把smbus.c和smbus.h连接起来？

Question

我在使用这段代码的时候创造了一个高度，在文章的末尾，它指出，

要编译，请确保下载了smbus.c和smbus.h文件，将smbus.c更改为正确链接到smbus.h，并将上面提到的定义行添加到smbus.c，这样编译器就不会抱怨。

这里是sbus.c

#include <errno.h>
#include <i2c/smbus.h>
#include <sys/ioctl.h>
#include <linux/types.h>
#include <linux/i2c.h>
#include <linux/i2c-dev.h>

/* Compatibility defines */
#ifndef I2C_SMBUS_I2C_BLOCK_BROKEN
#define I2C_SMBUS_I2C_BLOCK_BROKEN I2C_SMBUS_I2C_BLOCK_DATA
#endif
#ifndef I2C_FUNC_SMBUS_PEC
#define I2C_FUNC_SMBUS_PEC I2C_FUNC_SMBUS_HWPEC_CALC
#endif

__s32 i2c_smbus_access(int file, char read_write, __u8 command,
           int size, union i2c_smbus_data *data)
{
    struct i2c_smbus_ioctl_data args;
    __s32 err;

    args.read_write = read_write;
    args.command = command;
    args.size = size;
    args.data = data;

    err = ioctl(file, I2C_SMBUS, &args);
    if (err == -1)
        err = -errno;
    return err;
}


__s32 i2c_smbus_write_quick(int file, __u8 value)
{
    return i2c_smbus_access(file, value, 0, I2C_SMBUS_QUICK, NULL);
}

__s32 i2c_smbus_read_byte(int file)
{
    union i2c_smbus_data data;
    int err;

    err = i2c_smbus_access(file, I2C_SMBUS_READ, 0, I2C_SMBUS_BYTE, &data);
    if (err < 0)
        return err;

    return 0x0FF & data.byte;
}

__s32 i2c_smbus_write_byte(int file, __u8 value)
{
    return i2c_smbus_access(file, I2C_SMBUS_WRITE, value,
                I2C_SMBUS_BYTE, NULL);
}

__s32 i2c_smbus_read_byte_data(int file, __u8 command)
{
    union i2c_smbus_data data;
    int err;

    err = i2c_smbus_access(file, I2C_SMBUS_READ, command,
                   I2C_SMBUS_BYTE_DATA, &data);
    if (err < 0)
        return err;

    return 0x0FF & data.byte;
}

__s32 i2c_smbus_write_byte_data(int file, __u8 command, __u8 value)
{
    union i2c_smbus_data data;
    data.byte = value;
    return i2c_smbus_access(file, I2C_SMBUS_WRITE, command,
                I2C_SMBUS_BYTE_DATA, &data);
}

__s32 i2c_smbus_read_word_data(int file, __u8 command)
{
    union i2c_smbus_data data;
    int err;

    err = i2c_smbus_access(file, I2C_SMBUS_READ, command,
                   I2C_SMBUS_WORD_DATA, &data);
    if (err < 0)
        return err;

    return 0x0FFFF & data.word;
}

__s32 i2c_smbus_write_word_data(int file, __u8 command, __u16 value)
{
    union i2c_smbus_data data;
    data.word = value;
    return i2c_smbus_access(file, I2C_SMBUS_WRITE, command,
                I2C_SMBUS_WORD_DATA, &data);
}

__s32 i2c_smbus_process_call(int file, __u8 command, __u16 value)
{
    union i2c_smbus_data data;
    data.word = value;
    if (i2c_smbus_access(file, I2C_SMBUS_WRITE, command,
                 I2C_SMBUS_PROC_CALL, &data))
        return -1;
    else
        return 0x0FFFF & data.word;
}

/* Returns the number of read bytes */
__s32 i2c_smbus_read_block_data(int file, __u8 command, __u8 *values)
{
    union i2c_smbus_data data;
    int i, err;

    err = i2c_smbus_access(file, I2C_SMBUS_READ, command,
                   I2C_SMBUS_BLOCK_DATA, &data);
    if (err < 0)
        return err;

    for (i = 1; i <= data.block[0]; i++)
        values[i-1] = data.block[i];
    return data.block[0];
}

__s32 i2c_smbus_write_block_data(int file, __u8 command, __u8 length,
                 const __u8 *values)
{
    union i2c_smbus_data data;
    int i;
    if (length > I2C_SMBUS_BLOCK_MAX)
        length = I2C_SMBUS_BLOCK_MAX;
    for (i = 1; i <= length; i++)
        data.block[i] = values[i-1];
    data.block[0] = length;
    return i2c_smbus_access(file, I2C_SMBUS_WRITE, command,
                I2C_SMBUS_BLOCK_DATA, &data);
}

