irq_test

#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/version.h>
#include <linux/kallsyms.h>

#include <linux/interrupt.h>

MODULE_LICENSE( "GPL" );

static irqreturn_t
dummy_irq_handler( int irq, void *dev_id )
{
   return IRQ_HANDLED;
}

static int
check_name( void *data, const char *namebuf, struct module *stub, unsigned long addr )
{
   if ( !strcmp( ( char *) data, namebuf ) ) {
      return addr;
   }
   return 0;
}

#if LINUX_VERSION_CODE < KERNEL_VERSION( 2, 6, 36 )
static void noop( uint irq )
{
}

static uint noop_ret( uint irq )
{
   return 0;
}

struct irq_chip tst_irq_chip = {
   .name         = "tst_dummy",
   .startup      = noop_ret,
   .shutdown      = noop,
   .enable         = noop,
   .disable      = noop,

   .ack         = noop,
   .mask         = noop,
   .mask_ack      = noop,
   .unmask         = noop,
   .eoi         = noop,

   .end         = noop,
   //.set_affinity   = noop,
   //.retrigger      = noop,
   //.set_type       = noop,
   //.set_wake       = noop,
};
#else
static void noop( struct irq_data *data )
{
}

static uint noop_ret( struct irq_data *data )
{
   return 0;
}

struct irq_chip tst_irq_chip = {
   .name         = "tst_dummy",
   .irq_startup      = noop_ret,
   .irq_shutdown      = noop,
   .irq_enable         = noop,
   .irq_disable      = noop,

   .irq_ack         = noop,
   .irq_mask         = noop,
   .irq_unmask         = noop,

   //.irq_end         = noop,
   //.set_affinity   = noop,
   //.retrigger      = noop,
   //.set_type       = noop,
   //.set_wake       = noop,
};

#define set_irq_chip irq_set_chip

#endif


static int __init
mod_init( void )
{
   int irq;
   int r = 0;
   int (*test_can_request_irq)( unsigned int irq, unsigned long irqflags );

   test_can_request_irq = ( void * ) kallsyms_on_each_symbol( check_name, "can_request_irq" );
   if ( !test_can_request_irq ) {
      pr_err( "Can't get access to function can_request_irq.\n" );
      for_each_irq_nr( irq ) {
         r = request_irq( irq, dummy_irq_handler, 0, NULL, NULL );
         if ( -ENOSYS == r ) {
            set_irq_chip( irq, &tst_irq_chip );
            r = request_irq( irq, dummy_irq_handler, 0, 0, 0 );
         }
         if ( r ) {
            const char *reason = NULL;

            switch ( r ) {
               case -EBUSY:
                  reason = "EBUSY";
                  break;
               case -ENOSYS:
                  reason = "ENOSYS";
                  break;
               case -EINVAL:
                  reason = "EINVAL";
                  break;
               default:
                  reason = "UNKNOWN";
                  break;
            }
            pr_info( "IRQ_TEST: IRQ:%d FAIL CODE:%d REASON:%s\n", irq, r, reason );
         } else {
            pr_info( "IRQ_TEST: IRQ:%d SUCCESS\n", irq );
            set_irq_chip( irq, NULL );
            free_irq( irq, NULL );
         }
      }
   } else {
      for_each_irq_nr( irq ) {
         r = test_can_request_irq( irq, 0 );
         if ( r ) {
            pr_info( "IRQ_TEST: IRQ:%d SUCCESS\n", irq );
         } else {
            pr_info( "IRQ_TEST: IRQ:%d FAIL\n", irq );
         }
      }
   }

   return 0;
}

static void __exit
mod_exit( void )
{
}

module_init( mod_init );
module_exit( mod_exit );