Subject: Re: [PATCH] powerpc: i2c-mpc: make speed registers configurable via FDT

From: Timur Tabi <[email-masked]>
Date: Thu, 31 Jul 2008 14:24:41 -0500

Wolfgang Grandegger wrote:

> No, the source clock is not identical for all 8[356]xx. Some use half or 
> even a third of the SOC clock frequency. 

The platform clock divided by 2 or 3 *is* the source clock to the I2C.  That's
what I'm talking about.

> Linux must determine the real
> source clock frequency somehow. We may introduce the SOC property 
> "i2c-clock-frequency", which could be fixed up by U-Boot or a pre-loader 
> (in case U-Boot is not used). Like for other frequency properties as well.

That's what I'm proposing, but drop the "i2c-".

-- 
Timur Tabi
Linux kernel developer at Freescale