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 } 350