Hi,
I am using this type of display: https://www.newhavendisplay.com/specs/NHD-1.8-128160EF-SSXN-F.pdf
The communication to the display is through the spidev1.0, which is working. I would like to enable the class backlight to connect the PWM_3_DSI to a PWM-input to the display.
I have a patch file and a defconfig that I am including with a linux-toradex_%.bbappend -file.
I am running the following commands:
$ bitbake -c clean virtual/kernel
$ bitbake -c clean tdx-reference-minimal-image
$ bitbake virtual/kernel
$ bitbake tdx-reference-minimal-image
Then I extract the minimal image .tar file, put it on a USB and connect it to the dev board. But it seems that my .patch did not affect the availability of the class backlight since the directory is empty.
Am I doing anything wrong in the build process?
This is my linux-toradex_%.bbappend -file:
FILEEXTRAPATHS_prepend := “${THISDIR}/linux-toradex:”
unset KBUILD_DECONFIG
SRC_URI += "file://0001-display2.patch
file://defconfig
"
This is my defconfig file:
CONFIG_BACKLIGHT_GENERIC=m
CONFIG_BACKLIGHT_PWM=y
CONFIG_BACKLIGHT_GPIO=y
CONFIG_COMMON_CLK_PWM=y
CONFIG_PWM=y
CONFIG_PWM_BCM2835=m
CONFIG_PWM_CROS_EC=m
CONFIG_PWM_FSL_FTM=y
CONFIG_PWM_IMX=y
This is my patchfile:
diff --git a/imx8mm-verdin-wifi-dev.dts.orig b/imx8mm-verdin-wifi-dev.dts.astrid
index ae71a5d…4fa49d3 100755
— a/imx8mm-verdin-wifi-dev.dts
+++ b/imx8mm-verdin-wifi-dev.dts
@@ -16,3 +16,45 @@
“toradex,verdin-imx8mm”,
“fsl,imx8mm”;
};
+
+ aliases {
+ backlight_mipi = &backlight_mipi;
+ fb_mipi = &fb_mipi;
+ lcdif = &lcdif;
+ mipi = &fb_mipi;
+ mipi_cmds_ltk0680ytmdb = &mipi_cmds_ltk0680ytmdb;
+ mipi_cmds_ltk080a60a004t = &mipi_cmds_ltk080a60a004t;
+ mipi_cmds_m101nwwb = &mipi_cmds_ltk080a60a004t; /* Same commands work for both /
+ mipi_dsi = &mipi_dsi;
+ mipi_to_lvds = &mipi_to_lvds;
+ pinctrl_ltk0680ytmdb = &pinctrl_ltk0680ytmdb;
+ pinctrl_ltk080a60a004t = &pinctrl_ltk080a60a004t;
+ t_mipi = &t_mipi;
+ };
+
+
+ backlight_mipi: backlight-mipi {
+ brightness-levels = <0 1 2 3 4 5 6 7 8 9 10>;
+ compatible = “pwm-backlight”;
+ default-brightness-level = <8>;
+ display = <&display_subsystem>;
+ pwms = <&pwm3 0 30000>; / 33.3 Khz /
+ status = “okay”;
+ };
+
+
+&ecspi2 {
+ pinctrl-names = “default”;
+ pinctrl-0 = <&pinctrl_ecspi2>;
+ fsl,spi-num-chipselects = <1>;
+ cs-gpios = GP_ECSPI2_CS0;
+ status = “okay”;
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ spidev@0 {
+ compatible = “spidev”;
+ spi-max-frequency = <2000000>;
+ reg = <0>;
+ };
+};
+ backlight: backlight {
+ compatible = “pwm-backlight”;
+ brightness-levels = <0 45 63 88 119 158 203 255>;
+ default-brightness-level = <4>;
+ / Verdin I2S_2_D_OUT (DSI_1_BKL_EN/DSI_1_BKL_EN_LVDS, SODIMM 46) /
+ enable-gpios = <&gpio3 24 GPIO_ACTIVE_HIGH>;
+ pinctrl-names = “default”;
+ pinctrl-0 = <&pinctrl_i2s_2_d_out_dsi_1_bkl_en>;
+ power-supply = <®_3p3v>;
+ / Verdin PWM_3_DSI/PWM_3_DSI_LVDS (SODIMM 19) /
+ pwms = <&pwm1 0 6666667 PWM_POLARITY_INVERTED>;
- status = “disabled”;
+ status = “okay”;
+ };
+/ Verdin PWM_3_DSI */
+&pwm1 {
+ pinctrl-names = “default”;
+ pinctrl-0 = <&pinctrl_pwm_1>;
+ #pwm-cells = <3>;
+ status = “okay”;
+};
Here is a tree of how I put the files under my meta-layer.
Thank you very much for the support,
Astrid
