NanoPi NEO2 GPIO控制驱动

leddevice.c

#include <linux/init.h>
#include <linux/fs.h>
#include <linux/major.h>
#include <linux/blkdev.h>
#include <linux/backing-dev.h>
#include <linux/module.h>
#include <linux/gpio.h>
#include <linux/capability.h>
#include <linux/uio.h>
#include <linux/cdev.h>
#include <linux/device.h>
#include <linux/mutex.h>
#include <linux/gfp.h>
#include <linux/compat.h>
#include <linux/vmalloc.h>

#include <linux/uaccess.h>
#define PAD_SPIO_LOOK 66
#define PAD_GPIOG6 6
#define PAD_SPI0_MOSI 64

static struct class *led_dev_class;
static struct device *led_dev_class_dev;
static char val[64];

static int lde_dev_open(struct inode *inode, struct file *file)
{
    printk("lde_dev_open");
    return 0;
}

static ssize_t lde_dev_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
{
    printk("lde_dev_read");
    int ret=0;
    char vall[]="hello,woed!";
    ret = copy_to_user(buf, vall, count);
    if (ret < 0)
    {
        printk("ret=%d \n", ret);
        return ret;
    }
    return 0;
}

static ssize_t lde_dev_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
{
    printk("lde_dev_write");
    int ret=0;
    char status=0;
    ret = copy_from_user(val, buf, count);
    if(ret<0)
    {
    printk("ret = %d /n",ret);
    status=-ENOMEM;
    }
    char key=simple_strtoul(val,NULL,0);
    if (key <= 1)
    {
        gpio_set_value(PAD_GPIOG6, 1);
    }
    else
    {
        gpio_set_value(PAD_GPIOG6, 0);
    }
    if(!status)
    {
	    status=count;
    }

    return status;
}
static const struct file_operations led_dev_fops = {
    .owner = THIS_MODULE,
    .open = lde_dev_open,
    .read = lde_dev_read,
    .write = lde_dev_write,
};
int major;

static int __init led_device_init(void)
{
    printk("led_device_init");
    gpio_request(PAD_GPIOG6, "PAD_GPIOG6");
    gpio_direction_output(PAD_GPIOG6, 1);
    major = register_chrdev(0, "led_dev", &led_dev_fops);
    led_dev_class = class_create(THIS_MODULE, "led_dev");
    led_dev_class_dev = device_create(led_dev_class, NULL, MKDEV(major, 0), NULL, "led_dev");
    return 0;
}
module_init(led_device_init);

static void __exit led_device_exit(void)
{
    printk("led_device_exit");

    unregister_chrdev(major, "led_dev");

    device_unregister(led_dev_class_dev);

    class_destroy(led_dev_class);
    gpio_free(PAD_GPIOG6);
}
module_exit(led_device_exit);
MODULE_LICENSE("GPL");

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Makefile

obj-m += leddevice.o
KDIR=/home/root/linux
CROSS_COMPILE=aarch64-linux-gnu-
all:
	make -C $(KDIR) M=$(PWD) modules ARCH=arm64 CROSS_COMPILE=$(CROSS_COMPILE)
clean:
	rm -rf *.ko *.o *.mod.o *.mod.c *.symvers modul*.hello.*.tmp_versions.*.*.cmd  modules.order
help:
	@echo "nake KDIR=<your kernel path>CROSS_COMPILE=<your CROSS_COMPILE>"
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