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