platform_driver与file_operations两种方法开发led驱动

下面是两个LED灯的驱动程序 一个用platform_driver 另一个用file_operations

#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 ?  : ) ^
(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 ;
}  

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, );
s3c2410_gpio_cfgpin(pdata->gpio, S3C2410_GPIO_INPUT);
} else {
s3c2410_gpio_pullup(pdata->gpio, );
s3c2410_gpio_setpin(pdata->gpio, );
s3c2410_gpio_cfgpin(pdata->gpio, S3C2410_GPIO_OUTPUT);
}  

/* register our new led device */  

ret = led_classdev_register(&dev->dev, &led->cdev);
if (ret < ) {
dev_err(&dev->dev, "led_classdev_register failed\n");
goto exit_err1;
}  

return ;  

 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 ;
}  

static int s3c24xx_led_resume(struct platform_device *dev)
{
struct s3c24xx_gpio_led *led = pdev_to_gpio(dev);  

led_classdev_resume(&led->cdev);
return ;
}
#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");  

---------------------------

 #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 :
  case :
  if (arg > ) {
  return -EINVAL;
  }
  s3c2410_gpio_setpin(led_table[arg], !cmd);
  return ;
  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 = ; i < ; i++) {
  s3c2410_gpio_cfgpin(led_table[i], led_cfg_table[i]);
  s3c2410_gpio_setpin(led_table[i], );
  }   

  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.");    

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