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RE: [PATCH] iio: max5487: Add support for Maxim digital potentiometers

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Hi again,

Cristina Moraru wrote:
> Add implementation for Maxim MAX5487, MAX5488, MAX5489
> digital potentiometers.
> 
> Signed-off-by: Cristina Moraru <cristina.moraru09@gmail.com>
> CC: Daniel Baluta <daniel.baluta@intel.com>

Some more comments, the mcp4531 chips have n**2 + 1 positions,
therefore .max_pos in that driver isn't the number of wiper positions, it's
the actual maximum value. So, in this driver, the corrent number for
.max_pos would be 255, otherwise the reported scale is wrong (and then
you also need to adjust the EINVAL check in max5487_write_raw to use >
instead of >=).

Further comparison with the mcp4531 driver reveals that this driver does
not support IIO_CHAN_INFO_RAW in max5487_read_raw. I assume the SPI
interface does not support reading back the current value?

Cheers,
Peter

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Thread

[PATCH] iio: max5487: Add support for Maxim digital potentiometers Cristina Moraru <cristina.moraru09@gmail.com> - 2016-03-24 12:30 +0100
  Re: [PATCH] iio: max5487: Add support for Maxim digital potentiometers Daniel Baluta <daniel.baluta@intel.com> - 2016-03-24 12:50 +0100
  RE: [PATCH] iio: max5487: Add support for Maxim digital  potentiometers Peter Rosin <peda@axentia.se> - 2016-03-24 22:50 +0100
    Re: [PATCH] iio: max5487: Add support for Maxim digital potentiometers Daniel Baluta <daniel.baluta@intel.com> - 2016-04-01 10:30 +0200
  RE: [PATCH] iio: max5487: Add support for Maxim digital  potentiometers Peter Rosin <peda@axentia.se> - 2016-03-25 11:30 +0100
    Re: [PATCH] iio: max5487: Add support for Maxim digital potentiometers Daniel Baluta <daniel.baluta@intel.com> - 2016-04-01 10:40 +0200

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