Subject: Re: [PATCH 08/12] mpc5121: Added I2C support.

From: Wolfgang Grandegger <[email-masked]>
Date: Mon, 18 May 2009 16:29:04 +0200

Piotr Zięcik wrote:
>> Right. Furthermore, the i2c-mpc.c should be extened to support bus speed
>> setting for the MPC512x, which has been merged recently (see commit id
>> f2bd5efe).
> 
> I have simple question about bus speed setting support. Existing 
> implementation uses default safe speed if there is no 'clock-frequency' 
> property in i2c node. Comments in code suggest that this behaviour is left 
> for backward compatibility only. Should I make the 'clock-frequency'
> property mandatory for a new type of I2C controller (MPC5121) ?

I don't think so, for the same backward compatibility reason as for the
other boards. But the DTS file might be changed to use clock-frequency.
BTW, when I wrote the code I already had the MPC512x in mind. IIRC, the
FDR table and the function scanning it for the MPC52xx should work for
the MPC512x as well. It's mainly a matter of using the proper function
to get the source clock frequency and fiddling with multiple-arch support.

Wolfgang.