api,doc: add note about when each modem interface is available

introspection/org.freedesktop.ModemManager1.Modem.Firmware.xml

@@ -23,7 +23,10 @@
       the device. Instead, it exposes information about the expected firmware update
       method as well as method-specific details required for the upgrade to happen.
       The actual firmware upgrade may be performed via the Linux Vendor Firmware Service
-      and the <link linkend="https://fwupd.org">fwupd</link> daemon.
+      and the <ulink url="https://fwupd.org">fwupd</ulink> daemon.
+
+      This interface will always be available as long a the modem is considered
+      valid.
   -->
   <interface name="org.freedesktop.ModemManager1.Modem.Firmware">
 

introspection/org.freedesktop.ModemManager1.Modem.Location.xml

@@ -19,6 +19,11 @@
       client applications. Not all devices can provide this information, or even
       if they do, they may not be able to provide it while a data session is
       active.
+
+      This interface will only be available once the modem is ready to be
+      registered in the cellular network. 3GPP devices will require a valid
+      unlocked SIM card before any of the features in the interface can be
+      used (including GNSS module management).
   -->
   <interface name="org.freedesktop.ModemManager1.Modem.Location">
 

introspection/org.freedesktop.ModemManager1.Modem.Messaging.xml

@@ -17,6 +17,11 @@
 
       The Messaging interface handles sending SMS messages and notification of new
       incoming messages.
+
+      This interface will only be available once the modem is ready to be
+      registered in the cellular network. 3GPP devices will require a valid
+      unlocked SIM card before any of the features in the interface can be
+      used (including listing stored messages).
   -->
   <interface name="org.freedesktop.ModemManager1.Modem.Messaging">
 

introspection/org.freedesktop.ModemManager1.Modem.Modem3gpp.Ussd.xml

@@ -16,6 +16,11 @@
       @short_description: The ModemManager 3GPP USSD interface.
 
       This interface provides access to actions based on the USSD protocol.
+
+      This interface will only be available once the modem is ready to be
+      registered in the cellular network. 3GPP devices will require a valid
+      unlocked SIM card before any of the features in the interface can be
+      used.
   -->
   <interface name="org.freedesktop.ModemManager1.Modem.Modem3gpp.Ussd">
 

introspection/org.freedesktop.ModemManager1.Modem.Modem3gpp.xml

@@ -17,6 +17,11 @@
 
       This interface provides access to specific actions that may be performed
       in modems with 3GPP capabilities.
+
+      This interface will only be available once the modem is ready to be
+      registered in the cellular network. 3GPP devices will require a valid
+      unlocked SIM card before any of the features in the interface can be
+      used.
   -->
   <interface name="org.freedesktop.ModemManager1.Modem.Modem3gpp">
 

introspection/org.freedesktop.ModemManager1.Modem.ModemCdma.xml

@@ -17,6 +17,11 @@
 
       This interface provides access to specific actions that may be performed
       in modems with CDMA capabilities.
+
+      This interface will only be available once the modem is ready to be
+      registered in the cellular network. Mixed 3GPP+3GPP2 devices will require
+      a valid unlocked SIM card before any of the features in the interface can
+      be used.
   -->
   <interface name="org.freedesktop.ModemManager1.Modem.ModemCdma">
 

introspection/org.freedesktop.ModemManager1.Modem.Oma.xml

@@ -17,6 +17,11 @@
 
       Device management sessions are either on-demand (client-initiated), or
       automatically initiated by either the device itself or the network.
+
+      This interface will only be available once the modem is ready to be
+      registered in the cellular network. 3GPP devices will require a valid
+      unlocked SIM card before any of the features in the interface can be
+      used.
   -->
   <interface name="org.freedesktop.ModemManager1.Modem.Oma">
 

introspection/org.freedesktop.ModemManager1.Modem.Signal.xml

@@ -13,6 +13,11 @@
       @short_description: The ModemManager Signal interface.
 
       This interface provides access to extended signal quality information.
+
+      This interface will only be available once the modem is ready to be
+      registered in the cellular network. 3GPP devices will require a valid
+      unlocked SIM card before any of the features in the interface can be
+      used.
   -->
   <interface name="org.freedesktop.ModemManager1.Modem.Signal">
 

introspection/org.freedesktop.ModemManager1.Modem.Simple.xml

@@ -16,6 +16,11 @@
       @short_description: The ModemManager Simple interface.
 
       The Simple interface allows controlling and querying the status of Modems.
+
+      This interface will only be available once the modem is ready to be
+      registered in the cellular network. 3GPP devices will require a valid
+      unlocked SIM card before any of the features in the interface can be
+      used.
   -->
   <interface name="org.freedesktop.ModemManager1.Modem.Simple">
 

introspection/org.freedesktop.ModemManager1.Modem.Time.xml

@@ -16,6 +16,11 @@
 
       This interface allows clients to receive network time and timezone
       updates broadcast by mobile networks.
+
+      This interface will only be available once the modem is ready to be
+      registered in the cellular network. 3GPP devices will require a valid
+      unlocked SIM card before any of the features in the interface can be
+      used.
   -->
   <interface name="org.freedesktop.ModemManager1.Modem.Time">
 

introspection/org.freedesktop.ModemManager1.Modem.Voice.xml

@@ -14,6 +14,11 @@
       @short_description: The ModemManager Voice interface.
 
       The Voice interface handles Calls.
+
+      This interface will only be available once the modem is ready to be
+      registered in the cellular network. 3GPP devices will require a valid
+      unlocked SIM card before any of the features in the interface can be
+      used.
   -->
   <interface name="org.freedesktop.ModemManager1.Modem.Voice">
 

introspection/org.freedesktop.ModemManager1.Modem.xml

@@ -17,6 +17,9 @@
 
       The Modem interface controls the status and actions in a given modem
       object.
+
+      This interface will always be available as long a the modem is considered
+      valid.
   -->
   <interface name="org.freedesktop.ModemManager1.Modem">