[PATCH 0/8] i2c: improve RECV_LEN documentation & usage

From: Wolfram Sang
Date: Sat Jan 09 2021 - 07:44:31 EST


Because I want to clarify I2C_M_RECV len usage, this series updates the
documentation and some of its users. Patch 1 refactors the whole
documentation of 'i2c_msg', so all usage of I2C_M_* flags and their
conditions hopefully become clearer. Patch 2+3 remove some obvious
boilerplate in the UAPI headers while here. Patch 4 is a driver fix I
found while working on this series. Patch 5 introduces a new convenience
macro to enable SMBus transfers which need I2C_M_RECV_LEN. Then, some
drivers use the new macro, sometimes to remove boilerplate, sometimes
because these SMBus transfers have been forgotten before.

This series is the first part of a larger work to extend I2C_M_RECV_LEN
to allow larger transfer sizes (as specified in the SMBus 3.0 standard)
and to enable this on Renesas R-Car hardware.

Looking forward to comments and/or reviews; the driver patches are only
build-tested.

Happy hacking,

Wolfram


Wolfram Sang (8):
i2c: refactor documentation of struct i2c_msg
i2c: remove licence boilerplate from main UAPI header
i2c: remove licence boilerplate from i2c-dev UAPI header
i2c: octeon: check correct size of maximum RECV_LEN packet
i2c: uapi: add macro to describe support for all SMBus transfers
i2c: algo: bit: use new macro to specifiy capabilities
i2c: qup: advertise SMBus transfers using RECV_LEN
i2c: s3c2410: advertise SMBus transfers using RECV_LEN

drivers/i2c/algos/i2c-algo-bit.c | 4 +-
drivers/i2c/busses/i2c-octeon-core.c | 2 +-
drivers/i2c/busses/i2c-qup.c | 2 +-
drivers/i2c/busses/i2c-s3c2410.c | 2 +-
include/uapi/linux/i2c-dev.h | 25 ++----
include/uapi/linux/i2c.h | 128 ++++++++++++++-------------
6 files changed, 76 insertions(+), 87 deletions(-)

--
2.29.2