On Mon, May 23, 2016 at 12:57:41AM +0000, Kuninori Morimoto wrote:
>
> Hi Simon
>
> > From: Ai Kyuse <ai.kyuse.uw@xxxxxxxxxxx>
> >
> > Add tuning support for use with SDR104 mode
> > This includes adding support for the sampling clock controller (SCC).
> >
> > Signed-off-by: Ai Kyuse <ai.kyuse.uw@xxxxxxxxxxx>
> > Signed-off-by: Simon Horman <horms+renesas@xxxxxxxxxxxx>
> > ---
> (snip)
> > +static int sh_mobile_sdhi_select_tuning(struct tmio_mmc_host *host, bool *tap)
> > +{
> > + unsigned long tap_num, i;
> > + int ok_count;
> > +
> > + /* Clear SCC_RVSREQ */
> > + sd_scc_write32(host, SH_MOBILE_SDHI_SCC_RVSREQ, 0);
> > +
> > + /* Select SCC */
> > + tap_num = (sd_scc_read32(host, SH_MOBILE_SDHI_SCC_DTCNTL) >>
> > + SH_MOBILE_SDHI_SCC_DTCNTL_TAPNUM_SHIFT) &
> > + SH_MOBILE_SDHI_SCC_DTCNTL_TAPNUM_MASK;
> > +
> > + /*
> > + * Select clock where three consecutive bock reads succeeded.
> > + *
> > + * There may be multiple occurrences of three successive reads
> > + * and selecting any of them is correct. Here the first one is
> > + * selected.
> > + */
> > + ok_count = 0;
> > + for (i = 0; i < 2 * tap_num; i++) {
> > + if (tap[i])
> > + ok_count++;
> > + else
> > + ok_count = 0;
> > + if (ok_count == 3)
> > + break;
> > + }
>
> As I pointed on [1/3] patch, having "tap_array_size" on this function,
> and check tap_num <-> tap_array_size is nice idea IMO.
We could also provide the array parameter and
not read tap_num using sd_scc_read32() here at all.
Which do you feel is best?
