Re: [linux-sunxi] Re: [PATCH v3 23/24] ARM: dts: sun8i: r40: Add HDMI pipeline

From: Chen-Yu Tsai
Date: Sun Jul 01 2018 - 09:53:51 EST


On Sun, Jul 1, 2018 at 6:41 PM, Jernej Åkrabec <jernej.skrabec@xxxxxxxx> wrote:
> Dne Äetrtek, 28. junij 2018 ob 08:51:07 CEST je Chen-Yu Tsai napisal(a):
>> On Thu, Jun 28, 2018 at 1:15 PM, Jernej Åkrabec <jernej.skrabec@xxxxxxxx>
> wrote:
>> > Dne Äetrtek, 28. junij 2018 ob 04:50:09 CEST je Chen-Yu Tsai napisal(a):
>> >> On Mon, Jun 25, 2018 at 8:03 PM, Jernej Skrabec <jernej.skrabec@xxxxxxxx>
>> >
>> > wrote:
>> >> > Add all entries needed for HDMI to function properly.
>> >> >
>> >> > Since R40 has highly configurable pipeline, both mixers and both TCON
>> >> > TVs are added. Board specific DT should then connect them together
>> >> > trough TCON TOP muxers to best fit the purpose of the board.
>> >> >
>> >> > Signed-off-by: Jernej Skrabec <jernej.skrabec@xxxxxxxx>
>> >> > ---
>> >> >
>> >> > arch/arm/boot/dts/sun8i-r40.dtsi | 269 +++++++++++++++++++++++++++++++
>> >> > 1 file changed, 269 insertions(+)
>> >> >
>> >> > diff --git a/arch/arm/boot/dts/sun8i-r40.dtsi
>> >> > b/arch/arm/boot/dts/sun8i-r40.dtsi index 173dcc1652d2..a2a75fb04caf
>> >> > 100644
>> >> > --- a/arch/arm/boot/dts/sun8i-r40.dtsi
>> >> > +++ b/arch/arm/boot/dts/sun8i-r40.dtsi
>> >> > @@ -42,8 +42,11 @@
>> >> >
>> >> > */
>> >> >
>> >> > #include <dt-bindings/interrupt-controller/arm-gic.h>
>> >> >
>> >> > +#include <dt-bindings/clock/sun8i-de2.h>
>> >> >
>> >> > #include <dt-bindings/clock/sun8i-r40-ccu.h>
>> >> >
>> >> > +#include <dt-bindings/clock/sun8i-tcon-top.h>
>> >
>> > Maxime, above line breaks compilation for build robot, sorry.
>> >
>> >> > #include <dt-bindings/reset/sun8i-r40-ccu.h>
>> >> >
>> >> > +#include <dt-bindings/reset/sun8i-de2.h>
>> >> >
>> >> > / {
>> >> >
>> >> > #address-cells = <1>;
>> >> >
>> >> > @@ -99,12 +102,76 @@
>> >> >
>> >> > };
>> >> >
>> >> > };
>> >> >
>> >> > + de: display-engine {
>> >> > + compatible = "allwinner,sun8i-r40-display-engine",
>> >> > + "allwinner,sun8i-h3-display-engine";
>> >>
>> >> Given that the display pipeline looks different, they should not be
>> >> compatible.
>> >
>> > Ok.
>> >
>> >> > + allwinner,pipelines = <&mixer0>, <&mixer1>;
>> >> > + status = "disabled";
>> >> > + };
>> >> > +
>> >> >
>> >> > soc {
>> >> >
>> >> > compatible = "simple-bus";
>> >> > #address-cells = <1>;
>> >> > #size-cells = <1>;
>> >> > ranges;
>> >> >
>> >> > + display_clocks: clock@1000000 {
>> >> > + compatible = "allwinner,sun8i-r40-de2-clk",
>> >> > + "allwinner,sun8i-h3-de2-clk";
>> >> > + reg = <0x01000000 0x100000>;
>> >> > + clocks = <&ccu CLK_DE>,
>> >> > + <&ccu CLK_BUS_DE>;
>> >> > + clock-names = "mod",
>> >> > + "bus";
>> >> > + resets = <&ccu RST_BUS_DE>;
>> >> > + #clock-cells = <1>;
>> >> > + #reset-cells = <1>;
>> >> > + };
>> >> > +
>> >> > + mixer0: mixer@1100000 {
>> >> > + compatible = "allwinner,sun8i-r40-de2-mixer-0";
>> >> > + reg = <0x01100000 0x100000>;
>> >> > + clocks = <&display_clocks CLK_BUS_MIXER0>,
>> >> > + <&display_clocks CLK_MIXER0>;
>> >> > + clock-names = "bus",
>> >> > + "mod";
>> >> > + resets = <&display_clocks RST_MIXER0>;
>> >> > +
>> >> > + ports {
>> >> > + #address-cells = <1>;
>> >> > + #size-cells = <0>;
>> >> > +
>> >> > + mixer0_out: port@1 {
>> >> > + reg = <1>;
>> >> > + mixer0_out_tcon_top: endpoint {
>> >> > + remote-endpoint =
>> >> > <&tcon_top_mixer0_in_mixer0>; +
>> >> > };
>> >> > + };
>> >> > + };
>> >> > + };
