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 static void devm_pm_clear_wake_irq(void *dev) 107 { 108 dev_pm_clear_wake_irq(dev); 109 } 110 111 /** 112 * devm_pm_set_wake_irq - device-managed variant of dev_pm_set_wake_irq 113 * @dev: Device entry 114 * @irq: Device IO interrupt 115 * 116 * 117 * Attach a device IO interrupt as a wake IRQ, same with dev_pm_set_wake_irq, 118 * but the device will be auto clear wake capability on driver detach. 119 */ 120 int devm_pm_set_wake_irq(struct device *dev, int irq) 121 { 122 int ret; 123 124 ret = dev_pm_set_wake_irq(dev, irq); 125 if (ret) 126 return ret; 127 128 return devm_add_action_or_reset(dev, devm_pm_clear_wake_irq, dev); 129 } 130 EXPORT_SYMBOL_GPL(devm_pm_set_wake_irq); 131 132 /** 133 * handle_threaded_wake_irq - Handler for dedicated wake-up interrupts 134 * @irq: Device specific dedicated wake-up interrupt 135 * @_wirq: Wake IRQ data 136 * 137 * Some devices have a separate wake-up interrupt in addition to the 138 * device IO interrupt. The wake-up interrupt signals that a device 139 * should be woken up from it's idle state. This handler uses device 140 * specific pm_runtime functions to wake the device, and then it's 141 * up to the device to do whatever it needs to. Note that as the 142 * device may need to restore context and start up regulators, we 143 * use a threaded IRQ. 144 * 145 * Also note that we are not resending the lost device interrupts. 146 * We assume that the wake-up interrupt just needs to wake-up the 147 * device, and then device's pm_runtime_resume() can deal with the 148 * situation. 149 */ 150 static irqreturn_t handle_threaded_wake_irq(int irq, void *_wirq) 151 { 152 struct wake_irq *wirq = _wirq; 153 int res; 154 155 /* Maybe abort suspend? */ 156 if (irqd_is_wakeup_set(irq_get_irq_data(irq))) { 157 pm_wakeup_event(wirq->dev, 0); 158 159 return IRQ_HANDLED; 160 } 161 162 /* We don't want RPM_ASYNC or RPM_NOWAIT here */ 163 res = pm_runtime_resume(wirq->dev); 164 if (res < 0) 165 dev_warn(wirq->dev, 166 "wake IRQ with no resume: %i\n", res); 167 168 return IRQ_HANDLED; 169 } 170 171 static int __dev_pm_set_dedicated_wake_irq(struct device *dev, int irq, unsigned int flag) 172 { 173 struct wake_irq *wirq; 174 int err; 175 176 if (irq < 0) 177 return -EINVAL; 178 179 wirq = kzalloc(sizeof(*wirq), GFP_KERNEL); 180 if (!wirq) 181 return -ENOMEM; 182 183 wirq->name = kasprintf(GFP_KERNEL, "%s:wakeup", dev_name(dev)); 184 if (!wirq->name) { 185 err = -ENOMEM; 186 goto err_free; 187 } 188 189 wirq->dev = dev; 190 wirq->irq = irq; 191 192 /* Prevent deferred spurious wakeirqs with disable_irq_nosync() */ 193 irq_set_status_flags(irq, IRQ_DISABLE_UNLAZY); 194 195 /* 196 * Consumer device may need to power up and restore state 197 * so we use a threaded irq. 198 */ 199 err = request_threaded_irq(irq, NULL, handle_threaded_wake_irq, 200 IRQF_ONESHOT | IRQF_NO_AUTOEN, 201 wirq->name, wirq); 202 if (err) 203 goto err_free_name; 204 205 err = dev_pm_attach_wake_irq(dev, wirq); 206 if (err) 207 goto err_free_irq; 208 209 wirq->status = WAKE_IRQ_DEDICATED_ALLOCATED | flag; 210 211 return err; 212 213 err_free_irq: 214 free_irq(irq, wirq); 215 err_free_name: 216 kfree(wirq->name); 217 err_free: 218 kfree(wirq); 219 220 return err; 221 } 222 223 /** 224 * dev_pm_set_dedicated_wake_irq - Request a dedicated wake-up interrupt 225 * @dev: Device entry 226 * @irq: Device wake-up interrupt 227 * 228 * Unless your hardware has separate wake-up interrupts in addition 229 * to the device IO interrupts, you don't need this. 230 * 231 * Sets up a threaded interrupt handler for a device that has 232 * a dedicated wake-up interrupt in addition to the device IO 233 * interrupt. 