我正在编写代码以使用“/linux/i2c.h”中的标准接口访问i2c驱动程序(从内核空间)
当我试图调用如下所示的方法时,出现了一个错误:(参数太少)。附件是“i2c.c”中定义的方法的实现代码
我的代码:
static inline unsigned char i2cReadByte()
{
unsigned char retVal = 0x00;
struct i2c_msg value;
//TODO Fill in msg
i2c_transfer((struct i2c_msg*)&value); // Error: too few arguments to function 'i2c_transfer'
return retVal;
}
i2c.c中定义的i2c U传输码:
int i2c_transfer(struct i2c_msg *msg)
{
int ret;
if (!msg)
goto transfer_error_msg_empty;
switch(msg->direction) {
case I2C_WRITE:
/* check if bus is not busy */
if (!i2c_isr_set_cleared(0,ISR_IBB))
goto transfer_error_bus_busy;
/* start transmission */
ICR &= ~ICR_START;
ICR &= ~ICR_STOP;
IDBR = msg->data;
if (msg->condition == I2C_COND_START) ICR |= ICR_START;
if (msg->condition == I2C_COND_STOP) ICR |= ICR_STOP;
if (msg->acknack == I2C_ACKNAK_SENDNAK) ICR |= ICR_ACKNAK;
if (msg->acknack == I2C_ACKNAK_SENDACK) ICR &= ~ICR_ACKNAK;
ICR &= ~ICR_ALDIE;
ICR |= ICR_TB;
/* transmit register empty? */
if (!i2c_isr_set_cleared(ISR_ITE,0))
goto transfer_error_transmit_timeout;
/* clear 'transmit empty' state */
ISR |= ISR_ITE;
/* wait for ACK from slave */
if (msg->acknack == I2C_ACKNAK_WAITACK)
if (!i2c_isr_set_cleared(0,ISR_ACKNAK))
goto transfer_error_ack_missing;
break;
case I2C_READ:
/* check if bus is not busy */
if (!i2c_isr_set_cleared(0,ISR_IBB))
goto transfer_error_bus_busy;
/* start receive */
ICR &= ~ICR_START;
ICR &= ~ICR_STOP;
if (msg->condition == I2C_COND_START) ICR |= ICR_START;
if (msg->condition == I2C_COND_STOP) ICR |= ICR_STOP;
if (msg->acknack == I2C_ACKNAK_SENDNAK) ICR |= ICR_ACKNAK;
if (msg->acknack == I2C_ACKNAK_SENDACK) ICR &= ~ICR_ACKNAK;
ICR &= ~ICR_ALDIE;
ICR |= ICR_TB;
/* receive register full? */
if (!i2c_isr_set_cleared(ISR_IRF,0))
goto transfer_error_receive_timeout;
msg->data = IDBR;
/* clear 'receive empty' state */
ISR |= ISR_IRF;
break;
default:
goto transfer_error_illegal_param;
}
return 0;
transfer_error_msg_empty:
PRINTD(("i2c_transfer: error: 'msg' is empty\n"));
ret = -1; goto i2c_transfer_finish;
transfer_error_transmit_timeout:
PRINTD(("i2c_transfer: error: transmit timeout\n"));
ret = -2; goto i2c_transfer_finish;
transfer_error_ack_missing:
PRINTD(("i2c_transfer: error: ACK missing\n"));
ret = -3; goto i2c_transfer_finish;
transfer_error_receive_timeout:
PRINTD(("i2c_transfer: error: receive timeout\n"));
ret = -4; goto i2c_transfer_finish;
transfer_error_illegal_param:
PRINTD(("i2c_transfer: error: illegal parameters\n"));
ret = -5; goto i2c_transfer_finish;
transfer_error_bus_busy:
PRINTD(("i2c_transfer: error: bus is busy\n"));
ret = -6; goto i2c_transfer_finish;
i2c_transfer_finish:
PRINTD(("i2c_transfer: ISR: 0x%04x\n",ISR));
i2c_reset();
return ret;
}
最佳答案
您与linux/i2c.h
中的一个内核函数有名称冲突:
/* Transfer num messages.
*/
extern int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
int num);
关于c - 出现错误:我明确拥有正确数字的参数太少,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/5663472/