linux/drivers/base/power/wakeirq.c
Dmitry Torokhov 6f9b36cd24 PM / wakeirq: check that wake IRQ is valid before accepting it
Check that IRQ number passed to dev_pm_set_wake_irq() and
dev_pm_set_dedicated_wake_irq() is valid (not negative) before
accepting it.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-11-16 23:10:20 +01:00

278 lines
6.9 KiB
C

/*
* wakeirq.c - Device wakeirq helper functions
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed "as is" WITHOUT ANY WARRANTY of any
* kind, whether express or implied; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#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;
int err;
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;
}
err = device_wakeup_attach_irq(dev, wirq);
if (!err)
dev->power.wakeirq = wirq;
spin_unlock_irqrestore(&dev->power.lock, flags);
return err;
}
/**
* 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->dedicated_irq)
free_irq(wirq->irq, wirq);
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;
/* 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;
}
/**
* 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)
{
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;
wirq->dedicated_irq = true;
irq_set_status_flags(irq, IRQ_NOAUTOEN);
/*
* 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, dev_name(dev), wirq);
if (err)
goto err_free;
err = dev_pm_attach_wake_irq(dev, irq, wirq);
if (err)
goto err_free_irq;
return err;
err_free_irq:
free_irq(irq, wirq);
err_free:
kfree(wirq);
return err;
}
EXPORT_SYMBOL_GPL(dev_pm_set_dedicated_wake_irq);
/**
* dev_pm_enable_wake_irq - Enable device wake-up interrupt
* @dev: Device
*
* Called from the bus code or the device driver for
* runtime_suspend() to enable the wake-up interrupt while
* the device is running.
*
* 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->dedicated_irq)
enable_irq(wirq->irq);
}
EXPORT_SYMBOL_GPL(dev_pm_enable_wake_irq);
/**
* dev_pm_disable_wake_irq - Disable device wake-up interrupt
* @dev: Device
*
* Called from the bus code or the device driver for
* runtime_resume() to disable the wake-up interrupt while
* the device is running.
*/
void dev_pm_disable_wake_irq(struct device *dev)
{
struct wake_irq *wirq = dev->power.wakeirq;
if (wirq && wirq->dedicated_irq)
disable_irq_nosync(wirq->irq);
}
EXPORT_SYMBOL_GPL(dev_pm_disable_wake_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))
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);
}