[RFC] arm64: dts: imx8mm: Add MIPI and LCDIF nodes
Tim Harvey
tharvey at gateworks.com
Thu Nov 11 21:21:03 UTC 2021
On Thu, Nov 11, 2021 at 2:19 AM Jagan Teki <jagan at amarulasolutions.com> wrote:
>
> On Wed, Nov 10, 2021 at 11:58 PM Jagan Teki <jagan at amarulasolutions.com> wrote:
> >
> > On Wed, Nov 10, 2021 at 2:24 AM Tim Harvey <tharvey at gateworks.com> wrote:
> > >
> > > On Tue, Nov 9, 2021 at 12:39 PM Marek Vasut <marex at denx.de> wrote:
> > > >
> > > > On 11/9/21 8:35 PM, Adam Ford wrote:
> > > >
> > > > [...]
> > > >
> > > > >> diff --git a/arch/arm64/boot/dts/freescale/imx8mm.dtsi b/arch/arm64/boot/dts/freescale/imx8mm.dtsi
> > > > >> index 208a0ed840f4..195dcbff7058 100644
> > > > >> --- a/arch/arm64/boot/dts/freescale/imx8mm.dtsi
> > > > >> +++ b/arch/arm64/boot/dts/freescale/imx8mm.dtsi
> > > > >> @@ -188,6 +188,12 @@
> > > > >> clock-output-names = "clk_ext4";
> > > > >> };
> > > > >>
> > > > >> + mipi_phy: mipi-video-phy {
> > > > >> + compatible = "fsl,imx8mm-mipi-video-phy";
> > > > >> + syscon = <&disp_blk_ctrl>;
> > > > >> + #phy-cells = <1>;
> > > > >> + };
> > > > >> +
> > > > >> psci {
> > > > >> compatible = "arm,psci-1.0";
> > > > >> method = "smc";
> > > > >> @@ -1068,6 +1074,68 @@
> > > > >> #size-cells = <1>;
> > > > >> ranges = <0x32c00000 0x32c00000 0x400000>;
> > > > >>
> > > > >> + lcdif: lcdif at 32e00000 {
> > > > >> + #address-cells = <1>;
> > > > >> + #size-cells = <0>;
> > > > >> + compatible = "fsl,imx8mm-lcdif", "fsl,imx6sx-lcdif";
> > > > >
> > > > > The compatible "imx6sx-lcdif" implies MXSFB_V6. FWICT, it is like
> > > > > MXSFB_V4, but with overlays and those overlays have more registers
> > > > > configured in the mxsfb_kms driver. Have you tried using imx28-lcdif
> > > > > to see if it makes a difference?
> > > >
> > > > Indeed, MX6SX has AS overlay plane support, MX{2,}8 does not.
> > > >
> > > > LCDIFv3 (as NXP calls it) in MX8MP is like LCDIFv6 (in MX6SX) with
> > > > slightly reordered register bits, but nothing like LCDIF rev3 (in MX23)
> > > > ... just to make sure there is no confusion.
> > > >
> > > > [...]
> > > >
> > > > >> + mipi_dsi: mipi_dsi at 32e10000 {
> > > > >> + #address-cells = <1>;
> > > > >> + #size-cells = <0>;
> > > > >> + compatible = "fsl,imx8mm-mipi-dsim";
> > > > >> + reg = <0x32e10000 0x400>;
> > > > >> + clocks = <&clk IMX8MM_CLK_DSI_CORE>,
> > > > >> + <&clk IMX8MM_CLK_DSI_PHY_REF>;
> > > > >> + clock-names = "bus_clk", "sclk_mipi";
> > > > >> + assigned-clocks = <&clk IMX8MM_CLK_DSI_CORE>,
> > > > >> + <&clk IMX8MM_VIDEO_PLL1_OUT>,
> > > > >> + <&clk IMX8MM_CLK_DSI_PHY_REF>;
> > > > >> + assigned-clock-parents = <&clk IMX8MM_SYS_PLL1_266M>,
> > > > >> + <&clk IMX8MM_VIDEO_PLL1_BYPASS>,
> > > > >> + <&clk IMX8MM_VIDEO_PLL1_OUT>;
> > > > >> + assigned-clock-rates = <266000000>, <594000000>, <27000000>;
> > > > >> + interrupts = <GIC_SPI 18 IRQ_TYPE_LEVEL_HIGH>;
> > > > >> + phys = <&mipi_phy 0>;
> > > > >> + phy-names = "dsim";
> > > > >> + power-domains = <&disp_blk_ctrl IMX8MM_DISPBLK_PD_MIPI_DSI>;
> > > > >> + samsung,burst-clock-frequency = <891000000>;
> > > > >> + samsung,esc-clock-frequency = <54000000>;
> > > > >> + samsung,pll-clock-frequency = <27000000>;
> > > >
> > > > This 27 MHz is really IMX8MM_CLK_DSI_PHY_REF and
> > > > samsung,burst-clock-frequency is really the DSI link clock which is
> > > > panel/bridge specific ... but, why do we need to specify such policy in
> > > > DT rather than have the panel/bridge drivers negotiate the best clock
> > > > settings with DSIM bridge driver ? This should be something which should
> > > > be implemented in the DRM subsystem, not hard-coded in DT. These ad-hoc
> > > > samsung,*-clock-frequency properties shouldn't even be needed then.
