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z8 I2C driver now supports the I2C_TRANSFER method

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This commit is contained in:
Gregory Nutt
2016-01-31 13:49:34 -06:00
parent 74d2073fca
commit 2d41fb26b8
1 changed files with 170 additions and 80 deletions
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arch/z80/src/z8/z8_i2c.c
+170 -80
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@@ -58,8 +58,8 @@
* Pre-processor Definitions
****************************************************************************/
#define EZ80_NOSTOP (1 << 0) /* Bit 0: No STOP on this transfer */
#define EZ80_NOSTART (1 << 1) /* Bit 1: No address or START on this tranfers */
#define Z8_NOSTOP (1 << 0) /* Bit 0: No STOP on this transfer */
#define Z8_NOSTART (1 << 1) /* Bit 1: No address or START on this tranfers */
/****************************************************************************
* Private Types
@@ -279,7 +279,90 @@ static int z8_i2c_read_transfer(FAR struct z8_i2cdev_s *priv,
FAR uint8_t *buffer, int buflen,
uint8_t flags)
{
return -ENOSYS;
FAR uint8_t *ptr;
int retry;
int count;
/* Retry as necessary to receive the whole message */
for (retry = 0; retry < 100; retry++)
{
if ((flags & Z8_NOSTART) == 0)
{
/* Load the address into the transmit register. It is not sent
* until the START bit is set.
*/
I2CD = I2C_READADDR8(priv->addr);
/* If we want only a single byte of data, then set the NACK
* bit now.
*/
I2CCTL |= I2C_CTL_NAK;
/* The START bit begins the transaction */
I2CCTL |= I2C_CTL_START;
}
/* Now loop to receive each data byte */
ptr = buffer;
for (count = buflen; count; count--)
{
/* Wait for the receive buffer to fill */
z8_i2c_waitrxavail();
/* Did we get a byte? Or did an error occur? */
if (I2CSTAT & I2C_STAT_RDRF)
{
/* Save the data byte */
*ptr++ = I2CD;
/* If the next byte is the last byte, then set NAK now */
if (count == 2 && (flags & Z8_NOSTOP) == 0)
{
I2CCTL |= I2C_CTL_NAK;
}
/* If this was the last byte, then set STOP and return success */
else if (count == 1)
{
if ((flags & Z8_NOSTOP) == 0)
{
I2CCTL |= I2C_CTL_STOP;
}
return OK;
}
}
/* An error occurred. Clear byte bus and break out of the loop
* to retry now.
*/
else
{
/* No, flush the buffer and toggle the I2C on and off */
I2CCTL |= I2C_CTL_FLUSH;
I2CCTL &= ~I2C_CTL_IEN;
I2CCTL |= I2C_CTL_IEN;
/* Break out of the loop early and try again */
break;
}
}
}
return -ETIMEDOUT;
}
/****************************************************************************
@@ -306,7 +389,84 @@ static int z8_i2c_write_transfer(FAR struct z8_i2cdev_s *priv,
FAR const uint8_t *buffer, int buflen,
uint8_t flags)
{
return -ENOSYS;
FAR const uint8_t *ptr;
int retry;
int count;
/* Retry as necessary to send this whole message */
for (retry = 0; retry < 100; retry++)
{
if ((flags & Z8_NOSTART) == 0)
{
/* Load the address into the transmit register. It is not sent
* until the START bit is set.
*/
I2CD = I2C_WRITEADDR8(priv->addr);
I2CCTL |= I2C_CTL_START;
/* Wait for the xmt buffer to become empty */
z8_i2c_waittxempty();
}
/* Then send all of the bytes in the buffer */
ptr = buffer;
for (count = buflen; count; count--)
{
/* Send a byte of data and wait for it to be sent */
I2CD = *ptr++;
z8_i2c_waittxempty();
/* If this was the last byte, then send STOP immediately. This
* is because the ACK will not be valid until the STOP clocks out
* the last bit.. Hmmm. If this true then we will never be
* able to send more than one data byte???
