udev: define all generic tags as symbolsaleksander/tags-as-symbols

This prevents errors due to nasty typos in the strings.

We define all symbols in a single header file that is NOT considered
part of the API, as there is no need for MM clients to know about
these tags code-wise. These tags are only meaningful when associated
to devices in udev.

Information of each tag is included in the general API documentation.

https://gitlab.freedesktop.org/mobile-broadband/ModemManager/issues/88

10 files changed, 273 insertions, 24 deletions

diff --git a/docs/reference/api/ModemManager-docs.xml b/docs/reference/api/ModemManager-docs.xml
index 57e333843..156b6ff6d 100644
--- a/docs/reference/api/ModemManager-docs.xml
+++ b/docs/reference/api/ModemManager-docs.xml
@@ -49,6 +49,7 @@
       <year>2015</year>
       <year>2016</year>
       <year>2017</year>
+      <year>2018</year>
       <holder>The ModemManager Authors</holder>
     </copyright>
 
@@ -84,6 +85,11 @@
     <xi:include href="xml/mm-errors.xml"/>
   </part>
 
+  <part id="ref-udev">
+    <title>Common udev tag definitions</title>
+    <xi:include href="xml/mm-tags.xml"/>
+  </part>
+
   <!-- Part 2, DBus reference -->
   <xi:include href="xml/ModemManager-dbus-reference.xml"/>
 
diff --git a/docs/reference/api/ModemManager-sections.txt b/docs/reference/api/ModemManager-sections.txt
index 5ec728db8..6da6a3360 100644
--- a/docs/reference/api/ModemManager-sections.txt
+++ b/docs/reference/api/ModemManager-sections.txt
@@ -140,3 +140,22 @@ MM_MODEM_BAND_CDMA_BC19_US_LOWER_700
 <SUBSECTION Private>
 MMModemBandDeprecated
 </SECTION>
+
+<SECTION>
+<FILE>mm-tags</FILE>
+<TITLE>Common udev tags</TITLE>
+ID_MM_CANDIDATE
+ID_MM_PHYSDEV_UID
+ID_MM_PORT_IGNORE
+ID_MM_DEVICE_PROCESS
+ID_MM_DEVICE_IGNORE
+ID_MM_DEVICE_MANUAL_SCAN_ONLY
+ID_MM_PLATFORM_DRIVER_PROBE
+ID_MM_PORT_TYPE_AT_PPP
+ID_MM_PORT_TYPE_AT_PRIMARY
+ID_MM_PORT_TYPE_AT_SECONDARY
+ID_MM_PORT_TYPE_GPS
+ID_MM_PORT_TYPE_QCDM
+ID_MM_TTY_BAUDRATE
+ID_MM_TTY_FLOW_CONTROL
+</SECTION>
diff --git a/include/Makefile.am b/include/Makefile.am
index 237ee6bde..c0f3117cf 100644
--- a/include/Makefile.am
+++ b/include/Makefile.am
@@ -19,4 +19,5 @@ CLEANFILES = \
 	ModemManager-names.h
 
