In case of transaction with I2C_M_RECV_LEN set, make sure the driver reads
the first byte and then updates the RX fifo with the expected length. Set
threshold to 1 byte so that driver gets an interrupt on receiving the first byte.
After which the transfer length is updated depending on the received length.
Signed-off-by: George Cherian <george.cherian@xxxxxxxxxx>
---
drivers/i2c/busses/i2c-xlp9xx.c | 31 ++++++++++++++++++++++++-------
1 file changed, 24 insertions(+), 7 deletions(-)
diff --git a/drivers/i2c/busses/i2c-xlp9xx.c b/drivers/i2c/busses/i2c-xlp9xx.c
index 6d78cdc..b5b224e 100644
--- a/drivers/i2c/busses/i2c-xlp9xx.c
+++ b/drivers/i2c/busses/i2c-xlp9xx.c
@@ -125,7 +125,16 @@ static void xlp9xx_i2c_update_rx_fifo_thres(struct xlp9xx_i2c_dev *priv)
{
u32 thres;
- thres = min(priv->msg_buf_remaining, XLP9XX_I2C_FIFO_SIZE);
+ if (priv->len_recv)
+ /* interrupt after the first read to examine
+ * the length byte before proceeding further
+ */
+ thres = 1;
+ else if (priv->msg_buf_remaining > XLP9XX_I2C_FIFO_SIZE)
+ thres = XLP9XX_I2C_FIFO_SIZE;
+ else
+ thres = priv->msg_buf_remaining;
+
xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_MFIFOCTRL,
thres << XLP9XX_I2C_MFIFOCTRL_HITH_SHIFT);
}
@@ -144,7 +153,7 @@ static void xlp9xx_i2c_fill_tx_fifo(struct xlp9xx_i2c_dev *priv)
static void xlp9xx_i2c_drain_rx_fifo(struct xlp9xx_i2c_dev *priv)
{
- u32 len, i;
+ u32 len, i, val;
u8 rlen, *buf = priv->msg_buf;
len = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_FIFOWCNT) &
@@ -156,19 +165,27 @@ static void xlp9xx_i2c_drain_rx_fifo(struct xlp9xx_i2c_dev *priv)
rlen = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_MRXFIFO);
*buf++ = rlen;
len--;
+
if (priv->client_pec)
++rlen;
/* update remaining bytes and message length */
priv->msg_buf_remaining = rlen;
priv->msg_len = rlen + 1;
priv->len_recv = false;
- }
- len = min(priv->msg_buf_remaining, len);
- for (i = 0; i < len; i++, buf++)
- *buf = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_MRXFIFO);
+ /* Update transfer length to read only actual data */
+ val = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_CTRL);
+ val = (val & ~XLP9XX_I2C_CTRL_MCTLEN_MASK) |
+ ((rlen + 1) << XLP9XX_I2C_CTRL_MCTLEN_SHIFT);
+ xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_CTRL, val);
+ } else {
+ len = min(priv->msg_buf_remaining, len);
+ for (i = 0; i < len; i++, buf++)
+ *buf = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_MRXFIFO);
+
+ priv->msg_buf_remaining -= len;
+ }
- priv->msg_buf_remaining -= len;
priv->msg_buf = buf;
if (priv->msg_buf_remaining)
--
2.1.4
