topic Re: How To set MIPI Clock in IMX8M Nano? in i.MX Processors

How To set MIPI Clock in IMX8M Nano?

milav_soni — Sat, 11 Jun 2022 13:18:22 GMT

Hello Guys,

I want to set MIPI Clock in imx8m nano Board.

Can you please help me with how I can add frequency to the Device Tree File?

And what is the meaning of "link-frequencies" in the following snapshot?

&mipi_csi_1 { #address-cells = <1>; #size-cells = <0>; status = "okay"; port@0 { reg = <0>; mipi1_sensor_ep: endpoint { remote-endpoint = <&ov5640_ep>; data-lanes = <4>; link-frequencies = /bits/ 64 <496000000>; //extra csis-hs-settle = <13>; //orig csis-clk-settle = <2>; //orig csis-wclk; }; }; };

Following is the imx8mn.dtsi file snapshot.

mipi_csi_1: csi@32e30000 { compatible = "fsl,imx8mn-mipi-csi"; reg = <0x0 0x32e30000 0x0 0x10000>; interrupts = <GIC_SPI 17 IRQ_TYPE_LEVEL_HIGH>; clock-frequency = <333000000>; clocks = <&clk IMX8MN_CLK_CAMERA_PIXEL>, <&clk IMX8MN_CLK_DISP_AXI_ROOT>, <&clk IMX8MN_CLK_DISP_APB_ROOT>; clock-names = "mipi_clk", "disp_axi", "disp_apb"; assigned-clocks = <&clk IMX8MN_CLK_CAMERA_PIXEL>; assigned-clock-parents = <&clk IMX8MN_SYS_PLL2_1000M>; assigned-clock-rates = <333000000>; bus-width = <4>; csi-gpr = <&mipi2csi_gasket>; power-domains = <&mipi_pd>; resets = <&mipi_csi_resets>; status = "disabled"; };

please help me out with how I can update the MIPI D−PHY Clock Rate?

Thank You

Re: How To set MIPI Clock in IMX8M Nano?

Zhiming_Liu — Mon, 13 Jun 2022 05:52:45 GMT

What the value of clock do you want to generate?

Re: How To set MIPI Clock in IMX8M Nano?

milav_soni — Mon, 13 Jun 2022 06:17:02 GMT

Hello @Zhiming_Liu

Thank You for your Reply.

Actually, I want to know what is the meaning of link frequencies in the following section?

ov5640: ov5640_mipi@3c { compatible = "ovti,ov5640"; reg = <0x36>; pinctrl-names = "default"; pinctrl-0 = <&pinctrl_csi_pwn>, <&pinctrl_csi_rst>; clocks = <&clk IMX8MN_CLK_CLKO1>; clock-names = "xclk"; assigned-clocks = <&clk IMX8MN_CLK_CLKO1>; assigned-clock-parents = <&clk IMX8MN_CLK_24M>; assigned-clock-rates = <27000000>; csi_id = <0>; xclk-gpios = <&gpio2 9 GPIO_ACTIVE_HIGH>; reset-gpios = <&gpio1 11 GPIO_ACTIVE_HIGH>; mclk = <27000000>; mclk_source = <0>; mipi_csi; status = "okay"; port { ov5640_ep: endpoint { remote-endpoint = <&mipi1_sensor_ep>; data-lanes = <1 2 3 4>; clocks-lanes = <0>; link-frequencies = /bits/ 64 <496000000>; --> What is the menaing of this? }; }; }; &mipi_csi_1 { #address-cells = <1>; #size-cells = <0>; status = "okay"; port@0 { reg = <0>; mipi1_sensor_ep: endpoint { remote-endpoint = <&ov5640_ep>; data-lanes = <4>; link-frequencies = /bits/ 64 <496000000>; //extra csis-hs-settle = <13>; //orig csis-clk-settle = <2>; //orig csis-wclk; }; }; };

Is link frequencies mean pixel frequency? or else bandwidth?

Another thing I want to know is that, Is my camera MIPI rate and imx8m nano MIPI rate are the same or not?

The camera set the following values,

Pixel clock:- 82.8 Mhz
Data rate per lane:- 206Mpbs/lane
MIPI Clock Rate:- 103 Mhz

Can you please help me out?

Thank You

Re: How To set MIPI Clock in IMX8M Nano?

Zhiming_Liu — Wed, 15 Jun 2022 04:49:41 GMT

For the meaning of camera dts node, you can find answers in Documentation/devicetree/bindings/media/video-interfaces.txt

Is my camera MIPI rate and imx8m nano MIPI rate are the same or not?

-->Not same but the MIPI support this rate.