int
I2C::transfer(i2c_msg_s *msgv, unsigned msgs)
{
int ret;
unsigned retry_count = 0;
/* force the device address and Frequency into the message vector */
for (unsigned i = 0; i < msgs; i++) {
msgv[i].frequency = _bus_clocks[_bus - 1];
msgv[i].addr = _address;
}
do {
ret = I2C_TRANSFER(_dev, msgv, msgs);
/* success */
if (ret == OK) {
break;
}
/* if we have already retried once, or we are going to give up, then reset the bus */
if ((retry_count >= 1) || (retry_count >= _retries)) {
I2C_RESET(_dev);
}
} while (retry_count++ < _retries);
return ret;
}
int
I2C::transfer(const uint8_t *send, unsigned send_len, uint8_t *recv, unsigned recv_len)
{
struct i2c_msg_s msgv[2];
unsigned msgs;
int ret;
unsigned retry_count = 0;
do {
// DEVICE_DEBUG("transfer out %p/%u in %p/%u", send, send_len, recv, recv_len);
msgs = 0;
if (send_len > 0) {
msgv[msgs].frequency = _bus_clocks[_bus - 1];
msgv[msgs].addr = _address;
msgv[msgs].flags = 0;
msgv[msgs].buffer = const_cast<uint8_t *>(send);
msgv[msgs].length = send_len;
msgs++;
}
if (recv_len > 0) {
msgv[msgs].frequency = _bus_clocks[_bus - 1];;
msgv[msgs].addr = _address;
msgv[msgs].flags = I2C_M_READ;
msgv[msgs].buffer = recv;
msgv[msgs].length = recv_len;
msgs++;
}
if (msgs == 0) {
return -EINVAL;
}
ret = I2C_TRANSFER(_dev, &msgv[0], msgs);
/* success */
if (ret == OK) {
break;
}
/* if we have already retried once, or we are going to give up, then reset the bus */
if ((retry_count >= 1) || (retry_count >= _retries)) {
I2C_RESET(_dev);
}
} while (retry_count++ < _retries);
return ret;
}
static int i2cdrvr_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
{
FAR struct inode *inode = filep->f_inode;
FAR struct i2c_driver_s *priv;
FAR struct i2c_transfer_s *transfer;
int ret;
i2cvdbg("cmd=%d arg=%lu\n", cmd, arg);
/* Get our private data structure */
DEBUGASSERT(filep != NULL && filep->f_inode != NULL);
inode = filep->f_inode;
priv = (FAR struct i2c_driver_s *)inode->i_private;
DEBUGASSERT(priv);
/* Get exclusive access to the I2C driver state structure */
ret = sem_wait(&priv->exclsem);
if (ret < 0)
{
int errcode = errno;
DEBUGASSERT(errcode < 0);
return -errcode;
}
/* Process the IOCTL command */
switch (cmd)
{
/* Command: I2CIOC_TRANSFER
* Description: Perform an I2C transfer
* Argument: A reference to an instance of struct i2c_transfer_s.
* Dependencies: CONFIG_I2C_DRIVER
*/
case I2CIOC_TRANSFER:
{
/* Get the reference to the i2c_transfer_s structure */
transfer = (FAR struct i2c_transfer_s *)((uintptr_t)arg);
DEBUGASSERT(transfer != NULL);
/* Perform the transfer */
ret = I2C_TRANSFER(priv->i2c, transfer->msgv, transfer->msgc);
}
break;
#ifdef CONFIG_I2C_RESET
/* Command: I2CIOC_RESET
* Description: Perform an I2C bus reset in an attempt to break loose
* stuck I2C devices.
* Argument: None
* Dependencies: CONFIG_I2C_DRIVER && CONFIG_I2C_RESET
*/
case I2CIOC_RESET:
{
ret = I2C_RESET(priv->i2c);
}
break;
#endif
default:
ret = -ENOTTY;
break;
}
sem_post(&priv->exclsem);
return ret;
}
