大家好！我在用AM3358驱动一块10.1寸液晶，背光采用了eCap0。现在遇到的问题是背光的PWM波完全没有输出。我检查了管脚定义和dts文件，感觉也没什么问题。下面是我的dts内容，是基于am335x-evm编写的。请问是否有错误呢？
/*
* Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
/dts-v1/;
#include "am33xx.dtsi"
#include "am335x-bone-common.dtsi"
#include <dt-bindings/display/tda998x.h>
/ {
model = "TI AM335x BeagleBone Black";
compatible = "ti,am335x-bone-black", "ti,am335x-bone", "ti,am33xx";
};
&ldo3_reg {
regulator-min-microvolt = <1800000>;
regulator-max-microvolt = <1800000>;
regulator-always-on;
};
&mmc1 {
vmmc-supply = <&vmmcsd_fixed>;
};
&mmc2 {
vmmc-supply = <&vmmcsd_fixed>;
pinctrl-names = "default";
pinctrl-0 = <&emmc_pins>;
bus-width = <8>;
status = "okay";
};
&cpu0_opp_table {
/*
* All PG 2.0 silicon may not support 1GHz but some of the early
* BeagleBone Blacks have PG 2.0 silicon which is guaranteed
* to support 1GHz OPP so enable it for PG 2.0 on this board.
*/
oppnitro@1000000000 {
opp-supported-hw = <0x06 0x0100>;
};
};
&am33xx_pinmux {
/* 删除 2017-10-24 */
// nxp_hdmi_bonelt_pins: nxp_hdmi_bonelt_pins {
// pinctrl-single,pins = <
// AM33XX_IOPAD(0x9b0, PIN_OUTPUT_PULLDOWN | MUX_MODE3) /* xdma_event_intr0 */
// AM33XX_IOPAD(0x8a0, PIN_OUTPUT | MUX_MODE0) /* lcd_data0.lcd_data0 */
// AM33XX_IOPAD(0x8a4, PIN_OUTPUT | MUX_MODE0) /* lcd_data1.lcd_data1 */
// AM33XX_IOPAD(0x8a8, PIN_OUTPUT | MUX_MODE0) /* lcd_data2.lcd_data2 */
// AM33XX_IOPAD(0x8ac, PIN_OUTPUT | MUX_MODE0) /* lcd_data3.lcd_data3 */
// AM33XX_IOPAD(0x8b0, PIN_OUTPUT | MUX_MODE0) /* lcd_data4.lcd_data4 */
// AM33XX_IOPAD(0x8b4, PIN_OUTPUT | MUX_MODE0) /* lcd_data5.lcd_data5 */
// AM33XX_IOPAD(0x8b8, PIN_OUTPUT | MUX_MODE0) /* lcd_data6.lcd_data6 */
// AM33XX_IOPAD(0x8bc, PIN_OUTPUT | MUX_MODE0) /* lcd_data7.lcd_data7 */
// AM33XX_IOPAD(0x8c0, PIN_OUTPUT | MUX_MODE0) /* lcd_data8.lcd_data8 */
// AM33XX_IOPAD(0x8c4, PIN_OUTPUT | MUX_MODE0) /* lcd_data9.lcd_data9 */
// AM33XX_IOPAD(0x8c8, PIN_OUTPUT | MUX_MODE0) /* lcd_data10.lcd_data10 */
// AM33XX_IOPAD(0x8cc, PIN_OUTPUT | MUX_MODE0) /* lcd_data11.lcd_data11 */
// AM33XX_IOPAD(0x8d0, PIN_OUTPUT | MUX_MODE0) /* lcd_data12.lcd_data12 */
// AM33XX_IOPAD(0x8d4, PIN_OUTPUT | MUX_MODE0) /* lcd_data13.lcd_data13 */
// AM33XX_IOPAD(0x8d8, PIN_OUTPUT | MUX_MODE0) /* lcd_data14.lcd_data14 */
// AM33XX_IOPAD(0x8dc, PIN_OUTPUT | MUX_MODE0) /* lcd_data15.lcd_data15 */
