1 /* 2 * wakeirq.c - Device wakeirq helper functions 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License version 2 as 6 * published by the Free Software Foundation. 7 * 8 * This program is distributed "as is" WITHOUT ANY WARRANTY of any 9 * kind, whether express or implied; without even the implied warranty 10 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 11 * GNU General Public License for more details. 12 */ 13 14 #include <linux/device.h> 15 #include <linux/interrupt.h> 16 #include <linux/irq.h> 17 #include <linux/slab.h> 18 #include <linux/pm_runtime.h> 19 #include <linux/pm_wakeirq.h> 20 21 #include "power.h" 22 23 /** 24 * dev_pm_attach_wake_irq - Attach device interrupt as a wake IRQ 25 * @dev: Device entry 26 * @irq: Device wake-up capable interrupt 27 * @wirq: Wake irq specific data 28 * 29 * Internal function to attach either a device IO interrupt or a 30 * dedicated wake-up interrupt as a wake IRQ. 31 */ 32 static int dev_pm_attach_wake_irq(struct device *dev, int irq, 33 struct wake_irq *wirq) 34 { 35 unsigned long flags; 36 int err; 37 38 if (!dev || !wirq) 39 return -EINVAL; 40 41 spin_lock_irqsave(&dev->power.lock, flags); 42 if (dev_WARN_ONCE(dev, dev->power.wakeirq, 43 "wake irq already initialized\n")) { 44 spin_unlock_irqrestore(&dev->power.lock, flags); 45 return -EEXIST; 46 } 47 48 err = device_wakeup_attach_irq(dev, wirq); 49 if (!err) 50 dev->power.wakeirq = wirq; 51 52 spin_unlock_irqrestore(&dev->power.lock, flags); 53 return err; 54 } 55 56 /** 57 * dev_pm_set_wake_irq - Attach device IO interrupt as wake IRQ 58 * @dev: Device entry 59 * @irq: Device IO interrupt 60 * 61 * Attach a device IO interrupt as a wake IRQ. The wake IRQ gets 62 * automatically configured for wake-up from suspend based 63 * on the device specific sysfs wakeup entry. Typically called 64 * during driver probe after calling device_init_wakeup(). 65 */ 66 int dev_pm_set_wake_irq(struct device *dev, int irq) 67 { 68 struct wake_irq *wirq; 69 int err; 70 71 if (irq < 0) 72 return -EINVAL; 73 74 wirq = kzalloc(sizeof(*wirq), GFP_KERNEL); 75 if (!wirq) 76 return -ENOMEM; 77 78 wirq->dev = dev; 79 wirq->irq = irq; 80 81 err = dev_pm_attach_wake_irq(dev, irq, wirq); 82 if (err) 83 kfree(wirq); 84 85 return err; 86 } 87 EXPORT_SYMBOL_GPL(dev_pm_set_wake_irq); 88 89 /** 90 * dev_pm_clear_wake_irq - Detach a device IO interrupt wake IRQ 91 * @dev: Device entry 92 * 93 * Detach a device wake IRQ and free resources. 94 * 95 * Note that it's OK for drivers to call this without calling 96 * dev_pm_set_wake_irq() as all the driver instances may not have 97 * a wake IRQ configured. This avoid adding wake IRQ specific 98 * checks into the drivers. 99 */ 100 void dev_pm_clear_wake_irq(struct device *dev) 101 { 102 struct wake_irq *wirq = dev->power.wakeirq; 103 unsigned long flags; 104 105 if (!wirq) 106 return; 107 108 spin_lock_irqsave(&dev->power.lock, flags); 109 device_wakeup_detach_irq(dev); 110 dev->power.wakeirq = NULL; 111 spin_unlock_irqrestore(&dev->power.lock, flags); 112 113 if (wirq->status & WAKE_IRQ_DEDICATED_ALLOCATED) { 114 free_irq(wirq->irq, wirq); 115 wirq->status &= ~WAKE_IRQ_DEDICATED_MASK; 116 } 117 kfree(wirq); 