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 wirq = kzalloc(sizeof(*wirq), GFP_KERNEL); 72 if (!wirq) 73 return -ENOMEM; 74 75 wirq->dev = dev; 76 wirq->irq = irq; 77 78 err = dev_pm_attach_wake_irq(dev, irq, wirq); 79 if (err) 80 kfree(wirq); 81 82 return err; 83 } 84 EXPORT_SYMBOL_GPL(dev_pm_set_wake_irq); 85 86 /** 87 * dev_pm_clear_wake_irq - Detach a device IO interrupt wake IRQ 88 * @dev: Device entry 89 * 90 * Detach a device wake IRQ and free resources. 91 * 92 * Note that it's OK for drivers to call this without calling 93 * dev_pm_set_wake_irq() as all the driver instances may not have 94 * a wake IRQ configured. This avoid adding wake IRQ specific 95 * checks into the drivers. 96 */ 97 void dev_pm_clear_wake_irq(struct device *dev) 98 { 99 struct wake_irq *wirq = dev->power.wakeirq; 100 unsigned long flags; 101 102 if (!wirq) 103 return; 104 105 spin_lock_irqsave(&dev->power.lock, flags); 106 device_wakeup_detach_irq(dev); 107 dev->power.wakeirq = NULL; 108 spin_unlock_irqrestore(&dev->power.lock, flags); 109 110 if (wirq->dedicated_irq) 111 free_irq(wirq->irq, wirq); 112 kfree(wirq); 113 } 114 EXPORT_SYMBOL_GPL(dev_pm_clear_wake_irq); 115 116 /** 117 * handle_threaded_wake_irq - Handler for dedicated wake-up interrupts 118 * @irq: Device specific dedicated wake-up interrupt 119 * @_wirq: Wake IRQ data 120 * 121 * Some devices have a separate wake-up interrupt in addition to the 122 * device IO interrupt. The wake-up interrupt signals that a device 123 * should be woken up from it's idle state. This handler uses device 124 * specific pm_runtime functions to wake the device, and then it's 125 * up to the device to do whatever it needs to. Note that as the 126 * device may need to restore context and start up regulators, we 127 * use a threaded IRQ. 128 * 129 * Also note that we are not resending the lost device interrupts. 130 * We assume that the wake-up interrupt just needs to wake-up the 131 * device, and then device's pm_runtime_resume() can deal with the 132 * situation. 133 */ 134 static irqreturn_t handle_threaded_wake_irq(int irq, void *_wirq) 135 { 136 struct wake_irq *wirq = _wirq; 137 int res; 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 wirq = kzalloc(sizeof(*wirq), GFP_KERNEL); 171 if (!wirq) 172 return -ENOMEM; 173 174 wirq->dev = dev; 175 wirq->irq = irq; 176 wirq->dedicated_irq = true; 177 irq_set_status_flags(irq, IRQ_NOAUTOEN); 178 179 /* 180 * Consumer device may need to power up and restore state 181 * so we use a threaded irq. 182 */ 183 err = request_threaded_irq(irq, NULL, handle_threaded_wake_irq, 184 IRQF_ONESHOT, dev_name(dev), wirq); 185 if (err) 186 goto err_free; 187 188 err = dev_pm_attach_wake_irq(dev, irq, wirq); 189 if (err) 190 goto err_free_irq; 191 192 return err; 193 194 err_free_irq: 195 free_irq(irq, wirq); 196 err_free: 197 kfree(wirq); 198 199 return err; 200 } 201 EXPORT_SYMBOL_GPL(dev_pm_set_dedicated_wake_irq); 202 203 /** 204 * dev_pm_enable_wake_irq - Enable device wake-up interrupt 205 * @dev: Device 206 * 207 * Called from the bus code or the device driver for 208 * runtime_suspend() to enable the wake-up interrupt while 209 * the device is running. 210 * 211 * Note that for runtime_suspend()) the wake-up interrupts 212 * should be unconditionally enabled unlike for suspend() 213 * that is conditional. 214 */ 215 void dev_pm_enable_wake_irq(struct device *dev) 216 { 217 struct wake_irq *wirq = dev->power.wakeirq; 218 219 if (wirq && wirq->dedicated_irq) 220 enable_irq(wirq->irq); 221 } 222 EXPORT_SYMBOL_GPL(dev_pm_enable_wake_irq); 223 224 /** 225 * dev_pm_disable_wake_irq - Disable device wake-up interrupt 226 * @dev: Device 227 * 228 * Called from the bus code or the device driver for 229 * runtime_resume() to disable the wake-up interrupt while 230 * the device is running. 231 */ 232 void dev_pm_disable_wake_irq(struct device *dev) 233 { 234 struct wake_irq *wirq = dev->power.wakeirq; 235 236 if (wirq && wirq->dedicated_irq) 237 disable_irq_nosync(wirq->irq); 238 } 239 EXPORT_SYMBOL_GPL(dev_pm_disable_wake_irq); 240 241 /** 242 * dev_pm_arm_wake_irq - Arm device wake-up 243 * @wirq: Device wake-up interrupt 244 * 245 * Sets up the wake-up event conditionally based on the 246 * device_may_wake(). 247 */ 248 void dev_pm_arm_wake_irq(struct wake_irq *wirq) 249 { 250 if (!wirq) 251 return; 252 253 if (device_may_wakeup(wirq->dev)) 254 enable_irq_wake(wirq->irq); 255 } 256 257 /** 258 * dev_pm_disarm_wake_irq - Disarm device wake-up 259 * @wirq: Device wake-up interrupt 260 * 261 * Clears up the wake-up event conditionally based on the 262 * device_may_wake(). 263 */ 264 void dev_pm_disarm_wake_irq(struct wake_irq *wirq) 265 { 266 if (!wirq) 267 return; 268 269 if (device_may_wakeup(wirq->dev)) 270 disable_irq_wake(wirq->irq); 271 } 272