*/
if (count == 1)
{
if ((flags & Z8_NOSTOP) == 0)
{
I2CCTL |= I2C_CTL_STOP;
}
/* If this last byte was ACKed, then the whole buffer
* was successfully sent and we can return success.
*/
if ((I2CSTAT & I2C_STAT_ACK) != 0)
{
return OK;
}
/* If was was not ACKed, then this inner loop will
* terminated (because count will decrement to zero
* and the whole message will be resent
*/
}
/* Not the last byte... was this byte ACKed? */
else if ((I2CSTAT & I2C_STAT_ACK) == 0)
{
/* No, flush the buffer and toggle the I2C on and off */
I2CCTL |= I2C_CTL_FLUSH;
I2CCTL &= ~I2C_CTL_IEN;
I2CCTL |= I2C_CTL_IEN;
/* Break out of the loop early and try again */
break;
}
}
}
return -ETIMEDOUT;
}
/****************************************************************************
@@ -516,9 +676,7 @@ static int z8_i2c_read(FAR struct i2c_master_s *dev, FAR uint8_t *buffer,
int buflen)
{
FAR struct z8_i2cdev_s *priv = (FAR struct z8_i2cdev_s *)dev;
uint8_t *ptr;
int retry;
int count;
int ret;
DEBUGASSERT(dev != NULL && buffer != NULL && buflen > 0);
@@ -530,80 +688,12 @@ static int z8_i2c_read(FAR struct i2c_master_s *dev, FAR uint8_t *buffer,
z8_i2c_setbrg(priv->brg);
/* Retry as necessary to receive the whole message */
/* Perform the transfer */
for (retry = 0; retry < 100; retry++)
{
/* Load the address into the transmit register. It is not sent
* until the START bit is set.
*/
I2CD = I2C_READADDR8(priv->addr);
/* If we want only a single byte of data, then set the NACK
* bit now.
*/
I2CCTL |= I2C_CTL_NAK;
/* The START bit begins the transaction */
I2CCTL |= I2C_CTL_START;
/* Now loop to receive each data byte */
ptr = buffer;
for (count = buflen; count; count--)
{
/* Wait for the receive buffer to fill */
z8_i2c_waitrxavail();
/* Did we get a byte? Or did an error occur? */
if (I2CSTAT & I2C_STAT_RDRF)
{
/* Save the data byte */
*ptr++ = I2CD;
/* If the next byte is the last byte, then set NAK now */
if (count == 2)
{
I2CCTL |= I2C_CTL_NAK;
}
/* If this was the last byte, then set STOP and return success */
else if (count == 1)
{
I2CCTL |= I2C_CTL_STOP;
z8_i2c_semgive();
return OK;
}
}
/* An error occurred. Clear byte bus and break out of the loop
* to retry now.
*/
else
{
/* No, flush the buffer and toggle the I2C on and off */
I2CCTL |= I2C_CTL_FLUSH;
I2CCTL &= ~I2C_CTL_IEN;
I2CCTL |= I2C_CTL_IEN;
/* Break out of the loop early and try again */
break;
}
}
}
ret = z8_i2c_read_transfer(priv, buffer, buflen, 0);
z8_i2c_semgive();
return -ETIMEDOUT;
return ret;
}
/****************************************************************************
@@ -678,7 +768,7 @@ static int z8_i2c_transfer(FAR struct i2c_master_s *dev,
/* Perform the read or write operation */
flags |= (nostop) ? EZ80_NOSTOP : 0;
flags |= (nostop) ? Z8_NOSTOP : 0;
if ((msg->flags & I2C_M_READ) != 0)
{
ret = z8_i2c_read_transfer(priv, msg->buffer, msg->length, flags);
@@ -699,7 +789,7 @@ static int z8_i2c_transfer(FAR struct i2c_master_s *dev,
* START on the next segment.
*/
flags = (nostop) ? EZ80_NOSTART : 0;
flags = (nostop) ? Z8_NOSTART : 0;
}
z8_i2c_semgive();