Add support for the Linux wwan subsystem that started to expose
control channel as character devices (e.g. /dev/wwan0p1MBIM...).
Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
Most older Qualcomm SoCs (e.g. MSM8916, MSM8974, ...) communicate with
the integrated modem via shared memory (SMD channels). This is similar
to QRTR on newer SoCs, but without the "network" layer. In fact, the
older SoCs also have QRTR, but the modem QMI services are not exposed
there.
The mainline Linux kernel exposes SMD channels via the "remote processor
messaging bus" (rpmsg). Through special IOCTL calls it is possible to
create a char device for a rpmsg/SMD channel. We can then use these to
send QMI/AT messages to the modem, much like the ordinary serial char
devices when using a Qualcomm modem through USB.
This commit introduces support for the new 'rpmsg' subsystem, which
allows exporting QMI-capable and AT-capable ports.
By default NO rpmsg port is flagged as candidate, it is assumed that
the plugin adding support for the rpmsg subsystem will add specific
rules to do so (e.g. so that non-modem ports are explicitly not
flagged as candidate).
All rpmsg ports will be probed for AT or QMI capabilities, unless
explicit port type hints (e.g. ID_MM_PORT_TYPE_QMI or
ID_MM_PORT_TYPE_AT_PRIMARY) are set.
These changes are highly based on the initial integration work done by
Stephan Gerhold <stephan@gerhold.net> in postmarketOS, see:
https://gitlab.freedesktop.org/mobile-broadband/ModemManager/-/merge_requests/363
Back in Linux < 3.6 days, the cdc-wdm ports exposed by the QMI driver
were flagged as owned by the 'usb' subsystem. That changed in 3.6 when
the subsystem was renamed to 'usbmisc':
https://mail.gnome.org/archives/networkmanager-list/2012-June/msg00125.html
So, rename the port subsystem type enumn to 'usbmisc'.
Instead of flagging them as 'ignored' so that they aren't probed, we
can also flag them as 'audio' now, so that the logic knows which port
to report as used for audio in the Call object.
The mm_base_modem_grab_port() now receives a MMKernelDevice directly from the
plugin, which is then stored in the MMPort corresponding to the port.
This means that we have direct access to e.g. all properties set by udev rules
everywhere, and we don't need additional GUdevClient objects (e.g. like the one
used in the Huawei plugin to detect NDISDUP support during runtime).
For virtual ports (e.g. generated during unit tests), we have a new 'generic'
kernel device object which just provides the values from the kernel device
properties given during its creation.
For those who don't care about the QMI support through libqmi-glib, or if you're
stuck with glib 2.30 (libqmi-glib requires 2.32), this configure switch allows
disabling the QMI support completely.
The logic to detect cdc-wdm ports is still in place, but the QMI probing is
never launched at them. Also, all QMI-related objects won't be compiled.
Plugin may specify GPS-specific port tyeps when requesting to grab the port.
These could either be an AT-based GPS control port, or the raw GPS serial port
which emits the NMEA traces.
Make port roles more flexible. We have modems that do PPP
on interfaces other than the primary interface, and that
wasn't possible with the old code. So clean up all that
logic and move the port organization code into the core
so we can reduce code in the plugins.
In the new world order, the plugins say whether the port
is a QCDM port, an AT port, or ignored. If it's an AT
port the plugins get to tag it as primary, secondary, or
PPP, or any combination of the 3. This allows for modems
where PPP should really be done on the secondary port
(Huawei E220, Sierra devices) so that the primary port
stays open for command and status.
After all ports are grabbed by the generic classes, they get
"organized", which assigns various ports to the roles of
PRIMARY, SECONDARY, DATA, and QCDM based on specific rules
and hints that the plugin provided (which are expressed as
MMAtPortFlags).
The plugin code is responsible for determining the port
hints (ie MMAtPortFlags) at probe time, instead of having
a combination of the plugin and the modem class do the
job. This simplifies things greatly for the plugins at
the expense of more complicated logic in the core.
This is the port of commit 96505d42ed62327101dcee7c2bf31177b0bb1c9f
to the 06-api branch.
Make port roles more flexible. We have modems that do PPP
on interfaces other than the primary interface, and that
wasn't possible with the old code. So clean up all that
logic and move the port organization code into the core
so we can reduce code in the plugins.
In the new world order, the plugins say whether the port
is a QCDM port, an AT port, or ignored. If it's an AT
port the plugins get to tag it as primary, secondary, or
PPP, or any combination of the 3. This allows for modems
where PPP should really be done on the secondary port
(Huawei E220, Sierra devices) so that the primary port
stays open for command and status.
Modem subclasses no longer get asked to handle port grabbing
themselves. Instead, that's now done by the generic classes
(MMGenericCdma and MMGenericGsm) and the plugins are notified
when a port is grabbed so they can add unsolicited response
handlers for it. After all ports are grabbed by the generic
classes, they get "organized", which assigns various ports
to the roles of PRIMARY, SECONDARY, DATA, and QCDM based
on specific rules and hints that the plugin provided (which
are expressed as MMAtPortFlags). The plugins then have
a chance to perform fixups on the primary port if they choose.
The plugin code is responsible for determining the port
hints (ie MMAtPortFlags) at probe time, instead of having
a combination of the plugin and the modem class do the
job. This simplifies things greatly for the plugins at
the expense of more complicated logic in the core.
BUG=chrome-os-partner:2394
TEST=gmerge modemmanager, watch logs, see detected as Samsung modem, connect to AT&T network
Review URL: http://codereview.chromium.org/6614026
Patch from Jun Woo Lee <jw86.lee@samsung.com>.
Change-Id: I913628ff4a1cd16c8180e3c808644b0134e69e31
So many modems just don't implement carrier detect that it makes
the previous 'connected' logic useless, so base it off connect/disconnect
and fix up a few places that didn't check connect status before
trying to send commands. Also ensure the serial port is unlocked
for PPP to use when connected.
Loic Poulain
Andrew Lassalle
Aleksander Morgado
Aleksander Morgado
Dan Williams
Jun Woo Lee