Using ioctl from with the kernel ???

Hi there,

I use a device driver (/dev/status_led from DENX) to manipulate some frontpanel
LEDs from user space via some ioctls.

Now I'd like to access them from the kernel space. How can I do that? AFAIK I
can't use fopen and ioctl...

Thanks,

Steven

** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/

Hello Steven,

Your right IOCTL is not applicable for this. You can simply call the driver
functions directly. If these functions are called different from different
context(s) (like your driver and the IOCTL function) you have to add some
protection mechanism. (The code is not reentrant right?) You may try
spin_lock() for this job (linux/spinlock.h). If you are calling the
functions from interrupt contect too some extra protection is required...

Regards, Stephan

-----Original Message-----
From: owner-linuxppc-embedded@lists.linuxppc.org
[mailto:owner-linuxppc-embedded@lists.linuxppc.org]On Behalf Of Steven
Scholz
Sent: Dienstag, 12. November 2002 15:48
To: LinuxPPC
Subject: Using ioctl from with the kernel ???



Hi there,

I use a device driver (/dev/status_led from DENX) to manipulate
some frontpanel
LEDs from user space via some ioctls.

Now I'd like to access them from the kernel space. How can I do
that? AFAIK I
can't use fopen and ioctl...

Thanks,

Steven

** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/

Hi Stephan,

Your right IOCTL is not applicable for this. You can simply call the driver
functions directly. If these functions are called different from different
context(s) (like your driver and the IOCTL function) you have to add some
protection mechanism. (The code is not reentrant right?) You may try
spin_lock() for this job (linux/spinlock.h). If you are calling the
functions from interrupt contect too some extra protection is required...

Thanks for your reply.

But how could I call the ioctl handler of the driver?
I would need some (dummy) inode...

Steven

** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/

Hi,
  the driver is linked to the kernel, so global (not static) functions
declared in a driver can be called from the kernel and in particular from
another driver, so you can bound the code of your ioctl in a function and
call it from the ioctl handler and from the other driver ... using the
protection mechanism suggested by Stephan.

Bye.

Stefano.

-----Messaggio originale-----
Da: owner-linuxppc-embedded@lists.linuxppc.org
[mailto:owner-linuxppc-embedded@lists.linuxppc.org]Per conto di Steven
Scholz
Inviato: martedi 12 novembre 2002 16.11
A: Stephan Linke
Cc: Linuxppc-Embedded
Oggetto: Re: Using ioctl from with the kernel ???



Hi Stephan,

quoted

Your right IOCTL is not applicable for this. You can simply

call the driver

quoted

functions directly. If these functions are called different

from different

quoted

context(s) (like your driver and the IOCTL function) you have

to add some

quoted

protection mechanism. (The code is not reentrant right?) You may try
spin_lock() for this job (linux/spinlock.h). If you are calling the
functions from interrupt contect too some extra protection is

required...

Thanks for your reply.

But how could I call the ioctl handler of the driver?
I would need some (dummy) inode...

Steven

** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/

Hi Steve,

If you realy like to do so you can call the LEDDRIVER_ioctl() function
directly with some dummy parameter (the one of you LED driver, not the one
from user space wich is to be called using an file descriptor). But I would
prefer to move the functionality into some extra function and call these
function from LEDDRIVER_ioctl() and from OTHERDRIVER_change_led() (like
Stefano suggested).


Regards, Stephveano :)

Hi,
  the driver is linked to the kernel, so global (not static) functions
declared in a driver can be called from the kernel and in particular from
another driver, so you can bound the code of your ioctl in a function and
call it from the ioctl handler and from the other driver ... using the
protection mechanism suggested by Stephan.

Bye.

Stefano.

quoted

-----Messaggio originale-----
Da: owner-linuxppc-embedded@lists.linuxppc.org
[mailto:owner-linuxppc-embedded@lists.linuxppc.org]Per conto di Steven
Scholz
Inviato: martedi 12 novembre 2002 16.11
A: Stephan Linke
Cc: Linuxppc-Embedded
Oggetto: Re: Using ioctl from with the kernel ???



Hi Stephan,

quoted

Your right IOCTL is not applicable for this. You can simply

call the driver

quoted

functions directly. If these functions are called different

from different

quoted

context(s) (like your driver and the IOCTL function) you have

to add some

quoted

protection mechanism. (The code is not reentrant right?) You may try
spin_lock() for this job (linux/spinlock.h). If you are calling the
functions from interrupt contect too some extra protection is

required...

Thanks for your reply.

But how could I call the ioctl handler of the driver?
I would need some (dummy) inode...

Steven

** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/

Stephan Linke wrote:

Hi Steve,

If you realy like to do so you can call the LEDDRIVER_ioctl() function
directly with some dummy parameter (the one of you LED driver, not the one
from user space wich is to be called using an file descriptor). But I would
prefer to move the functionality into some extra function and call these
function from LEDDRIVER_ioctl() and from OTHERDRIVER_change_led() (like
Stefano suggested).

Many thanks to you both.

I'll try that!

Good luck,

Steven

** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/