MIPI-DSI on an iMX95 no clock output Software summary
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Bootloader: U-Boot
Kernel version: 6.6.138-7.6.1-devel #1 SMP PREEMPT Fri May 8 12:46:27 UTC 2026
Kernel command line: root=PARTUUID=74fae1d2-02 ro rootwait console=tty1 console=ttyLP0,115200
Distro name: NAME="TDX Wayland with XWayland Upstream"
Distro version: VERSION_ID=7.6.1-devel-20260728203137-build.0
Distro variant: -
Hostname: bmr-verdin-imx95-08828817
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Hardware info
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HW model: Toradex Verdin iMX95 WB on Verdin Development Board
Toradex version: 0089 V1.0C
Serial number: 08828817
Processor arch: aarch64
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We have a custom carrier board with the Toradex Verdin iMX95. We are running the Toradex multimedia image with customizations (the base device tree is imx95-verdin-wifi-dev.dts). We have a custom display from YES Optoelectronics (7” 1024x600) that is a MIPI-DSI 4 lane interface. I used the device tree and driver model from the raydium rm67191 as the starting point. I am able to get the power supply timing correct on startup and the backlight comes on and the BIST works (there is a pin on the display that can be pulled high for BIST), so I believe the display is working. All four data lanes show single-ended activity but the CLK lines are at 0 volts. At power up the CLK lines start at around 200mV and then they go to 1.2 volts for a little bit but then they go to 0 volts and they stay at 0 volts. I know the verdin SoM works because I can get the RVT70HSDNWCA0 display to work on a Mallow carrier board. The driver goes through probe → add panel → get modes → prepare → enable. Am I forgetting to turn on or configure a clock somewhere maybe? What does it mean when the CLK signals (both P and N) are at 0 volts? My overlay looks like /dts-v1/;
/plugin/;
&mipi_dsi {
status = "okay";
panel@0 {
compatible = "yes,ytc700tlbd";
reg = <0>;
reset-gpios = <&gpio2 17 1>;//GPIO_ACTIVE_HIGH>;
power-supply = <®_vcc_disp_dvdd>;
backlight = <&lvds_backlight>;
dsi-lanes = <4>;
port@0 {
reg = <0>;
panel1_in: endpoint {
remote-endpoint = <&mipi1_panel_out>;
};
};
};
ports {
/delete-node/ port@1;
port@1 {
reg = <1>;
mipi1_panel_out: endpoint {
remote-endpoint = <&panel1_in>;
};
};
};
};
&displaymix_irqsteer {
status = "okay";
};
&dpu {
assigned-clocks = <&scmi_clk 80>, //IMX95_CLK_DISP1PIX>,
<&scmi_clk 18>, //IMX95_CLK_VIDEOPLL1_VCO>,
<&scmi_clk 19>; //IMX95_CLK_VIDEOPLL1>;
assigned-clock-parents = <&scmi_clk 19>; //IMX95_CLK_VIDEOPLL1>;
assigned-clock-rates = <0>, <3360000000>, <420000000>;
status = "okay";
};
&pixel_interleaver {
#address-cells = <1>;
#size-cells = <0>;
status = "okay";
channel@0 {
reg = <0>;
status = "okay";
};
};
&display_pixel_link {
status = "okay";
}; Can someone confirm they were able to get a MIPI-DSI display to work with the iMX95? Any help would be appreciated! Graphics & Display Linux Multimedia Re: MIPI-DSI on an iMX95 no clock output Also, here is what my clock summary looks like. cat /sys/kernel/debug/clk/clk_summary | grep -iE "mipi|dsi|dpu|display"
ldbpll_vco 0 0 0 4800000000 0 0 50000 Y 4b400000.display-controller ldb_vco
ldb_pll_div7 0 0 0 342857142 0 0 50000 Y 4b400000.display-controller ldb
mipiphypllbypas 0 0 0 420000000 0 0 50000 Y deviceless no_connection_id
disp1pix 1 1 0 46666666 0 0 50000 Y 4b400000.display-controller pix
dispapb 4 5 0 133333333 0 0 50000 Y 4b400000.display-controller apb
camapb 3 6 0 133333333 0 0 50000 Y 4acf0000.dsi pclk
dispocram 1 1 0 400000000 0 0 50000 Y 4b400000.display-controller ocram
dispaxi 1 1 0 800000000 0 0 50000 Y 4b400000.display-controller axi
mipitestbyte 0 0 0 24000000 0 0 50000 Y deviceless no_connection_id
mipiphypllref 1 1 0 24000000 0 0 50000 Y 4acf0000.dsi ref
mipiphycfg 1 1 0 24000000 0 0 50000 Y 4acf0000.dsi cfg Re: MIPI-DSI on an iMX95 no clock output The target pixel clock is 51.2MHz. Re: MIPI-DSI on an iMX95 no clock output Hi @dastotz Please share the screen's pixel clock. Best Regards, Zhiming Re: MIPI-DSI on an iMX95 no clock output Here is my updated clock summary. cat /sys/kernel/debug/clk/clk_summary | grep -iE "mipi|dsi|dpu|display|video"