// AM33XX_IOPAD(0x8e0, PIN_OUTPUT_PULLDOWN | MUX_MODE0) /* lcd_vsync.lcd_vsync */
// AM33XX_IOPAD(0x8e4, PIN_OUTPUT_PULLDOWN | MUX_MODE0) /* lcd_hsync.lcd_hsync */
// AM33XX_IOPAD(0x8e8, PIN_OUTPUT_PULLDOWN | MUX_MODE0) /* lcd_pclk.lcd_pclk */
// AM33XX_IOPAD(0x8ec, PIN_OUTPUT_PULLDOWN | MUX_MODE0) /* lcd_ac_bias_en.lcd_ac_bias_en */
// >;
// };
// nxp_hdmi_bonelt_off_pins: nxp_hdmi_bonelt_off_pins {
// pinctrl-single,pins = <
// AM33XX_IOPAD(0x9b0, PIN_OUTPUT_PULLDOWN | MUX_MODE3) /* xdma_event_intr0 */
// >;
// };
/* 增加LCD节点管脚和背光控制节点管脚 2017-10-24 */
lcd_pins_default: lcd_pins_default {
pinctrl-single,pins = <
AM33XX_IOPAD(0x890, PIN_OUTPUT_PULLUP | MUX_MODE7) /* gpio2_2 lcd_backlight enable control */
AM33XX_IOPAD(0x8a0, PIN_OUTPUT | MUX_MODE0) /* lcd_data0.lcd_data0 */
AM33XX_IOPAD(0x8a4, PIN_OUTPUT | MUX_MODE0) /* lcd_data1.lcd_data1 */
AM33XX_IOPAD(0x8a8, PIN_OUTPUT | MUX_MODE0) /* lcd_data2.lcd_data2 */
AM33XX_IOPAD(0x8ac, PIN_OUTPUT | MUX_MODE0) /* lcd_data3.lcd_data3 */
AM33XX_IOPAD(0x8b0, PIN_OUTPUT | MUX_MODE0) /* lcd_data4.lcd_data4 */
AM33XX_IOPAD(0x8b4, PIN_OUTPUT | MUX_MODE0) /* lcd_data5.lcd_data5 */
AM33XX_IOPAD(0x8b8, PIN_OUTPUT | MUX_MODE0) /* lcd_data6.lcd_data6 */
AM33XX_IOPAD(0x8bc, PIN_OUTPUT | MUX_MODE0) /* lcd_data7.lcd_data7 */
AM33XX_IOPAD(0x8c0, PIN_OUTPUT | MUX_MODE0) /* lcd_data8.lcd_data8 */
AM33XX_IOPAD(0x8c4, PIN_OUTPUT | MUX_MODE0) /* lcd_data9.lcd_data9 */
AM33XX_IOPAD(0x8c8, PIN_OUTPUT | MUX_MODE0) /* lcd_data10.lcd_data10 */
AM33XX_IOPAD(0x8cc, PIN_OUTPUT | MUX_MODE0) /* lcd_data11.lcd_data11 */
AM33XX_IOPAD(0x8d0, PIN_OUTPUT | MUX_MODE0) /* lcd_data12.lcd_data12 */
AM33XX_IOPAD(0x8d4, PIN_OUTPUT | MUX_MODE0) /* lcd_data13.lcd_data13 */
AM33XX_IOPAD(0x8d8, PIN_OUTPUT | MUX_MODE0) /* lcd_data14.lcd_data14 */
AM33XX_IOPAD(0x8dc, PIN_OUTPUT | MUX_MODE0) /* lcd_data15.lcd_data15 */
AM33XX_IOPAD(0x8e0, PIN_OUTPUT | MUX_MODE0) /* lcd_vsync.lcd_vsync */
AM33XX_IOPAD(0x8e4, PIN_OUTPUT | MUX_MODE0) /* lcd_hsync.lcd_hsync */
AM33XX_IOPAD(0x8e8, PIN_OUTPUT | MUX_MODE0) /* lcd_pclk.lcd_pclk */
AM33XX_IOPAD(0x8ec, PIN_OUTPUT | MUX_MODE0) /* lcd_ac_bias_en.lcd_ac_bias_en */
>;
};
lcd_pins_sleep: lcd_pins_sleep {
pinctrl-single,pins = <
AM33XX_IOPAD(0x890, PULL_DISABLE | MUX_MODE7) /* gpio2_2 lcd_backlight enable control */
