diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/base/power/wakeirq.c | 412 |
1 files changed, 412 insertions, 0 deletions
diff --git a/drivers/base/power/wakeirq.c b/drivers/base/power/wakeirq.c new file mode 100644 index 000000000..aea690c64 --- /dev/null +++ b/drivers/base/power/wakeirq.c @@ -0,0 +1,412 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Device wakeirq helper functions */ +#include <linux/device.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/slab.h> +#include <linux/pm_runtime.h> +#include <linux/pm_wakeirq.h> + +#include "power.h" + +/** + * dev_pm_attach_wake_irq - Attach device interrupt as a wake IRQ + * @dev: Device entry + * @irq: Device wake-up capable interrupt + * @wirq: Wake irq specific data + * + * Internal function to attach either a device IO interrupt or a + * dedicated wake-up interrupt as a wake IRQ. + */ +static int dev_pm_attach_wake_irq(struct device *dev, int irq, + struct wake_irq *wirq) +{ + unsigned long flags; + + if (!dev || !wirq) + return -EINVAL; + + spin_lock_irqsave(&dev->power.lock, flags); + if (dev_WARN_ONCE(dev, dev->power.wakeirq, + "wake irq already initialized\n")) { + spin_unlock_irqrestore(&dev->power.lock, flags); + return -EEXIST; + } + + dev->power.wakeirq = wirq; + device_wakeup_attach_irq(dev, wirq); + + spin_unlock_irqrestore(&dev->power.lock, flags); + return 0; +} + +/** + * dev_pm_set_wake_irq - Attach device IO interrupt as wake IRQ + * @dev: Device entry + * @irq: Device IO interrupt + * + * Attach a device IO interrupt as a wake IRQ. The wake IRQ gets + * automatically configured for wake-up from suspend based + * on the device specific sysfs wakeup entry. Typically called + * during driver probe after calling device_init_wakeup(). + */ +int dev_pm_set_wake_irq(struct device *dev, int irq) +{ + struct wake_irq *wirq; + int err; + + if (irq < 0) + return -EINVAL; + + wirq = kzalloc(sizeof(*wirq), GFP_KERNEL); + if (!wirq) + return -ENOMEM; + + wirq->dev = dev; + wirq->irq = irq; + + err = dev_pm_attach_wake_irq(dev, irq, wirq); + if (err) + kfree(wirq); + + return err; +} +EXPORT_SYMBOL_GPL(dev_pm_set_wake_irq); + +/** + * dev_pm_clear_wake_irq - Detach a device IO interrupt wake IRQ + * @dev: Device entry + * + * Detach a device wake IRQ and free resources. + * + * Note that it's OK for drivers to call this without calling + * dev_pm_set_wake_irq() as all the driver instances may not have + * a wake IRQ configured. This avoid adding wake IRQ specific + * checks into the drivers. + */ +void dev_pm_clear_wake_irq(struct device *dev) +{ + struct wake_irq *wirq = dev->power.wakeirq; + unsigned long flags; + + if (!wirq) + return; + + spin_lock_irqsave(&dev->power.lock, flags); + device_wakeup_detach_irq(dev); + dev->power.wakeirq = NULL; + spin_unlock_irqrestore(&dev->power.lock, flags); + + if (wirq->status & WAKE_IRQ_DEDICATED_ALLOCATED) { + free_irq(wirq->irq, wirq); + wirq->status &= ~WAKE_IRQ_DEDICATED_MASK; + } + kfree(wirq->name); + kfree(wirq); +} +EXPORT_SYMBOL_GPL(dev_pm_clear_wake_irq); + +/** + * handle_threaded_wake_irq - Handler for dedicated wake-up interrupts + * @irq: Device specific dedicated wake-up interrupt + * @_wirq: Wake IRQ data + * + * Some devices have a separate wake-up interrupt in addition to the + * device IO interrupt. The wake-up interrupt signals that a device + * should be woken up from it's idle state. This handler uses device + * specific pm_runtime functions to wake the device, and then it's + * up to the device to do whatever it needs to. Note that as the + * device may need to restore context and start up regulators, we + * use a threaded IRQ. + * + * Also note that we are not resending the lost device interrupts. + * We assume that the wake-up interrupt just needs to wake-up the + * device, and then device's pm_runtime_resume() can deal with the + * situation. + */ +static irqreturn_t handle_threaded_wake_irq(int irq, void *_wirq) +{ + struct wake_irq *wirq = _wirq; + int res; + + /* Maybe