Re: [PATCHv8 0/6] n_gsm serdev support and GNSS driver for droid4

Greg Kroah-Hartman
2020-05-22T09:17:37Z

On Tue, May 12, 2020 at 02:47:07PM -0700, Tony Lindgren wrote:
> Hi all,
>
> Here's the updated set of these patches fixed up for Johan's and
> Pavel's earlier comments.
>
> This series does the following:
>
> 1. Adds functions to n_gsm.c for serdev-ngsm.c driver to use
>
> 2. Adds a generic serdev-ngsm.c driver that brings up the TS 27.010
> TTY ports configured in devicetree with help of n_gsm.c
>
> 3. Allows the use of standard Linux device drivers for dedicated
> TS 27.010 channels for devices like GNSS and ALSA found on some
> modems for example
>
> 4. Adds a gnss-motmdm consumer driver for the GNSS device found on
> the Motorola Mapphone MDM6600 modem on devices like droid4
>
> I've placed the serdev-ngsm.c under drivers/tty/serdev as it still
> seems to make most sense with no better places available. It's no
> longer an MFD driver as it really does not need to care what channel
> specific consumer drivers might be configured for the generic driver.
> Now serdev-ngsm just uses of_platform_populate() to probe whatever
> child nodes it might find.
>
> I'm not attached having the driver in drivers/tty/serdev. I just
> don't have any better locations in mind. So using Johan's earlier
> i2c example, the drivers/tty/serdev/serdev-ngsm.c driver is now a
> generic protocol and bus driver, so it's getting closer to the
> the drivers/i2c/busses analogy maybe :) Please do suggest better
> locations other than MFD and misc if you have better ideas.
>
> Now without the chardev support, the /dev/gsmtty* using apps need
> to use "U1234AT+CFUN?" format for the packets. The advantage is
> less kernel code, and we keep the existing /dev/gsmtty* interface.
>
> If we still really need the custom chardev support, that can now
> be added as needed with the channel specific consumer driver(s),
> but looks like this won't be needed based on Pavel's ofono work.

Johan and Rob, any objection/review of this series?

thanks,

greg k-h