[PATCH] arm64: dts: imx8mm: Add CSI nodes

Adam Ford aford173 at gmail.com
Fri Oct 15 16:05:18 PDT 2021


On Fri, Oct 15, 2021 at 5:39 PM Laurent Pinchart
<laurent.pinchart at ideasonboard.com> wrote:
>
> Hi Adam,
>
> On Fri, Oct 15, 2021 at 05:26:03PM -0500, Adam Ford wrote:
> > On Thu, Oct 14, 2021 at 4:16 PM Laurent Pinchart wrote:
> > > On Thu, Oct 14, 2021 at 03:32:33PM -0500, Adam Ford wrote:
> > > > On Wed, Oct 13, 2021 at 9:52 PM Adam Ford wrote:
> > > > >
> > > > > There is a csi bridge and csis interface that tie together
> > > > > to allow csi2 capture.
> > > > >
> > > > > Signed-off-by: Adam Ford <aford173 at gmail.com>
> > > >
> > > > Laurent,
> > > >
> > > > Since you did some work to make the csis functional on the imx8mm, I
> > > > was hoping you might have some insights.  Please see below:
> > > >
> > > > > diff --git a/arch/arm64/boot/dts/freescale/imx8mm.dtsi b/arch/arm64/boot/dts/freescale/imx8mm.dtsi
> > > > > index c2f3f118f82e..8a8a5d0a4a1e 100644
> > > > > --- a/arch/arm64/boot/dts/freescale/imx8mm.dtsi
> > > > > +++ b/arch/arm64/boot/dts/freescale/imx8mm.dtsi
> > > > > @@ -1068,6 +1068,22 @@ aips4: bus at 32c00000 {
> > > > >                         #size-cells = <1>;
> > > > >                         ranges = <0x32c00000 0x32c00000 0x400000>;
> > > > >
> > > > > +                       csi: csi at 32e20000 {
> > > > > +                               compatible = "fsl,imx7-csi";
> > >
> > > This should be
> > >
> > >         compatible = "fsl,imx8mm-csi", "fsl,imx7-csi";;
> > >
> > > > > +                               reg = <0x32e20000 0x1000>;
> > > > > +                               interrupts = <GIC_SPI 16 IRQ_TYPE_LEVEL_HIGH>;
> > > > > +                               clocks = <&clk IMX8MM_CLK_CSI1_ROOT>;
> > > > > +                               clock-names = "mclk";
> > > > > +                               power-domains = <&disp_blk_ctrl IMX8MM_DISPBLK_PD_CSI_BRIDGE>;
> > > > > +                               status = "disabled";
> > > > > +
> > > > > +                               port {
> > > > > +                                       csi_in: endpoint {
> > > > > +                                               remote-endpoint = <&imx8mm_mipi_csi_out>;
> > > > > +                                       };
> > > > > +                               };
> > > > > +                       };
> > > > > +
> > > > >                         disp_blk_ctrl: blk-ctrl at 32e28000 {
> > > > >                                 compatible = "fsl,imx8mm-disp-blk-ctrl", "syscon";
> > > > >                                 reg = <0x32e28000 0x100>;
> > > > > @@ -1095,6 +1111,41 @@ disp_blk_ctrl: blk-ctrl at 32e28000 {
> > > > >                                 #power-domain-cells = <1>;
> > > > >                         };
> > > > >
> > > > > +                       mipi_csi2: mipi-csi at 32e30000 {
> > > > > +                               compatible = "fsl,imx8mm-mipi-csi2";
> > > > > +                               reg = <0x32e30000 0x1000>;
> > > > > +                               interrupts = <GIC_SPI 17 IRQ_TYPE_LEVEL_HIGH>;
> > > > > +                               clock-frequency = <333000000>;
> > > > > +                               clocks = <&clk IMX8MM_CLK_DISP_APB_ROOT>,
> > > > > +                                        <&clk IMX8MM_CLK_CSI1_ROOT>,
> > > > > +                                        <&clk IMX8MM_CLK_CSI1_PHY_REF>,
> > > > > +                                        <&clk IMX8MM_CLK_DISP_AXI_ROOT>;
> > > >
> > > > When comparing clock parents and the clock rates to one of NXP's
> > > > kernels, it appears we need assigned-clocks and assigned-clock-parents
> > > > to allow the CSI1 clocks to run fast enough.
> > > >
> > > > assigned-clocks = <&clk IMX8MM_CLK_CSI1_PHY_REF>,
> > > >   <&clk IMX8MM_CLK_CSI1_CORE>,
> > > >   <&clk IMX8MM_CLK_CSI1_ROOT>,
> > > >   <&clk IMX8MM_CLK_CSI1_ESC>;
> > > > assigned-clock-parents = <&clk IMX8MM_SYS_PLL2_1000M>,
> > > >   <&clk IMX8MM_SYS_PLL2_1000M>,
> > > >   <&clk IMX8MM_CLK_CSI1_CORE>,
> > > >   <&clk IMX8MM_SYS_PLL1_800M>;
> > > >
> > > > However, even with this, I am attempting to capture.  While I can get
> > > > the pipeline enabled, when I try to capture a file, I get no data.  i
> > > > can use control-c to exit gstreamer, so I know the kernel didn't hang.
> > > > I don't get errors, but I don't get data either.
> > > >
> > > > Any ideas if what/if any other clock entries might be missing?
> > >
> > > Have you tried looking at the error interrupt counters to see if the
> > > CSI-2 bus side operates as expected ? I'd start there before blaming the
> > > clocks. Note that the issue could also be in the CSI bridge.
> >
> > I am not seeing interrupts on either the CSI, mipi-csi, or err:
> >
> >  54:          0          0          0          0     GICv3  48 Level     csi
> >  55:          0          0          0          0     GICv3  49 Level
> >   32e30000.mipi-csi
> > Err:          0
> >
> > > I've had issues capturing from one particular sensor on an i.MX8MM
> > > board, where I would get images, but with heavy corruption. The problem
> > > was solved by chance when trying a different SPL binary. I need to
> >
> > I wonder if the issue was related to different versions of ATF, and
> > depending on the power domain controls used, it could have been using
> > ATF to set the power domains.
> > I've had issues in the past too, but I have tried a couple different
> > binaries, and I am not seeing a change in behavior.
>
> We've just finished the investigation, and it turned out to be related
> to the clock frequencies. Here's the DT changes we had to make to get it
> working:
>
>         assigned-clocks = <&clk IMX8MM_CLK_DISP_AXI>,
>                 <&clk IMX8MM_CLK_DISP_AXI_ROOT>,
>                 <&clk IMX8MM_CLK_DISP_APB>,
>                 <&clk IMX8MM_CLK_DISP_APB_ROOT>;
>         assigned-clock-parents = <&clk IMX8MM_SYS_PLL2_1000M>,
>                 <&clk IMX8MM_CLK_DISP_AXI>,
>                 <&clk IMX8MM_SYS_PLL1_800M>,
>                 <&clk IMX8MM_CLK_DISP_APB>;
>         assigned-clock-rates = <500000000>, <500000000>, <200000000>, <200000000>;
>
> This results in the following clock configuration:
>
> sys_pll2_1000m 1000000000
>  disp_axi 500000000
>   disp_axi_root_clk 500000000
>
> sys_pll1_800m 800000000
>  disp_apb 200000000
>   disp_apb_root_clk 200000000
>
> I'll check which clock is the culprit, and see if we could program the
> clocks in the driver directly.