 EXTRA_DIST = \
+	ModemManager-tags.h \
 	ModemManager-version.h.in
diff --git a/include/ModemManager-tags.h b/include/ModemManager-tags.h
new file mode 100644
index 000000000..4be1e7918
--- /dev/null
+++ b/include/ModemManager-tags.h
@@ -0,0 +1,210 @@
+/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details:
+ *
+ * Copyright (C) 2018 Aleksander Morgado <aleksander@aleksander.es>
+ */
+
+/*
+ * NOTE! this file is NOT part of the installed ModemManager API.
+ *
+ * We keep this file under include/ because we want to build and
+ * expose the associated documentation.
+ */
+
+#ifndef MM_TAGS_H
+#define MM_TAGS_H
+
+/**
+ * SECTION:mm-tags
+ * @short_description: generic udev tags supported
+ *
+ * This section defines generic udev tags that are used by ModemManager,
+ * associated to full devices or to specific ports in a given device.
+ */
+
+/**
+ * ID_MM_CANDIDATE:
+ *
+ * This is a port-specific tag added automatically when all other
+ * ModemManager related tags have already been set.
+ */
+#define ID_MM_CANDIDATE "ID_MM_CANDIDATE"
+
+/**
+ * ID_MM_PHYSDEV_UID:
+ *
+ * This is a device-specific tag that allows users to 'name' modem
+ * devices with a predefined 'unique ID' string.
+ *
+ * When this tag is given per-port, the daemon will consider that all
+ * ports with the same UID value are associated to the same device.
+ * This is useful for e.g. modems that expose multiple RS232 ports
+ * connected to the system via different platform ports (or USB to
+ * RS232 adapters).
+ *
+ * This UID is exposed in
+ * the '<link linkend="gdbus-property-org-freedesktop-ModemManager1-Modem.Device">Device</link>'
+ * property and can then be used in mmcli calls to refer unequivocally
+ * to a specific device, regardless of its modem index, e.g.:
+ *  $ mmcli --modem=UID ...
+ */
+#define ID_MM_PHYSDEV_UID "ID_MM_PHYSDEV_UID"
+
+/**
+ * ID_MM_DEVICE_PROCESS:
+ *
+ * This is a device-specific tag that allows explicitly requesting the
+ * processing of all ports exposed by the device. This tag is usually
+ * used by users when the daemon runs with WHITELIST-ONLY filter policy
+ * type, and is associated to the MM_FILTER_RULE_EXPLICIT_WHITELIST rule.
+ *
+ * This tag may also be specified in specific ports, e.g. when the modem
+ * exposes a single platform port without any parent device.
+ */
+#define ID_MM_DEVICE_PROCESS "ID_MM_DEVICE_PROCESS"
+
+/**
+ * ID_MM_PORT_IGNORE:
+ *
+ * This is a port-specific tag that allows explicitly ignoring a given port
+ * in a device.
+ *
+ * This tag applies to all types of ports.
+ */
+#define ID_MM_PORT_IGNORE "ID_MM_PORT_IGNORE"
+
+/**
+ * ID_MM_DEVICE_IGNORE:
+ *
+ * This is a device-specific tag that allows explicitly blacklisting
+ * devices that expose TTY devices so that they are never probed.
+ *
+ * This tag is used when the daemon runs with DEFAULT or PARANOID
+ * filter policy type, and is associated to the MM_FILTER_RULE_TTY_BLACKLIST
+ * rule.
+ *
+ * This tag is ignored when the STRICT filter policy is used.
+ */
+#define ID_MM_DEVICE_IGNORE "ID_MM_DEVICE_IGNORE"
+
+/**
+ * ID_MM_DEVICE_MANUAL_SCAN_ONLY:
+ *
+ * This is a device-specific tag that allows explicitly greylisting
+ * devices that expose TTY devices so that they are never probed
+ * automatically. Instead, an explicit manual scan request may be sent
+ * to the daemon so that the TTY ports exposed by the device are
+ * probed.
+ *
+ * This tag is used when the daemon runs with DEFAULT or PARANOID
+ * filter policy type, and is associated to the MM_FILTER_RULE_TTY_MANUAL_SCAN_ONLY
+ * rule.
+ *
+ * This tag is ignored when the STRICT filter policy is used.
