Re: [PATCH 4/6] clk: actions: Fix AHPPREDIV-H-AHB clock chain on Owl S500 SoC

Cristian Ciocaltea
2021-03-16T18:51:02Z

On Tue, Mar 16, 2021 at 11:15:47AM +0530, Manivannan Sadhasivam wrote:
> On Mon, Mar 08, 2021 at 07:18:29PM +0200, Cristian Ciocaltea wrote:
> > There are a few issues with the setup of the Actions Semi Owl S500 SoC's
> > clock chain involving AHPPREDIV, H and AHB clocks:
> >
> > * AHBPREDIV clock is defined as a muxer only, although it also acts as
> > a divider.
> > * H clock is defined as a standard divider, although the raw value zero
> > is not supported.
>
> What do you mean by not supported? The datasheet lists "0" as the valid divisor
> value for divide by 1.

Unfortunately CMU_BUSCLK1 is not documented in my S500 Datasheet
(Version: 1.6, 2016-03-07). Do you have a newer (or a more official)
one?

The reference xapp-le code snipped is:

static struct owl_div divider_H_CLK = {
.type = DIV_T_NATURE,
.range_from = 1, /* reserve H_CLK divsor 1 */
.range_to = 3,
.reg = &divbit_H_CLK,
};

Not sure why divisor 1 has been reserved..

Thanks,
Cristi

> Rest looks good to me.
>
> Thanks,
> Mani
> …