Hi support team
I have a i.MX 8M plus board also implement LVDS display.
LVDS display well but brightness can not be control.
The log response "Display brightness support: false"
pwm_bl driver is working.
I can control the brightness from command line as below.
echo 1 > /sys/devices/platform/lvds_backlight/backlight/lvds_backlight/brightness
01-01 00:00:11.934 489 489 I SystemServer: StartLightsService
01-01 00:00:11.934 489 489 I SystemServiceManager: Starting com.android.server.lights.LightsService
01-01 00:00:11.940 489 489 D LightsService: Display brightness support: false
01-01 00:00:11.941 489 489 I chatty : uid=1000 system_server identical 6 lines
01-01 00:00:11.941 489 489 D LightsService: Display brightness support: false
......
LocalDisplayAdapter: tryConnectDisplayLocked 16625703383590656
01-01 00:00:11.959 330 487 E SurfaceFlinger: ro.sf.lcd_density must be defined as a build property
01-01 00:00:11.959 489 511 W LocalDisplayAdapter: tryConnectDisplayLocked 16625703383590656
01-01 00:00:11.959 489 511 W LocalDisplayAdapter: tryConnectDisplayLocked isInternal true
01-01 00:00:11.960 489 511 W LocalDisplayAdapter: internel LocalDisplayDevice 16625703383590656
01-01 00:00:11.960 489 511 W LocalDisplayAdapter: tryConnectDisplayLocked device != null
01-01 00:00:11.968 489 511 I DisplayManagerService: Display device added: DisplayDeviceInfo{"?批遣?恍": uniqueId="local:16625703383590656", 1280 x 800, modeId 1, defaultModeId 1, supportedModes [{id=1, width=1280, height=800, fps=52.0}], colorMode 0, supportedColorModes [0], HdrCapabilities android.view.Display$HdrCapabilities@40f16308, density 150, 149.824 x 149.411 dpi, appVsyncOff 1000000, presDeadline 19230769, touch INTERNAL, rotation 0, type BUILT_IN, address {port=0, model=0x3b10fd3851e7}, state UNKNOWN, FLAG_DEFAULT_DISPLAY, FLAG_ROTATES_WITH_CONTENT, FLAG_SECURE, FLAG_SUPPORTS_PROTECTED_BUFFERS}
below is dts
reg_lvds_pwr: regulator_lvdspwr {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_lvds0_pwr>;
compatible = "regulator-fixed";
regulator-name = "lvds0_vdden";
regulator-min-microvolt = <3300000>;
regulator-max-microvolt = <3300000>;
gpio = <&gpio4 12 GPIO_ACTIVE_HIGH>;
enable-active-high;
};
reg_lvds_backlight_pwr: regulator_lvdsblpwr {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_lvds0_backlight_pwr>;
compatible = "regulator-fixed";
regulator-name = "lvds0_bl_en";
regulator-min-microvolt = <3300000>;
regulator-max-microvolt = <3300000>;
gpio = <&gpio4 14 GPIO_ACTIVE_HIGH>;
enable-active-high;
regulator-always-on;
};
lvds_backlight: lvds_backlight {
compatible = "pwm-backlight";
pwms = <&pwm2 0 50000>;
power-supply = <®_lvds_backlight_pwr>;
brightness-levels = <0 36 72 108 144 180 216 255>;
default-brightness-level = <6>;
status = "okay";
};
lvds0_panel {
compatible = "vxt,vl10112880", "panel-lvds";
backlight = <&lvds_backlight>;
power-supply = <®_lvds_pwr>;
data-mapping = "vesa-24";
data-width = <24>;
height-mm = <136>; /* 135.6 */
width-mm = <217>; /* 216.96 */
panel-timing {
clock-frequency = <71100000>;
hactive = <1280>;
vactive = <800>;
hback-porch = <100>;
hfront-porch = <60>;
vback-porch = <15>;
vfront-porch = <8>;
hsync-len = <80>;
vsync-len = <80>;
};
port {
panel_lvds_in: endpoint {
remote-endpoint = <&lvds_out>;
};
};
};
&ldb {
status = "okay";
lvds-channel@0 {
fsl,data-mapping = "spwg";
fsl,data-width = <24>;
status = "okay";
port@1 {
reg = <1>;
lvds_out: endpoint {
remote-endpoint = <&panel_lvds_in>;
};
};
};
};
Thank you.
James
Solved! Go to Solution.
Hi James
one can look at EVK brightness example
Best regards
igor
Hi James
one can look at EVK brightness example
Best regards
igor
Hi Igor
Thank you for your help. The problem solved.
About display brightness not support problem I also modify init.rc as below
# Default backlight device
#setprop hw.backlight.dev "32e60000.mipi_dsi.0"
# Chmod/chown FSL specific sys entry
#chown system system /sys/class/backlight/32e60000.mipi_dsi.0/brightness
#chmod 0660 /sys/class/backlight/32e60000.mipi_dsi.0/brightness
setprop hw.backlight.dev "lvds_backlight"
chown system system /sys/class/backlight/lvds_backlight/brightness
chmod 0660 /sys/class/backlight/lvds_backlight/brightness
Best regards
James