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Re: [linux-sunxi] Re: [RFC PATCH 07/11] drm: sun4i: add support for the TV encoder in H3 SoC

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Hi,

Dne petek, 19. maj 2017 ob 20:08:18 CEST je Icenowy Zheng napisal(a):
> 于 2017年5月20日 GMT+08:00 上午2:03:30, Maxime Ripard <maxime.ripard@free-
electrons.com> 写到:
> >On Thu, May 18, 2017 at 12:43:50AM +0800, Icenowy Zheng wrote:
> >> Allwinner H3 features a TV encoder similar to the one in earlier
> >
> >SoCs,
> >
> >> but with some different points about clocks:
> >> - It has a mod clock and a bus clock.
> >> - The mod clock must be at a fixed rate to generate signal.
> >
> >Why?
> 
> It's experiment result by Jernej.
> 
> The clock rates in BSP kernel is also specially designed
> (PLL_DE at 432MHz) in order to be able to feed the TVE.

My experiments and search through BSP code showed that TVE seems to have 
additional fixed predivider 8. So if you want to generate 27 MHz clock, unit 
has to be feed with 216 MHz. 

TVE has only one PLL source PLL_DE. And since 216 MHz is a bit low for DE2, 
BSP defaults to 432 MHz for PLL_DE and use divider 2 to generate 216 MHz. This 
clock is then divided by 8 internaly to get final 27 MHz.

Please note that I don't have any hard evidence to support that, only 
experimental data. However, only that explanation make sense to me.

BTW, BSP H3/H5 TV driver supports only PAL and NTSC which both use 27 MHz base 
clock. Further experiments are needed to check if there is any possibility to 
have other resolutions by manipulating clocks and give other proper settings. 
I plan to do that, but not in very near future.

