[i2c] [RFC] Rework of i2c-mpc.c - Freescale i2c driver

Jon Smirl jonsmirl at gmail.com
Tue Nov 6 18:45:24 CET 2007


On 11/6/07, Jean Delvare <khali at linux-fr.org> wrote:
> Hi Scott, Jon,
>
> On Mon, 05 Nov 2007 14:51:51 -0600, Scott Wood wrote:
> > Jon Smirl wrote:
> > > How about renaming the old driver file and leaving it hooked to ppc?
> > > Then it would get deleted when ppc goes away. That would let work
> > > progress on the powerpc version.
> >
> > Or we could have one driver that has two probe methods.  I don't like
> > forking the driver.
>
> I agree with Scott here, I don't want to fork the drivers. It is
> possible (and easy) to support both methods in the same module, let's
> just to that. See for example David Brownell's work on the lm75 driver:
> http://lists.lm-sensors.org/pipermail/lm-sensors/2007-September/021270.html

I agree that it is easy to make make a chip driver support both new
and old style.

But when I call i2c_new_device() on an old style chip driver it exits
saying that it doesn't work for the old style adapters. Checks for
is_newstyle_driver() are in the i2c_new_device code. That's what
caused me to rewrite the rtc-pcf8563 driver for the new style. This
probably related to probing, I have to pass the address in struct
i2c_board_info. The old style drivers don't support having their
address passed in.

This may be complicated by the fact that the rtc drivers I'm working
on are not probable. That's why I want to add device tree support for
them.

If this is going to work on an old style driver, how do I get the address to it?

-- 
Jon Smirl
jonsmirl at gmail.com



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