[U-Boot] [PATCH V3+] I2C: mxc_i2c rework

[Marek Vasut]

On Thursday, September 15, 2011 03:43:42 AM Jason Hui wrote:
> On Thu, Sep 15, 2011 at 3:39 AM, Marek Vasut <marek.vasut at gmail.com> wrote:
> > On Friday, July 29, 2011 08:55:14 AM Jason Hui wrote:
> >> Hi, Marek,
> >> 
> >> On Thu, Jul 14, 2011 at 5:58 AM, Marek Vasut <marek.vasut at gmail.com> wrote:
> >> > Rewrite the mxc_i2c driver.
> >> >  * This version is much closer to Linux implementation.
> >> >  * Fixes IPG_PERCLK being incorrectly used as clock source
> >> >  * Fixes behaviour of the driver on iMX51
> >> >  * Clean up coding style a bit ;-)
> >> 
> >> why you change i2c clock from IPG_PERCLK to IPG_CLK?
> >> 
> >> [...]
> > 
> > Ok, I investigated a bit deeper and I suspect the clock.c is the culprit.
> > 
> > Apparently, the PERCLK doesn't run at the frequency the clock.c reports
> > it runs on. Therefore, the i2c miscalculates the divider etc -- falling
> > crap model (waterfall model).
> 
> But apparently, the i2c function clock should be IPG_PERCLK not IPG
> clock. And Linux also fix it already.

Then there's bulls**t in your mx51 and mx53 datasheet or what ? besides, PERCLK 
is faster than IPGCLK on MX51 so it makes even less sense! Can you please talk 
to the HW guys or whatever to clear this once and for all ? I smell noone really 
knows where the clock are sourced from and all this crap is just blind guessing.