I am using Shawn Guo's "for-next" branch, and by default the disp_axi
and disp_apb clocks appear to already have these parents and clock
rates.  They appear to be defined in the pgc_dispmix node.

          disp_axi                    1        1        0   500000000
        0     0  50000         Y
             disp_axi_root_clk        2        2        0   500000000
        0     0  50000         Y
          disp_apb                    1        1        0   200000000
        0     0  50000         Y
             disp_apb_root_clk        2        2        0   200000000
        0     0  50000         Y

Can you tell me which branch you're using?  I wonder if I should
switch branches.

adam
>
> > > investigate the differences there, and possibly update the driver
> > > accordingly. It may or may not be related to your issue.
> > >
> > > Apart from the compatible string issue mentioned above, the bindings
> > > match what I am using, so, with the compatible string fixed,
> >
> > Out of curiosity, I noticed the default csi clock parents point to a
> > 24MHz clock, but the csi-2 interface wants to set the clock to 333MHz.
> > Any chance you could share your clk_summary?
>
> Is the above information what you need ?
>
> > > Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> >
> > Thanks for the review
> >
> > > > > +                               clock-names = "pclk", "wrap", "phy", "axi";
> > > > > +                               power-domains = <&disp_blk_ctrl IMX8MM_DISPBLK_PD_MIPI_CSI>;
> > > > > +                               status = "disabled";
> > > > > +
> > > > > +                               ports {
> > > > > +                                       #address-cells = <1>;
> > > > > +                                       #size-cells = <0>;
> > > > > +
> > > > > +                                       port at 0 {
> > > > > +                                               reg = <0>;
> > > > > +
> > > > > +                                               imx8mm_mipi_csi_in: endpoint {
> > > > > +                                               };
> > > > > +                                       };
> > > > > +
> > > > > +                                       port at 1 {
> > > > > +                                               reg = <1>;
> > > > > +
> > > > > +                                               imx8mm_mipi_csi_out: endpoint {
> > > > > +                                                       remote-endpoint = <&csi_in>;
> > > > > +                                               };
> > > > > +                                       };
> > > > > +                               };
> > > > > +                       };
> > > > > +
> > > > > +
> > > > >                         usbotg1: usb at 32e40000 {
> > > > >                                 compatible = "fsl,imx8mm-usb", "fsl,imx7d-usb";
> > > > >                                 reg = <0x32e40000 0x200>;
>
> --
> Regards,
>
> Laurent Pinchart



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