ldbpll_vco 0 0 0 4800000000 0 0 50000 Y 4b400000.display-controller ldb_vco
ldb_pll_div7 0 0 0 342857142 0 0 50000 Y 4b400000.display-controller ldb
videopll1_vco 1 1 0 2520000000 0 0 50000 Y deviceless no_connection_id
videopll1 1 1 0 252000000 0 0 50000 Y deviceless no_connection_id
disp1pix 1 1 0 50400000 0 0 50000 Y 4b400000.display-controller pix
4acf0000.dsi pix
mipiphypllbypas 0 0 0 252000000 0 0 50000 Y deviceless no_connection_id
dispapb 4 5 0 133333333 0 0 50000 Y 4b400000.display-controller apb
camapb 3 6 0 133333333 0 0 50000 Y 4acf0000.dsi pclk
dispocram 1 1 0 400000000 0 0 50000 Y 4b400000.display-controller ocram
dispaxi 1 1 0 800000000 0 0 50000 Y 4b400000.display-controller axi
mipitestbyte 0 0 0 24000000 0 0 50000 Y deviceless no_connection_id
mipiphypllref 1 1 0 24000000 0 0 50000 Y 4acf0000.dsi ref
mipiphycfg 1 1 0 24000000 0 0 50000 Y 4acf0000.dsi cfg Re: MIPI-DSI on an iMX95 no clock output There is still no high speed video data. The CLK signals stay at 0 volts and the DATA signals are single ended (no differential output). Does a display need to respond to a LPM command for the MIPI-DSI interface to switch to high speed mode? Re: MIPI-DSI on an iMX95 no clock output Hi @dastotz
For a 51.2 MHz pixel clock, the PLL VCO should be 1792 MHz, and the PLL OUT should be 256 MHz. You can try to update the device tree and then check the logs to see if the PLL VCO, PLL OUT, and pixel clock are correct. Best Regards, Zhiming Re: MIPI-DSI on an iMX95 no clock output You are absolutely right; this was the problem! I chose one of those clock rates just to see if my oscilloscope would show a clock and now it does! I will update this post with the final settings and accept this as the solution once I get a clock rate closer to my desired rate. Thank you so much for the help! Re: MIPI-DSI on an iMX95 no clock output Hi @dastotz
Please try to use this configuration to get 51.2MHz pixel clock.
&dpu {
assigned-clocks = <&scmi_clk IMX95_CLK_DISP1PIX>,
<&scmi_clk IMX95_CLK_VIDEOPLL1_VCO>,
<&scmi_clk IMX95_CLK_VIDEOPLL1>;
assigned-clock-parents = <&scmi_clk IMX95_CLK_VIDEOPLL1>;
assigned-clock-rates = <0>, <3276800000>, <409600000>;
}; root@imx95evk:~# cat /sys/kernel/debug/clk/clk_summary | grep -iE "mipi|dsi|dpu|display|video"
ldbpll_vco 0 0 0 4800000000 0 0 50000 Y 4b400000.display-controller ldb_vco
ldb_pll_div7 0 0 0 342857142 0 0 50000 Y 4b400000.display-controller ldb
videopll1_vco 1 1 0 3276800000 0 0 50000 Y deviceless no_connection_id
videopll1 1 1 0 409600000 0 0 50000 Y deviceless no_connection_id
disp1pix 1 1 0 51200000 0 0 50000 Y 4b400000.display-controller pix
4acf0000.dsi pix
But the NXP didn't verified the 1024x600. According to a recent commit to the NXP linux-imx repository, the modes verified by NXP are as follows:
3 static bool imx95_dsi_is_mode_clock_valid(unsigned int clock)
914 {
915 switch (clock) {
916 case 25200: /* 640x480@60Hz (VGA) */
917 case 27000: /*
[email protected],
[email protected] (NTSC) */
918 case 27027: /* 480p@60Hz, 720x480@60Hz */
919 case 40000: /* 800x600@60Hz (SVGA) */
920 case 54000: /*
[email protected], 720x576@100Hz */
921 case 54054: /* 480p@120Hz, 720x480@120Hz */
922 case 65000: /* 1024x768@60Hz (XGA) */
923 case 74176: /*
[email protected],
[email protected] */
924 case 74250: /* 720p@60Hz, 1280x720@60Hz */
925 case 108000: /*
[email protected], 1280x1024@60Hz (SXGA) */
926 case 108108: /* 480p@240Hz, 720x480@240Hz */
927 case 132000: /* 1024x768@120Hz (XGA) */
928 case 148352: /*
[email protected],
[email protected] */
929 case 148500: /* 1080p@60Hz, 1920x1080@60Hz */
930 case 297000: /* 2160p@30Hz, 1080p@120Hz, 3840x2160@30Hz (4K) */
931 return true;
932 default:
933 return false;
934 }
935 }
According to the public code from here : https://github.com/nxp-imx/linux-imx/blob/lf-6.18.20-2.0.0/drivers/gpu/drm/bridge/imx/imx95-mipi-dsi.c#L883
If the clock is not verified clocks, the DSI will not generate clock. You could try to modify this line to return MODE_OK while the mode->clock = 51200. Best Regards, Zhiming
