Messages in this thread | | | Subject | Re: [PATCH] clk: meson: Fix GXL HDMI PLL fractional bits width | From | Neil Armstrong <> | Date | Thu, 22 Nov 2018 09:26:21 +0100 |
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Hi Martin,
On 21/11/2018 22:53, Martin Blumenstingl wrote: > Hi Neil, > > On Wed, Nov 21, 2018 at 12:19 PM Neil Armstrong <narmstrong@baylibre.com> 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
On S905, the HHI_HDMI_PLL_CNTL2 is at address 0xc9 << 2, but on S905X/S905D/S912 the equivalent register at same address is named HHI_HDMI_PLL_CNTL1.
They changed the numbering of registers between these 2 SoCs, but the register content and addresses are similar for m/n/frac/reset.
> > 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?
Is is part of HHI_HDMI_PLL_CNTL1 but at address of S905 HHI_HDMI_PLL_CNTL2.
When jerome pushed the PLL support earlier, he added a comment. I simply forgot to put it back when I added back the GXL HDMI PLL DCO.
Neil
> > > Regards > Martin >
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