+ */
+#define ID_MM_DEVICE_MANUAL_SCAN_ONLY "ID_MM_DEVICE_MANUAL_SCAN_ONLY"
+
+/**
+ * ID_MM_PLATFORM_DRIVER_PROBE:
+ *
+ * This is a port-specific tag applied to platform ports so that they
+ * are probed automatically by the daemon. Platform ports that don't
+ * have this tag will never probed. This tag is a bit redundant, as
+ * the user could also use ID_MM_DEVICE_PROCESS for the same purpose.
+ *
+ * This tag is associated to the MM_FILTER_RULE_TTY_PLATFORM_DRIVER
+ * rule, which is only meaningful when the daemon runs with the
+ * DEFAULT filter policy type, as that is the only one that would
+ * allow probing all ports not explicitly forbidden before the last
+ * MM_FILTER_RULE_TTY_DEFAULT_ALLOWED rule.
+ */
+#define ID_MM_PLATFORM_DRIVER_PROBE "ID_MM_PLATFORM_DRIVER_PROBE"
+
+/**
+ * ID_MM_PORT_TYPE_AT_PRIMARY:
+ *
+ * This is a port-specific tag applied to TTYs that we know in advance
+ * are AT ports to be used as primary control ports.
+ *
+ * This tag will also prevent QCDM probing on the port.
+ */
+#define ID_MM_PORT_TYPE_AT_PRIMARY "ID_MM_PORT_TYPE_AT_PRIMARY"
+
+/**
+ * ID_MM_PORT_TYPE_AT_SECONDARY:
+ *
+ * This is a port-specific tag applied to TTYs that we know in advance
+ * are AT ports to be used as secondary control ports.
+ *
+ * This tag will also prevent QCDM probing on the port.
+ */
+#define ID_MM_PORT_TYPE_AT_SECONDARY "ID_MM_PORT_TYPE_AT_SECONDARY"
+
+/**
+ * ID_MM_PORT_TYPE_AT_PPP:
+ *
+ * This is a port-specific tag applied to TTYs that we know in advance
+ * are AT ports to be used as data ports exclusively.
+ *
+ * This tag will also prevent QCDM probing on the port.
+ */
+#define ID_MM_PORT_TYPE_AT_PPP "ID_MM_PORT_TYPE_AT_PPP"
+
+/**
+ * ID_MM_PORT_TYPE_QCDM:
+ *
+ * This is a port-specific tag applied to TTYs that we know in advance
+ * are QCDM ports.
+ *
+ * The only purpose of this tag is to prevent AT probing in the port.
+ */
+#define ID_MM_PORT_TYPE_QCDM "ID_MM_PORT_TYPE_QCDM"
+
+/**
+ * ID_MM_PORT_TYPE_GPS:
+ *
+ * This is a port-specific tag applied to TTYs that we know in advance
+ * are GPS data ports where we expect to receive NMEA traces.
+ *
+ * This tag also prevents AT and QCDM probing in the port.
+ */
+#define ID_MM_PORT_TYPE_GPS "ID_MM_PORT_TYPE_GPS"
+
+/**
+ * ID_MM_TTY_BAUDRATE:
+ *
+ * This is a port-specific tag applied to TTYs that require a specific
+ * baudrate to work. USB modems will usually allow auto-bauding
+ * configuration, so this tag is really only meaningful to true RS232
+ * devices.
+ *
+ * The value of the tag should be the number of bauds per second to
+ * use when talking to the port, e.g. "115200". If not given, the
+ * default of 57600bps is assumed.
+ */
+#define ID_MM_TTY_BAUDRATE "ID_MM_TTY_BAUDRATE"
+
+/**
+ * ID_MM_TTY_FLOW_CONTROL:
+ *
+ * This is a port-specific tag applied to TTYs that require a specific
+ * flow control mechanism to work not only in data mode but also in
+ * control mode.
+ *
+ * The value of the tag should be either 'none', 'xon-xoff' or
+ * 'rts-cts', and must be a flow control value supported by the device
+ * where it's configured. If not given, it is assumed that the TTYs
+ * don't require any specific flow control setting in command mode.
+ */
+#define ID_MM_TTY_FLOW_CONTROL "ID_MM_TTY_FLOW_CONTROL"
+
+#endif /* MM_TAGS_H */
diff --git a/src/kerneldevice/mm-kernel-device-generic.c b/src/kerneldevice/mm-kernel-device-generic.c
index 34987e9d4..9d956bc37 100644
--- a/src/kerneldevice/mm-kernel-device-generic.c
+++ b/src/kerneldevice/mm-kernel-device-generic.c
@@ -21,6 +21,8 @@
 #define _LIBMM_INSIDE_MM
 #include <libmm-glib.h>
 
