ILI9881C device-tree modification

trongthinh — Wed, 10 Apr 2019 10:18:05 GMT

I am working on MIPI pannel (panel-iliteck-ili9881). I back port the driver panel-iliteck-ili9881c.c from kernel 4.19 to kernel 4.9.88. Fortunately, I can compile and make this driver works (know this by adding debug log to driver). Now I get trouble at modifying device tree.

There are lots of clock definition. which value that I need to modified? how to calculate these clock value?

Below is a part of my device tree that I modified for new LCD pannel

&hdmi {

status = "disabled";

};

&dcss {

status = "okay";

disp-dev = "mipi_disp";

clocks = <&clk IMX8MQ_CLK_DISP_APB_ROOT>,

<&clk IMX8MQ_CLK_DISP_AXI_ROOT>,

<&clk IMX8MQ_CLK_DISP_RTRM_ROOT>,

<&clk IMX8MQ_CLK_DC_PIXEL_DIV>,

<&clk IMX8MQ_CLK_DUMMY>,

<&clk IMX8MQ_CLK_DISP_DTRC_DIV>;

clock-names = "apb", "axi", "rtrm", "pix_div", "pix_out", "dtrc";

assigned-clocks = <&clk IMX8MQ_CLK_DC_PIXEL_SRC>,

<&clk IMX8MQ_CLK_DISP_AXI_SRC>,

<&clk IMX8MQ_CLK_DISP_RTRM_SRC>,

<&clk IMX8MQ_VIDEO_PLL1_REF_SEL>,

<&clk IMX8MQ_CLK_DISP_RTRM_PRE_DIV>,

<&clk IMX8MQ_VIDEO_PLL1>;

assigned-clock-parents = <&clk IMX8MQ_VIDEO_PLL1_OUT>,

<&clk IMX8MQ_SYS1_PLL_800M>,

<&clk IMX8MQ_CLK_25M>;

assigned-clock-rates = <600000000>,

<800000000>,

<400000000>,

<0>,

<400000000>,

<599999999>;

dcss_disp0: port@0 {

reg = <0>;

dcss_disp0_mipi_dsi: mipi_dsi {

remote-endpoint = <&mipi_dsi_in>;

};

&mipi_dsi_phy {

status = "okay";

};

&mipi_dsi {

status = "okay";

assigned-clocks = <&clk IMX8MQ_CLK_DSI_PHY_REF_SRC>,

<&clk IMX8MQ_CLK_DSI_CORE_SRC>,

<&clk IMX8MQ_VIDEO_PLL1_REF_SEL>,

<&clk IMX8MQ_VIDEO_PLL1>;

assigned-clock-parents = <&clk IMX8MQ_VIDEO_PLL1_OUT>,

<&clk IMX8MQ_SYS1_PLL_266M>,

<&clk IMX8MQ_CLK_25M>;

assigned-clock-rates = <24000000>,

<266000000>,

<0>,

<599999999>;

port@1 {

mipi_dsi_in: endpoint {

remote-endpoint = <&dcss_disp0_mipi_dsi>;

};

&mipi_dsi_bridge {

status = "okay";

panel@0 {

compatible = "bananapi,lhr050h41", "ilitek,ili9881c";

reg = <0>;

pinctrl-0 = <&pinctrl_mipi_dsi_en>;

reset-gpio = <&gpio5 6 GPIO_ACTIVE_HIGH>;

// dsi-lanes = <4>;

// panel-width-mm = <68>;

// panel-height-mm = <121>;

port {

panel1_in: endpoint {

remote-endpoint = <&mipi_dsi_bridge_out>;

};

port@1 {

mipi_dsi_bridge_out: endpoint {

remote-endpoint = <&panel1_in>;

};

Re: ILI9881C device-tree modification

igorpadykov — Wed, 10 Apr 2019 11:48:48 GMT

Hi Thinh

for new mipi-lcd one can use linux driver panel-raydium-rm67191.c:
fsl-imx8mq-evk-dcss-rm67191.dts\freescale\dts\boot\arm64\arch - linux-imx - i.MX Linux kernel
panel-raydium-rm67191.c\panel\drm\gpu\drivers - linux-imx - i.MX Linux kernel
use struct display_timing rad_default_timing[] for adjusting custom panel timings.
For available clocks one can look in
clk-imx8mq.c\imx\clk\drivers - linux-imx - i.MX Linux kernel

supported formats in imx_dcss.c fb_videomode imx_cea_mode:
imx_dcss.c\mxc\fbdev\video\drivers - linux-imx - i.MX Linux kernel

Best regards
igor
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ILI9881C device-tree modification

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