abort suspend? */ + if (irqd_is_wakeup_set(irq_get_irq_data(irq))) { + pm_wakeup_event(wirq->dev, 0); + + return IRQ_HANDLED; + } + + /* We don't want RPM_ASYNC or RPM_NOWAIT here */ + res = pm_runtime_resume(wirq->dev); + if (res < 0) + dev_warn(wirq->dev, + "wake IRQ with no resume: %i\n", res); + + return IRQ_HANDLED; +} + +static int __dev_pm_set_dedicated_wake_irq(struct device *dev, int irq, unsigned int flag) +{ + struct wake_irq *wirq; + int err; + + if (irq < 0) + return -EINVAL; + + wirq = kzalloc(sizeof(*wirq), GFP_KERNEL); + if (!wirq) + return -ENOMEM; + + wirq->name = kasprintf(GFP_KERNEL, "%s:wakeup", dev_name(dev)); + if (!wirq->name) { + err = -ENOMEM; + goto err_free; + } + + wirq->dev = dev; + wirq->irq = irq; + irq_set_status_flags(irq, IRQ_NOAUTOEN); + + /* Prevent deferred spurious wakeirqs with disable_irq_nosync() */ + irq_set_status_flags(irq, IRQ_DISABLE_UNLAZY); + + /* + * Consumer device may need to power up and restore state + * so we use a threaded irq. + */ + err = request_threaded_irq(irq, NULL, handle_threaded_wake_irq, + IRQF_ONESHOT, wirq->name, wirq); + if (err) + goto err_free_name; + + err = dev_pm_attach_wake_irq(dev, irq, wirq); + if (err) + goto err_free_irq; + + wirq->status = WAKE_IRQ_DEDICATED_ALLOCATED | flag; + + return err; + +err_free_irq: + free_irq(irq, wirq); +err_free_name: + kfree(wirq->name); +err_free: + kfree(wirq); + + return err; +} + + +/** + * dev_pm_set_dedicated_wake_irq - Request a dedicated wake-up interrupt + * @dev: Device entry + * @irq: Device wake-up interrupt + * + * Unless your hardware has separate wake-up interrupts in addition + * to the device IO interrupts, you don't need this. + * + * Sets up a threaded interrupt handler for a device that has + * a dedicated wake-up interrupt in addition to the device IO + * interrupt. + * + * The interrupt starts disabled, and needs to be managed for + * the device by the bus code or the device driver using + * dev_pm_enable_wake_irq*() and dev_pm_disable_wake_irq*() + * functions. + */ +int dev_pm_set_dedicated_wake_irq(struct device *dev, int irq) +{ + return __dev_pm_set_dedicated_wake_irq(dev, irq, 0); +} +EXPORT_SYMBOL_GPL(dev_pm_set_dedicated_wake_irq); + +/** + * dev_pm_set_dedicated_wake_irq_reverse - Request a dedicated wake-up interrupt + * with reverse enable ordering + * @dev: Device entry + * @irq: Device wake-up interrupt + * + * Unless your hardware has separate wake-up interrupts in addition + * to the device IO interrupts, you don't need this. + * + * Sets up a threaded interrupt handler for a device that has a dedicated + * wake-up interrupt in addition to the device IO interrupt. It sets + * the status of WAKE_IRQ_DEDICATED_REVERSE to tell rpm_suspend() + * to enable dedicated wake-up interrupt after running the runtime suspend + * callback for @dev. + * + * The interrupt starts disabled, and needs to be managed for + * the device by the bus code or the device driver using + * dev_pm_enable_wake_irq*() and dev_pm_disable_wake_irq*() + * functions. + */ +int dev_pm_set_dedicated_wake_irq_reverse(struct device *dev, int irq) +{ + return __dev_pm_set_dedicated_wake_irq(dev, irq, WAKE_IRQ_DEDICATED_REVERSE); +} +EXPORT_SYMBOL_GPL(dev_pm_set_dedicated_wake_irq_reverse); + +/** + * dev_pm_enable_wake_irq - Enable device wake-up interrupt + * @dev: Device + * + * Optionally called from the bus code or the device driver for + * runtime_resume() to override the PM runtime core managed wake-up + * interrupt handling to enable the wake-up interrupt. + * + * Note that for runtime_suspend()) the wake-up interrupts + * should be unconditionally enabled unlike for suspend() + * that is conditional. + */ +void dev_pm_enable_wake_irq(struct device *dev) +{ + struct wake_irq *wirq = dev->power.wakeirq; + + if (wirq && (wirq->status & WAKE_IRQ_DEDICATED_ALLOCATED)) + enable_irq(wirq->irq); +} +EXPORT_SYMBOL_GPL(dev_pm_enable_wake_irq); + +/** + * dev_pm_disable_wake_irq - Disable device