TaiShanPai/驱动文件/2024-11-4/platform1.c

#include <linux/module.h>
#include <linux/init.h>
#include <linux/of.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/leds.h>

struct gpio_led_data {
	struct led_classdev cdev; // LED 的类设备结构
	int gpio; // GPIO 引脚
};

struct gpio_leds_priv {
	struct gpio_led_data *leds; // 存储 LED 数据
	int num_leds; // LED 数量
};

static int gpio_led_probe(struct platform_device *pdev)
{
	struct gpio_leds_priv *priv;
	int ret;

	// 为 priv 分配内存
	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;

	priv->num_leds = /* 从设备树或其他来源获取 LED 数量 */;
	priv->leds = devm_kcalloc(&pdev->dev, priv->num_leds, sizeof(*priv->leds), GFP_KERNEL);
	if (!priv->leds)
		return -ENOMEM;

	// 初始化每个 LED
	for (int i = 0; i < priv->num_leds; i++) {
		priv->leds[i].gpio = /* 获取 GPIO 引脚 */;
		priv->leds[i].cdev.name = /* LED 名称 */;
		priv->leds[i].cdev.brightness = LED_OFF;
		priv->leds[i].cdev.max_brightness = LED_FULL;

		// 注册 LED
		ret = led_classdev_register(&pdev->dev, &priv->leds[i].cdev);
		if (ret) {
			dev_err(&pdev->dev, "Failed to register LED %s\n", priv->leds[i].cdev.name);
			goto error;
		}
	}

	platform_set_drvdata(pdev, priv); // 存储私有数据

	return 0;

error:
	// 清理已注册的 LED
	for (int j = 0; j < i; j++) {
		led_classdev_unregister(&priv->leds[j].cdev);
	}
	return ret;
}

static void gpio_led_shutdown(struct platform_device *pdev)
{
	struct gpio_leds_priv *priv = platform_get_drvdata(pdev);
	int i;

	for (i = 0; i < priv->num_leds; i++) {
		struct gpio_led_data *led = &priv->leds[i];

		if (!(led->cdev.flags & LED_RETAIN_AT_SHUTDOWN))
			gpio_led_set(&led->cdev, LED_OFF);
	}
}

static const struct of_device_id of_gpio_leds_match[] = {
	{ .compatible = "gpio-leds", },
	{}
};

MODULE_DEVICE_TABLE(of, of_gpio_leds_match);

static struct platform_driver gpio_led_driver = {
	.probe		= gpio_led_probe,
	.shutdown	= gpio_led_shutdown,
	.driver		= {
		.name	= "leds-gpio",
		.of_match_table = of_gpio_leds_match,
	},
};

module_platform_driver(gpio_led_driver);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("John Madieu <john.madieu@gmail.com>");
MODULE_DESCRIPTION("Linux kernel module skeleton for GPIO LEDs");