diff options
Diffstat (limited to 'drivers/i2c/busses')
| -rw-r--r-- | drivers/i2c/busses/i2c-xlp9xx.c | 30 |
1 files changed, 21 insertions, 9 deletions
diff --git a/drivers/i2c/busses/i2c-xlp9xx.c b/drivers/i2c/busses/i2c-xlp9xx.c index fe545127a74b..c268fde5bbd9 100644 --- a/drivers/i2c/busses/i2c-xlp9xx.c +++ b/drivers/i2c/busses/i2c-xlp9xx.c @@ -158,9 +158,28 @@ static void xlp9xx_i2c_fill_tx_fifo(struct xlp9xx_i2c_dev *priv) priv->msg_buf += len; } +static void xlp9xx_i2c_update_rlen(struct xlp9xx_i2c_dev *priv) +{ + u32 val, len; + + /* + * Update receive length. Re-read len to get the latest value, + * and then add 4 to have a minimum value that can be safely + * written. This is to account for the byte read above, the + * transfer in progress and any delays in the register I/O + */ + val = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_CTRL); + len = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_FIFOWCNT) & + XLP9XX_I2C_FIFO_WCNT_MASK; + len = max_t(u32, priv->msg_len, len + 4); + val = (val & ~XLP9XX_I2C_CTRL_MCTLEN_MASK) | + (len << XLP9XX_I2C_CTRL_MCTLEN_SHIFT); + xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_CTRL, val); +} + static void xlp9xx_i2c_drain_rx_fifo(struct xlp9xx_i2c_dev *priv) { - u32 len, i, val; + u32 len, i; u8 rlen, *buf = priv->msg_buf; len = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_FIFOWCNT) & @@ -171,20 +190,13 @@ static void xlp9xx_i2c_drain_rx_fifo(struct xlp9xx_i2c_dev *priv) /* read length byte */ 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; - - /* 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); + xlp9xx_i2c_update_rlen(priv); } else { len = min(priv->msg_buf_remaining, len); for (i = 0; i < len; i++, buf++) |