+#include <ModemManager-tags.h>
+
 #include "mm-kernel-device-generic.h"
 #include "mm-kernel-device-generic-rules.h"
 #include "mm-log.h"
@@ -486,7 +488,7 @@ kernel_device_get_physdev_uid (MMKernelDevice *self)
         return uid;
 
     /* Try to load from properties set */
-    if ((uid = mm_kernel_device_get_property (self, "ID_MM_PHYSDEV_UID")) != NULL)
+    if ((uid = mm_kernel_device_get_property (self, ID_MM_PHYSDEV_UID)) != NULL)
         return uid;
 
     /* Use physical device path, if any */
diff --git a/src/kerneldevice/mm-kernel-device-udev.c b/src/kerneldevice/mm-kernel-device-udev.c
index 730de98ef..da668f3c5 100644
--- a/src/kerneldevice/mm-kernel-device-udev.c
+++ b/src/kerneldevice/mm-kernel-device-udev.c
@@ -18,6 +18,8 @@
 #define _LIBMM_INSIDE_MM
 #include <libmm-glib.h>
 
+#include <ModemManager-tags.h>
+
 #include "mm-kernel-device-udev.h"
 #include "mm-log.h"
 
@@ -358,7 +360,7 @@ kernel_device_get_physdev_uid (MMKernelDevice *_self)
     }
 
     /* Try to load from properties set on the physical device */
-    if ((uid = mm_kernel_device_get_global_property (MM_KERNEL_DEVICE (self), "ID_MM_PHYSDEV_UID")) != NULL)
+    if ((uid = mm_kernel_device_get_global_property (MM_KERNEL_DEVICE (self), ID_MM_PHYSDEV_UID)) != NULL)
         return uid;
 
     /* Use physical device sysfs path, if any */
diff --git a/src/mm-base-manager.c b/src/mm-base-manager.c
index 3c09089cd..be92b5e2e 100644
--- a/src/mm-base-manager.c
+++ b/src/mm-base-manager.c
@@ -30,6 +30,8 @@
 #include "mm-kernel-device-generic.h"
 
 #include <ModemManager.h>
+#include <ModemManager-tags.h>
+
 #include <mm-errors-types.h>
 #include <mm-gdbus-manager.h>
 #include <mm-gdbus-test.h>
@@ -303,8 +305,8 @@ device_added (MMBaseManager  *manager,
      *
      * This udev tag applies to each port in a device. In other words, the flag
      * may be set in some ports, but not in others */
-    if (!mm_kernel_device_get_property_as_boolean (port, "ID_MM_CANDIDATE")) {
-        /* This could mean that device changed, losing its ID_MM_CANDIDATE
+    if (!mm_kernel_device_get_property_as_boolean (port, ID_MM_CANDIDATE)) {
+        /* This could mean that device changed, losing its candidate
          * flags (such as Bluetooth RFCOMM devices upon disconnect.
          * Try to forget it. */
         device_removed (manager, port);
diff --git a/src/mm-base-modem.c b/src/mm-base-modem.c
index c0ebb7f12..d748b3742 100644
--- a/src/mm-base-modem.c
+++ b/src/mm-base-modem.c
@@ -23,6 +23,8 @@
 #include <string.h>
 
 #include <ModemManager.h>
+#include <ModemManager-tags.h>
+
 #include <mm-errors-types.h>
 #include <mm-gdbus-modem.h>
 
@@ -215,13 +217,13 @@ mm_base_modem_grab_port (MMBaseModem         *self,
                                                    mm_serial_parser_v1_destroy);
             /* Prefer plugin-provided flags to the generic ones */
             if (at_pflags == MM_PORT_SERIAL_AT_FLAG_NONE) {
-                if (mm_kernel_device_get_property_as_boolean (kernel_device, "ID_MM_PORT_TYPE_AT_PRIMARY")) {
+                if (mm_kernel_device_get_property_as_boolean (kernel_device, ID_MM_PORT_TYPE_AT_PRIMARY)) {
                     mm_dbg ("AT port '%s/%s' flagged as primary", subsys, name);
                     at_pflags = MM_PORT_SERIAL_AT_FLAG_PRIMARY;
-                } else if (mm_kernel_device_get_property_as_boolean (kernel_device, "ID_MM_PORT_TYPE_AT_SECONDARY")) {
+                } else if (mm_kernel_device_get_property_as_boolean (kernel_device, ID_MM_PORT_TYPE_AT_SECONDARY)) {
                     mm_dbg ("AT port '%s/%s' flagged as secondary", subsys, name);
                     at_pflags = MM_PORT_SERIAL_AT_FLAG_SECONDARY;
-                } else if (mm_kernel_device_get_property_as_boolean (kernel_device, "ID_MM_PORT_TYPE_AT_PPP")) {
+                } else if (mm_kernel_device_get_property_as_boolean (kernel_device, ID_MM_PORT_TYPE_AT_PPP)) {
                     mm_dbg ("AT port '%s/%s' flagged as PPP", subsys, name);
                     at_pflags = MM_PORT_SERIAL_AT_FLAG_PPP;
                 }
@@ -249,12 +251,12 @@ mm_base_modem_grab_port (MMBaseModem         *self,
                               self);
 
