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为APP实验班添加dht11_drv

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weidongshan
2024-08-10 14:34:03 +08:00
parent debc96984a
commit b8376b23db
3 changed files with 413 additions and 0 deletions
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29
04a_嵌入式Linux应用开发实验班(快速入门)/04_使用文件IO操作硬件/source/03_QT使用驱动操作温湿度模块/dht11_drv/02_dht11_drv_imx6ull/Makefile Normal file
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# 1. 使用不同的开发板内核时, 一定要修改KERN_DIR
# 2. KERN_DIR中的内核要事先配置、编译, 为了能编译内核, 要先设置下列环境变量:
# 2.1 ARCH, 比如: export ARCH=arm64
# 2.2 CROSS_COMPILE, 比如: export CROSS_COMPILE=aarch64-linux-gnu-
# 2.3 PATH, 比如: export PATH=$PATH:/home/book/100ask_roc-rk3399-pc/ToolChain-6.3.1/gcc-linaro-6.3.1-2017.05-x86_64_aarch64-linux-gnu/bin
# 注意: 不同的开发板不同的编译器上述3个环境变量不一定相同,
# 请参考各开发板的高级用户使用手册
#KERN_DIR = /home/book/100ask_imx6ull-sdk/Linux-4.9.88 # 板子所用内核源码的目录
#KERN_DIR = /home/book/100ask_imx6ull_mini-sdk/Buildroot_2020.02.x/output/build/linux-origin_master
KERN_DIR = /home/book/100ask_imx6ull-sdk/Buildroot_2020.02.x/output/build/linux-origin_master
all:
make -C $(KERN_DIR) M=`pwd` modules
$(CROSS_COMPILE)gcc -o dht11_test dht11_test.c
clean:
make -C $(KERN_DIR) M=`pwd` modules clean
rm -rf modules.order dht11_test
# 参考内核源码drivers/char/ipmi/Makefile
# 要想把a.c, b.c编译成ab.ko, 可以这样指定:
# ab-y := a.o b.o
# obj-m += ab.o
obj-m += dht11_drv.o

329
04a_嵌入式Linux应用开发实验班(快速入门)/04_使用文件IO操作硬件/source/03_QT使用驱动操作温湿度模块/dht11_drv/02_dht11_drv_imx6ull/dht11_drv.c Normal file
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#include "asm-generic/errno-base.h"
#include "asm-generic/gpio.h"
#include "linux/jiffies.h"
#include <linux/module.h>
#include <linux/poll.h>
#include <linux/delay.h>
#include <linux/fs.h>
#include <linux/errno.h>
#include <linux/miscdevice.h>
#include <linux/kernel.h>
#include <linux/major.h>
#include <linux/mutex.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/stat.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/tty.h>
#include <linux/kmod.h>
#include <linux/gfp.h>
#include <linux/gpio/consumer.h>
#include <linux/platform_device.h>
#include <linux/of_gpio.h>
#include <linux/of_irq.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/slab.h>
#include <linux/fcntl.h>
#include <linux/timer.h>
struct gpio_desc{
int gpio;
int irq;
char *name;
int key;
struct timer_list key_timer;
} ;
static struct gpio_desc gpios[] = {
{115, 0, "dht11", },
};
/* 主设备号 */
static int major = 0;
static struct class *gpio_class;
static u64 g_dht11_irq_time[84];
static int g_dht11_irq_cnt = 0;
/* 环形缓冲区 */
#define BUF_LEN 128
static char g_keys[BUF_LEN];
static int r, w;
struct fasync_struct *button_fasync;
static irqreturn_t dht11_isr(int irq, void *dev_id);
static void parse_dht11_datas(void);
#define NEXT_POS(x) ((x+1) % BUF_LEN)
static int is_key_buf_empty(void)
{
return (r == w);
}
