Re: OF devices and non OF devices

From: "John Rigby" <jcrigby@gmail.com>
To: "Kári Davíðsson" <kari.davidsson@marel.is>
Cc: linuxppc-embedded@ozlabs.org
Subject: Re: OF devices and non OF devices
Date: Tue, 3 Jul 2007 10:31:00 -0600	[thread overview]
Message-ID: <4b73d43f0707030931v42aefc72x2598546e48ae87e8@mail.gmail.com> (raw)
In-Reply-To: <DD39B5C3F4963040ADC9768BE7E430CB020D3B9D@is-hdq-exchange.marel.net>

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One place to find binding between OF devices and non OF devices is in
arch/powerpc/sysdev/fsl_soc.c
The typical pattern is:
    if of_find_compatible_node "of-device-name"
        platform_device_register_simple ""platform-device-name"
        platform_device_add_data ...

On 7/3/07, Kári Davíðsson <kari.davidsson@marel.is> wrote:
>
> Hi,
>
> I am attempting to get some non OF devices working for an mpc 5200 board,
> in particular
> PCF8563 RTC.
>
> This device has an non OF device interface which I believe is correct.
> After all it should work
> on non OF platforms.
>
> I have managed to get the board to run the i2c initialization (and probe)
> for the fsl-mpc i2c driver by
> converting the fsl-mpc i2c driver to OF driver (I found some patch here
> that I based this work on).

fsl-i2c is one of the devices handled by fsl_soc.c so you shouldn't need to
change anything to
make it work in the latest kernel.  CONFIG_FSL_SOC was only added to
lite5200_defconfig recently so
that may explain why it's not on in your kernel.

Since the PCF8563 driver is not OF driver only its initaliziation code is
> run but the .probe function
> of the driver is never run. Basically (as far as I can understand) the
> .probe is never run because the
> driver is not an OF driver.
>
> I could convert the PCF8563 driver to OF driver and make it work for our
> puposes but I feel this is
> 1) Wrong
> 2) therefore wasted work.

Since the driver must run on non OF platforms then it should not be
converted.  You just need to add a platform_device_register somewhere.
I don't think fsl_soc.c is  the right place since it is not part of an
freescale SOC.
You could probably put it in a board specific startup routine.

What seems to elude me is some glue that glues together the OF part of the
> driver space to the non OF part
> of the driver space.
>
> Any hints or pointers on where to find this glue?
>
> Regards,
> kd
>
> P.S. Kernel is post 2.6.20.
>
> --
> Kári Davíðsson                   | kari.davidsson@marel.is
> Hugbúnaðargerð                   | www.marel.com
> Tel: 563-8156 Fax: +354 563 8001
> Iceland
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