Compile program using XGpio

Hi all,

I'm working with a Virtex2p. I have a running system using:

   - EDK 9.1
   - Crosstool-ng (svn)
   - linux-2.6-xlnx
   - BusyBox 1.12.1

Now, i'm trying to build a small program that turn off leds. I guess it
should be something like this:

void main (void){
    XGpio led;
    XGpio_Initialize (&led, XPAR_LEDS_4BIT_DEVICE_ID);
    XGpio_SetDataDirection(&led,1,0);
    XGpio_DiscreteWrite(&led,1,0xf);
}


I want to know how to compile it (without EDK). Any suggestion?


Thanks,
Bruno Monteiro

Hi Bruno,

 

I don't think you can do what you're trying to do, unless I'm
misunderstanding or just not smart enough.

 

The EDK from Xilinx ships with drivers that are not Linux drivers.
Those functions in main below are intended for a standalone (no RTOS)
system such they can't just be called from a user app in Linux.  You are
sort of trying to create a user mode driver with what you are doing.

 

There is a character mode gpio driver in the Xilinx git tree,
git://git.xilinx.com/linux-2.6-xlnx.git that has been used previously.
I don't currently test that driver as we're in the process of getting a
flattened gpio driver that is not char driver ready for mainline.

 

I plan to take a look at the char mode gpio driver today as there's
another question regarding it on the list.

 

Thanks,

John

 

 

________________________________

From: linuxppc-embedded-bounces+john.linn=xilinx.com@ozlabs.org
[mailto:linuxppc-embedded-bounces+john.linn=xilinx.com@ozlabs.org] On
Behalf Of Bruno Monteiro
Sent: Tuesday, October 21, 2008 8:36 AM
To: linuxppc-embedded@ozlabs.org
Subject: Compile program using XGpio

 

Hi all,

I'm working with a Virtex2p. I have a running system using:

*	EDK 9.1
*	Crosstool-ng (svn)
*	linux-2.6-xlnx
*	BusyBox 1.12.1

Now, i'm trying to build a small program that turn off leds. I guess it
should be something like this:

void main (void){
    XGpio led;    
    XGpio_Initialize (&led, XPAR_LEDS_4BIT_DEVICE_ID);
    XGpio_SetDataDirection(&led,1,0);
    XGpio_DiscreteWrite(&led,1,0xf);    
}


I want to know how to compile it (without EDK). Any suggestion? 


Thanks,
Bruno Monteiro 



This email and any attachments are intended for the sole use of the named recipient(s) and contain(s) confidential information that may be proprietary, privileged or copyrighted under applicable law. If you are not the intended recipient, do not read, copy, or forward this email message or any attachments. Delete this email message and any attachments immediately.

Hi,

I'm a new driver writer and i'm trying to understand how to deal with XGpio.
My goal is writing a small piece of code that can turn leds on and off. I
think this driver should do it:


#include <linux/init.h>
#include <linux/module.h>

#include "xgpio.h"
#include "xgpio_ioctl.h"
#include "xparameters.h"

XGpio led;

static int myteste_init(void)
{
    XGpio_Initialize (&led, LEDs_4Bit);
    XGpio_SetDataDirection(&led,1,0);
    XGpio_DiscreteWrite(&led,1,0xf);
    printk (KERN_ALERT "LEDS: Turn off\n");

    return 0;
}

static int myteste_exit(void)
{

    XGpio_DiscreteWrite(&led,1,0x0);
    printk (KERN_ALERT "LEDS: Turn on\n");
    return 0;
}

module_init(myteste_init);
module_exit(myteste_exit);

But i have this error:
ERROR: "XGpio_SetDataDirection" [drivers/char/mytest/mytest.ko] undefined!
ERROR: "XGpio_Initialize" [drivers/char/mytest/mytest.ko] undefined!
ERROR: "XGpio_DiscreteWrite" [drivers/char/mytest/mytest.ko] undefined!

