BSP_调试经验

[[toc]]

设备树解析与Platform_device创建过程

/ platform probe函数
static int led_probe(static platform_device *pdev)
{
    led_gpio_init(pdev->dev.of_node);
	printk("led_probe\n");
	return 0;
}

// platform remove函数
static int led_remove(static platform_device *dev)
{
	printk("led_remove\n");
	return 0;
}
//匹配列表
static const sturct of_device_id led_of_match[] = {
	{.compatible = "atk,led"},
	{},
}
// platform驱动结构体

struct platform_device led_device
{
	.driver = {
		.name = "atkmp157_led",
		.of_match_table = led_of_match,
	},
	.probe = led_probe, .remove = led_remove,
};

// platform驱动加载函数
static int __init leddriver_init(void)
{
	return platform_deiver_register(&led_device);
}

// platform驱动卸载函数
static void __exit leddriver_exit(void)
{
	platform_deiver_unregister(&led_device);
}

在platform_device的probe函数中有一个参数static platform_device *pdev关于这个参数的作用。

在drivers\of\platform.c中，of_platform_bus_create()为节点及其子节点创建设备。会忽略几类node，比如没有compatible属性的。然后of_platform_device_create_pdata 函数来创建节点.

/**
 * of_platform_bus_create() - 为节点及其子节点创建设备.
 * @bus: device node of the bus to instantiate
 * @matches: match table for bus nodes
 * @lookup: auxdata table for matching id and platform_data with device nodes
 * @parent: parent for new device, or NULL for top level.
 * @strict: require compatible property
 *
 * Creates a platform_device for the provided device_node, and optionally
 * recursively create devices for all the child nodes.
 */
static int of_platform_bus_create(struct device_node *bus,
				  const struct of_device_id *matches,
				  const struct of_dev_auxdata *lookup,
				  struct device *parent, bool strict)
{