why don't activated on imx8mq android p9.0.0_1.0.0-ga

[ksw1]

I want to use GPIO1_IO01 pin as backlight-pwm.

I already check pwm (for lcd backlight) in L4.9.88_2.0.0 package.

when boot on, backlight is turn-on and pwm pulse is generated in GPIO1_IO01 pin

but in android p9.0.0_1.0.0-ga package, pwm pulse do not enabled.

how can I enable pwm in GPIO1_IO01 pin ???

please guide to me.

my dts file is below.

/ {
 lvds_backlight0: backlight {
  compatible = "pwm-backlight";
  pwms = <&pwm1 0 1000000 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 = <80>;
  enable = <&gpio1 1 GPIO_ACTIVE_HIGH>;
  fb-names = "HY070NA01D";
  status = "okay";
 };
};

&pwm1 {
    pinctrl-names = "default";
    pinctrl-0 = <&pinctrl_pwm1>;
 status = "okay";
};

&iomuxc {
 imx8mq-evk {
  pinctrl_mipi_dsi_en: mipi_dsi_en {
   fsl,pins = <
    MX8MQ_IOMUXC_ECSPI1_SCLK_GPIO5_IO6 0x16
   >;
  };

  pinctrl_pwm1: pwm1grp {
   fsl,pins = <
    MX8MQ_IOMUXC_GPIO1_IO01_PWM1_OUT         0x06
   >;
  };
 };
};

[huilaizhan]

Hi sangwook:

I think that the issue is caused by default backlight device has been changed in android p9.

After boot, you can check the backlight device :

# getprop hw.backlight.dev

On android  p9, the device is 30a00000.mipi_dsi_bridge.0, which is registed by panel-raydium-rm67191.

When we change the backlight to PWM1, the device is "pwm-backlight.0" yet, which can be found in /sys/class/backlight.

It cause the backlight HAL can not find the correct backlight devices.

To correct it , you need to change the file :

/device/fsl/imx8m/evk_8mq/init.rc

change:

setprop hw.backlight.dev "30a00000.mipi_dsi_bridge.0"

to

setprop hw.backlight.dev "pwm-backlight" or  setprop hw.backlight.dev  "pwm-backlight.0" 

according to the filename displayed in  /sys/class/ on target board.

[ksw1]

Hi. igorpadykov

Sure. I rebuilded all kerel and android full build.

Same kernel DTS file and Panel driver source file used in L4.9.88_2.0.0 package merged in android p9.0.0_1.0.0-ga sw.

I modified panel drm driver (panel-raydium-rm67191.c) and touch driver (use goodix.c) .

After same source file merged and full- rebuild (4.14 kerel of android p9.0.0_1.0.0-ga sw),

I already checked PWM-backlight woring fine in L4.9.88_2.0.0 package.

but in android p9.0.0_1.0.0-ga sw, i can not see pwm pulse.

I want to use GPIO1_IO01 pin as PWM for backlight.

Where can I check what source or DTS files???

[igorpadykov]

>Where can I check what source or DTS files?

freescale\dts\boot\arm64\arch - linux-imx - i.MX Linux kernel 

Best regards
igor

[ksw1]

Please check and explain detail.

Could you check above my dts and explain to eable PWM sequence?

To enable pwm-pulse (GPIO1_IO01 pin) for LCD backlight,

is there any problem above in my dts ?

I also checked kernel configuration for PWM.

CONFIG_PWM=y
CONFIG_PWM_SYSFS=y
CONFIG_PWM_IMX=y

all OK, and full rebuiled kernel and android.

[igorpadykov]

one can try to debug it using pwm description in sect.2.7 Pulse-Width Modulator (PWM)

attached Linux Manual.

Best regards
igor

[igorpadykov]

Hi sangwook

android p9.0.0_1.0.0 uses L4.14 kernels as described on below links,

so one can try to rebuild image from scratch with correct kernel

i.MX Software | NXP 

i.MX Android proprietary Source Code

Best regards
igor
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