Any suggestion? This is the makefile:
  EXTRA_CFLAGS    += -I$(TOPDIR)/drivers/xilinx_common
  EXTRA_CFLAGS    += -I$(TOPDIR)/drivers/char/xilinx_gpio
  obj-$(CONFIG_MY_TEST)     := mytest.o


Is there any way to use *.dts instead xparameters.h

Thanks,
Bruno




On Tue, Oct 21, 2008 at 9:08 PM, John Linn [off-list ref] wrote:

 Hi Bruno,



I don't think you can do what you're trying to do, unless I'm
misunderstanding or just not smart enough.



The EDK from Xilinx ships with drivers that are not Linux drivers.  Those
functions in main below are intended for a standalone (no RTOS) system such
they can't just be called from a user app in Linux.  You are sort of trying
to create a user mode driver with what you are doing.



There is a character mode gpio driver in the Xilinx git tree, git://
git.xilinx.com/linux-2.6-xlnx.git that has been used previously.  I don't
currently test that driver as we're in the process of getting a flattened
gpio driver that is not char driver ready for mainline.



I plan to take a look at the char mode gpio driver today as there's another
question regarding it on the list.



Thanks,

John




  ------------------------------

*From:* linuxppc-embedded-bounces+john.linn=xilinx.com@ozlabs.org [mailto:
linuxppc-embedded-bounces+john.linn<linuxppc-embedded-bounces%2Bjohn.linn>
=xilinx.com@ozlabs.org] *On Behalf Of *Bruno Monteiro
*Sent:* Tuesday, October 21, 2008 8:36 AM
*To:* linuxppc-embedded@ozlabs.org
*Subject:* Compile program using XGpio



Hi all,


I'm working with a Virtex2p. I have a running system using:

   - EDK 9.1
   - Crosstool-ng (svn)
   - linux-2.6-xlnx
   - BusyBox 1.12.1

Now, i'm trying to build a small program that turn off leds. I guess it
should be something like this:

void main (void){
    XGpio led;
    XGpio_Initialize (&led, XPAR_LEDS_4BIT_DEVICE_ID);
    XGpio_SetDataDirection(&led,1,0);
    XGpio_DiscreteWrite(&led,1,0xf);
}


I want to know how to compile it (without EDK). Any suggestion?


Thanks,
Bruno Monteiro

This email and any attachments are intended for the sole use of the named
recipient(s) and contain(s) confidential information that may be
proprietary, privileged or copyrighted under applicable law. If you are not
the intended recipient, do not read, copy, or forward this email message or
any attachments. Delete this email message and any attachments immediately.

On Thu, Oct 23, 2008 at 10:58 AM, Bruno Monteiro [off-list ref] wrote:

Hi,

I'm a new driver writer and i'm trying to understand how to deal with XGpio.
My goal is writing a small piece of code that can turn leds on and off. I
think this driver should do it:


#include <linux/init.h>
#include <linux/module.h>

#include "xgpio.h"
#include "xgpio_ioctl.h"
#include "xparameters.h"

XGpio led;

static int myteste_init(void)
{
    XGpio_Initialize (&led, LEDs_4Bit);
    XGpio_SetDataDirection(&led,1,0);
    XGpio_DiscreteWrite(&led,1,0xf);
    printk (KERN_ALERT "LEDS: Turn off\n");

    return 0;
}

static int myteste_exit(void)
{

    XGpio_DiscreteWrite(&led,1,0x0);
    printk (KERN_ALERT "LEDS: Turn on\n");
    return 0;
}

module_init(myteste_init);
module_exit(myteste_exit);

But i have this error:
ERROR: "XGpio_SetDataDirection" [drivers/char/mytest/mytest.ko] undefined!
ERROR: "XGpio_Initialize" [drivers/char/mytest/mytest.ko] undefined!
ERROR: "XGpio_DiscreteWrite" [drivers/char/mytest/mytest.ko] undefined!

None of the XGpio functions are available in Linux.  You need to use
the Linux kernel memory access functions instead (in_be32() and
out_be32()).

