[PATCH] powerpc: i2c-mpc: make speed registers configurable via FDT
Grant Likely
grant.likely at secretlab.ca
Fri Aug 1 06:48:38 EST 2008
On Thu, Jul 31, 2008 at 03:37:07PM -0500, Timur Tabi wrote:
> Grant Likely wrote:
>
> > How is the divider controlled? Is it a fixed property of the SoC?
>
> Yes. The divider is either 1, 2, or 3, and the only way to know which one
> it is is to look up the specific SOC model number. And depending on the
> SOC model, there may also be a register that needs to be looked up.
>
> > a
> > shared register setting? or a register setting within the i2c device?
>
> The I2C device itself has no idea what the divider is. It only sees the
> result of the divider.
Then that absolutely suggests to me that either the final clock or the
divider should be encoded in the i2c node; not in the soc node.
g.
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