iface-modem: allow reporting the previous power state after an update

Let the caller of mm_iface_modem_set_power_state() know which was the
power state in the device before the actual update happened.

This is useful in cases where we want to temporarily switch to a given
power state (e.g. low) before returning to the original power state.

src/mm-base-manager.c

@@ -908,7 +908,7 @@ shutdown_low_power_ready (MMIfaceModem   *modem,
 {
     g_autoptr(GError) error = NULL;
 
-    if (!mm_iface_modem_set_power_state_finish (modem, res, &error))
+    if (!mm_iface_modem_set_power_state_finish (modem, res, NULL, &error))
         mm_obj_info (ctx->self, "changing to low power state failed: %s", error->message);
 
     if (ctx->remove)

src/mm-iface-modem.c

@@ -2418,7 +2418,7 @@ set_power_state_ready (MMIfaceModem               *self,
 {
     GError *error = NULL;
 
-    if (!mm_iface_modem_set_power_state_finish (self, res, &error)) {
+    if (!mm_iface_modem_set_power_state_finish (self, res, NULL, &error)) {
         mm_obj_warn (self, "failed setting power state '%s': %s", mm_modem_power_state_get_string (ctx->power_state), error->message);
         if (ctx->disable_after_update) {
             ctx->saved_error = error;
@@ -4152,10 +4152,17 @@ set_power_state_context_free (SetPowerStateContext *ctx)
 }
 
 gboolean
-mm_iface_modem_set_power_state_finish (MMIfaceModem  *self,
-                                       GAsyncResult  *res,
-                                       GError       **error)
+mm_iface_modem_set_power_state_finish (MMIfaceModem       *self,
+                                       GAsyncResult       *res,
+                                       MMModemPowerState  *previous_power_state,
+                                       GError            **error)
 {
+    SetPowerStateContext *ctx;
+
+    ctx = g_task_get_task_data (G_TASK (res));
+    if (previous_power_state)
+        *previous_power_state = ctx->previous_real_power_state;
+
     return g_task_propagate_boolean (G_TASK (res), error);
 }
 
@@ -4440,6 +4447,7 @@ mm_iface_modem_set_power_state (MMIfaceModem        *self,
     ctx = g_slice_new0 (SetPowerStateContext);
     ctx->step = SET_POWER_STATE_STEP_FIRST;
     ctx->requested_power_state = power_state;
+    ctx->previous_real_power_state = MM_MODEM_POWER_STATE_UNKNOWN;
 
     task = g_task_new (self, NULL, callback, user_data);
     g_task_set_task_data (task, ctx, (GDestroyNotify)set_power_state_context_free);
@@ -4562,7 +4570,7 @@ enabling_set_power_state_ready (MMIfaceModem *self,
     EnablingContext *ctx;
     GError *error = NULL;
 
-    if (!mm_iface_modem_set_power_state_finish (self, res, &error)) {
+    if (!mm_iface_modem_set_power_state_finish (self, res, NULL, &error)) {
         g_task_return_error (task, error);
         g_object_unref (task);
         return;

src/mm-iface-modem.h

@@ -499,13 +499,14 @@ gboolean mm_iface_modem_sync_finish    (MMIfaceModem *self,
 #endif
 
 /* Allow setting power state */
-void     mm_iface_modem_set_power_state        (MMIfaceModem *self,
-                                                MMModemPowerState power_state,
-                                                GAsyncReadyCallback callback,
-                                                gpointer user_data);
-gboolean mm_iface_modem_set_power_state_finish (MMIfaceModem *self,
-                                                GAsyncResult *res,
-                                                GError **error);
+void     mm_iface_modem_set_power_state        (MMIfaceModem        *self,
+                                                MMModemPowerState    power_state,
+                                                GAsyncReadyCallback  callback,
+                                                gpointer             user_data);
+gboolean mm_iface_modem_set_power_state_finish (MMIfaceModem        *self,
+                                                GAsyncResult        *res,
+                                                MMModemPowerState   *previous_power_state,
+                                                GError             **error);
 
 /* Request lock info update.
  * It will not only return the lock status, but also set the property values

src/plugins/fibocom/mm-shared-fibocom.c

@@ -196,7 +196,7 @@ after_attach_apn_modem_power_up_ready (MMIfaceModem *self,
 
     ctx = g_task_get_task_data (task);
 
-    if (!mm_iface_modem_set_power_state_finish (self, res, &error)) {
+    if (!mm_iface_modem_set_power_state_finish (self, res, NULL, &error)) {
         mm_obj_warn (self, "failed to power up modem after attach APN settings update: %s", error->message);
         if (!ctx->saved_error)
             ctx->saved_error = g_steal_pointer (&error);
@@ -260,7 +260,7 @@ before_attach_apn_modem_power_down_ready (MMIfaceModem *self,
 {
     GError *error = NULL;
 
-    if (!mm_iface_modem_set_power_state_finish (self, res, &error)) {
+    if (!mm_iface_modem_set_power_state_finish (self, res, NULL, &error)) {
         mm_obj_warn (self, "failed to power down modem before attach APN settings update: %s", error->message);
         g_task_return_error (task, error);
         g_object_unref (task);