Ubuntu Wiki

The following are notes on various bits of hardware that I own, have used, or plan to use with Ubuntu.

IrDA

Last tried with Ubuntu 6.06 LTS, 11 Aug 2006.

USB to IrDA - Dongle 1

Labeled: fapus IrDA, Mode: UIR-100, 5Vdc 400mA

usb 1-2: new full speed USB device using ohci_hcd and address 4
SigmaTel STIr4200 IRDA/USB found at address 4, Vendor: 66f, Product: 4200
drivers/net/irda/stir4200.c: IrDA: Registered SigmaTel device irda0
usbcore: registered new driver stir4200

Works well over a wide range of angles and ranges.

USB to IrDA Dongle 2

Labeled: U2IrDAmini - 4MBPS FIR USB IRDA - 5V DC 90mA

usb 1-1: new low speed USB device using ohci_hcd and address 7

Unregistered device, detected by USB system as (lsusb)

Bus 001 Device 007: ID 07d0:4100 Dazzle

Is known to work under windows, but with a limited range (sweet spot, not too far not too close).

Epson VGA Controller

Background

Epson have driver for their VGA controller ships (S1D13706, S1D13717, S1D13A03) available from their website for the 2.6.8 Linux kernel.

This driver was downloadad and the patch applied to the 2.6.18 Linux kernel with some failures. An email was sent to Epson for advice. The question on whether there were any plans to include the driver in the main Linux Kernel the response was:

• With regard to a contact with the core Linux group, no we have not maintained that contact. The issue, in this case, is not one of copyright but rather one of manpower. It takes a certain amount of dedication to see the drivers are added and maintained in the kernel distributions. Unfortunately programming resources are tight and there just isn't the time to allot to oversee this.

Correspondence set to ERD Epson

From: Paul Schulz 
Sent: August 3, 2006 11:48 PM
To: erdvdctech_info@erd.epson.com
Subject: Linux Driver for S1D13706

Greetings,

I am looking at the Linux Driver for the S1D13706 Embedded Memory LCD
Controller and would like to know the following:

  1. What licence has the Linux Driver code been released under?
     The files themselves say 'All rights reserved.'

  2. How would you fix the following?
     I have tried to use the 2.6.8 patch against the 2.6.18-rc2. It
     almost applies cleanly, but the following (attached)
     hunks were rejected.

       drivers/video/Makefile.rej  - 4 Hunks
       drivers/video/fbmem.c.rej - 2 Hunks

  3. Will you be applying to have the drivers included in the main
     Linux kernel at some stage?

Thanks in advance,

Regards,
Paul Schulz <p.schulz@robway.com.au>
Software Engineer

Response

From: ---name withheld ---

Hello Paul,

1) As I was told many years ago, the wording "all rights reserved" is a
required part of the copyright notice in order to make the copyright binding
in all countries.

Our driver distribution is for use with Epson controllers only, which is why
we must ensure the copyright is worded to protect Epson.

The wording is not intended to restrict future licensing. If, at any time,
Epson decided to change their policy regarding software distribution the
source packages would include a description of what those limitations were.


2) My Linux expert is away today so I don't have a suggestion for the patch
fix. I will forward your request to him and get back to you as soon as we
have an answer. In all likelihood this will involve obtaining the 2.6.18
kernel and preparing a new patch.


3) Epson drivers have been included in the kernel distributions in the past.
As we have a wide range of controllers and we support a variety of operating
systems, pursuing kernel distribution for our drivers has never been a top
priority.

Reply

From: Paul Schulz
Sent: August 6, 2006 5:15 PM
To: -- name withheld ---
Subject: RE: Linux Driver for S1D13706

Hi (snip),

> Hello Paul,
> 
> 1) As I was told many years ago, the wording "all rights reserved" is a
> required part of the copyright notice in order to make the copyright
binding
> in all countries.
> 
> Our driver distribution is for use with Epson controllers only, which is
why
> we must ensure the copyright is worded to protect Epson.
> 
> The wording is not intended to restrict future licensing. If, at any time,
> Epson decided to change their policy regarding software distribution the
> source packages would include a description of what those limitations
were.

Do you currently have any contact within the core Linux development
team? (Your Linux expert might know..) The reason I ask, is that if the
software is released to the Linux kernel developers under a GPL license,
you keep your copyrights to the original software, but the code can be
maintained by the kernel developers and be ported whenever internal
changes are make to the kernel itself.

The alternative (which has happened in other cases) is that a separate
GPL driver is written from your chip specifications, which the developer
community can then maintain.

> 2) My Linux expert is away today so I don't have a suggestion for the
patch
> fix. I will forward your request to him and get back to you as soon as we
> have an answer. In all likelihood this will involve obtaining the 2.6.18
> kernel and preparing a new patch.

Thanks.. as mentioned, the patch applied to 2.6.18 reasonably cleanly
other the 'hunks'/'changes' mentioned. This is was caused by changes in
the Linux kernel between 2.6.8 and 2.6.18. I haven't been able to
further identify exactly what those changes were, other than to say that
it was in the the way that Linux internally handled its frame buffer
memory. 

The hardware that I plan to use is still being designed, so I won't have
anything test it on just yet.

> 3) Epson drivers have been included in the kernel distributions in the
past.
> As we have a wide range of controllers and we support a variety of
operating
> systems, pursuing kernel distribution for our drivers has never been a top
> priority.

Thank you for the support that you have given to the Linux community. As
mentioned, the essential thing is to have the chip specifications freely
available (eg. not under an NDA) so we can at least write and maintain
our own drivers.

>       Regards
>       (snip)

Thank you again for your response.

Regards,
Paul Schulz
Software Engineer

Response

Hello Paul,

My Linux guy has recommended the following changes to permit the driver code
to install in your distro.


In the original 2.6.18-rc2 drivers/video/Makefile add this line:

obj-$(CONFIG_FB_EPSON)  += epson/ cfbfillrect.o cfbcopyarea.o cfbimgblt.o


In the original 2.6.18-rc2 drivers/video/fbmem.c and find this structure:

static struct {
        const char *name;
        int (*init)(void);
        int (*setup)(char*);
} fb_drivers[] __initdata = {
. . .

And add the following entry:

#ifdef CONFIG_FB_EPSON
        { "s1d13xxxfb", s1d13xxxfb_init, s1d13xxxfb_setup},
#endif

Add the following lines before the structure:

        extern int s1d13xxxfb_setup(char *);
        extern int s1d13xxxfb_init(void);


With regard to a contact with the core Linux group, no we have not
maintained that contact. The issue, in this case, is not one of copyright
but rather one of manpower. It takes a certain amount of dedication to see
the drivers are added and maintained in the kernel distributions.
Unfortunately programming resources are tight and there just isn't the time
to allot to oversee this.


        Regards
        (snip)