first commit

Makefile

@@ -0,0 +1,25 @@
+ifneq ($(KERNELRELEASE),)
+
+obj-m := ds18b20_223.o ds18b20_224.o
+ds18b20_223-objs := ds18b20.o t223.o
+ds18b20_224-objs := ds18b20.o t224.o
+
+else
+
+CC = gcc
+KDIR := /lib/modules/$(shell uname -r)/build
+PWD := $(shell pwd)
+all:
+		$(MAKE) -C $(KDIR) M=$(PWD) modules
+install:
+		\cp ds18b20_223.ko /data/modules/
+		\cp ds18b20_224.ko /data/modules/
+uninstall:
+		rm -f /data/modules/ds18b20_224.ko
+		rm -f /data/modules/ds18b20_223.ko
+load:
+		/data/modules/load-modules.sh
+clean:
+		rm -rf *.o *.ko .*.cmd *.mod.* modules.order Module.symvers .tmp_versions
+
+endif

ds18b20.c

@@ -0,0 +1,139 @@
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/ioctl.h>
+#include <linux/delay.h>
+
+#include <linux/gpio.h>
+#include <linux/of_gpio.h>
+
+unsigned int gpio_num = 223;
+
+#define DQ_IN gpio_direction_input(gpio_num)
+#define DQ_OUT gpio_direction_output(gpio_num, gpio_get_value(gpio_num))
+#define DQ_H gpio_set_value(gpio_num, 1)
+#define DQ_L gpio_set_value(gpio_num, 0)
+#define DQ_V gpio_get_value(gpio_num)
+
+spinlock_t lock;
+
+//********************************
+//功能:ds18b20复位
+//********************************
+int init_DS18B20(void)
+{
+	unsigned int result;
+	DQ_OUT;
+	DQ_L;
+	DQ_H;
+	udelay(2);
+	DQ_L;
+	udelay(480); //480~960
+	DQ_H;
+	udelay(60); //60-240
+	DQ_IN;
+	result = DQ_V;
+	udelay(420);
+	DQ_OUT;
+    printk("ds18b20 init result %d", result);
+    return result;
+}
+
+//*************************************
+//功能:从ds18b20读一个字节的数据
+//*************************************
+unsigned char read_char(void)
+{
+    unsigned int i = 0;
+    unsigned char dat = 0;
+
+    spin_lock(&lock);
+    for(i=0; i<8; i++) {
+		DQ_OUT;
+		DQ_L;
+		DQ_H;
+		udelay(2);
+		DQ_L;
+		udelay(2);
+		DQ_H;
+		udelay(8);
+		dat >>= 1;
+        DQ_IN;
+        if (DQ_V)
+            dat |= 0x80;
+        udelay(50);
+    }
+	DQ_OUT;
+	DQ_L;
+	DQ_H;
+    spin_unlock(&lock);
+    return dat;
+}
+
+//*************************************
+//功能:向ds18b20写一个字节的数据
+//*************************************
+void write_char(unsigned char dat)
+{
+    unsigned int i = 0;
+
+    spin_lock(&lock);
+    DQ_OUT;
+	DQ_H;
+    for(i=0; i<8; i++) 
+	{
+	    DQ_H;
+        udelay(2);
+        DQ_L;
+		if (dat & 0x01)
+			DQ_H;
+		else
+			DQ_L;
+        udelay(60);
+		dat >>= 1;
+    }
+	DQ_H;
+    spin_unlock(&lock);
+}
+
+int initDs18b20(unsigned int gpioNum)
+{
+    spin_lock_init(&lock);
+    gpio_num = gpioNum;
+    if (init_DS18B20())
+        return 1;
+    return 0;
+}
+
+/*读取数据*/
+void readDs18b20Data(unsigned char *value)
+{
+    if (init_DS18B20())
+    {
+        return;
+    }
+    write_char(0xCC);
+    write_char(0x44);
+
+    mdelay(800);
+
+    if (init_DS18B20())
+    {
+        return;
+    }
+    write_char(0xCC);
+    write_char(0xBE);
+
+    if (sizeof(&value) > 1)
+    {
+        value[0] = read_char();
+        value[1] = read_char();
+    }
+}
+
+void freeDs18b20(void)
+{
+    gpio_free(gpio_num);
+}
+