static int is_key_buf_full(void)
{
return (r == NEXT_POS(w));
}
static void put_key(char key)
{
if (!is_key_buf_full())
{
g_keys[w] = key;
w = NEXT_POS(w);
}
}
static char get_key(void)
{
char key = 0;
if (!is_key_buf_empty())
{
key = g_keys[r];
r = NEXT_POS(r);
}
return key;
}
static DECLARE_WAIT_QUEUE_HEAD(gpio_wait);
// static void key_timer_expire(struct timer_list *t)
static void key_timer_expire(unsigned long data)
{
// 解析数据, 放入环形buffer, 唤醒APP
parse_dht11_datas();
}
/* 实现对应的open/read/write等函数，填入file_operations结构体 */
static ssize_t dht11_read (struct file *file, char __user *buf, size_t size, loff_t *offset)
{
int err;
char kern_buf[2];
if (size != 2)
return -EINVAL;
g_dht11_irq_cnt = 0;
/* 1. 发送18ms的低脉冲 */
err = gpio_request(gpios[0].gpio, gpios[0].name);
gpio_direction_output(gpios[0].gpio, 0);
gpio_free(gpios[0].gpio);
mdelay(18);
gpio_direction_input(gpios[0].gpio); /* 引脚变为输入方向, 由上拉电阻拉为1 */
/* 2. 注册中断 */
err = request_irq(gpios[0].irq, dht11_isr, IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING, gpios[0].name, &gpios[0]);
mod_timer(&gpios[0].key_timer, jiffies + 20);
/* 3. 休眠等待数据 */
wait_event_interruptible(gpio_wait, !is_key_buf_empty());
free_irq(gpios[0].irq, &gpios[0]);
//printk("%s %s %d\n", __FILE__, __FUNCTION__, __LINE__);
/* 设置DHT11 GPIO引脚的初始状态: output 1 */
err = gpio_request(gpios[0].gpio, gpios[0].name);
if (err)
{
printk("%s %s %d, gpio_request err\n", __FILE__, __FUNCTION__, __LINE__);
}
gpio_direction_output(gpios[0].gpio, 1);
gpio_free(gpios[0].gpio);
/* 4. copy_to_user */
kern_buf[0] = get_key();
kern_buf[1] = get_key();
printk("get val : 0x%x, 0x%x\n", kern_buf[0], kern_buf[1]);
if ((kern_buf[0] == (char)-1) && (kern_buf[1] == (char)-1))
{
printk("get err val\n");
return -EIO;
}
err = copy_to_user(buf, kern_buf, 2);
return 2;
}
static int dht11_release (struct inode *inode, struct file *filp)
{
return 0;
}
/* 定义自己的file_operations结构体 */
static struct file_operations dht11_drv = {
.owner = THIS_MODULE,
.read = dht11_read,
.release = dht11_release,
};
static void parse_dht11_datas(void)
{
int i;
u64 high_time;
unsigned char data = 0;
int bits = 0;
unsigned char datas[5];
int byte = 0;
unsigned char crc;
printk("g_dht11_irq_cnt = %d\n", g_dht11_irq_cnt);
/* 数据个数: 可能是81、82、83、84 */
if (g_dht11_irq_cnt < 81)
{
/* 出错 */
put_key(-1);
put_key(-1);
// 唤醒APP
wake_up_interruptible(&gpio_wait);
g_dht11_irq_cnt = 0;
return;
}
// 解析数据
for (i = g_dht11_irq_cnt - 80; i < g_dht11_irq_cnt; i+=2)
{
high_time = g_dht11_irq_time[i] - g_dht11_irq_time[i-1];
data <<= 1;
if (high_time > 50000) /* data 1 */
{
data |= 1;
}
bits++;
if (bits == 8)
{
datas[byte] = data;
data = 0;
bits = 0;
byte++;
}
}
// 放入环形buffer
crc = datas[0] + datas[1] + datas[2] + datas[3];
if (crc == datas[4])
{
put_key(datas[0]);
put_key(datas[2]);
}
else
{
printk("dht11 crc err\n");
put_key(-1);
put_key(-1);
}
g_dht11_irq_cnt = 0;
// 唤醒APP
