编写input

• documentation/input/input-programming.txt
• documentation/input/event-codes.txt

• 申请中断
• 在中断服务程序里
  • 读取硬件获取数据
  • 上报数据

• 在设备树里创建一个节点
  • 指定硬件资源等信息
• 编译一个platform_driver驱动
  • 在probe函数里
    • 从设备树获得资源
    • 分配/设置/注册input_dev
    • 硬件相关的操作
      • request_irq等

#include 
#include 

static struct input_dev *g_input_dev;
static int g_irq;

static irqreturn_t input_dev_demo_irq(int irq, void *dev_id)
{
	

	
	input_event(g_input_dev, EV_KEY, XX, 0);
	input_sync(g_input_dev);

	return IRQ_HANDLED;
}

static int input_dev_demo_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	int error = 0;
	struct resource *irq;

	

	
	g_input_dev = devm_input_allocate_device(dev);

	g_input_dev->name = "input_dev_demo";
	g_input_dev->phys = "input_dev_demo";
	g_input_dev->dev.parent = dev;

	g_input_dev->id.bustype = BUS_HOST;
	g_input_dev->id.vendor  = 0x0001;
	g_input_dev->id.product = 0x0001;
	g_input_dev->id.version = 0x0001;


	
	__set_bit(EV_KEY, g_input_dev->evbit);
	__set_bit(EV_ABS, g_input_dev->evbit);

	
	__set_bit(BTN_TOUCH, g_input_dev->keybit);
	__set_bit(ABS_MT_SLOT, g_input_dev->absbit);
	__set_bit(ABS_MT_POSITION_X, g_input_dev->absbit);
	__set_bit(ABS_MT_POSITION_Y, g_input_dev->absbit);

	
	input_set_abs_params(g_input_dev, ABS_MT_POSITION_X, 0, 0xffff, 0, 0);
	input_set_abs_params(g_input_dev, ABS_MT_POSITION_Y, 0, 0xffff, 0, 0);

	error = input_register_device(g_input_dev);

	
	irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
	g_irq = irq->start;
	request_irq(irq->start, input_dev_demo_isr, IRQF_TRIGGER_RISING, "input_dev_demo_irq", NULL);

	return 0;
}

static int input_dev_demo_remove(struct platform_device *pdev)
{
	free_irq(g_irq, NULL);
	input_unregister_device(g_input_dev);
	return 0;
}

static struct of_device_id input_dev_demo_of_match = {
	{ .compatible = "100ask,input_dev_demo", },
	{ },
};

static struct platform_driver input_dev_demo_driver = {
	.probe = input_dev_demo_probe,
	.remove = input_dev_demo_remove,
	.driver = {
		.name = "input_dev_demo",
		.of_match_table = input_dev_demo_of_match,
	}
};

static int __init input_dev_demo_init(void)
{
	return platform_driver_register(&input_dev_demo_driver);
}

static void __exit input_dev_demo_exit(void)
{
	platform_driver_unregister(&input_dev_demo_driver);
}

module_init(input_dev_demo_init);
module_exit(input_dev_demo_exit);
MODULE_LINCESE("GPL");

设备树设置

/ {
    input_dev_demo {
        compatible = "100ask,input_dev_demo";
        interrupts = <...>;
    };
};