arm Linux 驱动LED子系统 测试
Linux内核在3.0以上引入了设备树概念（具体哪个版本不清楚）在编译内核后需要将与之对应的dtb文件也下载人板子上才能使内核与硬件关联起来。
dtb文件是有dts文件编译后生成的：例如
/* * 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. */ /* * AM335x Starter Kit * http://www.ti.com/tool/tmdssk3358 */ /dts-v1/; #include "am33xx.dtsi" #include <dt-bindings/pwm/pwm.h> / { model = "TI AM335x EVM-SK"; compatible = "ti,am335x-evmsk", "ti,am33xx"; cpus { cpu@0 { cpu0-supply = <&vdd1_reg>; }; }; memory { device_type = "memory"; reg = <0x80000000 0x10000000>; /* 256 MB */ }; vbat: fixedregulator@0 { compatible = "regulator-fixed"; regulator-name = "vbat"; regulator-min-microvolt = <5000000>; regulator-max-microvolt = <5000000>; regulator-boot-on; }; lis3_reg: fixedregulator@1 { compatible = "regulator-fixed"; regulator-name = "lis3_reg"; regulator-boot-on; }; leds { pinctrl-names = "default"; pinctrl-0 = <&user_leds_s0>; compatible = "gpio-leds"; led@1 { label = "zyrD1:green:usr0"; gpios = <&gpio1 4 GPIO_ACTIVE_HIGH>; default-state = "off"; }; led@2 { label = "zyrD2:green:usr1"; gpios = <&gpio1 5 GPIO_ACTIVE_HIGH>; default-state = "off"; }; led@3 { label = "zyrD4:green:mmc0"; gpios = <&gpio1 6 GPIO_ACTIVE_HIGH>; linux,default-trigger = "mmc0"; default-state = "off"; }; led@4 { label = "zyrD3:green:heartbeat"; gpios = <&gpio1 7 GPIO_ACTIVE_HIGH>; linux,default-trigger = "heartbeat"; default-state = "off"; }; }; gpio_buttons: gpio_buttons@0 { compatible = "gpio-keys"; #address-cells = <1>; #size-cells = <0>; switch@1 { label = "button0"; linux,code = <0x100>; gpios = <&gpio2 3 GPIO_ACTIVE_HIGH>; }; switch@2 { label = "button1"; linux,code = <0x101>; gpios = <&gpio2 2 GPIO_ACTIVE_HIGH>; }; switch@3 { label = "button2"; linux,code = <0x102>; gpios = <&gpio0 30 GPIO_ACTIVE_HIGH>; gpio-key,wakeup; }; switch@4 { label = "button3"; linux,code = <0x103>; gpios = <&gpio2 5 GPIO_ACTIVE_HIGH>; }; }; backlight { compatible = "pwm-backlight"; pwms = <&ecap2 0 50000 PWM_POLARITY_INVERTED>; brightness-levels = <0 58 61 66 75 90 125 170 255>; default-brightness-level = <8>; }; sound { compatible = "ti,da830-evm-audio"; ti,model = "AM335x-EVMSK"; ti,audio-codec = <&tlv320aic3106>; ti,mcasp-controller = <&mcasp1>; ti,codec-clock-rate = <24000000>; ti,audio-routing = "Headphone Jack", "HPLOUT", "Headphone Jack", "HPROUT"; }; }; &am33xx_pinmux { pinctrl-names = "default"; pinctrl-0 = <&gpio_keys_s0 &clkout2_pin>; user_leds_s0: user_leds_s0 { pinctrl-single,pins = < 0x10 (PIN_OUTPUT_PULLDOWN | MUX_MODE7) /* gpmc_ad4.gpio1_4 */ 0x14 (PIN_OUTPUT_PULLDOWN | MUX_MODE7) /* gpmc_ad5.gpio1_5 */ 0x18 (PIN_OUTPUT_PULLDOWN | MUX_MODE7) /* gpmc_ad6.gpio1_6 */ 0x1c (PIN_OUTPUT_PULLDOWN | MUX_MODE7) /* gpmc_ad7.gpio1_7 */ >; }; gpio_keys_s0: gpio_keys_s0 { pinctrl-single,pins = < 0x94 (PIN_INPUT_PULLDOWN | MUX_MODE7) /* gpmc_oen_ren.gpio2_3 */ 0x90 (PIN_INPUT_PULLDOWN | MUX_MODE7) /* gpmc_advn_ale.gpio2_2 */ 0x70 (PIN_INPUT_PULLDOWN | MUX_MODE7) /* gpmc_wait0.gpio0_30 */ 0x9c (PIN_INPUT_PULLDOWN | MUX_MODE7) /* gpmc_ben0_cle.gpio2_5 */ >; }; i2c0_pins: pinmux_i2c0_pins { pinctrl-single,pins = < 0x188 (PIN_INPUT_PULLUP | MUX_MODE0) /* i2c0_sda.i2c0_sda */ 0x18c (PIN_INPUT_PULLUP | MUX_MODE0) /* i2c0_scl.i2c0_scl */ >; }; uart0_pins: pinmux_uart0_pins { pinctrl-single,pins = < 0x170 (PIN_INPUT_PULLUP | MUX_MODE0) /* uart0_rxd.uart0_rxd */ 0x174 (PIN_OUTPUT_PULLDOWN | MUX_MODE0) /* uart0_txd.uart0_txd */ >; }; clkout2_pin: pinmux_clkout2_pin { pinctrl-single,pins = < 0x1b4 (PIN_OUTPUT_PULLDOWN | MUX_MODE3) /* xdma_event_intr1.clkout2 */ >; }; ecap2_pins: backlight_pins { pinctrl-single,pins = < 0x19c 0x4 /* mcasp0_ahclkr.ecap2_in_pwm2_out MODE4 */ >; }; cpsw_default: cpsw_default { pinctrl-single,pins = < /* Slave 1 */ 0x114 (PIN_OUTPUT_PULLDOWN | MUX_MODE2) /* mii1_txen.rgmii1_tctl */ 0x118 (PIN_INPUT_PULLDOWN | MUX_MODE2) /* mii1_rxdv.rgmii1_rctl */ 0x11c (PIN_OUTPUT_PULLDOWN | MUX_MODE2) /* mii1_txd3.rgmii1_td3 */ 0x120 (PIN_OUTPUT_PULLDOWN | MUX_MODE2) /* mii1_txd2.rgmii1_td2 */ 0x124 (PIN_OUTPUT_PULLDOWN | MUX_MODE2) /* mii1_txd1.rgmii1_td1 */ 0x128 (PIN_OUTPUT_PULLDOWN | MUX_MODE2) /* mii1_txd0.rgmii1_td0 */ 0x12c (PIN_OUTPUT_PULLDOWN | MUX_MODE2) /* mii1_txclk.rgmii1_tclk */ 0x130 (PIN_INPUT_PULLDOWN | MUX_MODE2) /* mii1_rxclk.rgmii1_rclk */ 0x134 (PIN_INPUT_PULLDOWN | MUX_MODE2) /* mii1_rxd3.rgmii1_rd3 */ 0x138 (PIN_INPUT_PULLDOWN | MUX_MODE2) /* mii1_rxd2.rgmii1_rd2 */ 0x13c (PIN_INPUT_PULLDOWN | MUX_MODE2) /* mii1_rxd1.rgmii1_rd1 */ 0x140 (PIN_INPUT_PULLDOWN | MUX_MODE2) /* mii1_rxd0.rgmii1_rd0 */ /* Slave 2 */ 0x40 (PIN_OUTPUT_PULLDOWN | MUX_MODE2) /* gpmc_a0.rgmii2_tctl */ 0x44 (PIN_INPUT_PULLDOWN | MUX_MODE2) /* gpmc_a1.rgmii2_rctl */ 0x48 (PIN_OUTPUT_PULLDOWN | MUX_MODE2) /* gpmc_a2.rgmii2_td3 */ 0x4c (PIN_OUTPUT_PULLDOWN | MUX_MODE2) /* gpmc_a3.rgmii2_td2 */ 0x50 (PIN_OUTPUT_PULLDOWN | MUX_MODE2) /* gpmc_a4.rgmii2_td1 */ 0x54 (PIN_OUTPUT_PULLDOWN | MUX_MODE2) /* gpmc_a5.rgmii2_td0 */ 0x58 (PIN_OUTPUT_PULLDOWN | MUX_MODE2) /* gpmc_a6.rgmii2_tclk */ 0x5c (PIN_INPUT_PULLDOWN | MUX_MODE2) /* gpmc_a7.rgmii2_rclk */ 0x60 (PIN_INPUT_PULLDOWN | MUX_MODE2) /* gpmc_a8.rgmii2_rd3 */ 0x64 (PIN_INPUT_PULLDOWN | MUX_MODE2) /* gpmc_a9.rgmii2_rd2 */ 0x68 (PIN_INPUT_PULLDOWN | MUX_MODE2) /* gpmc_a10.rgmii2_rd1 */ 0x6c (PIN_INPUT_PULLDOWN | MUX_MODE2) /* gpmc_a11.rgmii2_rd0 */ >; }; cpsw_sleep: cpsw_sleep { pinctrl-single,pins = < /* Slave 1 reset value */ 0x114 (PIN_INPUT_PULLDOWN | MUX_MODE7) 0x118 (PIN_INPUT_PULLDOWN | MUX_MODE7) 0x11c (PIN_INPUT_PULLDOWN | MUX_MODE7) 0x120 (PIN_INPUT_PULLDOWN | MUX_MODE7) 0x124 (PIN_INPUT_PULLDOWN | MUX_MODE7) 0x128 (PIN_INPUT_PULLDOWN | MUX_MODE7) 0x12c (PIN_INPUT_PULLDOWN | MUX_MODE7) 0x130 (PIN_INPUT_PULLDOWN | MUX_MODE7) 0x134 (PIN_INPUT_PULLDOWN | MUX_MODE7) 0x138 (PIN_INPUT_PULLDOWN | MUX_MODE7) 0x13c (PIN_INPUT_PULLDOWN | MUX_MODE7) 0x140 (PIN_INPUT_PULLDOWN | MUX_MODE7) /* Slave 2 reset value*/ 0x40 (PIN_INPUT_PULLDOWN | MUX_MODE7) 0x44 (PIN_INPUT_PULLDOWN | MUX_MODE7) 0x48 (PIN_INPUT_PULLDOWN | MUX_MODE7) 0x4c (PIN_INPUT_PULLDOWN | MUX_MODE7) 0x50 (PIN_INPUT_PULLDOWN | MUX_MODE7) 0x54 (PIN_INPUT_PULLDOWN | MUX_MODE7) 0x58 (PIN_INPUT_PULLDOWN | MUX_MODE7) 0x5c (PIN_INPUT_PULLDOWN | MUX_MODE7) 0x60 (PIN_INPUT_PULLDOWN | MUX_MODE7) 0x64 (PIN_INPUT_PULLDOWN | MUX_MODE7) 0x68 (PIN_INPUT_PULLDOWN | MUX_MODE7) 0x6c (PIN_INPUT_PULLDOWN | MUX_MODE7) >; }; davinci_mdio_default: davinci_mdio_default { pinctrl-single,pins = < /* MDIO */ 0x148 (PIN_INPUT_PULLUP | SLEWCTRL_FAST | MUX_MODE0) /* mdio_data.mdio_data */ 0x14c (PIN_OUTPUT_PULLUP | MUX_MODE0) /* mdio_clk.mdio_clk */ >; }; davinci_mdio_sleep: davinci_mdio_sleep { pinctrl-single,pins = < /* MDIO reset value */ 0x148 (PIN_INPUT_PULLDOWN | MUX_MODE7) 0x14c (PIN_INPUT_PULLDOWN | MUX_MODE7) >; }; mmc1_pins: pinmux_mmc1_pins { pinctrl-single,pins = < 0x160 (PIN_INPUT | MUX_MODE7) /* spi0_cs1.gpio0_6 */ >; }; mcasp1_pins: mcasp1_pins { pinctrl-single,pins = < 0x10c (PIN_INPUT_PULLDOWN | MUX_MODE4) /* mii1_crs.mcasp1_aclkx */ 0x110 (PIN_INPUT_PULLDOWN | MUX_MODE4) /* mii1_rxerr.mcasp1_fsx */ 0x108 (PIN_OUTPUT_PULLDOWN | MUX_MODE4) /* mii1_col.mcasp1_axr2 */ 0x144 (PIN_INPUT_PULLDOWN | MUX_MODE4) /* rmii1_ref_clk.mcasp1_axr3 */ >; }; }; &uart0 { pinctrl-names = "default"; pinctrl-0 = <&uart0_pins>; status = "okay"; }; &i2c0 { pinctrl-names = "default"; pinctrl-0 = <&i2c0_pins>; status = "okay"; clock-frequency = <400000>; tps: tps@2d { reg = <0x2d>; }; lis331dlh: lis331dlh@18 { compatible = "st,lis331dlh", "st,lis3lv02d"; reg = <0x18>; Vdd-supply = <&lis3_reg>; Vdd_IO-supply = <&lis3_reg>; st,click-single-x; st,click-single-y; st,click-single-z; st,click-thresh-x = <10>; st,click-thresh-y = <10>; st,click-thresh-z = <10>; st,irq1-click; st,irq2-click; st,wakeup-x-lo; st,wakeup-x-hi; st,wakeup-y-lo; st,wakeup-y-hi; st,wakeup-z-lo; st,wakeup-z-hi; st,min-limit-x = <120>; st,min-limit-y = <120>; st,min-limit-z = <140>; st,max-limit-x = <550>; st,max-limit-y = <550>; st,max-limit-z = <750>; }; tlv320aic3106: tlv320aic3106@1b { compatible = "ti,tlv320aic3106"; reg = <0x1b>; status = "okay"; /* Regulators */ AVDD-supply = <&vaux2_reg>; IOVDD-supply = <&vaux2_reg>; DRVDD-supply = <&vaux2_reg>; DVDD-supply = <&vbat>; }; }; &usb { status = "okay"; control@44e10620 { status = "okay"; }; usb-phy@47401300 { status = "okay"; }; usb@47401000 { status = "okay"; }; }; &epwmss2 { status = "okay"; ecap2: ecap@48304100 { status = "okay"; pinctrl-names = "default"; pinctrl-0 = <&ecap2_pins>; }; }; #include "tps65910.dtsi" &tps { vcc1-supply = <&vbat>; vcc2-supply = <&vbat>; vcc3-supply = <&vbat>; vcc4-supply = <&vbat>; vcc5-supply = <&vbat>; vcc6-supply = <&vbat>; vcc7-supply = <&vbat>; vccio-supply = <&vbat>; regulators { vrtc_reg: regulator@0 { regulator-always-on; }; vio_reg: regulator@1 { regulator-always-on; }; vdd1_reg: regulator@2 { /* VDD_MPU voltage limits 0.95V - 1.26V with +/-4% tolerance */ regulator-name = "vdd_mpu"; regulator-min-microvolt = <912500>; regulator-max-microvolt = <1312500>; regulator-boot-on; regulator-always-on; }; vdd2_reg: regulator@3 { /* VDD_CORE voltage limits 0.95V - 1.1V with +/-4% tolerance */ regulator-name = "vdd_core"; regulator-min-microvolt = <912500>; regulator-max-microvolt = <1150000>; regulator-boot-on; regulator-always-on; }; vdd3_reg: regulator@4 { regulator-always-on; }; vdig1_reg: regulator@5 { regulator-always-on; }; vdig2_reg: regulator@6 { regulator-always-on; }; vpll_reg: regulator@7 { regulator-always-on; }; vdac_reg: regulator@8 { regulator-always-on; }; vaux1_reg: regulator@9 { regulator-always-on; }; vaux2_reg: regulator@10 { regulator-always-on; }; vaux33_reg: regulator@11 { regulator-always-on; }; vmmc_reg: regulator@12 { regulator-min-microvolt = <1800000>; regulator-max-microvolt = <3300000>; regulator-always-on; }; }; }; &mac { pinctrl-names = "default", "sleep"; pinctrl-0 = <&cpsw_default>; pinctrl-1 = <&cpsw_sleep>; }; &davinci_mdio { pinctrl-names = "default", "sleep"; pinctrl-0 = <&davinci_mdio_default>; pinctrl-1 = <&davinci_mdio_sleep>; }; &cpsw_emac0 { phy_id = <&davinci_mdio>, <0>; phy-mode = "rgmii-txid"; }; &cpsw_emac1 { phy_id = <&davinci_mdio>, <1>; phy-mode = "rgmii-txid"; }; &mmc1 { status = "okay"; vmmc-supply = <&vmmc_reg>; bus-width = <4>; pinctrl-names = "default"; pinctrl-0 = <&mmc1_pins>; cd-gpios = <&gpio0 6 GPIO_ACTIVE_HIGH>; }; &sham { status = "okay"; }; &aes { status = "okay"; }; &gpio0 { ti,no-reset-on-init; }; &mcasp1 { pinctrl-names = "default"; pinctrl-0 = <&mcasp1_pins>; status = "okay"; op-mode = <0>; /* MCASP_IIS_MODE */ tdm-slots = <2>; /* 4 serializers */ serial-dir = < /* 0: INACTIVE, 1: TX, 2: RX */ 0 0 1 2 >; tx-num-evt = <1>; rx-num-evt = <1>; }; &tscadc { status = "okay"; tsc { ti,wires = <4>; ti,x-plate-resistance = <200>; ti,coordinate-readouts = <5>; ti,wire-config = <0x00 0x11 0x22 0x33>; }; };
红色部分为LED子系统调用硬件配置。dtb文件和Linux内核是怎么关联的呢？主要是通过这个参数：compatible = "gpio-leds";
在leds-gpio.c中有相同的参数传递，具体是怎么操作的，没有详细的去了解。
return priv; err: for (count = priv->num_leds - 2; count >= 0; count--) delete_gpio_led(&priv->leds[count]); return ERR_PTR(-ENODEV); } static const struct of_device_id of_gpio_leds_match[] = { { .compatible = "gpio-leds", }, {}, }; #else /* CONFIG_OF_GPIO */ static struct gpio_leds_priv *gpio_leds_create_of(struct platform_device *pdev) { return ERR_PTR(-ENODEV); } #endif /* CONFIG_OF_GPIO */ static int gpio_led_probe(struct platform_device *pdev) { struct gpio_led_platform_data *pdata = dev_get_platdata(&pdev->dev); struct gpio_leds_priv *priv; int i, ret = 0;
进入内核xxxx/drivers/leds/将led-class.c、led-core.c、leds.h、leds-gpio.c文件拷出来以模块的方法编译出leds-gpio.ko加载入模块中
编译模块的Makfile：
ifneq ($(KERNELRELEASE),) obj-m := leds-gpio.o else KDIR :=/home/zyr/Source_code/linux-3.14.65/ all: make -C $(KDIR) M=$(PWD) modules ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- -j8 clean: rm -f *.ko *.o *.mod.o *.mod.c *.symvers *.order endif
编写led子系统的测试：
1、点亮熄灭LED
[root@zyr-am335x ]#cd /sys/class [root@zyr-am335x class]#ls bdi hwmon mem regulator tty block i2c-adapter misc rtc ubi dma i2c-dev mmc_host scsi_device udc extcon input mtd scsi_disk usbmon firmware lcd net scsi_host vc gpio leds phy spi_master vtconsole graphics mdio_bus power_supply thermal watchdog [root@zyr-am335x class]#cd leds [root@zyr-am335x leds]#ls zyrD1:green:usr0 zyrD3:green:heartbeat zyrD2:green:usr1 zyrD4:green:mmc0 [root@zyr-am335x leds]#cd zyrD1\:green\:usr0/ [root@zyr-am335x zyrD1:green:usr0]#echo 1 > brightness [root@zyr-am335x zyrD1:green:usr0]#echo 0 > brightness [root@zyr-am335x zyrD1:green:usr0]#