wake_up_interruptible(&gpio_wait);
}
static irqreturn_t dht11_isr(int irq, void *dev_id)
{
struct gpio_desc *gpio_desc = dev_id;
u64 time;
/* 1. 记录中断发生的时间 */
time = ktime_get_ns();
g_dht11_irq_time[g_dht11_irq_cnt] = time;
/* 2. 累计次数 */
g_dht11_irq_cnt++;
/* 3. 次数足够: 解析数据, 放入环形buffer, 唤醒APP */
if (g_dht11_irq_cnt == 84)
{
del_timer(&gpio_desc->key_timer);
parse_dht11_datas();
}
return IRQ_HANDLED;
}
/* 在入口函数 */
static int __init dht11_init(void)
{
int err;
int i;
int count = sizeof(gpios)/sizeof(gpios[0]);
printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
for (i = 0; i < count; i++)
{
gpios[i].irq = gpio_to_irq(gpios[i].gpio);
/* 设置DHT11 GPIO引脚的初始状态: output 1 */
err = gpio_request(gpios[i].gpio, gpios[i].name);
gpio_direction_output(gpios[i].gpio, 1);
gpio_free(gpios[i].gpio);
setup_timer(&gpios[i].key_timer, key_timer_expire, (unsigned long)&gpios[i]);
//timer_setup(&gpios[i].key_timer, key_timer_expire, 0);
//gpios[i].key_timer.expires = ~0;
//add_timer(&gpios[i].key_timer);
//err = request_irq(gpios[i].irq, dht11_isr, IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING, "100ask_gpio_key", &gpios[i]);
}
/* 注册file_operations */
major = register_chrdev(0, "100ask_dht11", &dht11_drv); /* /dev/gpio_desc */
gpio_class = class_create(THIS_MODULE, "100ask_dht11_class");
if (IS_ERR(gpio_class)) {
printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
unregister_chrdev(major, "100ask_dht11");
return PTR_ERR(gpio_class);
}
device_create(gpio_class, NULL, MKDEV(major, 0), NULL, "mydht11"); /* /dev/mydht11 */
return err;
}
/* 有入口函数就应该有出口函数：卸载驱动程序时，就会去调用这个出口函数
*/
static void __exit dht11_exit(void)
{
int i;
int count = sizeof(gpios)/sizeof(gpios[0]);
printk("%s %s line %d\n", __FILE__, __FUNCTION__, __LINE__);
device_destroy(gpio_class, MKDEV(major, 0));
class_destroy(gpio_class);
unregister_chrdev(major, "100ask_dht11");
for (i = 0; i < count; i++)
{
//free_irq(gpios[i].irq, &gpios[i]);
//del_timer(&gpios[i].key_timer);
}
}
/* 7. 其他完善：提供设备信息，自动创建设备节点 */
module_init(dht11_init);
module_exit(dht11_exit);
MODULE_LICENSE("GPL");

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04a_嵌入式Linux应用开发实验班(快速入门)/04_使用文件IO操作硬件/source/03_QT使用驱动操作温湿度模块/dht11_drv/02_dht11_drv_imx6ull/dht11_test.c Normal file
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#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdio.h>
#include <string.h>
#include <poll.h>
#include <signal.h>
static int fd;
/*
* ./button_test /dev/mydht11
*
*/
int main(int argc, char **argv)
{
char buf[2];
int ret;
int i;
/* 1. 判断参数 */
if (argc != 2)
{
printf("Usage: %s <dev>\n", argv[0]);
return -1;
}
/* 2. 打开文件 */
fd = open(argv[1], O_RDWR | O_NONBLOCK);
if (fd == -1)
{
printf("can not open file %s\n", argv[1]);
return -1;
}
while (1)
{
if (read(fd, buf, 2) == 2)
{
printf("get Humidity: %d, Temperature : %d\n", buf[0], buf[1]);
sleep(1);
}
}
//sleep(30);
close(fd);
return 0;
}