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Date: Mon, 27 Nov 2023 15:54:24 +0200
From: Tony Lindgren <tony@atomide.com>
To: Andreas Kemnade <andreas@kemnade.info>
Cc: marcel@holtmann.org, johan.hedberg@gmail.com, luiz.dentz@gmail.com,
	johan@kernel.org, arnd@arndb.de, gregkh@linuxfoundation.org,
	linux-bluetooth@vger.kernel.org, linux-kernel@vger.kernel.org,
	tomi.valkeinen@ideasonboard.com,
	=?utf-8?B?UMOpdGVy?= Ujfalusi <peter.ujfalusi@gmail.com>,
	robh@kernel.org
Subject: Re: [RFC PATCH 0/3] bluetooth/gnss: GNSS support for TiWi chips
Message-ID: <20231127135424.GO5169@atomide.com>
References: <20231126191840.110564-1-andreas@kemnade.info>
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In-Reply-To: <20231126191840.110564-1-andreas@kemnade.info>

* Andreas Kemnade <andreas@kemnade.info> [231126 19:18]:
> So the main questions I see:
> - is the approach right to abandon drivers/misc/ti-st?

Yes.

> - Output at /dev/gnssX:
>   AI2 vs. NMEA
>   The chip can be configured into sending AI2-encapsulated NMEA,
>   or proving data in a binary format.
>   Some research has to be done yet for the details.
>   A pile of logs is waiting for further analysis...
> 
>   Arguments for/against NMEA:
>   + Userspace is prepared to handle it
>   + Power management can be easily done by the kernel
>   - Less functionality can be used.

I'd go with NMEA format as the default setting :)

>   Arguments for/against AI2:
>   + Full functionality can be accessed from userspace (incl. A-GPS,
>     maybe raw satellite data)
>   - Userspace has to behave to have proper power management
>   - No freely (not even as in beer) tool available to fully use AI2,
>     so there will be only a real advantage after long "French Cafe"
>     sessions.

Seems AI2 could be optionally enabled as needed with some writes
to /dev/gnss0 to change the mode?

Regards,

Tony