Hi,
I'm trying to replace the standard keyboard driver with my own
module ( which i have copied from kernel_module_programming guide
by Peter Jay Salzman,Ori Pomerantz )
after insmod i see this:
In /var/log/messages
---------------------
Feb 23 11:00:27 localhost kernel: request_irq successful!
in /proc/interrupts
-------------------
[root@localhost study]# cat /proc/interrupts
CPU0
0: 922981 XT-PIC timer
1: 7 XT-PIC test_keyboard_irq_handler
2: 0 XT-PIC cascade
5: 58852 XT-PIC usb-uhci, eth0
in /proc/modules/
------------------
intrpt 1841 0 (unused)
soundcore 6532 0 (autoclean)
bcm5700 103780 1
i.e. module gets loaded properly, but on pressing any key, i don't
see any message from got_char function. Don't know whether the handler
is being called or not! i had put a prink in the handler function
( not sure its allowed or not!/) to see if control reaches there.
But i don't see this in the /var/log/messages file.
Kernel version is 2.4.18-14.
am i missing something here?
Pls Help!
Dhanashri
=================================================================
Here's the code:
/* intrpt.c - An interrupt handler. */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/tqueue.h>
#include <asm/io.h>
#include <linux/interrupt.h>
#ifndef KERNEL_VERSION
#define KERNEL_VERSION(a,b,c) ((a)*65536+(b)*256+(c))
#endif
/* Bottom Half */
static void got_char(void *scancode)
{
printk("Scan Code %x %s.\n",
(int) *((char *) scancode) & 0x7F,
*((char *) scancode) & 0x80 ? "Released" : "Pressed");
}
/* The keyboard interrupt handler function */
void irq_handler(int irq, void *dev_id, struct pt_regs *regs)
{
/* This variables are static because they need to be
* * accessible (through pointers) to the bottom half routine.
* */
static unsigned char scancode;
static struct tq_struct task =
{
routine:got_char,
data:&scancode
};
unsigned char status;
/* Read keyboard status */
status = inb(0x64);
scancode = inb(0x60);
printk( "<1> in the irq_handler function\n");
/* Scheduale bottom half to run */
#if LINUX_VERSION_CODE > KERNEL_VERSION(2,2,0)
queue_task(&task, &tq_immediate);
#else
queue_task_irq(&task, &tq_immediate);
#endif
mark_bh(IMMEDIATE_BH);
}
/* Initialize the module . register the IRQ handler */
int init_module()
{
int result = 0;
/* Since the keyboard handler won't co.exist with another handler,
* * such as us, we have to disable it (free its IRQ) before we do
* * anything. Since we don't know where it is, there's no way to
* * reinstate it later . so the computer will have to be rebooted
* * when we're done.
* */
free_irq(1, NULL);
/* Request IRQ 1, the keyboard IRQ, to go to our irq_handler. */
/* return value 0 => success */
result = request_irq(1,irq_handler,0,"test_keyboard_irq_handler",NULL);
if ( result != 0 )
{
printk ( "<1>request_irq failed, with result=%d\n",result );
return -1;
}
else
{
printk ( "<1>request_irq successful!\n" );
return 0;
}
}
/* Cleanup */
void cleanup_module()
{
free_irq(1, NULL);
}
===============================================================
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