Re: [PATCH] clk: meson: Fix GXL HDMI PLL fractional bits width

From: Martin Blumenstingl
Date: Wed Nov 21 2018 - 16:54:12 EST


Hi Neil,

On Wed, Nov 21, 2018 at 12:19 PM Neil Armstrong <narmstrong@xxxxxxxxxxxx> wrote:
>
> The GXL Documentation specifies 12 bits for the Fractional bit field,
> bit the last bits have a different purpose that we cannot handle right
> now, so update the bitwidth to have correct fractional calculations.
I assume you have more accurate documentation than what's available publicly:
- the S805 datasheet doesn't have any documentation for this register at all
- the S905 datasheet states that HHI_HDMI_PLL_CNTL2[11:0] are DIV_FRAC
- the S905X and S912 datasheets state that SDMNC_POWER is at
HHI_HDMI_PLL_CNTL2[6:0], SDMNC_ULMS is at HHI_HDMI_PLL_CNTL2[9:7] and
SSC_DEP_SEL is at HHI_HDMI_PLL_CNTL2[13:10]
- the S905X and S912 datasheets state that HHI_HDMI_PLL_CNTL1[11:0] are DIV_FRAC

can you confirm that the public S905X and S912 documentation is wrong
and that the .frac field is really part of HHI_HDMI_PLL_CNTL2 instead
of HHI_HDMI_PLL_CNTL1?


Regards
Martin