>> >> > +
>> >> > + mixer1: mixer@1200000 {
>> >> > + compatible = "allwinner,sun8i-r40-de2-mixer-1";
>> >> > + reg = <0x01200000 0x100000>;
>> >> > + clocks = <&display_clocks CLK_BUS_MIXER1>,
>> >> > + <&display_clocks CLK_MIXER1>;
>> >> > + clock-names = "bus",
>> >> > + "mod";
>> >> > + resets = <&display_clocks RST_WB>;
>> >> > +
>> >> > + ports {
>> >> > + #address-cells = <1>;
>> >> > + #size-cells = <0>;
>> >> > +
>> >> > + mixer1_out: port@1 {
>> >> > + reg = <1>;
>> >> > + mixer1_out_tcon_top: endpoint {
>> >> > + remote-endpoint =
>> >> > <&tcon_top_mixer1_in_mixer1>; +
>> >> > };
>> >> > + };
>> >> > + };
>> >> > + };
>> >> > +
>> >> >
>> >> > nmi_intc: interrupt-controller@1c00030 {
>> >> >
>> >> > compatible = "allwinner,sun7i-a20-sc-nmi";
>> >> > interrupt-controller;
>> >> >
>> >> > @@ -451,6 +518,163 @@
>> >> >
>> >> > #size-cells = <0>;
>> >> >
>> >> > };
>> >> >
>> >> > + tcon_top: tcon-top@1c70000 {
>> >> > + compatible = "allwinner,sun8i-r40-tcon-top";
>> >> > + reg = <0x01c70000 0x1000>;
>> >> > + clocks = <&ccu CLK_BUS_TCON_TOP>,
>> >> > + <&ccu CLK_TCON_TV0>,
>> >> > + <&ccu CLK_TVE0>,
>> >> > + <&ccu CLK_TCON_TV1>,
>> >> > + <&ccu CLK_TVE1>,
>> >> > + <&ccu CLK_DSI_DPHY>;
>> >> > + clock-names = "bus",
>> >> > + "tcon-tv0",
>> >> > + "tve0",
>> >> > + "tcon-tv1",
>> >> > + "tve1",
>> >> > + "dsi";
>> >> > + clock-output-names = "tcon-top-tv0",
>> >> > + "tcon-top-tv1",
>> >> > + "tcon-top-dsi";
>> >> > + resets = <&ccu RST_BUS_TCON_TOP>;
>> >> > + #clock-cells = <1>;
>> >> > +
>> >> > + ports {
>> >> > + #address-cells = <1>;
>> >> > + #size-cells = <0>;
>> >> > +
>> >> > + tcon_top_mixer0_in: port@0 {
>> >> > + reg = <0>;
>> >> > +
>> >> > + tcon_top_mixer0_in_mixer0:
>> >> > endpoint { +
>> >> > remote-endpoint = <&mixer0_out_tcon_top>; +
>> >> >
>> >> > };
>> >> >
>> >> > + };
>> >> > +
>> >> > + tcon_top_mixer0_out: port@1 {
>> >> > + #address-cells = <1>;
>> >> > + #size-cells = <0>;
>> >> > + reg = <1>;
>> >> > +
>> >> > + tcon_top_mixer0_out_tcon_lcd0:
>> >> > endpoint@0 { + reg = <0>;
>> >> > + };
>> >> > +
>> >> > + tcon_top_mixer0_out_tcon_lcd1:
>> >> > endpoint@1 { + reg = <1>;
>> >> > + };
>> >> > +
>> >> > + tcon_top_mixer0_out_tcon_tv0:
>> >> > endpoint@2 { + reg = <2>;
>> >> > + };
>> >> > +
>> >> > + tcon_top_mixer0_out_tcon_tv1:
>> >> > endpoint@3 { + reg = <3>;
>> >> > + };
>> >> > + };
>> >> > +
>> >> > + tcon_top_mixer1_in: port@2 {
>> >> > + reg = <2>;
>> >> > +
>> >> > + tcon_top_mixer1_in_mixer1:
>> >> > endpoint { +
>> >> > remote-endpoint = <&mixer1_out_tcon_top>; +
>> >> >
>> >> > };
>> >> >
>> >> > + };
>> >> > +
>> >> > + tcon_top_mixer1_out: port@3 {
>> >> > + #address-cells = <1>;
>> >> > + #size-cells = <0>;
>> >> > + reg = <3>;
>> >> > +
>> >> > + tcon_top_mixer1_out_tcon_lcd0:
>> >> > endpoint@0 { + reg = <0>;
>> >> > + };
>> >> > +
>> >> > + tcon_top_mixer1_out_tcon_lcd1:
>> >> > endpoint@1 { + reg = <1>;
>> >> > + };
>> >> > +
>> >> > + tcon_top_mixer1_out_tcon_tv0:
>> >> > endpoint@2 { + reg = <2>;
>> >> > + };
>> >> > +
>> >> > + tcon_top_mixer1_out_tcon_tv1:
>> >> > endpoint@3 { + reg = <3>;
>> >> > + };
>> >> > + };
>> >> > +
>> >> > + tcon_top_hdmi_in: port@4 {
>> >> > + #address-cells = <1>;
>> >> > + #size-cells = <0>;
>> >> > + reg = <4>;
>> >> > +
>> >> > + tcon_top_hdmi_in_tcon_tv0:
>> >> > endpoint@0 { + reg = <0>;
>> >> > + };
>> >> > +
>> >> > + tcon_top_hdmi_in_tcon_tv1:
>> >> > endpoint@1 { + reg = <1>;
>> >> > + };
>> >> > + };
>> >> > +
