static struct platform_driver hello_driver = {
.probe = hello_probe,
.remove = hello_remove,
.driver = {
.name = HELLO_DEV_NAME,
.owner = THIS_MODULE,
},
};
static struct file_operations hello_fops = {
.owner = THIS_MODULE,
.open = hello_open, //外部测试调用open打开设备文件时触发
.release = hello_close, //外部调用close时触发
.read = hello_read, //外部 write 时触发
.write = hello_write, //外部 read 时触发
};
请问上面的怎么用？什么时候触发呢？
下面是两个LED灯的驱动程序 一个用platform_driver 另一个用file_operations 不知有什么区别？ 请帮忙解释下 谢谢了。
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/leds.h>
#include <mach/hardware.h>
#include <mach/regs-gpio.h>
#include <mach/leds-gpio.h>
/* our context */
struct s3c24xx_gpio_led {
struct led_classdev cdev;
struct s3c24xx_led_platdata *pdata;
};
static inline struct s3c24xx_gpio_led *pdev_to_gpio(struct platform_device *dev)
{
return platform_get_drvdata(dev);
}
static inline struct s3c24xx_gpio_led *to_gpio(struct led_classdev *led_cdev)
{
return container_of(led_cdev, struct s3c24xx_gpio_led, cdev);
}
static void s3c24xx_led_set(struct led_classdev *led_cdev,
enum led_brightness value)
{
struct s3c24xx_gpio_led *led = to_gpio(led_cdev);
struct s3c24xx_led_platdata *pd = led->pdata;
/* there will be a short delay between setting the output and
* going from output to input when using tristate. */
s3c2410_gpio_setpin(pd->gpio, (value ? 1 : 0) ^
(pd->flags & S3C24XX_LEDF_ACTLOW));
if (pd->flags & S3C24XX_LEDF_TRISTATE)
s3c2410_gpio_cfgpin(pd->gpio,
value ? S3C2410_GPIO_OUTPUT : S3C2410_GPIO_INPUT);
}
static int s3c24xx_led_remove(struct platform_device *dev)
{
struct s3c24xx_gpio_led *led = pdev_to_gpio(dev);
led_classdev_unregister(&led->cdev);
kfree(led);
return 0;
}
static int s3c24xx_led_probe(struct platform_device *dev)
{
struct s3c24xx_led_platdata *pdata = dev->dev.platform_data;
struct s3c24xx_gpio_led *led;
int ret;
led = kzalloc(sizeof(struct s3c24xx_gpio_led), GFP_KERNEL);
if (led == NULL) {
dev_err(&dev->dev, "No memory for device\n");
return -ENOMEM;
}
platform_set_drvdata(dev, led);
led->cdev.brightness_set = s3c24xx_led_set;
led->cdev.default_trigger = pdata->def_trigger;
led->cdev.name = pdata->name;
led->pdata = pdata;
/* no point in having a pull-up if we are always driving */
if (pdata->flags & S3C24XX_LEDF_TRISTATE) {
s3c2410_gpio_setpin(pdata->gpio, 0);
s3c2410_gpio_cfgpin(pdata->gpio, S3C2410_GPIO_INPUT);
} else {
s3c2410_gpio_pullup(pdata->gpio, 0);
s3c2410_gpio_setpin(pdata->gpio, 0);
s3c2410_gpio_cfgpin(pdata->gpio, S3C2410_GPIO_OUTPUT);
}
/* register our new led device */
ret = led_classdev_register(&dev->dev, &led->cdev);
if (ret < 0) {
dev_err(&dev->dev, "led_classdev_register failed\n");
goto exit_err1;
}
return 0;
exit_err1:
kfree(led);
return ret;
}
#ifdef CONFIG_PM
static int s3c24xx_led_suspend(struct platform_device *dev, pm_message_t state)
{
struct s3c24xx_gpio_led *led = pdev_to_gpio(dev);
led_classdev_suspend(&led->cdev);
return 0;
}
static int s3c24xx_led_resume(struct platform_device *dev)
{
struct s3c24xx_gpio_led *led = pdev_to_gpio(dev);
led_classdev_resume(&led->cdev);