linux-i2c驱动-ap3216c

1.应用程序

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdio.h>
#include <string.h>int main(int argc, char**argv)
{int fd;char buf[6];int len;fd = open("/dev/Ap3216c", O_RDWR);if (fd == -1){printf("can not open /dev/Ap3216c");return -1;}while(1){len = read(fd,buf,6);printf("App read: ");for (len = 0; len < 6; len++){printf("%02x ",buf[len]);}printf("\n");sleep(2);}close(fd);return 0;
}

2.i2c-driver程序

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/mutex.h>
#include <linux/mod_devicetable.h>
#include <linux/bitops.h>
#include <linux/jiffies.h>
#include <linux/property.h>
#include <linux/acpi.h>
#include <linux/i2c.h>
#include <linux/nvmem-provider.h>
#include <linux/regmap.h>
#include <linux/pm_runtime.h>
#include <linux/gpio/consumer.h>
#include <linux/uaccess.h>
#include <linux/fs.h>static int major = 0;
static struct i2c_client *Ap3216c_client;
static struct class *Ap3216c_class;static int Ap3216c_open(struct inode *node, struct file *file)
{//printk("%s %s %d\n", __FILE__, __FUNCTION__, __LINE__);i2c_smbus_write_byte_data(Ap3216c_client, 0, 0x4);mdelay(250);i2c_smbus_write_byte_data(Ap3216c_client, 0, 0x3);mdelay(250);return 0;
}static ssize_t Ap3216c_read(struct file *file, char __user *buf, size_t size, loff_t *offset)
{int err;char kernel_buf[6];int val;//printk("%s %s %d\n", __FILE__, __FUNCTION__, __LINE__);if (size != 6){return -EINVAL;}val = i2c_smbus_read_word_data(Ap3216c_client, 0xA); /* read IR */kernel_buf[0] = val & 0xff;kernel_buf[1] = (val >> 8) & 0xff;val = i2c_smbus_read_word_data(Ap3216c_client, 0xC); /* read 光强 */kernel_buf[2] = val & 0xff;kernel_buf[3] = (val >> 8) & 0xff;val = i2c_smbus_read_word_data(Ap3216c_client, 0xE); /* read 距离 */kernel_buf[4] = val & 0xff;kernel_buf[5] = (val >> 8) & 0xff;err = copy_to_user(buf, kernel_buf, size);if (err < 0){printk("copy_to_user err\n");return -1;}return size;	
}static const struct of_device_id of_match_ids_Ap3216c[] ={{.compatible = "lite-on,Ap3216c", .data = NULL },{/* END OF LIST */}
};static const struct file_operations Ap3216c_ops = {.owner = THIS_MODULE,.open = Ap3216c_open,.read = Ap3216c_read,
};static int Ap3216c_probe(struct i2c_client * client, const struct i2c_device_id * id)
{printk("%s %s %d\n", __FILE__, __FUNCTION__, __LINE__);Ap3216c_client = client;/* 注册字符设备 */major = register_chrdev(major, "Ap3216c", &Ap3216c_ops);if (major < 0){printk("register_chrdev err\n");return -1;}/* 注册类 */Ap3216c_class = class_create(THIS_MODULE, "Ap3216c_class");/* 注册设备 */device_create(Ap3216c_class, NULL, MKDEV(major,0), NULL, "Ap3216c");return 0;
}static int Ap3216c_remove(struct i2c_client * client)
{printk("%s %s %d\n", __FILE__, __FUNCTION__, __LINE__);device_destroy(Ap3216c_class, MKDEV(major,0));class_destroy(Ap3216c_class);unregister_chrdev(major, "Ap3216c");return 0;
}static const struct i2c_device_id Ap3216c_ids[] = {{"Ap3216c", (kernel_ulong_t)NULL },{/* END OF LIST */}
};static struct i2c_driver i2c_Ap3216c_driver = {.driver = {.name = "Ap3216c",.of_match_table = of_match_ids_Ap3216c,},.probe = Ap3216c_probe,.remove = Ap3216c_remove,.id_table = Ap3216c_ids,
};static int __init i2c_driver_Ap3216c_init(void)
{printk("%s %s line: %d\n", __FILE__, __FUNCTION__, __LINE__);return i2c_add_driver(&i2c_Ap3216c_driver);
}static void __exit i2c_driver_Ap3216c_exit(void)
{i2c_del_driver(&i2c_Ap3216c_driver);
}module_init(i2c_driver_Ap3216c_init);
module_exit(i2c_driver_Ap3216c_exit);
MODULE_LICENSE("GPL");

3.i2c-client程序

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/mutex.h>
#include <linux/mod_devicetable.h>
#include <linux/bitops.h>
#include <linux/jiffies.h>
#include <linux/property.h>
#include <linux/acpi.h>
#include <linux/i2c.h>
#include <linux/nvmem-provider.h>
#include <linux/regmap.h>
#include <linux/pm_runtime.h>
#include <linux/gpio/consumer.h>
#include <linux/uaccess.h>
#include <linux/fs.h>#if 1
static struct i2c_client *Ap3216c_client;
static int __init i2c_client_Ap3216c_init(void)
{struct i2c_adapter* adapter;struct i2c_board_info board_info = {I2C_BOARD_INFO("Ap3216c", 0x1e),};printk("%s %s %d\n", __FILE__, __FUNCTION__, __LINE__);/* register I2C device */adapter = i2c_get_adapter(0);Ap3216c_client = i2c_new_device(adapter, &board_info);i2c_put_adapter(adapter);return 0;
}
#else
static i2c_client *Ap3216c_client;
/* Addresses to scan */
static const unsigned short normal_i2c[] = {0x1e, I2C_CLIENT_END
};static int __init i2c_client_ap3216c_init(void)
{struct i2c_adapter *adapter;struct i2c_board_info board_info;memset(&board_info, 0, sizeof(struct i2c_board_info));strscpy(board_info.type, "Ap3216c", sizeof(board_info.type));printk("%s %s %d\n", __FILE__, __FUNCTION__, __LINE__);/* register I2C device */adapter = i2c_get_adapter(0);Ap3216c_client = i2c_new_probed_device(adapter, &board_info,normal_i2c, NULL);i2c_put_adapter(adapter);return 0;
}#endifstatic void __init i2c_client_Ap3216c_exit(void)
{printk("%s %s %d\n", __FILE__, __FUNCTION__, __LINE__);i2c_unregister_device(Ap3216c_client);
}module_init(i2c_client_Ap3216c_init);
module_exit(i2c_client_Ap3216c_exit);
MODULE_LICENSE("GPL");

4.Makefile

KERN_DIR = /home/book/100ask_imx6ull-sdk/Linux-4.9.88
all:make -C $(KERN_DIR) M=`pwd` modules$(CROSS_COMPILE)gcc -o ap3216c_drv_test ap3216c_drv_test.c 
clean:make -C $(KERN_DIR) M=`pwd` modules cleanrm -rf modules.orderrm -rf ap3216c_drv_testobj-m += ap3216c_drv.o
obj-m += ap3216c_client.o

5.测试结果

6.文件路径

/home/book/nfs_rootfs/CSDN/02_I2C/ap3216c