>> >> > + tcon_top_hdmi_out: port@5 {
>> >> > + reg = <5>;
>> >> > +
>> >> > + tcon_top_hdmi_out_hdmi:
>> >> > endpoint {
>> >> > + remote-endpoint =
>> >> > <&hdmi_in_tcon_top>; + };
>> >> > + };
>> >> > + };
>> >> > + };
>> >> > +
>> >> > + tcon_tv0: lcd-controller@1c73000 {
>> >> > + compatible = "allwinner,sun8i-r40-tcon-tv",
>> >> > + "allwinner,sun8i-a83t-tcon-tv";
>> >> > + reg = <0x01c73000 0x1000>;
>> >> > + interrupts = <GIC_SPI 51 IRQ_TYPE_LEVEL_HIGH>;
>> >> > + clocks = <&ccu CLK_BUS_TCON_TV0>, <&tcon_top
>> >> > 0>;
>> >> > + clock-names = "ahb", "tcon-ch1";
>> >> > + resets = <&ccu RST_BUS_TCON_TV0>;
>> >> > + reset-names = "lcd";
>> >> > +
>> >> > + ports {
>> >> > + #address-cells = <1>;
>> >> > + #size-cells = <0>;
>> >> > +
>> >> > + tcon_tv0_in: port@0 {
>> >> > + reg = <0>;
>> >> > + };
>> >> > +
>> >> > + tcon_tv0_out: port@1 {
>> >> > + reg = <1>;
>> >> > + };
>> >> > + };
>> >> > + };
>> >> > +
>> >> > + tcon_tv1: lcd-controller@1c74000 {
>> >> > + compatible = "allwinner,sun8i-r40-tcon-tv",
>> >> > + "allwinner,sun8i-a83t-tcon-tv";
>> >> > + reg = <0x01c74000 0x1000>;
>> >> > + interrupts = <GIC_SPI 52 IRQ_TYPE_LEVEL_HIGH>;
>> >> > + clocks = <&ccu CLK_BUS_TCON_TV1>, <&tcon_top
>> >> > 1>;
>> >> > + clock-names = "ahb", "tcon-ch1";
>> >> > + resets = <&ccu RST_BUS_TCON_TV1>;
>> >> > + reset-names = "lcd";
>> >> > +
>> >> > + ports {
>> >> > + #address-cells = <1>;
>> >> > + #size-cells = <0>;
>> >> > +
>> >> > + tcon_tv1_in: port@0 {
>> >> > + reg = <0>;
>> >> > + };
>> >> > +
>> >> > + tcon_tv1_out: port@1 {
>> >> > + reg = <1>;
>> >>
>> >> You are missing the remote-endpoints for all the TCON-TOP <-> TCON
>> >> connections. Also, on the driver side, there's no code to handle
>> >> dynamically mapping mixers to the TCONs that are being used. In the past
>> >> we
>> >> had simple 1:1 mappings. This is no longer the case, and it needs to be
>> >> dealt with.
>> >
>> > How would TCON TOP driver know how to set muxes? There are no appropriate
>> > bingings for muxes, except for V4L2 subsystem, which doesn't really work
>> > here.
>> This will end up being a bunch of custom functions exported from the TCON
>> TOP driver to the TCON driver. As for bindings, the stuff you already have
>> is mostly enough. You do have to specify the endpoint ID vs component
>> mapping, so you can find the correct one.
>>
>> For example, you would specify that the IDs for TCON LCDs be 0 and 1, and
>> TCON TVs be 2 and 3. Matching the actual register values is a nice
>> convenience. These would be used by the driver as the TCON ID.
>
> So something that's already done (minus full connections).
>
>>
>> Also, we might want to consider them as two pairs of two TCONs (LCD + TV).
>> The CRTC in DRM land is actually the mixer + TCON on our platform. This
>> means we only have two CRTCs. So we could have CRTC 0 = mixer 0 + TCON LCD
>> 0 + TCON TV 0. The "TCON_TVx_OUTSEL" and "DE_PORTx PERH Select" muxes would
>> be set at run time in the mode set function, selecting either LCD or TV
>> based on what encoder is attached.
>
> That proposal would still limit some combinations. For example, that would put
> DSI always on mixer1, since it can be connected to only LCD TCON 1. It can
> also cause undesired combination in laptop solutions. Consider that PCB
> designer connected LCD1 pins to panel for some reason. Panel is definetly main
> screen and should definetly be connected to mixer0, but in that case, it would
> be to mixer1.

