keyboard driver question

[Peter Teoh]

If your keyboard is not USB based, then perhaps article like this is
possibly your answer:

http://www.computer-engineering.org/ps2keyboard/
http://eduunix.ccut.edu.cn/index2/html/linux/Sybex%20Linux%20Power%20Tools%202003/6222final/LiB0023.html
http://freeworld.thc.org/papers/writing-linux-kernel-keylogger.txt

Since your KB is usb-based, u can look here for internal info:

http://www.emntech.com/docs/USB_KeyBoard_Driver_eMNTech.pdf

Inside there is a picture on the overall flow.

Essentially is the usb_kbd_probe() function.   Your problem of
linking/delinking the KB may also be answered by:

http://unix.stackexchange.com/questions/12005/how-to-use-linux-kernel-driver-bind-unbind-interface-for-usb-hid-devices

Another good ref is:

http://www.linux.it/~rubini/docs/usb/usb.html

as it simplified the complex flow of USB processing in the kernel for HID
part in particular.

A good analogy to your problem is the apple keyboard:

http://www.cyberciti.biz/faq/linux-apple-usb-keyboard-driver-installation/

and looking into implementation drivers/hid/hid-apple.c (kernel source)
perhaps can give u some insight.

Another thing is the non-kernel processing of scancode:


http://eduunix.ccut.edu.cn/index2/html/linux/Sybex%20Linux%20Power%20Tools%202003/6222final/LiB0023.html

As describe within, X windows keymap may also be used to change the mapping.

http://www.in-ulm.de/~mascheck/X11/xmodmap.html

http://bochs.sourceforge.net/doc/docbook/user/keymap.html

http://madduck.net/docs/extending-xkb/

http://www.pixelbeat.org/docs/xkeyboard/



On Fri, Jan 4, 2013 at 2:17 AM, Racz Zoli <racz.zoli at gmail.com> wrote:

> Hi.
>
> I`m sorry if this isn`t the right place to post my question, but first I
> tried posting it on forum.kernelnewbies.org and nobody answered. Here`s
> my question:
>
>
> I have a Gembird kb-9140l keyboard with some multimedia keys which are not
> working on linux. I thought about writing my own driver for it, so as a
> start, I wrote a small module, which registers an interrupt handler on irq
> 1 with the IRQF_SHARED flag. In the handler function I put a simple printk
> with the scancode read from the keyboard. The problem is, that the handler
> never gets executed. I searched on google, and found that because the
> native driver doesn`t share its interrupt with another modules, before I
> call request_irq I have to free the original interrupt handler from the
> native driver. This would make my computer practically unusable until I
> reboot, but at least I would see, it works, but it doesn`t. The original
> driver works fine after I insert my module, and the interrupt handler still
> doesn`t get called. The weird thing is, when I remove my module, my handler
> executes ones, and the scancode is 0xFE.
>
> The code is the following:
>
> #include <linux/module.h>
> #include <linux/kernel.h>
> #include <linux/init.h>
> #include <linux/interrupt.h>
> #include <asm/io.h>
>
>
> MODULE_LICENSE("Dual BSD/GPL");
>
> static int gembirdkb_init(void);
> static void gembirdkb_exit(void);
>
>
> irq_handler_t irq_handler (int irq, void *dev_id, struct pt_regs *regs)
> {
> static unsigned char scancode;
>
> scancode = inb (0x60);
>
> printk("gembirdkb: irq handled... scancode: %d\n",scancode);
>
> return (irq_handler_t) IRQ_HANDLED;
> }
>
>
> static int gembirdkb_init(void)
> {
> int ret;
>
> /* free original interrupt handler */
> // free_irq(1, NULL);
>
> ret = request_irq (1, (irq_handler_t) irq_handler, IRQF_SHARED,
> "gembirdkb", (void *)&irq_handler);
>
> printk("gembirdkb: request_irq result: %d\n", ret);
>
> return ret;
> }
>
> static void gembirdkb_exit(void)
> {
> free_irq(1, (void *)&irq_handler);
> }
>
>
> module_init(gembirdkb_init);
> module_exit(gembirdkb_exit);
>
> Is there any way I can remove the native driver, or I need to recompile
> the kernel without it, and insert mine?
>
> P.s.: Why every topic on the forum is full with questions about mac,
> iphone, samsung galaxy etc.?
>
> _______________________________________________
> Kernelnewbies mailing list
> Kernelnewbies at kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
>
>


-- 
Regards,
Peter Teoh
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