关于驱动结构体 platform_driver 和 file_operations
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);
return 0;
}
#else
#define s3c24xx_led_suspend NULL
#define s3c24xx_led_resume NULL
#endif
static struct platform_driver s3c24xx_led_driver = {
.probe= s3c24xx_led_probe,
.remove= s3c24xx_led_remove,
.suspend= s3c24xx_led_suspend,
.resume= s3c24xx_led_resume,
.driver= {
.name= "s3c24xx_led",
.owner= THIS_MODULE,
},
};
static int __init s3c24xx_led_init(void)
{
return platform_driver_register(&s3c24xx_led_driver);
}
static void __exit s3c24xx_led_exit(void)
{
platform_driver_unregister(&s3c24xx_led_driver);
}
module_init(s3c24xx_led_init);
module_exit(s3c24xx_led_exit);
MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
MODULE_DESCRIPTION("S3C24XX LED driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:s3c24xx_led");
另一个如下：
#include <asm/uaccess.h>
#include <asm/atomic.h>
#include <asm/unistd.h>
#define DEVICE_NAME "leds"
static unsigned long led_table [] = {
S3C2410_GPB5,
S3C2410_GPB6,
S3C2410_GPB7,
S3C2410_GPB8,
};
static unsigned int led_cfg_table [] = {
S3C2410_GPB5_OUTP,
S3C2410_GPB6_OUTP,
S3C2410_GPB7_OUTP,
S3C2410_GPB8_OUTP,
};
static int sbc2440_leds_ioctl(
struct inode *inode,
struct file *file,
unsigned int cmd,
unsigned long arg)
{
switch(cmd) {
case 0:
case 1:
if (arg > 4) {
return -EINVAL;
}
s3c2410_gpio_setpin(led_table[arg], !cmd);
return 0;
default:
return -EINVAL;
}
}
static struct file_operations dev_fops = {
.owner = THIS_MODULE,
.ioctl = sbc2440_leds_ioctl,
};
static struct miscdevice misc = {
.minor = MISC_DYNAMIC_MINOR,
.name = DEVICE_NAME,
.fops = &dev_fops,
};
static int __init dev_init(void)
{
int ret;
int i;
for (i = 0; i < 4; i++) {
s3c2410_gpio_cfgpin(led_table[i], led_cfg_table[i]);
s3c2410_gpio_setpin(led_table[i], 0);
}
ret = misc_register(&misc);
printk (DEVICE_NAME"\tinitialized\n");
return ret;
}
static void __exit dev_exit(void)
{
misc_deregister(&misc);
}
module_init(dev_init);
module_exit(dev_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("FriendlyARM Inc.");
[解决办法]
去看内核里看看吧，这就是基于Linux操作系统驱动程序开发的难度，想入门还真得对内核有一定的理解才行，本人也不敢动手写主要是先看懂别人写的。对照相关函数去找函数的源码，是怎么样实现的。如果连需要用到什么函数，需要用到那些接口都不知道，别提写驱动。
[解决办法]
楼上的哥们 别装行么 不懂就别说这些大道理 看得就烦
[解决办法]
好久不见哦，这两个玩意我都用过，呵呵，但是也是不太明白，但是我的理解一个是对驱动中接口函数的操作是对一个设备的操作，一个是对驱动中的数据操作，主要是对一些功能的实现操作，并且可以用作一类的设备的操作，例如power的开关什么的，我靠，我也不太清楚，你自己查资料吧。
[解决办法]
话说深圳的日子怎么样？哥们我在这不能上网，只能上指定的几个网站，你什么时候混牛了，把我接走啊，今年哥们做的手机就能上市了，为了支持我，你一定要买一部！！！怎么样？在这见到你真的很差异，哈哈，别说不知道我是谁