There's no reason we can't have dynamically assigned mixer+tcon pairs, but
that would mean implementing additional scheduling code that we don't have
yet. The current sunxi-drm and CRTC code assume static mappings.

We could do this as a second step if you're up to it.

> Additionaly, since HDMI would became floating between TV TCON 0 and 1, whoever
> would write board DT would need to know this and enable only TV TCON1 if LCD
> is desired to be connected to mixer0 (or vice versa).

There's no reason not to have all TCONs enabled by default. We would consider
the display-engine node controlling whether everything actually gets used.

> If we really want universal solution with full connections, addtional property
> has to be defined and used for that.
>
>>
>> This limitation is a software one, and should not bleed over into the
>> hardware representation.
>>
>> > Additionaly, how would HDMI know which TCON belongs to it to appropriately
>> > set possible_crtcs?
>>
>> HDMI is connected to the two TCON TVs through the TCON TOP mux. We handle
>> TCON output muxing in the TCON driver, using the set_mux callback in the
>> quirks. For R40, this callback would probably call into the TCON TOP driver
>> asking it to set the mux to some value.
>>
>> > Currently, my idea is that board DT creates wanted connections. Since
>> > there is only one valid connection for each mux, driver knows eactly what
>> > to write into mux register. HDMI driver can simply check which TCON
>> > connection is valid in HDMI input mux and select it in possible_crtcs.
>>
>> But that is not how the actual hardware looks like. The device tree should
>> model the hardware, not a subset of it just because one thinks the
>> implementation is difficult or won't be used at all.
>>
>> Furthermore, I think you have it backwards. possible_crtcs is generated
>> based on (in our case) the connections between TCON and HDMI based on the
>> device tree graph. So if you have both hooked up, both will show up in
>> possible_crtcs, but only one crtc will actually be selected to feed the
>> HDMI encoder. If you really need to access the current crtc, the
>> drm_encoder struct contains a pointer to it.
>>
>> In DE 1.0 driver, we leave all the muxing to the TCON driver. See
>>
>>
>> https://elixir.bootlin.com/linux/latest/source/drivers/gpu/drm/sun4i/sun4i_
>> tcon.c#L537
>>
>> So in a sense, the HDMI encoder should be and is hooked up to both TCONs,
>> but only one is active at any given time.
>
> So something like that I had in v1 series. I'll implement something similar.
> That would also mean we need R40 specific TV TCON compatible. I'll restore
> that.
>
> Just a question on future situation when TVE driver will be implemented.
> Suppose that R40 board has TVE0 and HDMI as outputs. This would mean that TVE0
> has possible crtcs set as 0b01 and HDMI 0b11. Will be DRM framework smart
> enough that it will put HDMI on second crtc because TVE0 can be connected to
> only to first crtc?

