Re: [PATCH v6 08/11] i2c: designware: Convert driver to using regmap API

From: Wolfram Sang
Date: Sat May 30 2020 - 07:09:47 EST


On Thu, May 28, 2020 at 12:33:18PM +0300, Serge Semin wrote:
> Seeing the DW I2C driver is using flags-based accessors with two
> conditional clauses it would be better to replace them with the regmap
> API IO methods and to initialize the regmap object with read/write
> callbacks specific to the controller registers map implementation. This
> will be also handy for the drivers with non-standard registers mapping
> (like an embedded into the Baikal-T1 System Controller DW I2C block, which
> glue-driver is a part of this series).
>
> As before the driver tries to detect the mapping setup at probe stage and
> creates a regmap object accordingly, which will be used by the rest of the
> code to correctly access the controller registers. In two places it was
> appropriate to convert the hand-written read-modify-write and
> read-poll-loop design patterns to the corresponding regmap API
> ready-to-use methods.
>
> Note the regmap IO methods return value is checked only at the probe
> stage. The rest of the code won't do this because basically we have
> MMIO-based regmap so non of the read/write methods can fail (this also
> won't be needed for the Baikal-T1-specific I2C controller).
>
> Suggested-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> Signed-off-by: Serge Semin <Sergey.Semin@xxxxxxxxxxxxxxxxxxxx>
> Tested-by: Jarkko Nikula <jarkko.nikula@xxxxxxxxxxxxxxx>
> Acked-by: Jarkko Nikula <jarkko.nikula@xxxxxxxxxxxxxxx>
> Cc: Alexey Malahov <Alexey.Malahov@xxxxxxxxxxxxxxxxxxxx>
> Cc: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>
> Cc: Rob Herring <robh+dt@xxxxxxxxxx>
> Cc: devicetree@xxxxxxxxxxxxxxx
> Cc: linux-mips@xxxxxxxxxxxxxxx

My codecheckers found these, rightfully I'd say:

SPARSE
drivers/i2c/busses/i2c-designware-master.c:427:53: warning: incorrect type in argument 3 (different signedness)
drivers/i2c/busses/i2c-designware-master.c:427:53: expected unsigned int *val
drivers/i2c/busses/i2c-designware-master.c:427:53: got int *

CC
drivers/i2c/busses/i2c-designware-common.c:127: warning: Excess function parameter 'base' description in 'i2c_dw_init_regmap'

^ means there is an argument documented which does not exist in the
function declaration

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