嵌入式 ARM 平台 libsoc 开发示例

供稿:韬睿(上海)计算机科技有限公司

  • 关键词:arm,linux,libsoc
  • 作者:ByToradex秦海
  • 摘要:在之前的一篇文章中已经介绍过如何基于嵌入式Linux部署libsoc支持, 本文就继续基于NXP IMX6平台演示基于libsoc分别对GPIO,I2C,PWM以及SPI进行开发示例。


1). 简介

在之前的一篇文章中已经介绍过如何基于嵌入式Linux部署libsoc支持, 本文就继续基于NXP IMX6平台演示基于libsoc分别对GPIO,I2C,PWM以及SPI进行开发示例。


本文所演示的ARM平台同样来自于Toradex 基于NXP iMX6 ARM处理器的Apalis iMX6 ARM嵌入式平台。  


2. 准备

a). ApalisiMX6Q ARM核心版配合ApalisEvaluation Board载板,连接调试串口UART1(载板X29)到开发主机方便调试。更多关于Apalis iMX6配合Apalis Evaluation Board载板的说明请参考Datasheet和开发上手指南。


b). Apalis iMX6Q ARM核心版配合Ixora载板,连接调试串口UART1(载板X22)到开发主机方便调试。更多关于Apalis iMX6配合Ixora载板的说明请参考Datasheet和开发上手指南。


c). Apalis iMX6Q 安装Toradex Linux BSP V2.8b5,系统中已经默认包含了本文测试所需要的libsoc相关库支持,详细安装方法请参考这里,编译libsoc相关demo所需要的SDK配置请参考简介中提到的之前文章说明,本文不再赘述。



3). GPIO 测试示例

a). 基于Apalis Evaluation Board测试,硬件连接配置如下,基于C代码的GPIO测试请参考这里,本文是基于libsoc来重新测试。

X4 GPIO05 <-> X34 SW5

X4 GPIO06 <-> X34 LED1


b). 源代码请参考如下,实现功能就是按键交替点亮和关闭LED灯。

https://github.com/simonqin09/libsoc-examples/blob/master/gpiotest/gpiointtest.c


c). Makefile 请参考如下,直接下载的libsoc官方示例里面包含的Makefile需要进行一些修改,这里也将修改的patch附上。

./ Makefile

https://github.com/simonqin09/libsoc-examples/blob/master/gpiotest/Makefile

./ Patch file

https://github.com/simonqin09/libsoc-examples/blob/master/gpiotest/libsoc-examples_Makefile.patch


d). 测试运行结果如下:

-----------------------

root@apalis-imx6:~# ./gpiointtest

Waiting for interrupt. Press 'q' and'Enter' at any time to exit

LED turns on

Interrupt occurred 1 times

LED turns off

Interrupt occurred 2 times

-----------------------

4). PWM 测试示例

a). 基于Apalis Evaluation Board测试,硬件连接配置如下, 基于C代码的PWM测试请参考这里,本文是基于libsoc来重新测试。

X4 GPIO05 <-> X34 SW5

X4 PWM1 <-> X34 LED1


b). 源代码和Makefile请参考如下,实现功能就是程序运行后,PWM以50%占空比输出,通过按键让PWM输出占空比按照50%,75%,25% 交替调整。

https://github.com/simonqin09/libsoc-examples/blob/master/pwmtest/pwmtest.c

https://github.com/simonqin09/libsoc-examples/blob/master/pwmtest/Makefile


PWM2和PWM3也都可以测试,只是PWM3默认被ov5640_mipi驱动占用,需要修改device tree释放。


d). 测试运行结果如下:

-----------------------

root@apalis-imx6:~# ./pwmtest

Waiting for interrupt. Press 'q' and'Enter' at any time to exit

Interrupt occurred 1 times

PWM Duty set to 75%

Interrupt occurred 2 times

PWM Duty set to 25%

Interrupt occurred 3 times

PWM Duty set to 50%

Interrupt occurred 4 times

PWM Duty set to 75%

-----------------------



5). I2C 测试示例

a). 基于Ixora 载板测试,针对载板上面连接到i2c-1的总线上面的EEPROM进行读写,基于C代码的详细测试文档可以参考这里,本文重新基于libsoc代码进行测试。


b). 源代码和Makefile请参考如下,实现功能就是程序运行后,针对指定的page号码写入数据,然后再读取后验证是否读写一致。

I2ctest.c - https://github.com/simonqin09/libsoc-examples/blob/master/i2ctest/i2ctest.c

eeprom.c - https://github.com/simonqin09/libsoc-examples/blob/master/i2ctest/eeprom.c

eeprom.h - https://github.com/simonqin09/libsoc-examples/blob/master/i2ctest/eeprom.h

