Re: [PATCH net-next v4 1/2] net: Add a WWAN subsystem

[Greg KH <gregkh@linuxfoundation.org>]

On Thu, Mar 11, 2021 at 05:39:05PM +0100, Loic Poulain wrote:
> This change introduces initial support for a WWAN subsystem. Given the
> complexity and heterogeneity of existing WWAN hardwares and interfaces,
> there is no strict definition of what a WWAN device is and how it should
> be represented. It's often a collection of multiple components/devices
> that perform the global WWAN feature (netdev, tty, chardev, etc).
> 
> One usual way to expose modem controls and configuration is via high
> level protocols such as the well known AT command protocol, MBIM or
> QMI. The USB modems started to expose that as character devices, and
> user daemons such as ModemManager learnt how to deal with that. This
> initial version adds the concept of WWAN port, which can be registered
> by any driver to expose one of these protocols. The WWAN core takes
> care of the generic part, including character device creation and lets
> the driver implementing access (fops) to the selected protocol.
> 
> Since the different components/devices do no necesserarly know about
> each others, and can be created/removed in different orders, the
> WWAN core ensures that devices being part of the same hardware are
> also represented as a unique WWAN device, relying on the provided
> parent device (e.g. mhi controller, USB device). It's a 'trick' I
> copied from Johannes's earlier WWAN subsystem proposal.
> 
> This initial version is purposely minimalist, it's essentially moving
> the generic part of the previously proposed mhi_wwan_ctrl driver inside
> a common WWAN framework, but the implementation is open and flexible
> enough to allow extension for further drivers.
> 
> Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
> ---
>  drivers/net/Kconfig          |   2 +
>  drivers/net/Makefile         |   1 +
>  drivers/net/wwan/Kconfig     |  19 ++++++
>  drivers/net/wwan/Makefile    |   8 +++
>  drivers/net/wwan/wwan_core.c | 150 +++++++++++++++++++++++++++++++++++++++++++
>  drivers/net/wwan/wwan_core.h |  20 ++++++
>  drivers/net/wwan/wwan_port.c | 136 +++++++++++++++++++++++++++++++++++++++
>  include/linux/wwan.h         | 121 ++++++++++++++++++++++++++++++++++
>  8 files changed, 457 insertions(+)
>  create mode 100644 drivers/net/wwan/Kconfig
>  create mode 100644 drivers/net/wwan/Makefile
>  create mode 100644 drivers/net/wwan/wwan_core.c
>  create mode 100644 drivers/net/wwan/wwan_core.h
>  create mode 100644 drivers/net/wwan/wwan_port.c
>  create mode 100644 include/linux/wwan.h

What changed from the last version(s)?  That should be below the ---
somewhere, right?

v5?

thanks,

greg k-h