wake-up interrupt + * @dev: Device + * + * Optionally called from the bus code or the device driver for + * runtime_suspend() to override the PM runtime core managed wake-up + * interrupt handling to disable the wake-up interrupt. + */ +void dev_pm_disable_wake_irq(struct device *dev) +{ + struct wake_irq *wirq = dev->power.wakeirq; + + if (wirq && (wirq->status & WAKE_IRQ_DEDICATED_ALLOCATED)) + disable_irq_nosync(wirq->irq); +} +EXPORT_SYMBOL_GPL(dev_pm_disable_wake_irq); + +/** + * dev_pm_enable_wake_irq_check - Checks and enables wake-up interrupt + * @dev: Device + * @can_change_status: Can change wake-up interrupt status + * + * Enables wakeirq conditionally. We need to enable wake-up interrupt + * lazily on the first rpm_suspend(). This is needed as the consumer device + * starts in RPM_SUSPENDED state, and the the first pm_runtime_get() would + * otherwise try to disable already disabled wakeirq. The wake-up interrupt + * starts disabled with IRQ_NOAUTOEN set. + * + * Should be only called from rpm_suspend() and rpm_resume() path. + * Caller must hold &dev->power.lock to change wirq->status + */ +void dev_pm_enable_wake_irq_check(struct device *dev, + bool can_change_status) +{ + struct wake_irq *wirq = dev->power.wakeirq; + + if (!wirq || !(wirq->status & WAKE_IRQ_DEDICATED_MASK)) + return; + + if (likely(wirq->status & WAKE_IRQ_DEDICATED_MANAGED)) { + goto enable; + } else if (can_change_status) { + wirq->status |= WAKE_IRQ_DEDICATED_MANAGED; + goto enable; + } + + return; + +enable: + if (!can_change_status || !(wirq->status & WAKE_IRQ_DEDICATED_REVERSE)) { + enable_irq(wirq->irq); + wirq->status |= WAKE_IRQ_DEDICATED_ENABLED; + } +} + +/** + * dev_pm_disable_wake_irq_check - Checks and disables wake-up interrupt + * @dev: Device + * @cond_disable: if set, also check WAKE_IRQ_DEDICATED_REVERSE + * + * Disables wake-up interrupt conditionally based on status. + * Should be only called from rpm_suspend() and rpm_resume() path. + */ +void dev_pm_disable_wake_irq_check(struct device *dev, bool cond_disable) +{ + struct wake_irq *wirq = dev->power.wakeirq; + + if (!wirq || !(wirq->status & WAKE_IRQ_DEDICATED_MASK)) + return; + + if (cond_disable && (wirq->status & WAKE_IRQ_DEDICATED_REVERSE)) + return; + + if (wirq->status & WAKE_IRQ_DEDICATED_MANAGED) { + wirq->status &= ~WAKE_IRQ_DEDICATED_ENABLED; + disable_irq_nosync(wirq->irq); + } +} + +/** + * dev_pm_enable_wake_irq_complete - enable wake IRQ not enabled before + * @dev: Device using the wake IRQ + * + * Enable wake IRQ conditionally based on status, mainly used if want to + * enable wake IRQ after running ->runtime_suspend() which depends on + * WAKE_IRQ_DEDICATED_REVERSE. + * + * Should be only called from rpm_suspend() path. + */ +void dev_pm_enable_wake_irq_complete(struct device *dev) +{ + struct wake_irq *wirq = dev->power.wakeirq; + + if (!wirq || !(wirq->status & WAKE_IRQ_DEDICATED_MASK)) + return; + + if (wirq->status & WAKE_IRQ_DEDICATED_MANAGED && + wirq->status & WAKE_IRQ_DEDICATED_REVERSE) + enable_irq(wirq->irq); +} + +/** + * dev_pm_arm_wake_irq - Arm device wake-up + * @wirq: Device wake-up interrupt + * + * Sets up the wake-up event conditionally based on the + * device_may_wake(). + */ +void dev_pm_arm_wake_irq(struct wake_irq *wirq) +{ + if (!wirq) + return; + + if (device_may_wakeup(wirq->dev)) { + if (wirq->status & WAKE_IRQ_DEDICATED_ALLOCATED && + !(wirq->status & WAKE_IRQ_DEDICATED_ENABLED)) + enable_irq(wirq->irq); + + enable_irq_wake(wirq->irq); + } +} + +/** + * dev_pm_disarm_wake_irq - Disarm device wake-up + * @wirq: Device wake-up interrupt + * + * Clears up the wake-up event conditionally based on the + * device_may_wake(). + */ +void dev_pm_disarm_wake_irq(struct wake_irq *wirq) +{ + if (!wirq) + return; + + if (device_may_wakeup(wirq->dev)) { + disable_irq_wake(wirq->irq); + + if (wirq->status & WAKE_IRQ_DEDICATED_ALLOCATED && + !(wirq->status & WAKE_IRQ_DEDICATED_ENABLED)) + disable_irq_nosync(wirq->irq); + } +} |