critical section 中断唤醒系统流程(2)

{

enable_irq_wake(irq);

}

static int smcdef_resume(struct device *dev)

{

disable_irq_wake(irq);

}

static int smcdef_probe(struct i2c_client *client,

const struct i2c_device_id *id)

{

/* ... */

request_thread_irq(irq,

smcdef_event_handler,

NULL,

IRQF_TRIGGER_FALLING,

"smcdef",

pdata);

return 0;

}

static int smcdef_remove(struct i2c_client *client)

{

return 0;

}

static const struct of_device_id smcdef_dt_ids[] = {

{.compatible = "wowo,smcdef" },

{ }

};

MODULE_DEVICE_TABLE(of, smcdef_dt_ids);

static SIMPLE_DEV_PM_OPS(smcdef_pm_ops, smcdef_suspend, smcdef_resume);

static struct i2c_driver smcdef_driver = {

.driver = {

.name= "smcdef",

.of_match_table = of_match_ptr(smcdef_dt_ids),

.pm= &smcdef_pm_ops,

},

.probe = smcdef_probe,

.remove = smcdef_remove,

};

module_i2c_driver(smcdef_driver);

MODULE_AUTHOR("smcdef");

MODULE_DESCRIPTION("IRQ test");

MODULE_LICENSE("GPL");

在probe函数中通过request_thread_irq接口注册驱动的中断服务函数smcdef_event_handler，注意这里smcdef_event_handler的执行环境是中断上下文，thread_fn的方式下面也会介绍。

2.1. enable_irq_wake

当系统睡眠（echo "mem" > /sys/power/state）的时候，回想一下suspend的流程就会知道，最终会调用smcdef_suspend使能中断唤醒功能。enable_irq_wake主要工作是在irq_set_irq_wake中完成，代码如下：

int irq_set_irq_wake(unsigned int irq, unsigned int on)

{

unsigned long flags;

struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);

int ret = 0;

/* wakeup-capable irqs can be shared between drivers that

* don‘t need to have the same sleep mode behaviors.

*/

if (on) {

if (desc->wake_depth++ == 0) {

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