gsm: add ability for subclasses to handle power-on response

This lets subclasses handle errors when they know the device supports
the power-up command.  Also will let us simplify a number of plugins.

src/mm-generic-gsm.c

@@ -495,6 +495,16 @@ mm_generic_gsm_enable_complete (MMGenericGsm *modem,
     mm_callback_info_schedule (info);
 }
 
+static void
+real_do_enable_power_up_done (MMGenericGsm *self,
+                              GString *response,
+                              GError *error,
+                              MMCallbackInfo *info)
+{
+    /* Ignore power-up errors as not all devices actually support CFUN=1 */
+    mm_generic_gsm_enable_complete (MM_GENERIC_GSM (info->modem), NULL, info);
+}
+
 static void
 enable_done (MMSerialPort *port,
              GString *response,
@@ -503,16 +513,15 @@ enable_done (MMSerialPort *port,
 {
     MMCallbackInfo *info = (MMCallbackInfo *) user_data;
 
-    /* Ignore power-up command errors, not all devices actually support
+    /* Let subclasses handle the power up command response/error; many devices
-     * CFUN=1.
+     * don't support +CFUN, but for those that do let them handle the error
+     * correctly.
      */
-    /* FIXME: instead of just ignoring errors, since we allow subclasses
+    g_assert (MM_GENERIC_GSM_GET_CLASS (info->modem)->do_enable_power_up_done);
-     * to override the power-on command, make a class function for powering
+    MM_GENERIC_GSM_GET_CLASS (info->modem)->do_enable_power_up_done (MM_GENERIC_GSM (info->modem),
-     * on the phone and let the subclass decided whether it wants to handle
+                                                                     response,
-     * errors or ignore them.
+                                                                     error,
-     */
+                                                                     info);
-
-    mm_generic_gsm_enable_complete (MM_GENERIC_GSM (info->modem), NULL, info);
 }
 
 static void
@@ -2396,6 +2405,7 @@ mm_generic_gsm_class_init (MMGenericGsmClass *klass)
     object_class->finalize = finalize;
 
     klass->do_enable = real_do_enable;
+    klass->do_enable_power_up_done = real_do_enable_power_up_done;
 
     /* Properties */
     g_object_class_override_property (object_class,

src/mm-generic-gsm.h

@@ -65,6 +65,17 @@ typedef struct {
      * callback and user_data passed in here.
      */
     void (*do_enable) (MMGenericGsm *self, MMModemFn callback, gpointer user_data);
+
+    /* Called after the generic class has attempted to power up the modem.
+     * Subclasses can handle errors here if they know the device supports their
+     * power up command.  Will only be called if the device does *not* override
+     * the MMModem enable() command or allows the generic class' do_enable()
+     * handler to execute.
+     */
+    void (*do_enable_power_up_done) (MMGenericGsm *self,
+                                     GString *response,
+                                     GError *error,
+                                     MMCallbackInfo *info);
 } MMGenericGsmClass;
 
 GType mm_generic_gsm_get_type (void);