ds18b20.h

@@ -0,0 +1,12 @@
+#ifndef DS18B20_H
+#define DS18B20_H
+
+int initDs18b20(unsigned int gpioNum);
+
+ /*读取数据*/
+void readDs18b20Data(unsigned char *value);
+
+void freeDs18b20(void);
+
+#endif
+

gettemp.c

@@ -0,0 +1,65 @@
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/select.h>
+
+float getTempByDev(char *devName);
+
+int main(int argc, char *argv[])
+{
+    if (argc == 2)
+    {
+        char * ch = argv[1];
+        //        int gpio = atoi(ch);
+        char * name = "/dev/ds18b20-";
+        char devName[16];
+        strcpy(devName, name);
+        strcat(devName, ch);
+        float t223 = getTempByDev(devName);
+        printf("%.4f", t223);
+    }
+    else
+    {
+        printf("-1");
+    }
+    return 0; 
+}
+
+float getTempByDev(char *devName)
+{
+    int fd;  
+    unsigned char result[2] = {0};  
+    unsigned int hightBitValue = 0;  
+    unsigned int lowBitValue = 0;  
+    float p = 0.0625;
+    float value = 1024.0f;
+
+    fd = open(devName, 0);  
+    if (fd >= 0) 
+    {
+        int i = read(fd, &result, sizeof(&result));
+        if (i >= 0)
+        {
+            //        printf("%xH-%xH\n", result[1], result[0]);
+            hightBitValue = result[1];
+            lowBitValue = result[0];
+            hightBitValue <<= 8;
+            hightBitValue = hightBitValue + lowBitValue;
+            if ((result[1] & 0xf8))
+            {
+                //                printf("aaa\n");
+                hightBitValue = ~hightBitValue + 1;
+                value = hightBitValue * p * -1;
+            }
+            else
+            {
+                value = hightBitValue * p;
+            }
+
+        }  
+        close(fd);
+    }
+    return value;
+}

t223.c

@@ -0,0 +1,75 @@
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/miscdevice.h>
+#include <linux/fs.h>
+#include <linux/types.h>
+#include <linux/moduleparam.h>
+#include <linux/slab.h>
+#include <linux/cdev.h>
+
+#include <linux/gpio.h>
+#include <linux/of_gpio.h>
+  
+#include <asm/uaccess.h>
+#include "ds18b20.h"
+
+#define DEVICE_NAME "ds18b20-223"
+#define NODE_NAME "ds18b20-223"
+
+#define gpio_num 223
+
+static int ds18b20_open(struct inode *inode, struct file *filp)
+{
+    //printk (KERN_INFO "Device opened\n");
+    int flag = initDs18b20(gpio_num);
+    if(flag & 0x01)
+        return -1;
+    return 0;
+}
+
+ /*读取数据*/
+static int ds18b20_read(struct file *filp, char __user *buffer, size_t count, loff_t *ppos)
+{
+    unsigned char tmp[2];
+    readDs18b20Data(tmp);
+	return copy_to_user(buffer, &tmp, sizeof(tmp));
+}
+
+
+static struct file_operations ds18b20_fops = {
+    .owner  = THIS_MODULE,
+    .open   = ds18b20_open,
+    .read   = ds18b20_read,
+};
+
+static struct miscdevice ds18b20_dev = {
+    .minor           = MISC_DYNAMIC_MINOR,
+    .name            = DEVICE_NAME,
+    .nodename        = NODE_NAME,
+    .fops            = &ds18b20_fops,
+};
+
+static int __init ds18b20_dev_init(void) {
+    int ret;
+    ret = gpio_request(gpio_num, DEVICE_NAME);
+    if (ret) {
+        printk("%s: request GPIO %d for GPE0 failed, ret = %d\n", DEVICE_NAME, gpio_num, ret);
+        return ret;
+    }
+    ret = misc_register(&ds18b20_dev);//注册杂设备驱动
+    printk(DEVICE_NAME"\tinitialized\n");
+    return ret;
+}
+
+static void __exit ds18b20_dev_exit(void) {
+    freeDs18b20();
+    misc_deregister(&ds18b20_dev);
+}
+
+module_init(ds18b20_dev_init);
+module_exit(ds18b20_dev_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_VERSION("1.0");
+MODULE_AUTHOR("shuixx.");
+

