Comments on device tree for pcm030

[Jon Smirl]

On 6/9/08, Juergen Beisert <jbe at pengutronix.de> wrote:
> On Monday 09 June 2008 01:28, Grant Likely wrote:
>  > On Sun, Jun 8, 2008 at 1:08 PM, Jon Smirl <jonsmirl at gmail.com> wrote:
>  > > Why not a compatible field in the top of the tree? Then you wouldn't
>  > > need to list the boards in mpc5200_simple.c.
>  > >        compatible = "phytec,pcm030","simple-mpc5200";
>  >
>  > Here's the problem; what does compatible really mean at the board
>  > level?  Does it mean the board has 100% of the same capabilities?
>  > Does it mean that it uses the same chip?  Does it mean that the chip
>  > is configured in a particular way?  It is really hard to define what a
>  > compatible value means at the board level.  The meaning of compatible
>  > at the device level is very well defined, but that meaning does not
>  > extend well to the board level.
>  >
>  > Therefore, it is best to be conservative here and require a specific
>  > list of supported boards in platform code.
>  >
>  > Besides, it is really a Linux specific thing that is trying to be
>  > described.  In Linux, we've decided to support as many 5200 boards as
>  > possible using the same platform code, but that may not be true, or it
>  > may be a different set of boards, when a different OS is used.  To
>  > attempt to encode those decisions is overreaching the intent of using
>  > the device tree.
>  >
>  > > Device tree has an entry for AC97 on PSC1. I don't think the Phytec
>  > > module or carrier board has AC97 hardware.
>  >
>  > Might be a bug
>
>
> NACK. The baseboard for the pcm030 CPU board has AC97 hardware connected to
>  PSC1. And it plays audio...
>
>
>  > > The RTC chip says pcf8563, phytec doc says it is a pcf8564.
>  >
>  > Sounds like a bug
>
>
> These devices are mostly the same. You can use the pcf8563 driver for the
>  pcf8564.

Let's put the right chip number in the tree. While these have the same
drivers on Linux they may not on other OSes.

>
>
>  > > There should be an i2c entry for the eeprom but I don't know the part
>  > > number for it.
>  >
>  > Yes, i2c devices should be described.
>
>
> Its a 24C32.
>
>  I believe Wolfram has a newer OFtree for the pcm030 so I add him as CC.
>
>  Regards,
>  Juergen
>
>
>  --
>  Dipl.-Ing. Juergen Beisert | http://www.pengutronix.de
>   Pengutronix - Linux Solutions for Science and Industry
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-- 
Jon Smirl
jonsmirl at gmail.com