Makefile - https://github.com/simonqin09/libsoc-examples/blob/master/i2ctest/Makefile


d). 测试运行结果如下:

-----------------------

root@apalis-imx6:~# ./i2ctest 15

Writing to page starting at byte address:0xf0

Waiting for data to be written

libsoc-i2c-debug: No such device or address

Waiting...

libsoc-i2c-debug: No such device or address

Waiting...

libsoc-i2c-debug: No such device or address

Waiting...

libsoc-i2c-debug: No such device or address

Waiting...

Data sucessfully written!

Reading page starting at byte address: 0xf0

data_write[0] = 0xf0 : data_read[0] = 0xf0: Correct

data_write[1] = 0xf1 : data_read[1] = 0xf1: Correct

data_write[2] = 0xf2 : data_read[2] = 0xf2: Correct

data_write[3] = 0xf3 : data_read[3] = 0xf3: Correct

data_write[4] = 0xf4 : data_read[4] = 0xf4: Correct

data_write[5] = 0xf5 : data_read[5] = 0xf5: Correct

data_write[6] = 0xf6 : data_read[6] = 0xf6: Correct

data_write[7] = 0xf7 : data_read[7] = 0xf7: Correct

data_write[8] = 0xf8 : data_read[8] = 0xf8: Correct

data_write[9] = 0xf9 : data_read[9] = 0xf9: Correct

data_write[10] = 0xfa : data_read[10] =0xfa : Correct

data_write[11] = 0xfb : data_read[11] =0xfb : Correct

data_write[12] = 0xfc : data_read[12] =0xfc : Correct

data_write[13] = 0xfd : data_read[13] =0xfd : Correct

data_write[14] = 0xfe : data_read[14] =0xfe : Correct

data_write[15] = 0xff : data_read[15] =0xff : Correct

-----------------------


6). SPI Master 测试示例

a). 基于Apalis Evaluation Board测试,需要配合Toradex另外一个基于NXP iMX7的平台作为SPI slave进行共同测试,关于硬件连接和SPI slave的配制和相关代码请参考下面文章,本文是基于libsoc来测试 SPI Master 端。

https://www.toradex.com/zh-cn/blog/nxp-imx7-m4-he-xin-spi-slave-ce-shi


b). 源代码和Makefile请参考如下,实现功能就是程序运行后,通过Apalis iMX6 SPI0.0 向 SPI slave写入一组随机数据,然后再次通讯读出刚才写入的数据后确认读写是否一致。

spitest.c - https://github.com/simonqin09/libsoc-examples/blob/master/spitest/spitest.c

Makefile - https://github.com/simonqin09/libsoc-examples/blob/master/spitest/Makefile


d). 测试运行结果如下:

-----------------------

root@apalis-imx6:~# ./spitest

Start to transfer!

data_send[0] = 0xca : data_read[0] = 0xca :Correct

data_send[1] = 0x03 : data_read[1] = 0x03 :Correct

data_send[2] = 0x01 : data_read[2] = 0x01 :Correct

data_send[3] = 0x56 : data_read[3] = 0x56 :Correct

data_send[4] = 0xb2 : data_read[4] = 0xb2 :Correct

data_send[5] = 0x64 : data_read[5] = 0x64 :Correct

data_send[6] = 0xf9 : data_read[6] = 0xf9 :Correct

data_send[7] = 0x34 : data_read[7] = 0x34 :Correct

data_send[8] = 0x91 : data_read[8] = 0x91 :Correct

data_send[9] = 0x84 : data_read[9] = 0x84 :Correct

data_send[10] = 0x19 : data_read[10] = 0x19: Correct

data_send[11] = 0x0c : data_read[11] = 0x0c: Correct

data_send[12] = 0xb1 : data_read[12] = 0xb1: Correct

data_send[13] = 0xd3 : data_read[13] = 0xd3: Correct

data_send[14] = 0x1f : data_read[14] = 0x1f: Correct

data_send[15] = 0xf4 : data_read[15] = 0xf4: Correct

-----------------------



7). 总结

如上述示例,通过基于iMX6测试了GPIOI2CPWMSPI接口,对比C代码,libsoc使用和配置起来更方便简洁。

发布时间:2019年5月14日 10:27  人气:   审核编辑(王静 )
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