234 */ 235 int dev_pm_set_dedicated_wake_irq(struct device *dev, int irq) 236 { 237 return __dev_pm_set_dedicated_wake_irq(dev, irq, 0); 238 } 239 EXPORT_SYMBOL_GPL(dev_pm_set_dedicated_wake_irq); 240 241 /** 242 * dev_pm_set_dedicated_wake_irq_reverse - Request a dedicated wake-up interrupt 243 * with reverse enable ordering 244 * @dev: Device entry 245 * @irq: Device wake-up interrupt 246 * 247 * Unless your hardware has separate wake-up interrupts in addition 248 * to the device IO interrupts, you don't need this. 249 * 250 * Sets up a threaded interrupt handler for a device that has a dedicated 251 * wake-up interrupt in addition to the device IO interrupt. It sets 252 * the status of WAKE_IRQ_DEDICATED_REVERSE to tell rpm_suspend() 253 * to enable dedicated wake-up interrupt after running the runtime suspend 254 * callback for @dev. 255 */ 256 int dev_pm_set_dedicated_wake_irq_reverse(struct device *dev, int irq) 257 { 258 return __dev_pm_set_dedicated_wake_irq(dev, irq, WAKE_IRQ_DEDICATED_REVERSE); 259 } 260 EXPORT_SYMBOL_GPL(dev_pm_set_dedicated_wake_irq_reverse); 261 262 /** 263 * dev_pm_enable_wake_irq_check - Checks and enables wake-up interrupt 264 * @dev: Device 265 * @can_change_status: Can change wake-up interrupt status 266 * 267 * Enables wakeirq conditionally. We need to enable wake-up interrupt 268 * lazily on the first rpm_suspend(). This is needed as the consumer device 269 * starts in RPM_SUSPENDED state, and the first pm_runtime_get() would 270 * otherwise try to disable already disabled wakeirq. The wake-up interrupt 271 * starts disabled with IRQ_NOAUTOEN set. 272 * 273 * Should be only called from rpm_suspend() and rpm_resume() path. 274 * Caller must hold &dev->power.lock to change wirq->status 275 */ 276 void dev_pm_enable_wake_irq_check(struct device *dev, 277 bool can_change_status) 278 { 279 struct wake_irq *wirq = dev->power.wakeirq; 280 281 if (!wirq || !(wirq->status & WAKE_IRQ_DEDICATED_MASK)) 282 return; 283 284 if (likely(wirq->status & WAKE_IRQ_DEDICATED_MANAGED)) { 285 goto enable; 286 } else if (can_change_status) { 287 wirq->status |= WAKE_IRQ_DEDICATED_MANAGED; 288 goto enable; 289 } 290 291 return; 292 293 enable: 294 if (!can_change_status || !(wirq->status & WAKE_IRQ_DEDICATED_REVERSE)) { 295 enable_irq(wirq->irq); 296 wirq->status |= WAKE_IRQ_DEDICATED_ENABLED; 297 } 298 } 299 300 /** 301 * dev_pm_disable_wake_irq_check - Checks and disables wake-up interrupt 302 * @dev: Device 303 * @cond_disable: if set, also check WAKE_IRQ_DEDICATED_REVERSE 304 * 305 * Disables wake-up interrupt conditionally based on status. 306 * Should be only called from rpm_suspend() and rpm_resume() path. 307 */ 308 void dev_pm_disable_wake_irq_check(struct device *dev, bool cond_disable) 309 { 310 struct wake_irq *wirq = dev->power.wakeirq; 311 312 if (!wirq || !(wirq->status & WAKE_IRQ_DEDICATED_MASK)) 313 return; 314 315 if (cond_disable && (wirq->status & WAKE_IRQ_DEDICATED_REVERSE)) 316 return; 317 318 if (wirq->status & WAKE_IRQ_DEDICATED_MANAGED) { 319 wirq->status &= ~WAKE_IRQ_DEDICATED_ENABLED; 320 disable_irq_nosync(wirq->irq); 321 } 322 } 323 324 /** 325 * dev_pm_enable_wake_irq_complete - enable wake IRQ not enabled before 326 * @dev: Device using the wake IRQ 327 * 328 * Enable wake IRQ conditionally based on status, mainly used if want to 329 * enable wake IRQ after running ->runtime_suspend() which depends on 330 * WAKE_IRQ_DEDICATED_REVERSE. 331 * 332 * Should be only called from rpm_suspend() path. 333 */ 334 void dev_pm_enable_wake_irq_complete(struct device *dev) 335 { 336 struct wake_irq *wirq = dev->power.wakeirq; 337 338 if (!wirq || !(wirq->status & WAKE_IRQ_DEDICATED_MASK)) 339 return; 340 341 if (wirq->status & WAKE_IRQ_DEDICATED_MANAGED && 342 wirq->status & WAKE_IRQ_DEDICATED_REVERSE) { 343 enable_irq(wirq->irq); 344 wirq->status |= WAKE_IRQ_DEDICATED_ENABLED; 345 } 346 } 347 348 /** 349 * dev_pm_arm_wake_irq - Arm device wake-up 350 * @wirq: Device wake-up interrupt 351 * 352 * Sets up the wake-up event conditionally based on the 353 * device_may_wake(). 354 */ 355 void dev_pm_arm_wake_irq(struct wake_irq *wirq) 356 { 357 if (!wirq) 358 return; 359 360 if (device_may_wakeup(wirq->dev)) { 361 if (wirq->status & WAKE_IRQ_DEDICATED_ALLOCATED && 362 !(wirq->status & WAKE_IRQ_DEDICATED_ENABLED)) 363 enable_irq(wirq->irq); 364 365 enable_irq_wake(wirq->irq); 366 } 367 } 368 369 /** 370 * dev_pm_disarm_wake_irq - Disarm device wake-up 371 * @wirq: Device wake-up interrupt 372 * 373 * Clears up the wake-up event conditionally based on the 374 * device_may_wake(). 375 */ 376 void dev_pm_disarm_wake_irq(struct wake_irq *wirq) 377 { 378 if (!wirq) 379 return; 380 381 if (device_may_wakeup(wirq->dev)) { 382 disable_irq_wake(wirq->irq); 383 384 if (wirq->status & WAKE_IRQ_DEDICATED_ALLOCATED && 385 !(wirq->status & WAKE_IRQ_DEDICATED_ENABLED)) 386 disable_irq_nosync(wirq->irq); 387 } 388 } 389