【Firefly-RK3399 试用体验】05.GPIO驱动-电子芯吧客

【Firefly-RK3399 试用体验】05.GPIO驱动

wuQAQ
LV4工程师
| 2017-07-11 21:02:10
浏览量 6852
回复：2

本帖最后由 wuQAQ 于 2017-7-11 21:03 编辑 1、下载内核源码并编译

// 下载内核

git clone https://TeeFirefly@gitlab.com/TeeFirefly/linux-kernel.git

// 下载工具链

git clone https://TeeFirefly@gitlab.com/TeeFirefly/prebuilts.git



// 上面两个文件夹要放在同一个目录下

//编译

make ARCH=arm64 firefly_linux_defconfig

make ARCH=arm64 rk3399-firefly-linux.img -j8

2、修改DTS文件 DTS是Device Tree Source的缩写，用来描述设备的硬件细节。在firefly RK3399的内核源码中，使用的DTS路径是~/linuxkernel/arch/arm64/boot/dts/rockchip，使用的dts文件是rk3399-firefly-linux.dts 在这个文件下添加如下代码：

gpio_demo: gpio_demo {

    status = "okay";

    compatible = "firefly,rk3399-gpio";

    firefly-gpio = <&gpio0 12 GPIO_ACTIVE_HIGH>;          /* GPIO1_B4 */

};

对应的引脚为下图中红色画圈的引脚：引脚接线图.png

3、增加驱动源码在~/linux-kernel/drivers/目录下增加自己的驱动文件夹wu_led

cd ~/linux-kernel/drivers/

mkdir wu_led

修改~/linux-kernel/drivers/目录下的Kconfig和Makefile文件在Kconfig文件的endmenu前添加下面这行代码：

source "drivers/wu_led/Kconfig"

在Makefile文件最后添加下面这行代码：

obj-y   += wu_led/

在新建的wu_led.c文件内添加自己的驱动代码

#include 

#include 

#include 

#include 

#include 

#include 

#include 

#include 

#include 

#include 

#include 

#include 

#include 



#define GPIO_LOW 0

#define GPIO_HIGH 1



static int firefly_hello_probe(struct platform_device *pdev)

{

        int i;

        int gpio;

    enum of_gpio_flags flag;

    struct firefly_gpio_info *gpio_info;

        struct device_node *firefly_gpio_node = pdev->dev.of_node;



        printk(KERN_INFO "Firefly GPIO Test Program Probe\n");

        gpio_info = devm_kzalloc(&pdev->dev,sizeof(struct firefly_gpio_info *), GFP_KERNEL);

        if (!gpio_info) {

                return -ENOMEM;

        }



        gpio = of_get_named_gpio_flags(firefly_gpio_node, "firefly-gpio", 0, &flag);

        if (!gpio_is_valid(gpio)) {

                printk("firefly-gpio: %d is invalid\n", gpio);

                return -ENODEV;

        }

        while (gpio_request(gpio, "firefly-gpio")) {

                printk("gpio %d request failed!\n", gpio);

                gpio_free(gpio);

                return -ENODEV;

        }



        gpio_direction_output(gpio, GPIO_HIGH);



        for(i=0; i < 10; i++)

        {

                gpio_set_value(gpio,GPIO_LOW);

                mdelay(500);

                gpio_set_value(gpio,GPIO_HIGH);

                mdelay(500);

        }

            

        printk("%s-%d: exit\n",__FUNCTION__,__LINE__);

        

        return 0;  //return Ok

}





static int firefly_hello_remove(struct platform_device *pdev)

{ 

    return 0;

}

#ifdef CONFIG_OF

static const struct of_device_id of_firefly_hello_match = {

        { .compatible = "firefly,rk3399-gpio" },

        { /* Sentinel */ }

};

#endif



static struct platform_driver firefly_hello_driver = {

        .probe                = firefly_hello_probe,

        .remove                = firefly_hello_remove,

        .driver                = {

                .name        = "wu_led",

                .owner        = THIS_MODULE,

                .of_match_table        = of_firefly_hello_match,

        },



};



static int __init hello_init(void)

{

        int a;

    printk(KERN_INFO "Enter %s\n", __FUNCTION__);

    a = platform_driver_register(&firefly_hello_driver);

        printk(KERN_INFO "Info %d\n", a);

    return 0;

}



static void __exit hello_exit(void)

{

        platform_driver_unregister(&firefly_hello_driver);

    printk("Exit Hello world\n");

}



subsys_initcall(hello_init);

module_exit(hello_exit);



MODULE_AUTHOR("wuQAQ");

MODULE_DESCRIPTION("Firefly gpio driver");

MODULE_LICENSE("GPL");

在wu_led文件夹内增加Kconfig文件：

config WU_LED

        tristate "Firefly wu led support"

    depends on GPIOLIB

        default y

        help

                Select this option if your Firefly board needs to run LED demo.

在wu_led文件夹内增加Makefile文件：

obj-$(CONFIG_WU_LED)                += wu_led.o

4、再次编译

//重新编译

make ARCH=arm64 firefly_linux_defconfig

make ARCH=arm64 rk3399-firefly-linux.img -j8

//然后将生成的Kernel.img和resource.img文件一同烧录到板子中

5、效果显示：

代码包：