Yes. If the possible_clones setting for the encoder is not set, the DRM
framework will not do mirroring, and will keep each active encoder on a
separate crtc.

>
>>
>> > Please also note that mixer0 and mixer1 don't have same capabilities and
>> > you generally want mixer0 to be connected to main output. This is in
>> > contrast to DE1 SoCs, where both backends and both frontends have same
>> > capability.
>> Yes. But who's to say the two display outputs can't be reversed or swapped
>> around? With fixed singular connections, you also rule out mirrored output.
>
> I don't think there is standard way to swap around mixers at runtime,
> expecially if crtcs are represented as mixer + TCON pair.

As I mentioned above, we will have to do this on our own.

> I'm not sure what do you mean with mirrored output or at least why singular
> connections would prevent mirroring. HW mirroring needs DRM writeback support
> which is currently in RFC phase if I'm not mistaken. Once implemented in DRM
> framework and in sun4i-drm, it would be possible only to mirror mixer0 ->
> mixer1, because mixer1 doesn't support writeback (at least on existing SoCs).

What I meant was it might be possible to drive two TCONs with one mixer, or
two encoders with one TCON. I guess the latter is not possible since each
TCON only has one channel. Not sure about the former.

Regards
ChenYu

> Best regards,
> Jernej
>
>>
>> ChenYu
>>
>> >> ChenYu
>> >>
>> >> > + };
>> >> > + };
>> >> > + };
>> >> > +
>> >> >
>> >> > gic: interrupt-controller@1c81000 {
>> >> >
>> >> > compatible = "arm,gic-400";
>> >> > reg = <0x01c81000 0x1000>,
>> >> >
>> >> > @@ -461,6 +685,51 @@
>> >> >
>> >> > #interrupt-cells = <3>;
>> >> > interrupts = <GIC_PPI 9 (GIC_CPU_MASK_SIMPLE(4)
>> >> > |
>> >> > IRQ_TYPE_LEVEL_HIGH)>;
>> >> >
>> >> > };
>> >> >
>> >> > +
>> >> > + hdmi: hdmi@1ee0000 {
>> >> > + compatible = "allwinner,sun8i-r40-dw-hdmi",
>> >> > + "allwinner,sun8i-a83t-dw-hdmi";
>> >> > + reg = <0x01ee0000 0x10000>;
>> >> > + reg-io-width = <1>;
>> >> > + interrupts = <GIC_SPI 58 IRQ_TYPE_LEVEL_HIGH>;
>> >> > + clocks = <&ccu CLK_BUS_HDMI0>, <&ccu
>> >> > CLK_HDMI_SLOW>, + <&ccu CLK_HDMI>;
>> >> > + clock-names = "iahb", "isfr", "tmds";
>> >> > + resets = <&ccu RST_BUS_HDMI1>;
>> >> > + reset-names = "ctrl";
>> >> > + phys = <&hdmi_phy>;
>> >> > + phy-names = "hdmi-phy";
>> >> > + status = "disabled";
>> >> > +
>> >> > + ports {
>> >> > + #address-cells = <1>;
>> >> > + #size-cells = <0>;
>> >> > +
>> >> > + hdmi_in: port@0 {
>> >> > + reg = <0>;
>> >> > +
>> >> > + hdmi_in_tcon_top: endpoint {
>> >> > + remote-endpoint =
>> >> > <&tcon_top_hdmi_out_hdmi>; + };
>> >> > + };
>> >> > +
>> >> > + hdmi_out: port@1 {
>> >> > + reg = <1>;
>> >> > + };
>> >> > + };
>> >> > + };
>> >> > +
>> >> > + hdmi_phy: hdmi-phy@1ef0000 {
>> >> > + compatible = "allwinner,sun8i-r40-hdmi-phy",
>> >> > + "allwinner,sun50i-a64-hdmi-phy";
>> >> > + reg = <0x01ef0000 0x10000>;
>> >> > + clocks = <&ccu CLK_BUS_HDMI1>, <&ccu
>> >> > CLK_HDMI_SLOW>, + <&ccu 7>, <&ccu 16>;
>> >> > + clock-names = "bus", "mod", "pll-0", "pll-1";
>> >> > + resets = <&ccu RST_BUS_HDMI0>;
>> >> > + reset-names = "phy";
>> >> > + #phy-cells = <0>;
>> >> > + };
>> >> >
>> >> > };
>> >> >
>> >> > timer {
>> >> >
>> >> > --
>> >> > 2.18.0
>> >
>> > --
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>
>