# QSDK reset按键

## 内核配置

![image-20241022163758908](media/image-20241022163758908.png)

## dts配置

以`qcom-ipq6018-cp02-c1.dts`为例说明

- pinctrl配置

  ```
  &tlnm{
  	button_pins: button_pins {
  		reset_button {
  			pins = "gpio18";
  			function = "gpio";
  			drive-strength = <8>;
  			bias-pull-down;
  		};
  	};
  };
  ```

  

- reset按键配置

  ```
  &soc{
  	gpio_keys {
  		compatible = "gpio-keys";
  		pinctrl-0 = <&button_pins>;
  		pinctrl-names = "default";
  
  		reset {
  			label = "reset";
  			linux,code = <KEY_POWER>;
  			gpios = <&tlmm 18 GPIO_ACTIVE_LOW>;
  			linux,input-type = <1>;
  			debounce-interval = <60>;
  		};
  	};
  };
  ```

从上面的信息可以看出io使用的是gpio18，驱动使用的是`compatible = "gpio-keys";`

## 平台驱动

```c
static struct platform_driver gpio_keys_driver = {
	.probe	= gpio_keys_probe,
	.remove	= gpio_keys_remove,
	.driver	= {
		.name	= "gpio-keys",
		.owner	= THIS_MODULE,
		.of_match_table = of_match_ptr(gpio_keys_of_match),
	},
};
```

```c
static int __init gpio_button_init(void)
{
	int ret;
	ret = platform_driver_register(&gpio_keys_driver);
	if (ret)
		return ret;

	return ret;
}
```



```
gpio_keys_probe
	gpio_keys_button_probe(pdev, &bdev, 0); // 启动工作队列和定时器
		INIT_WORK(&bdata->work_irq, gpio_keys_gpio_work_func);
		setup_timer(&bdata->timer, gpio_keys_gpio_timer,);
	devm_request_irq						// 申请中断
	button_hotplug_event					// 创建hotplug事件
```

- `gpio_keys_gpio_work_fun`函数

  ```
  	bdata->last_state = gpio_button_get_value(bdata);
  	button_hotplug_event(bdata, bdata->b->type ?: EV_KEY, bdata->last_state);
  ```

  

- `gpio_keys_gpio_timer`函数

  ```
  struct gpio_keys_button_data *bdata = (struct gpio_keys_button_data *)_data;
  
  schedule_work(&bdata->work_irq); //启动
  ```

  

- `button_hotplug_event`函数

  ```
  	button_hotplug_create_event(button_map[btn].name, type,
  			(seen - priv->seen) / HZ, value);
  ```

- `button_hotplug_create_event`函数

  ```
  static int button_hotplug_create_event(const char *name, unsigned int type,
  		unsigned long seen, int pressed)
  {
  	struct bh_event *event;
  
  	BH_DBG("create event, name=%s, seen=%lu, pressed=%d\n",
  		name, seen, pressed);
  
  	event = kzalloc(sizeof(*event), GFP_KERNEL);
  	if (!event)
  		return -ENOMEM;
  
  	event->name = name;
  	event->type = type;
  	event->seen = seen;
  	event->action = pressed ? "pressed" : "released";
  
  	INIT_WORK(&event->work, (void *)(void *)button_hotplug_work);
  	schedule_work(&event->work);
  
  	return 0;
  }
  ```

  

- `button_hotplug_work`函数

  ```c
  static void button_hotplug_work(struct work_struct *work)
  {
  	struct bh_event *event = container_of(work, struct bh_event, work);
  	int ret = 0;
  
  	event->skb = alloc_skb(BH_SKB_SIZE, GFP_KERNEL);
  	if (!event->skb)
  		goto out_free_event;
  
  	ret = bh_event_add_var(event, 0, "%s@", event->action);
  	if (ret)
  		goto out_free_skb;
  
  	ret = button_hotplug_fill_event(event);
  	if (ret)
  		goto out_free_skb;
  
  	NETLINK_CB(event->skb).dst_group = 1;
  	broadcast_uevent(event->skb, 0, 1, GFP_KERNEL); //通过broadcast_uevent发到用户层。
  
   out_free_skb:
  	if (ret) {
  		BH_ERR("work error %d\n", ret);
  		kfree_skb(event->skb);
  	}
   out_free_event:
  	kfree(event);
  }
  ```

  

驱动程序参见[reset按键和ipget按键在openwrt中的处理逻辑 - 轻轻的吻 - 博客园](https://www.cnblogs.com/yuanqiangfei/p/15252923.html)



## reset按键应用层处理

```
#!/bin/sh

[ "${ACTION}" = "released" ] || exit 0

. /lib/functions.sh

logger "$BUTTON pressed for $SEEN seconds"

if [ "$SEEN" -lt 1 ]
then
	echo "REBOOT" > /dev/console
	sync
	reboot
elif [ "$SEEN" -gt 5 ]
then
	echo "FACTORY RESET" > /dev/console
	jffs2reset -y && reboot &
fi

return 0

```

## jffs2reset原理