/* Returns the number of read bytes */
/* Until kernel 2.6.22, the length is hardcoded to 32 bytes. If you
   ask for less than 32 bytes, your code will only work with kernels
   2.6.23 and later. */
__s32 i2c_smbus_read_i2c_block_data(int file, __u8 command, __u8 length,
                    __u8 *values)
{
    union i2c_smbus_data data;
    int i, err;

    if (length > I2C_SMBUS_BLOCK_MAX)
        length = I2C_SMBUS_BLOCK_MAX;
    data.block[0] = length;

    err = i2c_smbus_access(file, I2C_SMBUS_READ, command,
                   length == 32 ? I2C_SMBUS_I2C_BLOCK_BROKEN :
                I2C_SMBUS_I2C_BLOCK_DATA, &data);
    if (err < 0)
        return err;

    for (i = 1; i <= data.block[0]; i++)
        values[i-1] = data.block[i];
    return data.block[0];
}

__s32 i2c_smbus_write_i2c_block_data(int file, __u8 command, __u8 length,
                     const __u8 *values)
{
    union i2c_smbus_data data;
    int i;
    if (length > I2C_SMBUS_BLOCK_MAX)
        length = I2C_SMBUS_BLOCK_MAX;
    for (i = 1; i <= length; i++)
        data.block[i] = values[i-1];
    data.block[0] = length;
    return i2c_smbus_access(file, I2C_SMBUS_WRITE, command,
                I2C_SMBUS_I2C_BLOCK_BROKEN, &data);
}

/* Returns the number of read bytes */
__s32 i2c_smbus_block_process_call(int file, __u8 command, __u8 length,
                   __u8 *values)
{
    union i2c_smbus_data data;
    int i, err;

    if (length > I2C_SMBUS_BLOCK_MAX)
        length = I2C_SMBUS_BLOCK_MAX;
    for (i = 1; i <= length; i++)
        data.block[i] = values[i-1];
    data.block[0] = length;

    err = i2c_smbus_access(file, I2C_SMBUS_WRITE, command,
                   I2C_SMBUS_BLOCK_PROC_CALL, &data);
    if (err < 0)
        return err;

    for (i = 1; i <= data.block[0]; i++)
        values[i-1] = data.block[i];
    return data.block[0];
}

这里是埋伏，

#ifndef LIB_I2C_SMBUS_H
#define LIB_I2C_SMBUS_H

#include <linux/types.h>
#include <linux/i2c.h>

extern __s32 i2c_smbus_access(int file, char read_write, __u8 command,
              int size, union i2c_smbus_data *data);

extern __s32 i2c_smbus_write_quick(int file, __u8 value);
extern __s32 i2c_smbus_read_byte(int file);
extern __s32 i2c_smbus_write_byte(int file, __u8 value);
extern __s32 i2c_smbus_read_byte_data(int file, __u8 command);
extern __s32 i2c_smbus_write_byte_data(int file, __u8 command, __u8 value);
extern __s32 i2c_smbus_read_word_data(int file, __u8 command);
extern __s32 i2c_smbus_write_word_data(int file, __u8 command, __u16 value);
extern __s32 i2c_smbus_process_call(int file, __u8 command, __u16 value);

/* Returns the number of read bytes */
extern __s32 i2c_smbus_read_block_data(int file, __u8 command, __u8 *values);
extern __s32 i2c_smbus_write_block_data(int file, __u8 command, __u8 length,
                    const __u8 *values);

/* Returns the number of read bytes */
/* Until kernel 2.6.22, the length is hardcoded to 32 bytes. If you
   ask for less than 32 bytes, your code will only work with kernels
   2.6.23 and later. */
extern __s32 i2c_smbus_read_i2c_block_data(int file, __u8 command, __u8 length,
                       __u8 *values);
extern __s32 i2c_smbus_write_i2c_block_data(int file, __u8 command, __u8 length,
                        const __u8 *values);

/* Returns the number of read bytes */
extern __s32 i2c_smbus_block_process_call(int file, __u8 command, __u8 length,
                      __u8 *values);

#endif /* LIB_I2C_SMBUS_H */

最后，下面是前面提到的定义命令，

‘#定义空0

有了这些信息，我如何链接这两个文件并定义null？

Answer 1

将标题包含在程序中。

#include <smbus.h> 

或者如果.c和.h都在同一个目录中；

#include "smbus.h"

把这个包括在你的埋伏里。