RE: [PATCH v2 2/4] iio: adc: xilinx: limit pcap clock frequency value
From: Manish Narani
Date: Mon Jul 30 2018 - 06:13:39 EST
Hi Jonathan,
> -----Original Message-----
> From: Jonathan Cameron [mailto:jic23@xxxxxxxxxx]
> Sent: Sunday, July 29, 2018 5:21 PM
> To: Manish Narani <MNARANI@xxxxxxxxxx>
> Cc: Sai Krishna Potthuri <lakshmis@xxxxxxxxxx>; Michal Simek
> <michals@xxxxxxxxxx>; pmeerw@xxxxxxxxxx; lars@xxxxxxxxxx;
> knaack.h@xxxxxx; Anirudha Sarangi <anirudh@xxxxxxxxxx>; Srinivas Goud
> <sgoud@xxxxxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx; linux-arm-
> kernel@xxxxxxxxxxxxxxxxxxx; linux-iio@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH v2 2/4] iio: adc: xilinx: limit pcap clock frequency value
>
> On Mon, 23 Jul 2018 20:32:01 +0530
> Manish Narani <manish.narani@xxxxxxxxxx> wrote:
>
> > This patch limits the xadc pcap clock frequency value to be less than
> > 200MHz. This fixes the issue when zynq is booted at higher frequency
> > values, pcap crosses the maximum limit of 200MHz(Fmax) as it is
> > derived from IOPLL.
> > If this limit is crossed it is required to alter the WEDGE and REDGE
> > bits of XADC_CFG register to make timings better in the interface. So
> > to avoid alteration of these bits every time, the pcap value should
> > not cross the Fmax limit.
> >
> > Signed-off-by: Manish Narani <manish.narani@xxxxxxxxxx>
>
> Applied, to the togreg branch of iio.git. If you want this backported to stable,
> then request it once this patch is upstream. It may be sometime given we've
> probably just missed the coming merge window.
>
> If you do need it faster then let me know and I'll look at moving it over to the
> branch of fixes during the RC phases.
Thanks for getting this applied. There is no concern for this to be in the stable
ASAP. I can wait.
Thanks & Regards,
Manish Narani