Help configuring i.MX6 IPUv3 with a parrallel display

[Philippe Leduc]

Hello,

I would like to use the barebox framebuffer on a iMX6S chip. My goal
is to display a splashscreen. However, I can't manage to use the
framebuffer for now...

Here is the output of "devinfo fb0":
Resources:
  num: 0
  start: 0x00000000
  size: 0x00000000
Available modes:
Parameters:
  enable: 0
  mode_name: invalid:0
  shadowfb: 1

Is this a correct behavior that there is NO availables modes? I do not
manage to add one through the DTS.

If I try to enable the framebuffer (fb0.enable=1), barebox hangs:
fb0.enable=1
unable to handle NULL pointer dereference at address 0x0000001d
pc : [<2ff1ab1c>]    lr : [<2ff17f41>]
sp : 2ffffa3c  ip : 2ff1a3fa  fp : 2ffffa78
r10: 20212d0c  r9 : 00000000  r8 : 00000000
r7 : 20024210  r6 : f57fffff  r5 : 0c000000  r4 : 0000001d
r3 : 2ff1a1e5  r2 : 0c000000  r1 : 0000005c  r0 : 00000022
Flags: nzcv  IRQs off  FIQs off  Mode SVC_32
[<2ff1ab1c>] (clk_is_enabled+0x34/0x38) from [<7f8d1fc0>] (0x7f8d1fc0)

[<2ff389d9>] (unwind_backtrace+0x1/0x58) from [<2ff00d19>] (panic+0x1d/0x34)
[<2ff00d19>] (panic+0x1d/0x34) from [<2ff38e7d>] (do_exception+0xd/0x10)
[<2ff38e7d>] (do_exception+0xd/0x10) from [<2ff38edd>] (do_data_abort+0x21/0x2c)
[<2ff38edd>] (do_data_abort+0x21/0x2c) from [<2ff38bd4>] (do_abort_6+0x48/0x54)
Switch to console [serial0]

Here is what I put in the DTS to enable the display:

display0: display at di0 {
      compatible = "fsl,imx-parallel-display";
//      crtcs = <&ipu1 0>;
      interface-pix-fmt = "rgb24";
      pinctrl-names = "default";
      pinctrl-0 = <&pinctrl_ipu_disp>;
      status = "okay";

      display-timings {
        rk043fn07h {
          native-mode;
          clock-frequency = <9000000 15000000>;
          hactive = <480>;
          vactive = <272>;
          hfront-porch = <2 2 82>;
          hback-porch = <2 2 41>;
          hsync-len = <2 41 41>;
          vback-porch = <1 2 11>;
          vfront-porch = <1 2 227>;
          vsync-len = <1 10 11>;
          pixelclk-active = <1>;
          hsync-active = <0>;
          vsync-active = <0>;
          de-active = <1>;
        };
      };

      port {
        display0_in: endpoint {
          remote-endpoint = <&ipu1_di0_disp0>;
        };
      };


&ipu1_di0_disp0 {
  remote-endpoint = <&display0_in>;
};

Thank you in advance,

Best regards,

--
Philippe LEDUC
ledphilippe at gmail.com