AM33XX_IOPAD(0x8a0, PULL_DISABLE | MUX_MODE7) /* lcd_data0.lcd_data0 */
AM33XX_IOPAD(0x8a4, PULL_DISABLE | MUX_MODE7) /* lcd_data1.lcd_data1 */
AM33XX_IOPAD(0x8a8, PULL_DISABLE | MUX_MODE7) /* lcd_data2.lcd_data2 */
AM33XX_IOPAD(0x8ac, PULL_DISABLE | MUX_MODE7) /* lcd_data3.lcd_data3 */
AM33XX_IOPAD(0x8b0, PULL_DISABLE | MUX_MODE7) /* lcd_data4.lcd_data4 */
AM33XX_IOPAD(0x8b4, PULL_DISABLE | MUX_MODE7) /* lcd_data5.lcd_data5 */
AM33XX_IOPAD(0x8b8, PULL_DISABLE | MUX_MODE7) /* lcd_data6.lcd_data6 */
AM33XX_IOPAD(0x8bc, PULL_DISABLE | MUX_MODE7) /* lcd_data7.lcd_data7 */
AM33XX_IOPAD(0x8c0, PULL_DISABLE | MUX_MODE7) /* lcd_data8.lcd_data8 */
AM33XX_IOPAD(0x8c4, PULL_DISABLE | MUX_MODE7) /* lcd_data9.lcd_data9 */
AM33XX_IOPAD(0x8c8, PULL_DISABLE | MUX_MODE7) /* lcd_data10.lcd_data10 */
AM33XX_IOPAD(0x8cc, PULL_DISABLE | MUX_MODE7) /* lcd_data11.lcd_data11 */
AM33XX_IOPAD(0x8d0, PULL_DISABLE | MUX_MODE7) /* lcd_data12.lcd_data12 */
AM33XX_IOPAD(0x8d4, PULL_DISABLE | MUX_MODE7) /* lcd_data13.lcd_data13 */
AM33XX_IOPAD(0x8d8, PULL_DISABLE | MUX_MODE7) /* lcd_data14.lcd_data14 */
AM33XX_IOPAD(0x8dc, PULL_DISABLE | MUX_MODE7) /* lcd_data15.lcd_data15 */
AM33XX_IOPAD(0x8e0, PIN_INPUT_PULLDOWN | MUX_MODE7) /* lcd_vsync.lcd_vsync */
AM33XX_IOPAD(0x8e4, PIN_INPUT_PULLDOWN | MUX_MODE7) /* lcd_hsync.lcd_hsync */
AM33XX_IOPAD(0x8e8, PIN_INPUT_PULLDOWN | MUX_MODE7) /* lcd_pclk.lcd_pclk */
AM33XX_IOPAD(0x8ec, PIN_INPUT_PULLDOWN | MUX_MODE7) /* lcd_ac_bias_en.lcd_ac_bias_en */
>;
};
/* 背光控制节点 */
ecap0_pins: backlight_pins {
pinctrl-single,pins = <
AM33XX_IOPAD(0x964, MUX_MODE0) /* eCAP0_in_PWM0_out.eCAP0_in_PWM0_out */
>;
};
mcasp0_pins: mcasp0_pins {
pinctrl-single,pins = <
AM33XX_IOPAD(0x9ac, PIN_INPUT_PULLUP | MUX_MODE0) /* mcasp0_ahcklx.mcasp0_ahclkx */
AM33XX_IOPAD(0x99c, PIN_OUTPUT_PULLDOWN | MUX_MODE2) /* mcasp0_ahclkr.mcasp0_axr2*/
AM33XX_IOPAD(0x994, PIN_OUTPUT_PULLUP | MUX_MODE0) /* mcasp0_fsx.mcasp0_fsx */
AM33XX_IOPAD(0x990, PIN_OUTPUT_PULLDOWN | MUX_MODE0) /* mcasp0_aclkx.mcasp0_aclkx */
AM33XX_IOPAD(0x86c, PIN_OUTPUT_PULLDOWN | MUX_MODE7) /* gpmc_a11.GPIO1_27 */
>;
};
};
&lcdc {
status = "okay";
/* If you want to get 24 bit RGB and 16 BGR mode instead of
* current 16 bit RGB and 24 BGR modes, set the propety
* below to "crossed" and uncomment the video-ports -property
* in tda19988 node.
