小结linux框架下函数如何可以使其被其他文件调用

http://blog.csdn.net/eqwewr/article/details/7664775
1：通常export该函数。

2：获取结构体指针：在driver设个全局变量。

下面贴出自己写的xenon flash driver部分代码。

struct xenon_flash_chip {

struct i2c_client *xenon_flash_client;

};

static struct xenon_flash_chip *xenon_chip;

//this is just for debug

int xenon_flash_reread(void)

{

int err = 0;

u8 data;

struct xenon_flash_chip *chip;

if(xenon_chip==NULL)

return err;

chip=xenon_chip;

//read 07

err = xenon_flash_i2c_read(chip->xenon_flash_client,0x07,&data);

if (err < 0)

return err;

CDBG("[xenon_flash]reg_control reg=0x07 data=0x0%x\n",data);

//read 06

err = xenon_flash_i2c_read(chip->xenon_flash_client,0x06,&data);

if (err < 0)

return err;

CDBG("[xenon_flash]reg_control reg=0x06 data=0x0%x\n",data);

//read 04

err = xenon_flash_i2c_read(chip->xenon_flash_client,0x04,&data);

if (err < 0)

return err;

CDBG("[xenon_flash]reg_control reg=0x04 data=0x0%x\n",data);

return err;

}

EXPORT_SYMBOL(xenon_flash_reread);

static int __devinit xenon_flash_i2c_probe(struct i2c_client *client,

const struct i2c_device_id *id)

{

int rc = 0;

static const u32 i2c_funcs = I2C_FUNC_SMBUS_BYTE_DATA |

I2C_FUNC_SMBUS_WRITE_WORD_DATA;

struct xenon_flash_chip *chip;

struct xenon_flash_platform_data *pdata;

CDBG("xenon_flash_i2c_probe called!\n");

/* check */

if (client->dev.platform_data == NULL) {

dev_err(&client->dev, "xenon_flash platform data is NULL.

exiting.\n");

return -ENODEV;

}

/* Copy to global variable */

pdata = client->dev.platform_data;

/*check i2c func*/

if (!i2c_check_functionality(client->adapter, i2c_funcs))

return -ENOSYS;

/* Allocate memory for driver data */

chip = kzalloc(sizeof(struct xenon_flash_chip), GFP_KERNEL);

if (!chip)

return -ENOMEM;

xenon_chip = chip;

i2c_set_clientdata(client,chip);

chip->xenon_flash_client = client;

rc = xenon_flash_init_hw(chip,pdata);

if (rc < 0)

CDBG("xenon_flash_init_hw initlised failed!\n");

return 0;

}

在driver调试过程中，通常需要将关键函数export出来，在其他地方extern声明再调用调试。

以上摘自自己写的疝气闪光灯driver.