powermanagement.example.c

LINUX内核编程的一些程序例子

/** @file example.c
 *
 * @author marco corvi <[e-mail]>
 * @date   apr. 2003
 *
 * \brief first example of power managenemt aware driver
 *
 */

#include <linux/input.h>   /* input_dev */
#include <linux/module.h>
/* #include <linux/modversions.h> */
#include <linux/init.h>
#include <linux/pm.h>

MODULE_LICENSE( "GPL" );

static struct pm_dev * example_pm;

static int example_data;
static int example_callback
  ( struct pm_dev * dev, pm_request_t rqst, void * data)
{
  int driver = *(int *)(dev->data);
  printk(KERN_ALERT "Example callback: data %d rqst %d\n", driver, rqst );

  // take any necessary action
  return 0;
}

static int __init example_init( void )
{
  // allocate and initialize driver data
  example_data = 123;
  
  example_pm = pm_register( PM_SYS_DEV, 0, example_callback );
  if ( example_pm ) {
    example_pm->data = (void *) &example_data ; // private driver data
    printk(KERN_ALERT "Example registered with PM\n"); 
  } else {
    printk(KERN_ALERT "Example could not registered with PM\n"); 
  }
  return 0;
}

static void __init example_exit()
{

  if ( example_pm ) 
    pm_unregister( example_pm );

  // deallocate driver data
}

module_init( example_init );
module_exit( example_exit );