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->dedicated_irq) 114 free_irq(wirq->irq, wirq); 115 kfree(wirq); 116 } 117 EXPORT_SYMBOL_GPL(dev_pm_clear_wake_irq); 118 119 /** 120 * handle_threaded_wake_irq - Handler for dedicated wake-up interrupts 121 * @irq: Device specific dedicated wake-up interrupt 122 * @_wirq: Wake IRQ data 123 * 124 * Some devices have a separate wake-up interrupt in addition to the 125 * device IO interrupt. The wake-up interrupt signals that a device 126 * should be woken up from it's idle state. This handler uses device 127 * specific pm_runtime functions to wake the device, and then it's 128 * up to the device to do whatever it needs to. Note that as the 129 * device may need to restore context and start up regulators, we 130 * use a threaded IRQ. 131 * 132 * Also note that we are not resending the lost device interrupts. 133 * We assume that the wake-up interrupt just needs to wake-up the 134 * device, and then device's pm_runtime_resume() can deal with the 135 * situation. 136 */ 137 static irqreturn_t handle_threaded_wake_irq(int irq, void *_wirq) 138 { 139 struct wake_irq *wirq = _wirq; 140 int res; 141 142 /* We don't want RPM_ASYNC or RPM_NOWAIT here */ 143 res = pm_runtime_resume(wirq->dev); 144 if (res < 0) 145 dev_warn(wirq->dev, 146 "wake IRQ with no resume: %i\n", res); 147 148 return IRQ_HANDLED; 149 } 150 151 /** 152 * dev_pm_set_dedicated_wake_irq - Request a dedicated wake-up interrupt 153 * @dev: Device entry 154 * @irq: Device wake-up interrupt 155 * 156 * Unless your hardware has separate wake-up interrupts in addition 157 * to the device IO interrupts, you don't need this. 158 * 159 * Sets up a threaded interrupt handler for a device that has 160 * a dedicated wake-up interrupt in addition to the device IO 161 * interrupt. 162 * 163 * The interrupt starts disabled, and needs to be managed for 164 * the device by the bus code or the device driver using 165 * dev_pm_enable_wake_irq() and dev_pm_disable_wake_irq() 166 * functions. 167 */ 168 int dev_pm_set_dedicated_wake_irq(struct device *dev, int irq) 169 { 170 struct wake_irq *wirq; 171 int err; 172 173 if (irq < 0) 174 return -EINVAL; 175 176 wirq = kzalloc(sizeof(*wirq), GFP_KERNEL); 177 if (!wirq) 178 return -ENOMEM; 179 180 wirq->dev = dev; 181 wirq->irq = irq; 182 wirq->dedicated_irq = true; 183 irq_set_status_flags(irq, IRQ_NOAUTOEN); 184 185 /* 186 * Consumer device may need to power up and restore state 187 * so we use a threaded irq. 188 */ 189 err = request_threaded_irq(irq, NULL, handle_threaded_wake_irq, 190 IRQF_ONESHOT, dev_name(dev), wirq); 191 if (err) 192 goto err_free; 193 194 err = dev_pm_attach_wake_irq(dev, irq, wirq); 195 if (err) 196 goto err_free_irq; 197 198 return err; 199 200 err_free_irq: 201 free_irq(irq, wirq); 202 err_free: 203 kfree(wirq); 204 205 return err; 206 } 207 EXPORT_SYMBOL_GPL(dev_pm_set_dedicated_wake_irq); 208 209 /** 210 * dev_pm_enable_wake_irq - Enable device wake-up interrupt 211 * @dev: Device 212 * 213 * Called from the bus code or the device driver for 214 * runtime_suspend() to enable the wake-up interrupt while 215 * the device is running. 216 * 217 * Note that for runtime_suspend()) the wake-up interrupts 218 * should be unconditionally enabled unlike for suspend() 219 * that is conditional. 220 */ 221 void dev_pm_enable_wake_irq(struct device *dev) 222 { 223 struct wake_irq *wirq = dev->power.wakeirq; 224 225 if (wirq && wirq->dedicated_irq) 226 enable_irq(wirq->irq); 227 } 228 EXPORT_SYMBOL_GPL(dev_pm_enable_wake_irq); 229 230 /** 231 * dev_pm_disable_wake_irq - Disable device wake-up interrupt 232 * @dev: Device 233 * 234 * Called from the bus code or the device driver for 235 * runtime_resume() to disable the wake-up interrupt while 236 * the device is running. 237 */ 238 void dev_pm_disable_wake_irq(struct device *dev) 239 { 240 struct wake_irq *wirq = dev->power.wakeirq; 241 242 if (wirq && wirq->dedicated_irq) 243 disable_irq_nosync(wirq->irq); 244 } 245 EXPORT_SYMBOL_GPL(dev_pm_disable_wake_irq); 246 247 /** 248 * dev_pm_arm_wake_irq - Arm device wake-up 249 * @wirq: Device wake-up interrupt 250 * 251 * Sets up the wake-up event conditionally based on the 252 * device_may_wake(). 253 */ 254 void dev_pm_arm_wake_irq(struct wake_irq *wirq) 255 { 256 if (!wirq) 257 return; 258 259 if (device_may_wakeup(wirq->dev)) 260 enable_irq_wake(wirq->irq); 261 } 262 263 /** 264 * dev_pm_disarm_wake_irq - Disarm device wake-up 265 * @wirq: Device wake-up interrupt 266 * 267 * Clears up the wake-up event conditionally based on the 268 * device_may_wake(). 269 */ 270 void dev_pm_disarm_wake_irq(struct wake_irq *wirq) 271 { 272 if (!wirq) 273 return; 274 275 if (device_may_wakeup(wirq->dev)) 276 disable_irq_wake(wirq->irq); 277 } 278