Re: GPS driver for Linux - kernel or user-space driver?

[Greg KH <gregkh@linuxfoundation.org>]

On Wed, Apr 03, 2013 at 05:52:03PM -0700, Tim Bird wrote:
> I've been approached by a developer at Sony who wants to publish an
> open source driver for a Sony GPS receiver module.

What does the device look like?  USB device?  UART?  Something else?

> I've looked in the kernel source, and only see one standalone GPS
> driver, for Garmin.  It appears that most GPS support in Linux is done
> via user-space drivers.  Many GPS hardware modules appear to be
> accessed via a serial line, or USB/serial port.  The Sony
> module is pretty much the same, accepting commands and delivering
> data via a uart from the chip.
> 
> I planning to recommend writing a user-space driver (based on
> gpsd and/or the Android GPS HAL specification).  But I'm worried
> I'm missing something.  Is this the correct approach, or is there
> an established kernel API for GPS modules - such that I should
> recommend that this developer writes a kernel module instead
> of, or in addition to, the user-space support for the hardware?

If it's just a uart-like device, just write a serial driver and drive it
from gpsd.  That way seems to be the simplest and then the kernel just
becomes a dumb-pipe, which is fine.

thanks,

greg k-h