Hi Daniel,
On Wed, 2015-07-01 at 19:54 +0800, Daniel Kurtz wrote:
> On Wed, Jul 1, 2015 at 2:49 PM, Sascha Hauer <s.hauer@xxxxxxxxxxxxxx> wrote:
> > The problem is not that you use fixed clocks for non software
> > controllable clocks of unknwown rates, but that you try to use a single
> > clock for all of them and name it 'dummy' or 'null'. Name it
> >
> > dpi_ck {
> > compatible = "fixed-clock";
> > rate = <0>; /* unknown, generated by some Analog block */
> > };
>
> It would be nice, though, to use the real clock rates.
> Otherwise, we end up with a bunch of unknown clock rates, like this:
>
> clock enable_cnt prepare_cnt rate
> accuracy phase
> ----------------------------------------------------------------------------------------
> clk_null 2 2 0
> 0 0
> mm_lvds_cts 0 0 0
> 0 0
> mm_lvds_pixel 0 0 0
> 0 0
> mm_dpi1_pixel 0 0 0
> 0 0
> Furthermore, at least some of these children clocks are possible
> source clocks for other clocks for which we do want to know the
> resulting frequency. For example, the "dmpll_*" clocks are mux inputs
> for many of the subsystem clocks.
These clocks such as clkph_mck_o are configured by other modules before
kernel init, and their rates may different among platforms. So we can't
use a hard-coded rate for them. And we also don't care the actual rate
of these clocks, so assign a dummy rate such as 0 to them should be a
better way.
Best regards,
james
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
