Re: [Gta04-owner] [PATCH 3/3] tty/slaves: add a driver to power on/off UART attached devices.

Pavel Machek
2015-03-25T20:42:15Z

Hi!

> > In the case of our GPS, it receives control over the serial connection from
> > the UART,
>
> Ahem - does it?
>
> AFAIK the chip simply starts to emit NMEA records if powered on. There is no
> command going over the serial interface to address it or control it.

Well _most_ GPSes enable you to control them over the serial
line. (Things like sampling rate, AGPS data upload, ...)

> > I think the GPS is “primarily" a uart-attached device.
>
> But not in the same way as an I2C device.
>
> Especially the serial interface is not a bus and not used for signalling and
> power control. It is payload data (only).

Serial interface looks a lot like a (point-to-point) bus to
me. Similar to SATA, for example.
Pavel
--
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