i2c-dev: Add support for I2C_M_RECV_LEN
authorJean Delvare <khali@linux-fr.org>
Wed, 30 May 2012 08:55:34 +0000 (10:55 +0200)
committerJean Delvare <khali@endymion.delvare>
Wed, 30 May 2012 08:55:34 +0000 (10:55 +0200)
commit838bfa6049fb84dc66c9c9bbeb3a968ec987fd3d
tree5c6cf6d3d7dee7514f62b874b50bf88726144b11
parent731a7378b81c2f5fa88ca1ae20b83d548d5613dc
i2c-dev: Add support for I2C_M_RECV_LEN

As the bus driver side implementation of I2C_M_RECV_LEN is heavily
tied to SMBus, we can't support received length over 32 bytes, but
let's at least support that.

In practice, the caller will have to setup a buffer large enough to
cover the case where received length byte has value 32, so minimum
32 + 1 = 33 bytes, possibly more if there is a fixed number of bytes
added for the specific slave (for example a checksum.)

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Tested-by: Douglas Gilbert <dgilbert@interlog.com>
drivers/i2c/i2c-dev.c