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Subject: Re: [PATCH v2 0/9] Serial slave device bus
From: Marcel Holtmann <marcel@holtmann.org>
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Date: Fri, 20 Jan 2017 15:14:04 +0100
Cc: Rob Herring <robh@kernel.org>,
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To: Linus Walleij <linus.walleij@linaro.org>
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Hi Linus,

>> There's still some discussion about what to do with devices that pass thru
>> data to userspace unmodified like GPS and could still use tty device for
>> the data path. IMO, we should treat this as a separate problem following
>> this series. Drivers we want to convert to serdev and already in the
>> kernel don't need this functionality.
> 
> In my simple opinion GPSes shound live in drivers/iio/gps simply by
> usecase association: streaming out a series of accelerometer readings
> periodically through IIOs chardevs and other data about the physical
> world is not any different from the GPS usecase that give you a stream
> of coordinates on where on this planet you are.
> 
> The fact that vendors like to defer GPS processing to userspace because
> it is considered "secret sauce" is not the concern of the kernel community,
> though problems like that in general is the great tragedy of our time.
> 
> It would be fun to see a pure, reverse-engineered GPS driver in IIO.

except for the pure NMEA devices. Which are pretty much defined as terminal devices using RS422 and 4800 baud. For anything non-NMEA, I would agree that using IIO might be a good option. So instead of a GPS subsystem, might just have a GPS class / type in the IIO subsystem.

Regards

Marcel