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

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

[Wolfram Sang]

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

[PATCH 8/8] i2c: s3c2410: advertise SMBus transfers using RECV_LEN

[Wolfram Sang]

This driver implements I2C_M_RECV_LEN, so it can advertise the SMBus
transfers needing it. This also enables client devices to check for the
RECV_LEN capability.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---
 drivers/i2c/busses/i2c-s3c2410.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c
index 3eafe0eb3e4c..62a903fbe912 100644
--- a/drivers/i2c/busses/i2c-s3c2410.c
+++ b/drivers/i2c/busses/i2c-s3c2410.c
@@ -781,7 +781,7 @@ static int s3c24xx_i2c_xfer(struct i2c_adapter *adap,
 /* declare our i2c functionality */
 static u32 s3c24xx_i2c_func(struct i2c_adapter *adap)
 {
-	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_NOSTART |
+	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL_ALL | I2C_FUNC_NOSTART |
 		I2C_FUNC_PROTOCOL_MANGLING;
 }
 
-- 
2.29.2

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

[Wolfram Sang]

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On Sat, Jan 09, 2021 at 01:43:04PM +0100, Wolfram Sang wrote:
> 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 +-

Applied to for-next, thanks!


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