RK3588上电源按键接在PMIC芯片RK806的PWRON引脚，但不像之前RK3399那样电源键会同时接到主控RK3399的GPIO引脚作为gpio按键处理。RK3588上电源键的处理是以RK806的中断信号处理的。即电源按键的按下和释放动作会通过RK806的INT引脚发送中断事件给RK3588，RK3588收到后作为电源键事件发送给上层系统处理。其主要处理电源键中断的驱动代码在：kernel-5.10\drivers\input\misc\rk805-pwrkey.c中。代码解析如下：
//电源键按下中断处理程序
static irqreturn_t pwrkey_fall_irq(int irq, void *_pwr)
{
struct input_dev *pwr = _pwr;
//发送电源键按下事件给上层系统
input_report_key(pwr, KEY_POWER, 1);
input_sync(pwr);
return IRQ_HANDLED;
}
//电源键释放中断处理程序
static irqreturn_t pwrkey_rise_irq(int irq, void *_pwr)
{
struct input_dev *pwr = _pwr;
//发送电源键释放事件给上层系统
input_report_key(pwr, KEY_POWER, 0);
input_sync(pwr);
return IRQ_HANDLED;
}
static int rk805_pwrkey_probe(struct platform_device *pdev)
{
struct input_dev *pwr;
int fall_irq, rise_irq;
struct device_node *np;
int err;
//找到dts中是否打开了"pwrkey"节点
np = of_get_child_by_name(pdev->dev.parent->of_node, "pwrkey");
if (np && !of_device_is_available(np)) {
dev_info(&pdev->dev, "device is disabled\n");
return -EINVAL;
}
pwr = devm_input_allocate_device(&pdev->dev);
if (!pwr) {
dev_err(&pdev->dev, "Can't allocate power button\n");
return -ENOMEM;
}
pwr->name = "rk805 pwrkey";
pwr->phys = "rk805_pwrkey/input0";
pwr->id.bustype = BUS_HOST;
//打开电源键功能
input_set_capability(pwr, EV_KEY, KEY_POWER);
//获取电源键按下中断号
fall_irq = platform_get_irq(pdev, 0);
if (fall_irq < 0)
return fall_irq;
//获取电源键释放中断号
rise_irq = platform_get_irq(pdev, 1);
if (rise_irq < 0)
return rise_irq;
//注册电源键按下中断程序
err = devm_request_any_context_irq(&pwr->dev, fall_irq,
pwrkey_fall_irq,
IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
"rk805_pwrkey_fall", pwr);
if (err < 0) {
dev_err(&pdev->dev, "Can't register fall irq: %d\n", err);
return err;
}
//注册电源键释放中断程序
err = devm_request_any_context_irq(&pwr->dev, rise_irq,
pwrkey_rise_irq,
IRQF_TRIGGER_RISING | IRQF_ONESHOT,
"rk805_pwrkey_rise", pwr);
if (err < 0) {
dev_err(&pdev->dev, "Can't register rise irq: %d\n", err);
return err;
}
//注册输入设备
err = input_register_device(pwr);
if (err) {
dev_err(&pdev->dev, "Can't register power button: %d\n", err);
return err;
}
//设置平台驱动私有数据
platform_set_drvdata(pdev, pwr);
//设置电源键可唤醒系统
device_init_wakeup(&pdev->dev, true);
return 0;
}
//注册平台设备驱动
static struct platform_driver rk805_pwrkey_driver = {
.probe = rk805_pwrkey_probe,
.driver = {
.name = "rk805-pwrkey",
},
};
module_platform_driver(rk805_pwrkey_driver);