2、也可以编写测试程序LED_zixitong.c
/******************************************************************** * copyright (C) 2014 all rights reserved * @file: 子系统_led.c * @Created: 2017-6-27 14:00nd * @Author: Yinrui Zhu * @Description: test user leds * @Modify Date: 2017-6-27 14:00 *********************************************************************/ #include <stdio.h> #include<stdlib.h> #include<unistd.h> #include<sys/ioctl.h> #include<sys/stat.h> #include<sys/select.h> #include<sys/time.h> #include<fcntl.h> #include<errno.h> #include<linux/input.h> int main(int argc, char *argv[]) { int ledn; char *tmp; int keys_fd; //char timer=6; tmp = (unsigned char*)malloc(64); while(1) { sprintf(tmp, "echo 1 > /sys/class/leds/zyrD1:green:usr0/brightness"); printf("status led4%d on \n", ledn); system(tmp); usleep(1000*500); sprintf(tmp, "echo 0 > /sys/class/leds/zyrD1:green:usr0/brightness"); printf("status led4%d on \n", ledn); system(tmp); usleep(1000*500); sprintf(tmp, "echo 1 > /sys/class/leds/zyrD2:green:usr1/brightness"); printf("status led3%d on \n", ledn); system(tmp); usleep(1000*500); sprintf(tmp, "echo 0 > /sys/class/leds/zyrD2:green:usr1/brightness"); printf("status led3%d on \n", ledn); system(tmp); usleep(1000*500); sprintf(tmp, "echo 1 > /sys/class/leds/zyrD3:green:heartbeat/brightness"); printf("status led1%d on \n", ledn); system(tmp); usleep(1000*500); sprintf(tmp, "echo 0 > /sys/class/leds/zyrD3:green:heartbeat/brightness"); printf("status led1%d on \n", ledn); system(tmp); usleep(1000*500); //sprintf(tmp, "echo 1 > /sys/class/leds/evmsk:green:usr0/brightness"); printf("status led2%d on \n", ledn); system("echo 1 > /sys/class/leds/zyrD4:green:mmc0/brightness"); usleep(1000*500); //sprintf(tmp, "echo 0 > /sys/class/leds/evmsk:green:usr0/brightness"); printf("status led2%d on \n", ledn); system("echo 0 > /sys/class/leds/zyrD4:green:mmc0/brightness"); usleep(1000*500); } }
测试文件的Makefile；
#---------------------------- CC = arm-linux-gnueabihf-gcc CFLAGS = main : LED_zixitong.c $(CC) $(CFLAGS) LED_zixitong.c -o LED_zixitong
将生成可执行文件LED_zixitong copy到挂载配置好的nfs目录中执行既可以依次点亮4个LED了。
[root@zyr-am335x zyrD1:green:usr0]#cd [root@zyr-am335x ]#cd /mnt/ [root@zyr-am335x mnt]#ls LED_zixitong led_test leds-gpio.ko zleds-gpio.ko zyr-hello.ko [root@zyr-am335x mnt]#./LED_zixitong status led40 on status led40 on status led30 on status led30 on status led10 on