         /* For serial ports, optionally use a specific baudrate and flow control */
-        if (mm_kernel_device_has_property (kernel_device, "ID_MM_TTY_BAUDRATE"))
+        if (mm_kernel_device_has_property (kernel_device, ID_MM_TTY_BAUDRATE))
             g_object_set (port,
-                          MM_PORT_SERIAL_BAUD, mm_kernel_device_get_property_as_int (kernel_device, "ID_MM_TTY_BAUDRATE"),
+                          MM_PORT_SERIAL_BAUD, mm_kernel_device_get_property_as_int (kernel_device, ID_MM_TTY_BAUDRATE),
                           NULL);
 
-        flow_control_tag = mm_kernel_device_get_property (kernel_device, "ID_MM_TTY_FLOW_CONTROL");
+        flow_control_tag = mm_kernel_device_get_property (kernel_device, ID_MM_TTY_FLOW_CONTROL);
         if (flow_control_tag) {
             MMFlowControl flow_control;
             GError *inner_error = NULL;
diff --git a/src/mm-filter.c b/src/mm-filter.c
index cf877b7e1..e65a628ca 100644
--- a/src/mm-filter.c
+++ b/src/mm-filter.c
@@ -16,6 +16,9 @@
 #include <config.h>
 #include <string.h>
 
+#include <ModemManager.h>
+#include <ModemManager-tags.h>
+
 #include "mm-daemon-enums-types.h"
 #include "mm-filter.h"
 #include "mm-log.h"
@@ -51,8 +54,8 @@ mm_filter_port (MMFilter        *self,
      * allow specifying this flag per-port instead of for the full device, e.g.
      * for platform tty ports where there's only one port anyway. */
     if ((self->priv->enabled_rules & MM_FILTER_RULE_EXPLICIT_WHITELIST) &&
-        (mm_kernel_device_get_global_property_as_boolean (port, "ID_MM_DEVICE_PROCESS") ||
-         mm_kernel_device_get_property_as_boolean (port, "ID_MM_DEVICE_PROCESS"))) {
+        (mm_kernel_device_get_global_property_as_boolean (port, ID_MM_DEVICE_PROCESS) ||
+         mm_kernel_device_get_property_as_boolean (port, ID_MM_DEVICE_PROCESS))) {
         mm_dbg ("[filter] (%s/%s) port allowed: device is whitelisted", subsystem, name);
         return TRUE;
     }
@@ -89,7 +92,7 @@ mm_filter_port (MMFilter        *self,
 
         /* Ignore blacklisted tty devices. */
         if ((self->priv->enabled_rules & MM_FILTER_RULE_TTY_BLACKLIST) &&
-            (mm_kernel_device_get_global_property_as_boolean (port, "ID_MM_DEVICE_IGNORE"))) {
+            (mm_kernel_device_get_global_property_as_boolean (port, ID_MM_DEVICE_IGNORE))) {
             mm_dbg ("[filter] (%s/%s): port filtered: device is blacklisted", subsystem, name);
             return FALSE;
         }
@@ -97,7 +100,7 @@ mm_filter_port (MMFilter        *self,
         /* Is the device in the manual-only greylist? If so, return if this is an
          * automatic scan. */
         if ((self->priv->enabled_rules & MM_FILTER_RULE_TTY_MANUAL_SCAN_ONLY) &&
-            (!manual_scan && mm_kernel_device_get_global_property_as_boolean (port, "ID_MM_DEVICE_MANUAL_SCAN_ONLY"))) {
+            (!manual_scan && mm_kernel_device_get_global_property_as_boolean (port, ID_MM_DEVICE_MANUAL_SCAN_ONLY))) {
             mm_dbg ("[filter] (%s/%s): port filtered: device probed only in manual scan", subsystem, name);
             return FALSE;
         }
@@ -111,7 +114,7 @@ mm_filter_port (MMFilter        *self,
              !g_strcmp0 (physdev_subsystem, "pci") ||
              !g_strcmp0 (physdev_subsystem, "pnp") ||
              !g_strcmp0 (physdev_subsystem, "sdio"))) {
-            if (!mm_kernel_device_get_global_property_as_boolean (port, "ID_MM_PLATFORM_DRIVER_PROBE")) {
+            if (!mm_kernel_device_get_global_property_as_boolean (port, ID_MM_PLATFORM_DRIVER_PROBE)) {
                 mm_dbg ("[filter] (%s/%s): port filtered: port's parent platform driver is not whitelisted", subsystem, name);
                 return FALSE;
             }
diff --git a/src/mm-port-probe.c b/src/mm-port-probe.c
index fd66d20a7..9913001b3 100644
--- a/src/mm-port-probe.c
+++ b/src/mm-port-probe.c
@@ -22,6 +22,8 @@
 #include <string.h>
 
