Re: [PATCH 2/2] i2c: designware: Add support for AMD I2C controller

[Christian Ruppert <christian.ruppert-ux6zf3SgZrrQT0dZR+AlfA@public.gmane.org>]

Dear Mika,

On Mon, Sep 22, 2014 at 12:12:07PM +0300, Mika Westerberg wrote:
> On Sat, Sep 20, 2014 at 11:36:34AM +0200, Wolfram Sang wrote:
> > On Thu, Sep 18, 2014 at 12:26:07PM +0300, Mika Westerberg wrote:
> > > From: Carl Peng <carlpeng008-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> > > 
> > > Add support for AMD version of the DW I2C host controller. The device is
> > > enumerated from ACPI namespace with ACPI ID AMD0010. Because the core
> > > driver needs an input source clock, and this is not an Intel LPSS device
> > > where clocks are provided through drivers/acpi/acpi_lpss.c, we register the
> > > clock ourselves if the clock rate is given in ->driver_data.
> > > 
> > > Signed-off-by: Carl Peng <carlpeng008-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> > > Signed-off-by: Mika Westerberg <mika.westerberg-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
> > > ---
> > 
> > Applied to for-next, still wondering...
> 
> Thanks!
> 
> > 
> > >  drivers/i2c/busses/Kconfig                  |  1 +
> > >  drivers/i2c/busses/i2c-designware-platdrv.c | 27 +++++++++++++++++++++++++++
> > >  2 files changed, 28 insertions(+)
> > > 
> > > diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
> > > index 2ac87fa3058d..9384498ef3c1 100644
> > > --- a/drivers/i2c/busses/Kconfig
> > > +++ b/drivers/i2c/busses/Kconfig
> > > @@ -422,6 +422,7 @@ config I2C_DESIGNWARE_CORE
> > >  
> > >  config I2C_DESIGNWARE_PLATFORM
> > >  	tristate "Synopsys DesignWare Platform"
> > > +	depends on COMMON_CLK
> > 
> > ... do all previous users have COMMON_CLK?
> 
> The driver is being used on x86, ARM and ARC it seems. For x86 and ARM
> we pretty much have COMMON_CLK nowadays but I'm not sure about ARC.
> That's why I have copied Christian Ruppert.
> 
> Christian,
> 
> Do you see problems on your side if we depend on COMMON_CLK?

COMMON_CLK is not selected by the ARC architecture in general. However,
we do select COMMON_CLK in the TB10x platform which uses the designware
I2C driver so this new dependency is no problem for us.

Vineet,

Do you see any issues with this on other existing ARC platforms, e.g.
arcfpga?

Greetings,
  Christian