> > > >
> > > > Also, are the DSIM bindings stable now ?
> > >
> > > Thanks Marek.
> > >
> > > No, there is no dsim driver yet. I'm not clear if there is still
> > > dissagreement on if the drm/exynos driver can be split up or if a
> > > whole new somewhat duplicate driver needs to be made. I know Jagan
> > > also has a series he is working on that uses drm/exynos which I
> > > believe he will share an update on in a day or so.
> > >
> > > I'm still using the work that Michael [1] and you [2] did a long time back.
> > >
> > > I had this solution working on a 5.10 kernel but it was based on the
> > > old unapproved IMX8MM blk-ctl and pd drivers. Therefore I believe the
> > > issue I'm having is something not setup correctly with blk-ctl per my
> > > dt settings or perhaps something missing from the blk-ctl driver like
> > > Adam found [3]
> > >
> > > I am hanging at:
> > > [ 1.064088] imx_pgc_power_up gpumix
> > > [ 1.077506] imx_pgc_power_down gpumix
> > > [ 1.097685] imx8m_blk_ctrl_power_on dispblk-mipi-dsi
> > > [ 1.102682] imx_pgc_power_up dispmix
> > > [ 1.106825] imx_pgc_power_up mipi
> > > [ 1.110232] imx-dsim-dsi 32e10000.mipi_dsi: supply vddcore not
> > > found, using dummy regulator
> > > [ 1.118760] imx-dsim-dsi 32e10000.mipi_dsi: supply vddio not found,
> > > using dummy regulator
> > > [ 1.127361] imx-dsim-dsi 32e10000.mipi_dsi: [drm] *ERROR* modalias
> > > failure on /soc at 0/bus at 32c00000/mipi_dsi at 32e10000/port at 0
> > > [ 1.138676] imx8m_blk_ctrl_power_off dispblk-mipi-dsi
> > > [ 1.143788] imx_pgc_power_down mipi
> > > [ 1.145278] imx8m_blk_ctrl_power_on dispblk-lcdif
> > > [ 1.147316] imx_pgc_power_down dispmix
> > > [ 1.155804] imx_pgc_power_up dispmix
> > > [ 1.159820] [drm:drm_bridge_attach] *ERROR* failed to attach bridge
> > > /soc at 0/bus at 32c00000/mipi_dsi at 32e10000 to encoder None-34: -517
> > > ^^^ this is just a defer
> > > [ 1.171789] imx8m_blk_ctrl_power_off dispblk-lcdif
> > > [ 1.176655] imx_pgc_power_down dispmix
> > > [ 1.181790] libphy: fec_enet_mii_bus: probed
> > > [ 3.915806] panel-simple panel: Expected bpc in {6,8} but got: 0
> > > ^^^ not sure what this is but had it back in my 5.10 solution as well
> > > so did not investigate
> > > [ 3.921912] imx8m_blk_ctrl_power_on dispblk-mipi-dsi
> > > [ 3.926936] imx_pgc_power_up dispmix
> > > [ 3.931109] imx_pgc_power_up mipi
> > > [ 3.935409] imx8m_blk_ctrl_power_on dispblk-lcdif
> > > [ 3.940547] imx8m_blk_ctrl_power_off dispblk-lcdif
> > > [ 3.945626] [drm] Initialized mxsfb-drm 1.0.0 20160824 for
> > > 32e00000.lcdif on minor 0
> > > ^^^ not clear why dispblk-lcdif got disabled here
> >
> > I've reproduced this. look like lcdif power-domains are not notified
> > ON. checking on the power-sequence for lcdif side. old patches from
> > Lucas on v5.13 seems working as expected.
>
> I've found the issue on lcdif atomic_enable, where the bus format is
> retrieved from NULL bus_state. Here is the diff for it.
>
> --- a/drivers/gpu/drm/mxsfb/mxsfb_kms.c
> +++ b/drivers/gpu/drm/mxsfb/mxsfb_kms.c
> @@ -359,13 +359,14 @@ static void mxsfb_crtc_atomic_enable(struct
> drm_crtc *crtc,
> drm_crtc_vblank_on(crtc);
>
> /* If there is a bridge attached to the LCDIF, use its bus format */
> - if (mxsfb->bridge) {
> + if (mxsfb->bridge && state) {
> bridge_state =
> drm_atomic_get_new_bridge_state(state,
> mxsfb->bridge);
> - bus_format = bridge_state->input_bus_cfg.format;
> + if (bridge_state)
> + bus_format = bridge_state->input_bus_cfg.format;
>'
> I believe this can be fixed via DSIM bridge. working on for those
> changes, the key challenges is to make the DSIM to work even for
> exynos, which indeed blocker for me to validate in hardware (i don't
> have DSI based exynos).
>
> Meanwhile, I have posed RFC for DSIM DTS changes, please check it here.
> https://patchwork.kernel.org/project/dri-devel/cover/20211111101456.584061-1-jagan@amarulasolutions.com/
>
Jagan,
Thank you! This does resolve the hang on my end as well. I will look
at your 'arm64: imx8mm: Add MIPI DSI support' series.
There was some discussion regarding giving up on trying to split up
the exynos driver such that it could work with IMX8MM vs just
duplicating it. I thought the recommendation was to duplicate it as it
wasn't clear if there was a way to split it out without breaking
current exynos DSI but I'll have to see if I can find the thread.
Best regards,
Tim
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