 #include <ModemManager.h>
+#include <ModemManager-tags.h>
+
 #include <mm-errors-types.h>
 
 #include "mm-port-probe.h"
@@ -637,12 +639,12 @@ common_serial_port_setup (MMPortProbe  *self,
 {
     const gchar *flow_control_tag;
 
-    if (mm_kernel_device_has_property (self->priv->port, "ID_MM_TTY_BAUDRATE"))
+    if (mm_kernel_device_has_property (self->priv->port, ID_MM_TTY_BAUDRATE))
         g_object_set (serial,
-                      MM_PORT_SERIAL_BAUD, mm_kernel_device_get_property_as_int (self->priv->port, "ID_MM_TTY_BAUDRATE"),
+                      MM_PORT_SERIAL_BAUD, mm_kernel_device_get_property_as_int (self->priv->port, ID_MM_TTY_BAUDRATE),
                       NULL);
 
-    flow_control_tag = mm_kernel_device_get_property (self->priv->port, "ID_MM_TTY_FLOW_CONTROL");
+    flow_control_tag = mm_kernel_device_get_property (self->priv->port, ID_MM_TTY_FLOW_CONTROL);
     if (flow_control_tag) {
         MMFlowControl flow_control;
         GError *error = NULL;
@@ -1896,12 +1898,12 @@ set_property (GObject *object,
     case PROP_PORT:
         /* construct only */
         self->priv->port = g_value_dup_object (value);
-        self->priv->is_ignored = mm_kernel_device_get_property_as_boolean (self->priv->port, "ID_MM_PORT_IGNORE");
-        self->priv->is_gps = mm_kernel_device_get_property_as_boolean (self->priv->port, "ID_MM_PORT_TYPE_GPS");
-        self->priv->maybe_at_primary = mm_kernel_device_get_property_as_boolean (self->priv->port, "ID_MM_PORT_TYPE_AT_PRIMARY");
-        self->priv->maybe_at_secondary = mm_kernel_device_get_property_as_boolean (self->priv->port, "ID_MM_PORT_TYPE_AT_SECONDARY");
-        self->priv->maybe_at_ppp = mm_kernel_device_get_property_as_boolean (self->priv->port, "ID_MM_PORT_TYPE_AT_PPP");
-        self->priv->maybe_qcdm = mm_kernel_device_get_property_as_boolean (self->priv->port, "ID_MM_PORT_TYPE_QCDM");
+        self->priv->is_ignored = mm_kernel_device_get_property_as_boolean (self->priv->port, ID_MM_PORT_IGNORE);
+        self->priv->is_gps = mm_kernel_device_get_property_as_boolean (self->priv->port, ID_MM_PORT_TYPE_GPS);
+        self->priv->maybe_at_primary = mm_kernel_device_get_property_as_boolean (self->priv->port, ID_MM_PORT_TYPE_AT_PRIMARY);
+        self->priv->maybe_at_secondary = mm_kernel_device_get_property_as_boolean (self->priv->port, ID_MM_PORT_TYPE_AT_SECONDARY);
+        self->priv->maybe_at_ppp = mm_kernel_device_get_property_as_boolean (self->priv->port, ID_MM_PORT_TYPE_AT_PPP);
+        self->priv->maybe_qcdm = mm_kernel_device_get_property_as_boolean (self->priv->port, ID_MM_PORT_TYPE_QCDM);
         break;
     default:
         G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);