example3.c

LINUX内核编程的一些程序例子

/** @file example3.c
 *
 * \brief third example of input subsystem driver
 *
 * See Linux Journal Feb. 2003
 *
 * Requires
 *   insmod input
 *   ???
 * I did not manage to make it work
 */

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

/* MODULE_LICENSE( "GPL" ); */

struct input_dev example3_dev;


void example3_timeout( unsigned long unused /* UNUSED */ )
{ 
  int state = (int)example3_dev.private;
  if ( state < 30 ) 
    input_report_rel( &example3_dev, REL_X, 5 );
  else if ( state < 60 ) 
    input_report_rel( &example3_dev, REL_Y, 5 );
  else if ( state < 90 ) 
    input_report_rel( &example3_dev, REL_X, -5 );
  else
    input_report_rel( &example3_dev, REL_Y, -5 );

  /* input_sync( &example3_dev ); */

  if ( (++(state)) >= 120)
    state = 0;
  example3_dev.private = (void *)state;

  mod_timer( &example3_dev.timer, jiffies + HZ );
}

static int __init example3_init( void )
{
  /* extra safe initialization */
  memset( &example3_dev, 0, sizeof(struct input_dev) );
#if 0
  init_input_dev( &example3_dev );
#endif

  example3_dev.private = (void *)0;

  /* set up descriptive labels */
  example3_dev.name = "Example 3 device";
#if 0
  example3_dev.phys = "A/Fake/Path";
  example3_dev.id.bustype = BUS_HOST;
  example3_dev.id.vendor  = 0x0001;
  example3_dev.id.product = 0x0003;  // our third product
  example3_dev.id.version = 0x0101;  // version 1.1
#else
  example3_dev.idbus     = BUS_ISA;
  example3_dev.idvendor  = 0x0001;
  example3_dev.idproduct = 0x0003;  // our third product
  example3_dev.idversion = 0x0101;  // version 1.1
#endif
  
  set_bit( EV_REL, example3_dev.evbit );
  set_bit( REL_X,  example3_dev.relbit );
  set_bit( REL_Y,  example3_dev.relbit );

  set_bit( EV_KEY, example3_dev.evbit );
  set_bit( BTN_LEFT, example3_dev.keybit ); /* mouse button is a key */

  input_register_device( &example3_dev );

  init_timer( &example3_dev.timer );
  example3_dev.timer.function = example3_timeout;
  example3_dev.timer.expires  = jiffies + HZ;
  add_timer( &example3_dev.timer );

  return 0;
}

static void __exit example3_exit( void )
{
  del_timer_sync( &example3_dev.timer );
  input_unregister_device( &example3_dev );
}

module_init( example3_init );
module_exit( example3_exit );