Best regards,
Jernej

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[RFC PATCH 00/11] Support for H3 Composite Output support Icenowy Zheng <icenowy@aosc.io> - 2017-05-17 18:50 +0200
  [RFC PATCH 11/11] [DO NOT MERGE] ARM: sun8i: h3: enable TV output on Orange Pi PC Icenowy Zheng <icenowy@aosc.io> - 2017-05-17 18:50 +0200
  [RFC PATCH 01/11] dt-bindings: update the binding for Allwinner H3 TVE support Icenowy Zheng <icenowy@aosc.io> - 2017-05-17 18:50 +0200
    Re: [RFC PATCH 01/11] dt-bindings: update the binding for Allwinner H3 TVE support Icenowy Zheng <icenowy@aosc.io> - 2017-05-19 20:10 +0200
      Re: [linux-sunxi] Re: [RFC PATCH 01/11] dt-bindings: update the  binding for Allwinner H3 TVE support Chen-Yu Tsai <wens@csie.org> - 2017-05-20 04:10 +0200
    Re: [RFC PATCH 01/11] dt-bindings: update the binding for Allwinner  H3 TVE support Maxime Ripard <maxime.ripard@free-electrons.com> - 2017-05-19 20:10 +0200
  [RFC PATCH 03/11] drm: sun4i: ignore swapped mixer<->tcon connection for DE2 Icenowy Zheng <icenowy@aosc.io> - 2017-05-17 18:50 +0200
    Re: [RFC PATCH 03/11] drm: sun4i: ignore swapped mixer<->tcon connection for DE2 Icenowy Zheng <icenowy@aosc.io> - 2017-05-19 20:10 +0200
      Re: [RFC PATCH 03/11] drm: sun4i: ignore swapped mixer<->tcon  connection for DE2 Maxime Ripard <maxime.ripard@free-electrons.com> - 2017-05-24 10:20 +0200
    Re: [RFC PATCH 03/11] drm: sun4i: ignore swapped mixer<->tcon  connection for DE2 Maxime Ripard <maxime.ripard@free-electrons.com> - 2017-05-19 20:10 +0200
  [RFC PATCH 05/11] drm: sun4i: add compatible for H3 display engine Icenowy Zheng <icenowy@aosc.io> - 2017-05-17 18:50 +0200
  [RFC PATCH 02/11] drm: sun4i: add support for H3 mixers Icenowy Zheng <icenowy@aosc.io> - 2017-05-17 18:50 +0200
    Re: [linux-sunxi] Re: [RFC PATCH 02/11] drm: sun4i: add support for H3 mixers Icenowy Zheng <icenowy@aosc.io> - 2017-05-19 20:00 +0200
      Re: [linux-sunxi] Re: [RFC PATCH 02/11] drm: sun4i: add support for H3 mixers Jernej Škrabec <jernej.skrabec@siol.net> - 2017-05-19 20:20 +0200
    Re: [RFC PATCH 02/11] drm: sun4i: add support for H3 mixers Maxime Ripard <maxime.ripard@free-electrons.com> - 2017-05-19 20:00 +0200
  [RFC PATCH 04/11] drm: sun4i: add support for H3's TCON0/1 Icenowy Zheng <icenowy@aosc.io> - 2017-05-17 19:00 +0200
  [RFC PATCH 09/11] clk: sunxi-ng: export CLK_PLL_DE for H3 Icenowy Zheng <icenowy@aosc.io> - 2017-05-17 19:10 +0200
  [RFC PATCH 10/11] ARM: sun8i: h3: add display engine pipeline for TVE Icenowy Zheng <icenowy@aosc.io> - 2017-05-17 19:10 +0200
    Re: [linux-sunxi] [RFC PATCH 10/11] ARM: sun8i: h3: add display engine pipeline for TVE Jernej Škrabec <jernej.skrabec@siol.net> - 2017-05-17 22:30 +0200
    Re: [RFC PATCH 10/11] ARM: sun8i: h3: add display engine pipeline  for TVE Maxime Ripard <maxime.ripard@free-electrons.com> - 2017-05-19 20:10 +0200
      Re: [linux-sunxi] Re: [RFC PATCH 10/11] ARM: sun8i: h3: add display engine pipeline for TVE Icenowy Zheng <icenowy@aosc.io> - 2017-05-19 20:30 +0200
        Re: [linux-sunxi] Re: [RFC PATCH 10/11] ARM: sun8i: h3: add display  engine pipeline for TVE Maxime Ripard <maxime.ripard@free-electrons.com> - 2017-05-24 10:30 +0200
    Re: [linux-sunxi] [RFC PATCH 10/11] ARM: sun8i: h3: add display  engine pipeline for TVE Chen-Yu Tsai <wens@csie.org> - 2017-05-24 07:30 +0200
      Re: [linux-sunxi] [RFC PATCH 10/11] ARM: sun8i: h3: add display engine pipeline for TVE Icenowy Zheng <icenowy@aosc.io> - 2017-05-24 07:30 +0200
        Re: [linux-sunxi] [RFC PATCH 10/11] ARM: sun8i: h3: add display engine pipeline for TVE Icenowy Zheng <icenowy@aosc.io> - 2017-05-24 07:40 +0200
        Re: [linux-sunxi] [RFC PATCH 10/11] ARM: sun8i: h3: add display  engine pipeline for TVE Chen-Yu Tsai <wens@csie.org> - 2017-05-24 07:40 +0200
  [RFC PATCH 06/11] drm: sun4i: add color space correction support for DE2 mixer Icenowy Zheng <icenowy@aosc.io> - 2017-05-17 19:10 +0200
    Re: [linux-sunxi] [RFC PATCH 06/11] drm: sun4i: add color space correction support for DE2 mixer Jernej Škrabec <jernej.skrabec@siol.net> - 2017-05-17 22:30 +0200
  [RFC PATCH 07/11] drm: sun4i: add support for the TV encoder in H3 SoC Icenowy Zheng <icenowy@aosc.io> - 2017-05-17 19:10 +0200
    Re: [RFC PATCH 07/11] drm: sun4i: add support for the TV encoder in  H3 SoC Maxime Ripard <maxime.ripard@free-electrons.com> - 2017-05-19 20:10 +0200
      Re: [RFC PATCH 07/11] drm: sun4i: add support for the TV encoder in H3 SoC Icenowy Zheng <icenowy@aosc.io> - 2017-05-19 20:10 +0200
        Re: [linux-sunxi] Re: [RFC PATCH 07/11] drm: sun4i: add support for the TV encoder in H3 SoC Jernej Škrabec <jernej.skrabec@siol.net> - 2017-05-19 20:30 +0200
          Re: [linux-sunxi] Re: [RFC PATCH 07/11] drm: sun4i: add support for  the TV encoder in H3 SoC Chen-Yu Tsai <wens@csie.org> - 2017-05-20 03:40 +0200
            Re: [linux-sunxi] Re: [RFC PATCH 07/11] drm: sun4i: add support for the TV encoder in H3 SoC Jernej Škrabec <jernej.skrabec@siol.net> - 2017-05-22 20:00 +0200
              Re: [linux-sunxi] Re: [RFC PATCH 07/11] drm: sun4i: add support for the TV encoder in H3 SoC Icenowy Zheng <icenowy@aosc.io> - 2017-05-23 15:00 +0200
              Re: [linux-sunxi] Re: [RFC PATCH 07/11] drm: sun4i: add support for  the TV encoder in H3 SoC Maxime Ripard <maxime.ripard@free-electrons.com> - 2017-05-23 15:00 +0200
                Re: [linux-sunxi] Re: [RFC PATCH 07/11] drm: sun4i: add support for  the TV encoder in H3 SoC icenowy@aosc.io - 2017-05-23 15:10 +0200
                Re: [linux-sunxi] Re: [RFC PATCH 07/11] drm: sun4i: add support for  the TV encoder in H3 SoC Maxime Ripard <maxime.ripard@free-electrons.com> - 2017-05-24 09:40 +0200
                Re: [linux-sunxi] Re: [RFC PATCH 07/11] drm: sun4i: add support for the TV encoder in H3 SoC Icenowy Zheng <icenowy@aosc.io> - 2017-05-24 10:30 +0200
                Re: [linux-sunxi] Re: [RFC PATCH 07/11] drm: sun4i: add support for the TV encoder in H3 SoC Jernej Škrabec <jernej.skrabec@siol.net> - 2017-05-24 17:30 +0200
  [RFC PATCH 08/11] clk: sunxi-ng: allow CLK_DE to set CLK_PLL_DE for H3 Icenowy Zheng <icenowy@aosc.io> - 2017-05-17 19:10 +0200

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