118 } 119 EXPORT_SYMBOL_GPL(dev_pm_clear_wake_irq); 120 121 /** 122 * handle_threaded_wake_irq - Handler for dedicated wake-up interrupts 123 * @irq: Device specific dedicated wake-up interrupt 124 * @_wirq: Wake IRQ data 125 * 126 * Some devices have a separate wake-up interrupt in addition to the 127 * device IO interrupt. The wake-up interrupt signals that a device 128 * should be woken up from it's idle state. This handler uses device 129 * specific pm_runtime functions to wake the device, and then it's 130 * up to the device to do whatever it needs to. Note that as the 131 * device may need to restore context and start up regulators, we 132 * use a threaded IRQ. 133 * 134 * Also note that we are not resending the lost device interrupts. 135 * We assume that the wake-up interrupt just needs to wake-up the 136 * device, and then device's pm_runtime_resume() can deal with the 137 * situation. 138 */ 139 static irqreturn_t handle_threaded_wake_irq(int irq, void *_wirq) 140 { 141 struct wake_irq *wirq = _wirq; 142 int res; 143 144 /* We don't want RPM_ASYNC or RPM_NOWAIT here */ 145 res = pm_runtime_resume(wirq->dev); 146 if (res < 0) 147 dev_warn(wirq->dev, 148 "wake IRQ with no resume: %i\n", res); 149 150 return IRQ_HANDLED; 151 } 152 153 /** 154 * dev_pm_set_dedicated_wake_irq - Request a dedicated wake-up interrupt 155 * @dev: Device entry 156 * @irq: Device wake-up interrupt 157 * 158 * Unless your hardware has separate wake-up interrupts in addition 159 * to the device IO interrupts, you don't need this. 160 * 161 * Sets up a threaded interrupt handler for a device that has 162 * a dedicated wake-up interrupt in addition to the device IO 163 * interrupt. 164 * 165 * The interrupt starts disabled, and needs to be managed for 166 * the device by the bus code or the device driver using 167 * dev_pm_enable_wake_irq() and dev_pm_disable_wake_irq() 168 * functions. 169 */ 170 int dev_pm_set_dedicated_wake_irq(struct device *dev, int irq) 171 { 172 struct wake_irq *wirq; 173 int err; 174 175 if (irq < 0) 176 return -EINVAL; 177 178 wirq = kzalloc(sizeof(*wirq), GFP_KERNEL); 179 if (!wirq) 180 return -ENOMEM; 181 182 wirq->dev = dev; 183 wirq->irq = irq; 184 irq_set_status_flags(irq, IRQ_NOAUTOEN); 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, dev_name(dev), wirq); 192 if (err) 193 goto err_free; 194 195 err = dev_pm_attach_wake_irq(dev, irq, wirq); 196 if (err) 197 goto err_free_irq; 198 199 wirq->status = WAKE_IRQ_DEDICATED_ALLOCATED; 200 201 return err; 202 203 err_free_irq: 204 free_irq(irq, wirq); 205 err_free: 206 kfree(wirq); 207 208 return err; 209 } 210 EXPORT_SYMBOL_GPL(dev_pm_set_dedicated_wake_irq); 211 212 /** 213 * dev_pm_enable_wake_irq - Enable device wake-up interrupt 214 * @dev: Device 215 * 216 * Optionally called from the bus code or the device driver for 217 * runtime_resume() to override the PM runtime core managed wake-up 218 * interrupt handling to enable the wake-up interrupt. 219 * 220 * Note that for runtime_suspend()) the wake-up interrupts 221 * should be unconditionally enabled unlike for suspend() 222 * that is conditional. 