*/
blue-and-red-wiring = "straight";
/* 删除 2017-10-23
* port {
* lcdc_0: endpoint@0 {
* remote-endpoint = <&hdmi_0>;
* };
* };
*/
};
/* 删除此节点，2017-10-23， */
//&i2c0 {
// tda19988: tda19988 {
// compatible = "nxp,tda998x";
// reg = <0x70>;
// pinctrl-names = "default", "off";
// pinctrl-0 = <&nxp_hdmi_bonelt_pins>;
// pinctrl-1 = <&nxp_hdmi_bonelt_off_pins>;
/* Convert 24bit BGR to RGB, e.g. cross red and blue wiring */
/* video-ports = <0x234501>; */
// #sound-dai-cells = <0>;
// audio-ports = < TDA998x_I2S 0x03>;
// ports {
// port@0 {
// hdmi_0: endpoint@0 {
// remote-endpoint = <&lcdc_0>;
// };
// };
// };
// };
//};
&rtc {
system-power-controller;
};
&mcasp0 {
#sound-dai-cells = <0>;
pinctrl-names = "default";
pinctrl-0 = <&mcasp0_pins>;
status = "okay";
op-mode = <0>; /* MCASP_IIS_MODE */
tdm-slots = <2>;
serial-dir = < /* 0: INACTIVE, 1: TX, 2: RX */
0 0 1 0
>;
tx-num-evt = <32>;
rx-num-evt = <32>;
};
&sgx {
status = "okay";
};
/* 增加背光控制节点 2017-10-24 */
&epwmss0 {
status = "okay";
ecap0: ecap@48300100 {
status = "okay";
pinctrl-names = "default";
pinctrl-0 = <&ecap0_pins>;
};
};
/* 增加触摸屏节点 2017-10-24 */
&tscadc {
status = "okay";
tsc {
ti,wires = <4>;
ti,x-plate-resistance = <235>;
ti,coordinate-readouts = <5>;
ti,wire-config = <0x00 0x11 0x22 0x33>;
ti,charge-delay = <0x400>;
};
};
/ {
clk_mcasp0_fixed: clk_mcasp0_fixed {
#clock-cells = <0>;
compatible = "fixed-clock";
clock-frequency = <24576000>;
};
clk_mcasp0: clk_mcasp0 {
#clock-cells = <0>;
compatible = "gpio-gate-clock";
clocks = <&clk_mcasp0_fixed>;
enable-gpios = <&gpio1 27 0>; /* BeagleBone Black Clk enable on GPIO1_27 */
};
/* 以下部分删除,2017-10-23
*sound {
* compatible = "simple-audio-card";
* simple-audio-card,name = "TI BeagleBone Black";
* simple-audio-card,format = "i2s";
* simple-audio-card,bitclock-master = <&dailink0_master>;
* simple-audio-card,frame-master = <&dailink0_master>;
* dailink0_master: simple-audio-card,cpu {
* sound-dai = <&mcasp0>;
* clocks = <&clk_mcasp0>;
* };
* simple-audio-card,codec {
* sound-dai = <&tda19988>;
* };
*};
*/
// 添加下面的LCD面板，背光控制节点
lcd_bl: backlight {
compatible = "pwm-backlight";
pwms = <&ecap0 0 5000000 0>; // 用ecap0节点 0通道 5000000nS(200Hz) 正极性
brightness-levels = <0 51 53 56 62 75 101 152 200 255>; // 增加一个亮度 200,方便测试
default-brightness-level = <8>;
};
panel {
compatible = "ti,tilcdc,panel";
// pinctrl-names = "default", "sleep";
pinctrl-names = "default";
pinctrl-0 = <&lcd_pins_default>;
// pinctrl-1 = <&lcd_pins_sleep>;
backlight = <&lcd_bl>;
enable-gpios = <&gpio2 2 GPIO_ACTIVE_HIGH>;
status = "okay";
panel-info {
ac-bias = <255>;
ac-bias-intrpt = <0>;
dma-burst-sz = <16>;
bpp = <16>;
fdd = <0x80>;
sync-edge = <0>;
sync-ctrl = <1>;
raster-order = <0>;
fifo-th = <0>;
};
display-timings {
1280x800 {
hactive = <1280>;
vactive = <800>;
hback-porch = <159>;
hfront-porch = <0>;
hsync-len = <0>;
vback-porch = <0>;
vfront-porch = <23>;
vsync-len = <0>;
clock-frequency = <71100000>;
hsync-active = <0>;
vsync-active = <0>;
};
};
};
};
------------------------------------------------------------------------------------------------------------
另外，我在启动日志里发现了下面的提示错误，会有影响吗？
[ 0.318778] pwm-backlight backlight: GPIO lookup for consumer enable
[ 0.318789] pwm-backlight backlight: using device tree for GPIO lookup
[ 0.318800] of_get_named_gpiod_flags: can't parse 'enable-gpios' property of node '/backlight[0]'
[ 0.318807] of_get_named_gpiod_flags: can't parse 'enable-gpio' property of node '/backlight[0]'
[ 0.318812] pwm-backlight backlight: using lookup tables for GPIO lookup
[ 0.318818] pwm-backlight backlight: lookup for GPIO enable failed
[ 0.318836] backlight supply power not found, using dummy regulator
[ 0.985953] panel panel: found backlight
谢谢！