[RFC PATCH 2/8] i2c-octeon: Support I2C_M_RECV_LEN

From: Jan Glauber
Date: Thu Feb 18 2016 - 03:23:14 EST


From: David Daney <ddaney@xxxxxxxxxxxxxxxxxx>

If I2C_M_RECV_LEN is set consider the length byte.

Signed-off-by: David Daney <ddaney@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Jan Glauber <jglauber@xxxxxxxxxx>
---
drivers/i2c/busses/i2c-octeon.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/drivers/i2c/busses/i2c-octeon.c b/drivers/i2c/busses/i2c-octeon.c
index 1f14094..fa4d439 100644
--- a/drivers/i2c/busses/i2c-octeon.c
+++ b/drivers/i2c/busses/i2c-octeon.c
@@ -392,13 +392,14 @@ static int octeon_i2c_write(struct octeon_i2c *i2c, int target,
* @target: Target address
* @data: Pointer to the location to store the data
* @rlength: Length of the data
+ * @recv_len: flag for length byte
*
* The address is sent over the bus, then the data is read.
*
* Returns 0 on success, otherwise a negative errno.
*/
static int octeon_i2c_read(struct octeon_i2c *i2c, int target, u8 *data,
- u16 *rlength)
+ u16 *rlength, bool recv_len)
{
int length = *rlength;
int i, result;
@@ -438,6 +439,15 @@ static int octeon_i2c_read(struct octeon_i2c *i2c, int target, u8 *data,
return result;

data[i] = octeon_i2c_read_sw(i2c, SW_TWSI_EOP_TWSI_DATA);
+ if (recv_len && i == 0) {
+ if (data[i] > I2C_SMBUS_BLOCK_MAX + 1) {
+ dev_err(i2c->dev,
+ "%s: read len > I2C_SMBUS_BLOCK_MAX %d\n",
+ __func__, data[i]);
+ return -EIO;
+ }
+ length += data[i];
+ }
}
*rlength = length;
return 0;
@@ -466,7 +476,8 @@ static int octeon_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
pmsg->len, pmsg->addr, i + 1, num);
if (pmsg->flags & I2C_M_RD)
ret = octeon_i2c_read(i2c, pmsg->addr, pmsg->buf,
- &pmsg->len);
+ &pmsg->len,
+ pmsg->flags & I2C_M_RECV_LEN);
else
ret = octeon_i2c_write(i2c, pmsg->addr, pmsg->buf,
pmsg->len);
--
1.9.1