Linux学习笔记（20）——基于platform的设备驱动
- 设备树文件仍与第18节的保持不变
- 编写led设备程序
/*
* 文件名 : leddevice.c
* 作者 : glen
* 描述 : leddevice驱动文件
*/
#include - 编写led驱动程序
/*
* 文件名 : leddriver.c
* 作者 : glen
* 描述 : leddriver驱动文件
*/
#include - 编写测试程序并拷贝到NFS文件系统目录下
/*
* 文件名 : platform_test.c
* 作者 : glen
* 描述 : platform测试程序
*/
#include "stdio.h"
#include "unistd.h"
#include "sys/types.h"
#include "sys/stat.h"
#include "fcntl.h"
#include "stdlib.h"
#include "string.h"
#include "poll.h"
#include "sys/select.h"
#include "sys/time.h"
#include "linux/ioctl.h"
#include "signal.h"
/**
* @brief : main函数
* @par : argc argv数组元素的个数
* argv 参数数组
* @retval : 0 成功 其它 失败
*/
int main(int argc, char *argv[])
{
static int fd = 0; /* 文件描述符 */
int ret = 0;
char *filename;
if (argc != 3) {
printf("Error Usage!\r\n");
return -1;
}
filename = argv[1];
/* 打开驱动文件 */
fd = open(filename, O_RDWR); /* 阻塞访问 */
if (fd < 0) {
printf("Can't open file %s\r\n", filename);
return -1;
}
ret = write(fd, argv[2], sizeof(argv[2]));
if (ret < 0) {
printf("LED control failure!\r\n");
close(fd);
return -1;
}
/* 关闭文件 */
ret = close(fd);
if (ret < 0) {
printf("file %s close failed!\r\n", argv[1]);
return -1;
}
return 0;
}
拷贝到NFS文件系统目录下
glen@ubuntu:~/linux/imx6ull/linux/driver/15_platform$ sudo cp leddevice.ko leddriver.ko platform_test ~/linux/nfs/rootfs/lib/modules/4.1.15 -rf
- 测试程序
5.1 加载设备程序模块和驱动程序模块
/lib/modules/4.1.15 # insmod leddevice.ko
/lib/modules/4.1.15 # insmod leddriver.ko
led driver and device has matched!
5.2 查看platform平台的设备和驱动信息
查看platform平台的设备信息
/lib/modules/4.1.15 # ls /sys/bus/platform/devices/
20a8000.gpio 2290000.iomuxc-snvs
20ac000.gpio 2294000.snvs-gpr
20b0000.snvs 900000.sram
20b4000.ethernet 904000.sram
20bc000.wdog 905000.sram
20c4000.ccm Vivante GCCore
20c8000.anatop a01000.interrupt-controller
20c8000.anatop:regulator-3p0@120 alarmtimer
20c8000.anatop:regulator-vddcore@140 backlight
20c8000.anatop:regulator-vddsoc@140 beep
20c9000.usbphy ci_hdrc.0
20ca000.usbphy ci_hdrc.1
20cc000.snvs glen-led
查看platform平台的驱动信息
/lib/modules/4.1.15 # ls /sys/bus/platform/drivers/
CCI-400 imx-gpc imx6sll-pinctrl of-flash
CCI-400 PMU imx-gpcv2 imx6sx-pinctrl pata_imx
ahci imx-i2c imx6ul-pinctrl platform-lcd
ahci-imx imx-ipuv3 imx6ul-tsc pwm-backlight
alarmtimer imx-keypad imx7d-pinctrl pxp-v4l2
anatop_regulator imx-mmdc imx_busfreq reg-dummy
arm-pmu imx-mu imx_mc13783 reg-fixed-voltage
chipidea-usb2 imx-pre imx_thermal sdhci-esdhc-imx
ci_hdrc imx-prg imx_usb smc911x
coda imx-pwm ldo2p5-dummy smc91x
da9052-regulator imx-pxp leds-gpio smsc911x
eukrea_tlv320 imx-rpmsg mc13783-regulator snd-soc-dummy
fec imx-sdma mc13892-regulator snvs_pwrkey
fsl-lpuart imx-sema4 msm_hsusb snvs_rtc
fsl-quadspi imx-sgtl5000 mx3-camera soc-audio
fsl-spdif-dai imx-spdif mx3_sdc_fb soc-camera-pdrv
fsl-ssi-dai imx-ssi mxc-ehci spi_imx
generic-bl imx-uart mxc_lcdif sram
glen-led imx-weim mxc_mlb150 stmpe-ts
gpio-keys imx-wm8962 mxc_nand syscon
gpio-mxc imx2-wdt mxc_rtc usb_phy_generic
gpio-rc-recv imx50-pinctrl mxc_sdc_fb usbmisc_imx
gpio-reset imx53-pinctrl mxc_vdoa vf610-pinctrl
gpio-vf610 imx6dl-pinctrl mxc_vpu zevio_usb
gpmi-nand imx6q-cpufreq mxs-dma
imx-audmux imx6q-pinctrl mxs_phy
imx-ddrc imx6sl-pinctrl mxsfb
5.3 测试
/lib/modules/4.1.15 # ./platform_test /dev/platled ON
/lib/modules/4.1.15 # ./platform_test /dev/platled OFF
/lib/modules/4.1.15 # ./platform_test /dev/platled ON
/lib/modules/4.1.15 # ./platform_test /dev/platled OFF
/lib/modules/4.1.15 # ./platform_test /dev/platled ON
/lib/modules/4.1.15 # ./platform_test /dev/platled OFF
/lib/modules/4.1.15 # ./platform_test /dev/platled ON
/lib/modules/4.1.15 # ./platform_test /dev/platled OFF