t224.c

@@ -0,0 +1,75 @@
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/miscdevice.h>
+#include <linux/fs.h>
+#include <linux/types.h>
+#include <linux/moduleparam.h>
+#include <linux/slab.h>
+#include <linux/cdev.h>
+
+#include <linux/gpio.h>
+#include <linux/of_gpio.h>
+
+#include <asm/uaccess.h>
+#include "ds18b20.h"
+
+#define DEVICE_NAME "ds18b20-224"
+#define NODE_NAME "ds18b20-224"
+
+#define gpio_num 224
+
+static int ds18b20_open(struct inode *inode, struct file *filp)
+{
+    //printk (KERN_INFO "Device opened\n");
+    int flag = initDs18b20(gpio_num);
+    if(flag & 0x01)
+        return -1;
+    return 0;
+}
+
+ /*读取数据*/
+static int ds18b20_read(struct file *filp, char __user *buffer, size_t count, loff_t *ppos)
+{
+    unsigned char tmp[2];
+    readDs18b20Data(tmp);
+	return copy_to_user(buffer, &tmp, sizeof(tmp));
+}
+
+
+static struct file_operations ds18b20_fops = {
+    .owner  = THIS_MODULE,
+    .open   = ds18b20_open,
+    .read   = ds18b20_read,
+};
+
+static struct miscdevice ds18b20_dev = {
+    .minor           = MISC_DYNAMIC_MINOR,
+    .name            = DEVICE_NAME,
+    .nodename        = NODE_NAME,
+    .fops            = &ds18b20_fops,
+};
+
+static int __init ds18b20_dev_init(void) {
+    int ret;
+    ret = gpio_request(gpio_num, DEVICE_NAME);
+    if (ret) {
+        printk("%s: request GPIO %d for GPE0 failed, ret = %d\n", DEVICE_NAME, gpio_num, ret);
+        return ret;
+    }
+    ret = misc_register(&ds18b20_dev);//注册杂设备驱动
+    printk(DEVICE_NAME"\tinitialized\n");
+    return ret;
+}
+
+static void __exit ds18b20_dev_exit(void) {
+    freeDs18b20();
+    misc_deregister(&ds18b20_dev);
+}
+
+module_init(ds18b20_dev_init);
+module_exit(ds18b20_dev_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_VERSION("1.0");
+MODULE_AUTHOR("shuixx.");
+

temp.c

@@ -0,0 +1,51 @@
+#include <fcntl.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/select.h>
+
+float getTempByDev(char *devName);
+
+int main(int argc, char *argv[])
+{
+    float t223 = getTempByDev("/dev/ds18b20-223");
+    float t224 = getTempByDev("/dev/ds18b20-224");
+    printf("%.4f#%.4f\n", t223, t224);
+    return 0; 
+}
+
+float getTempByDev(char *devName)
+{
+    int fd;  
+    unsigned char result[2] = {0};  
+    unsigned int hightBitValue = 0;  
+    unsigned int lowBitValue = 0;  
+    float p = 0.0625;
+    float value = 1024.0f;
+
+    fd = open(devName, 0);  
+    if (fd >= 0) 
+    {
+        int i = read(fd, &result, sizeof(&result));
+        if (i >= 0)
+        {
+    //        printf("%xH-%xH\n", result[1], result[0]);
+            hightBitValue = result[1];
+            lowBitValue = result[0];
+            hightBitValue <<= 8;
+            hightBitValue = hightBitValue + lowBitValue;
+            if ((result[1] & 0xf8))
+            {
+//                printf("aaa\n");
+                hightBitValue = ~hightBitValue + 1;
+                value = hightBitValue * p * -1;
+            }
+            else
+            {
+                value = hightBitValue * p;
+            }
+
+        }  
+        close(fd);
+    }
+    return value;
+}