RE: Driver on Linux

RE: Driver on Linux

[Jean-Denis Boyer]

> I thought I could make fd=open("/dev/visu", 0) in init of the
> driver 2 but I
> get ooops.

To open a device from kernel mode, you need to:

  /* Bypass argument validity check in FS calls. See <asm/uaccess.h> */
  mm_segment_t oldfs = get_fs();
  set_fs(KERNEL_DS);
  fd=open("/dev/visu", 0)

  /* Restore argument validity check */
  set_fs(oldfs);


> I also need to make something like ioctl(fd, IO_Special...
> )but the function
> ioctl is unknown in the kernel.

To have the ioctl, you should add to the beginning of your source file:

#include <linux/unistd.h>
/* Declare "ioctl" system call */
static inline _syscall3(int,ioctl,int,fd,int,request,void*,arg1)


Regards,
--------------------------------------------
 Jean-Denis Boyer, Software Designer
 M5T Centre d'Excellence en Télécom Inc.
 4283 Garlock Street
 Sherbrooke (Québec)
 J1L 2C8  CANADA
 (819)829-3972 x241
--------------------------------------------

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Cheap FBDev for LinuxPPC

[James Dougherty]

Hello,

I am working on a project with MPC8245 and have
the need for a VGA device which I can use to map
the frame-buffer ram directly.

A colleague of mine is recommending the SiliconMotion
chipset.. could anyone comment on this?

If so, what cards could I purchase at Frye's or some
store..

Finally, does anyone have any code for this baby?

Many thanks in advance.

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Re: Cheap FBDev for LinuxPPC

[Laurent Mohin]

>>I am working on a project with MPC8245 and have the need for a VGA
>>device which I can use to map the frame-buffer ram directly.
>>
>>A colleague of mine is recommending the SiliconMotion chipset.. could
>>anyone comment on this?

Excellent choice. I'm currently designing a board with a 405GPr and a
Silicon Motion SMI712 (also called LynxEM+).

>>If so, what cards could I purchase at Frye's or some store..

I don't know. I directly designed my board without buying an evaluation
board. I think that Eltec has a board with a Silicon Motion chip.

>>Finally, does anyone have any code for this baby?

Current version of U-Boot includes support for this chip.
I've found a framebuffer driver for Linux in the devel tree of Penguin
PPC.

At the time beeing, I have a problem with this chip which works in little
endian format and I have been unable to put it in big endian. So in 16bpp,
colors aren't displayed correcly.

>>Many thanks in advance.

You welcome

Laurent

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