i.MX8Q 设置背光PWM无输出

cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 

i.MX8Q 设置背光PWM无输出

1,129 Views
lizboxy
Contributor I
imx8q 使用SC_P_MIPI_DSI0_GPIO0_00_MIPI_DSI0_PWM0_OUT作为背光PWM输出,电路板PWM口电压一直为0V,请帮忙看看有哪些建议,谢谢! 在fsl-imx8qm-mek.dtsi添加如下内容: 步骤1; gen_backlight0: gen_backlight@0 { compatible = "pwm-backlight"; pwms = <&pwm0 0 100000 0>; brightness-levels = < 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100>; default-brightness-level = <60>; }; }; 步骤2: pinctrl_pwm0_lsio: pwm0grp { fsl,pins = < //SC_P_UART1_TX_LSIO_PWM0_OUT 0x0000020 SC_P_MIPI_DSI0_GPIO0_00_MIPI_DSI0_PWM0_OUT 0x00000020 //20200910 >; }; 步骤3: &pwm0{ pinctrl-names = "default"; pinctrl-0 = <&pinctrl_pwm0_lsio>; status = "okay"; }; 串口消息: [ 1.412894] pwm-backlight gen_backlight@0: gen_backlight@0 supply power not found, using dummy regulator [ 1.422349] pwm-backlight gen_backlight@0: Linked as a consumer to regulator.0 [ 1.440864] Bus freq driver module loaded 串口输入命令: root@imx8qmmek:/sys/class/backlight/gen_backlight@0# ls actual_brightness brightness max_brightness subsystem uevent bl_power device power type root@imx8qmmek:/sys/class/backlight/gen_backlight@0# root@imx8qmmek:/sys/class/backlight/gen_backlight@0# root@imx8qmmek:/sys/class/backlight/gen_backlight@0# echo 50 >brightness root@imx8qmmek:/sys/class/backlight/gen_backlight@0# cat brightness 50
0 Kudos
2 Replies

1,128 Views
lizboxy
Contributor I

fsl-imx8qm-mek.dtsi添加如下内容:

步骤1

gen_backlight0: gen_backlight@0 {

                compatible = "pwm-backlight";

                pwms = <&pwm0 0 100000 0>;

                brightness-levels = < 0  1  2  3  4  5  6  7  8  9

                                     10 11 12 13 14 15 16 17 18 19

                                     20 21 22 23 24 25 26 27 28 29

                                     30 31 32 33 34 35 36 37 38 39

                                     40 41 42 43 44 45 46 47 48 49

                                     50 51 52 53 54 55 56 57 58 59

                                     60 61 62 63 64 65 66 67 68 69

                                     70 71 72 73 74 75 76 77 78 79

                                     80 81 82 83 84 85 86 87 88 89

                                     90 91 92 93 94 95 96 97 98 99

                                    100>;

                default-brightness-level = <60>;

        };

};

 

步骤2

pinctrl_pwm0_lsio: pwm0grp {

                       fsl,pins = <

                            //SC_P_UART1_TX_LSIO_PWM0_OUT                 0x0000020

                     SC_P_MIPI_DSI0_GPIO0_00_MIPI_DSI0_PWM0_OUT 0x00000020 //20200910     

                       >;

                };

 

步骤3

&pwm0{

       pinctrl-names = "default";

       pinctrl-0 = <&pinctrl_pwm0_lsio>;

       status = "okay";

};

串口消息:

[    1.412894] pwm-backlight gen_backlight@0: gen_backlight@0 supply power not found, using dummy regulator

[    1.422349] pwm-backlight gen_backlight@0: Linked as a consumer to regulator.0

[    1.440864] Bus freq driver module loaded

串口输入命令:

root@imx8qmmek:/sys/class/backlight/gen_backlight@0# ls

actual_brightness  brightness  max_brightness  subsystem  uevent

bl_power           device      power           type

root@imx8qmmek:/sys/class/backlight/gen_backlight@0# 

root@imx8qmmek:/sys/class/backlight/gen_backlight@0# 

root@imx8qmmek:/sys/class/backlight/gen_backlight@0# echo 50 >brightness 

root@imx8qmmek:/sys/class/backlight/gen_backlight@0# cat brightness 50

0 Kudos

1,124 Views
jimmychan
NXP TechSupport
NXP TechSupport

According to the pads-imx8qm.h, the name of the pin should be

IMX8QM_MIPI_DSI0_GPIO0_00_MIPI_DSI0_PWM0_OUT

0 Kudos