You also need to use the ioremap() function to map the physical
address of the GPIO block into a virtual address that the kernel can
use:

ie:
static int myteste_init(void)
{
    u32 __iomem *regs;

    regs = ioremap([address of GPIO block], 0x100);
    if (regs == NULL)
        return -ENOMEM;

    /* configure as output */
    out_be32(regs + 4, 0);
    /* turn on leds */
    out_be32(regs, 0);
    printk (KERN_ALERT "LEDS: Turn on\n");
    return 0;
}

This is just a simple example though.  You should follow the pattern
of other device drivers and bind against the of_platform_bus so your
device can be described in the device tree (.dts) file.

Or, better yet, use the existing driver from the Xilinx linux-2.6 git tree.

g.

-- 
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.

Hi Bruno,

If you're needing a GPIO driver (not wanting to write one) we have one
in the development branch of our GIT tree that's working.  This is
arch/powerpc only, no arch/ppc.

You could use it for turning LEDS on as I just tested it and updated the
wiki to show how to use it from user space.  There is also an LED driver
that is in the kernel that sits on top of a GPIO driver specifically for
LEDs.

http://xilinx.wikidot.com/osl-gpio-driver

Thanks,
John

-----Original Message-----
From: Grant Likely [mailto:grant.likely@secretlab.ca]
Sent: Thursday, October 23, 2008 11:46 AM
To: Bruno Monteiro
Cc: John Linn; linuxppc-embedded@ozlabs.org
Subject: Re: Compile program using XGpio
=

On Thu, Oct 23, 2008 at 10:58 AM, Bruno Monteiro

[off-list ref] wrote:

quoted

Hi,

I'm a new driver writer and i'm trying to understand how to deal

with XGpio.

quoted

My goal is writing a small piece of code that can turn leds on and

off. I

quoted

think this driver should do it:


#include <linux/init.h>
#include <linux/module.h>

#include "xgpio.h"
#include "xgpio_ioctl.h"
#include "xparameters.h"

XGpio led;

static int myteste_init(void)
{
    XGpio_Initialize (&led, LEDs_4Bit);
    XGpio_SetDataDirection(&led,1,0);
    XGpio_DiscreteWrite(&led,1,0xf);
    printk (KERN_ALERT "LEDS: Turn off\n");

    return 0;
}

static int myteste_exit(void)
{

    XGpio_DiscreteWrite(&led,1,0x0);
    printk (KERN_ALERT "LEDS: Turn on\n");
    return 0;
}

module_init(myteste_init);
module_exit(myteste_exit);

But i have this error:
ERROR: "XGpio_SetDataDirection" [drivers/char/mytest/mytest.ko]

undefined!

quoted

ERROR: "XGpio_Initialize" [drivers/char/mytest/mytest.ko] undefined!
ERROR: "XGpio_DiscreteWrite" [drivers/char/mytest/mytest.ko]

undefined!

=

None of the XGpio functions are available in Linux.  You need to use
the Linux kernel memory access functions instead (in_be32() and
out_be32()).
=

You also need to use the ioremap() function to map the physical
address of the GPIO block into a virtual address that the kernel can
use:
=

ie:
static int myteste_init(void)
{
    u32 __iomem *regs;
=

    regs =3D ioremap([address of GPIO block], 0x100);
    if (regs =3D=3D NULL)
        return -ENOMEM;
=

    /* configure as output */
    out_be32(regs + 4, 0);
    /* turn on leds */
    out_be32(regs, 0);
    printk (KERN_ALERT "LEDS: Turn on\n");
    return 0;
}
=

This is just a simple example though.  You should follow the pattern
of other device drivers and bind against the of_platform_bus so your
device can be described in the device tree (.dts) file.
=

Or, better yet, use the existing driver from the Xilinx linux-2.6 git

tree.

=

g.
=

--
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.

This email and any attachments are intended for the sole use of the named r=
ecipient(s) and contain(s) confidential information that may be proprietary=
, privileged or copyrighted under applicable law. If you are not the intend=
ed recipient, do not read, copy, or forward this email message or any attac=
hments. Delete this email message and any attachments immediately.