diff options
| author | Kamlakant Patel <kamlakant.patel@cavium.com> | 2017-10-10 08:27:56 +0200 |
|---|---|---|
| committer | Wolfram Sang <wsa@the-dreams.de> | 2017-10-17 23:53:28 +0200 |
| commit | 5515ae112172e20667f02b16f45fbf992923dcb0 (patch) | |
| tree | 8f55504663432f580091f434941c3a3c268671ca /drivers/i2c | |
| parent | i2c: xlp9xx: Get clock frequency with clk API (diff) | |
| download | linux-5515ae112172e20667f02b16f45fbf992923dcb0.tar.xz linux-5515ae112172e20667f02b16f45fbf992923dcb0.zip | |
i2c: xlp9xx: Handle I2C_M_RECV_LEN in msg->flags
The driver needs to handle the flag I2C_M_RECV_LEN during receive to
support SMBus emulation.
Update receive logic to handle the case where the length is received
as the first byte of a transaction.
Also update the code to handle I2C_CLIENT_PEC, which is set when the
client sends a packet error checking code byte.
Signed-off-by: Jayachandran C <jnair@caviumnetworks.com>
Signed-off-by: Kamlakant Patel <kamlakant.patel@cavium.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/busses/i2c-xlp9xx.c | 30 |
1 files changed, 27 insertions, 3 deletions
diff --git a/drivers/i2c/busses/i2c-xlp9xx.c b/drivers/i2c/busses/i2c-xlp9xx.c index f0bef2d5306c..b970bf8f38e5 100644 --- a/drivers/i2c/busses/i2c-xlp9xx.c +++ b/drivers/i2c/busses/i2c-xlp9xx.c @@ -82,6 +82,8 @@ struct xlp9xx_i2c_dev { struct completion msg_complete; int irq; bool msg_read; + bool len_recv; + bool client_pec; u32 __iomem *base; u32 msg_buf_remaining; u32 msg_len; @@ -143,10 +145,25 @@ 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; - u8 *buf = priv->msg_buf; + u8 rlen, *buf = priv->msg_buf; len = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_FIFOWCNT) & XLP9XX_I2C_FIFO_WCNT_MASK; + if (!len) + return; + if (priv->len_recv) { + /* 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; + } + len = min(priv->msg_buf_remaining, len); for (i = 0; i < len; i++, buf++) *buf = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_MRXFIFO); @@ -230,7 +247,7 @@ static int xlp9xx_i2c_xfer_msg(struct xlp9xx_i2c_dev *priv, struct i2c_msg *msg, int last_msg) { unsigned long timeleft; - u32 intr_mask, cmd, val; + u32 intr_mask, cmd, val, len; priv->msg_buf = msg->buf; priv->msg_buf_remaining = priv->msg_len = msg->len; @@ -263,9 +280,13 @@ static int xlp9xx_i2c_xfer_msg(struct xlp9xx_i2c_dev *priv, struct i2c_msg *msg, else val &= ~XLP9XX_I2C_CTRL_ADDMODE; + priv->len_recv = msg->flags & I2C_M_RECV_LEN; + len = priv->len_recv ? XLP9XX_I2C_FIFO_SIZE : msg->len; + priv->client_pec = msg->flags & I2C_CLIENT_PEC; + /* set data length to be transferred */ val = (val & ~XLP9XX_I2C_CTRL_MCTLEN_MASK) | - (msg->len << XLP9XX_I2C_CTRL_MCTLEN_SHIFT); + (len << XLP9XX_I2C_CTRL_MCTLEN_SHIFT); xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_CTRL, val); /* fill fifo during tx */ @@ -312,6 +333,9 @@ static int xlp9xx_i2c_xfer_msg(struct xlp9xx_i2c_dev *priv, struct i2c_msg *msg, return -ETIMEDOUT; } + /* update msg->len with actual received length */ + if (msg->flags & I2C_M_RECV_LEN) + msg->len = priv->msg_len; return 0; } |