223 */ 224 void dev_pm_enable_wake_irq(struct device *dev) 225 { 226 struct wake_irq *wirq = dev->power.wakeirq; 227 228 if (wirq && (wirq->status & WAKE_IRQ_DEDICATED_ALLOCATED)) 229 enable_irq(wirq->irq); 230 } 231 EXPORT_SYMBOL_GPL(dev_pm_enable_wake_irq); 232 233 /** 234 * dev_pm_disable_wake_irq - Disable device wake-up interrupt 235 * @dev: Device 236 * 237 * Optionally called from the bus code or the device driver for 238 * runtime_suspend() to override the PM runtime core managed wake-up 239 * interrupt handling to disable the wake-up interrupt. 240 */ 241 void dev_pm_disable_wake_irq(struct device *dev) 242 { 243 struct wake_irq *wirq = dev->power.wakeirq; 244 245 if (wirq && (wirq->status & WAKE_IRQ_DEDICATED_ALLOCATED)) 246 disable_irq_nosync(wirq->irq); 247 } 248 EXPORT_SYMBOL_GPL(dev_pm_disable_wake_irq); 249 250 /** 251 * dev_pm_enable_wake_irq_check - Checks and enables wake-up interrupt 252 * @dev: Device 253 * @can_change_status: Can change wake-up interrupt status 254 * 255 * Enables wakeirq conditionally. We need to enable wake-up interrupt 256 * lazily on the first rpm_suspend(). This is needed as the consumer device 257 * starts in RPM_SUSPENDED state, and the the first pm_runtime_get() would 258 * otherwise try to disable already disabled wakeirq. The wake-up interrupt 259 * starts disabled with IRQ_NOAUTOEN set. 260 * 261 * Should be only called from rpm_suspend() and rpm_resume() path. 262 * Caller must hold &dev->power.lock to change wirq->status 263 */ 264 void dev_pm_enable_wake_irq_check(struct device *dev, 265 bool can_change_status) 266 { 267 struct wake_irq *wirq = dev->power.wakeirq; 268 269 if (!wirq || !((wirq->status & WAKE_IRQ_DEDICATED_MASK))) 270 return; 271 272 if (likely(wirq->status & WAKE_IRQ_DEDICATED_MANAGED)) { 273 goto enable; 274 } else if (can_change_status) { 275 wirq->status |= WAKE_IRQ_DEDICATED_MANAGED; 276 goto enable; 277 } 278 279 return; 280 281 enable: 282 enable_irq(wirq->irq); 283 } 284 285 /** 286 * dev_pm_disable_wake_irq_check - Checks and disables wake-up interrupt 287 * @dev: Device 288 * 289 * Disables wake-up interrupt conditionally based on status. 290 * Should be only called from rpm_suspend() and rpm_resume() path. 291 */ 292 void dev_pm_disable_wake_irq_check(struct device *dev) 293 { 294 struct wake_irq *wirq = dev->power.wakeirq; 295 296 if (!wirq || !((wirq->status & WAKE_IRQ_DEDICATED_MASK))) 297 return; 298 299 if (wirq->status & WAKE_IRQ_DEDICATED_MANAGED) 300 disable_irq_nosync(wirq->irq); 301 } 302 303 /** 304 * dev_pm_arm_wake_irq - Arm device wake-up 305 * @wirq: Device wake-up interrupt 306 * 307 * Sets up the wake-up event conditionally based on the 308 * device_may_wake(). 309 */ 310 void dev_pm_arm_wake_irq(struct wake_irq *wirq) 311 { 312 if (!wirq) 313 return; 314 315 if (device_may_wakeup(wirq->dev)) 316 enable_irq_wake(wirq->irq); 317 } 318 319 /** 320 * dev_pm_disarm_wake_irq - Disarm device wake-up 321 * @wirq: Device wake-up interrupt 322 * 323 * Clears up the wake-up event conditionally based on the 324 * device_may_wake(). 325 */ 326 void dev_pm_disarm_wake_irq(struct wake_irq *wirq) 327 { 328 if (!wirq) 329 return; 330 331 if (device_may_wakeup(wirq->dev)) 332 disable_irq_wake(wirq->irq); 333 } 334