev_pm_set_dedicated_wake_irq(dev, irq, WAKE_IRQ_DEDICATED_REVERSE); 262 } 263 EXPORT_SYMBOL_GPL(dev_pm_set_dedicated_wake_irq_reverse); 264 265 /** 266 * dev_pm_enable_wake_irq_check - Checks and enables wake-up interrupt 267 * @dev: Device 268 * @can_change_status: Can change wake-up interrupt status 269 * 270 * Enables wakeirq conditionally. We need to enable wake-up interrupt 271 * lazily on the first rpm_suspend(). This is needed as the consumer device 272 * starts in RPM_SUSPENDED state, and the first pm_runtime_get() would 273 * otherwise try to disable already disabled wakeirq. The wake-up interrupt 274 * starts disabled with IRQ_NOAUTOEN set. 275 * 276 * Should be only called from rpm_suspend() and rpm_resume() path. 277 * Caller must hold &dev->power.lock to change wirq->status 278 */ 279 void dev_pm_enable_wake_irq_check(struct device *dev, 280 bool can_change_status) 281 { 282 struct wake_irq *wirq = dev->power.wakeirq; 283 284 if (!wirq || !(wirq->status & WAKE_IRQ_DEDICATED_MASK)) 285 return; 286 287 if (likely(wirq->status & WAKE_IRQ_DEDICATED_MANAGED)) { 288 goto enable; 289 } else if (can_change_status) { 290 wirq->status |= WAKE_IRQ_DEDICATED_MANAGED; 291 goto enable; 292 } 293 294 return; 295 296 enable: 297 if (!can_change_status || !(wirq->status & WAKE_IRQ_DEDICATED_REVERSE)) { 298 enable_irq(wirq->irq); 299 wirq->status |= WAKE_IRQ_DEDICATED_ENABLED; 300 } 301 } 302 303 /** 304 * dev_pm_disable_wake_irq_check - Checks and disables wake-up interrupt 305 * @dev: Device 306 * @cond_disable: if set, also check WAKE_IRQ_DEDICATED_REVERSE 307 * 308 * Disables wake-up interrupt conditionally based on status. 309 * Should be only called from rpm_suspend() and rpm_resume() path. 310 */ 311 void dev_pm_disable_wake_irq_check(struct device *dev, bool cond_disable) 312 { 313 struct wake_irq *wirq = dev->power.wakeirq; 314 315 if (!wirq || !(wirq->status & WAKE_IRQ_DEDICATED_MASK)) 316 return; 317 318 if (cond_disable && (wirq->status & WAKE_IRQ_DEDICATED_REVERSE)) 319 return; 320 321 if (wirq->status & WAKE_IRQ_DEDICATED_MANAGED) { 322 wirq->status &= ~WAKE_IRQ_DEDICATED_ENABLED; 323 disable_irq_nosync(wirq->irq); 324 } 325 } 326 327 /** 328 * dev_pm_enable_wake_irq_complete - enable wake IRQ not enabled before 329 * @dev: Device using the wake IRQ 330 * 331 * Enable wake IRQ conditionally based on status, mainly used if want to 332 * enable wake IRQ after running ->runtime_suspend() which depends on 333 * WAKE_IRQ_DEDICATED_REVERSE. 334 * 335 * Should be only called from rpm_suspend() path. 336 */ 337 void dev_pm_enable_wake_irq_complete(struct device *dev) 338 { 339 struct wake_irq *wirq = dev->power.wakeirq; 340 341 if (!wirq || !(wirq->status & WAKE_IRQ_DEDICATED_MASK)) 342 return; 343 344 if (wirq->status & WAKE_IRQ_DEDICATED_MANAGED && 345 wirq->status & WAKE_IRQ_DEDICATED_REVERSE) { 346 enable_irq(wirq->irq); 347 wirq->status |= WAKE_IRQ_DEDICATED_ENABLED; 348 } 349 } 350 351 /** 352 * dev_pm_arm_wake_irq - Arm device wake-up 353 * @wirq: Device wake-up interrupt 354 * 355 * Sets up the wake-up event conditionally based on the 356 * device_may_wake(). 357 */ 358 void dev_pm_arm_wake_irq(struct wake_irq *wirq) 359 { 360 if (!wirq) 361 return; 362 363 if (device_may_wakeup(wirq->dev)) { 364 if (wirq->status & WAKE_IRQ_DEDICATED_ALLOCATED && 365 !(wirq->status & WAKE_IRQ_DEDICATED_ENABLED)) 366 enable_irq(wirq->irq); 367 368 enable_irq_wake(wirq->irq); 369 } 370 } 371 372 /** 373 * dev_pm_disarm_wake_irq - Disarm device wake-up 374 * @wirq: Device wake-up interrupt 375 * 376 * Clears up the wake-up event conditionally based on the 377 * device_may_wake(). 378 */ 379 void dev_pm_disarm_wake_irq(struct wake_irq *wirq) 380 { 381 if (!wirq) 382 return; 383 384 if (device_may_wakeup(wirq->dev)) { 385 disable_irq_wake(wirq->irq); 386 387 if (wirq->status & WAKE_IRQ_DEDICATED_ALLOCATED && 388 !(wirq->status & WAKE_IRQ_DEDICATED_ENABLED)) 389 disable_irq_nosync(wirq->irq); 390 } 391 } 392