1 files changed, 87 insertions, 0 deletions

diff --git a/sound/soc/soc-dapm.c b/sound/soc/soc-dapm.c
index fd2d774797bb..746349faf2db 100644
--- a/sound/soc/soc-dapm.c
+++ b/sound/soc/soc-dapm.c
@@ -593,6 +593,9 @@ static int is_connected_output_ep(struct snd_soc_dapm_widget *widget)
         }
 
         list_for_each_entry(path, &widget->sinks, list_source) {
+                if (path->weak)
+                        continue;
+
                 if (path->walked)
                         continue;
 
@@ -643,6 +646,9 @@ static int is_connected_input_ep(struct snd_soc_dapm_widget *widget)
         }
 
         list_for_each_entry(path, &widget->sources, list_sink) {
+                if (path->weak)
+                        continue;
+
                 if (path->walked)
                         continue;
 
@@ -724,6 +730,9 @@ static int dapm_supply_check_power(struct snd_soc_dapm_widget *w)
 
         /* Check if one of our outputs is connected */
         list_for_each_entry(path, &w->sinks, list_source) {
+                if (path->weak)
+                        continue;
+
                 if (path->connected &&
                     !path->connected(path->source, path->sink))
                         continue;
@@ -1806,6 +1815,84 @@ int snd_soc_dapm_add_routes(struct snd_soc_dapm_context *dapm,
 }
 EXPORT_SYMBOL_GPL(snd_soc_dapm_add_routes);
 
+static int snd_soc_dapm_weak_route(struct snd_soc_dapm_context *dapm,
+                                   const struct snd_soc_dapm_route *route)
+{
+        struct snd_soc_dapm_widget *source = dapm_find_widget(dapm,
+                                                              route->source,
+                                                              true);
+        struct snd_soc_dapm_widget *sink = dapm_find_widget(dapm,
+                                                            route->sink,
+                                                            true);
+        struct snd_soc_dapm_path *path;
+        int count = 0;
+
+        if (!source) {
+                dev_err(dapm->dev, "Unable to find source %s for weak route\n",
+                        route->source);
+                return -ENODEV;
+        }
+
+        if (!sink) {
+                dev_err(dapm->dev, "Unable to find sink %s for weak route\n",
+                        route->sink);
+                return -ENODEV;
+        }
+
+        if (route->control || route->connected)
+                dev_warn(dapm->dev, "Ignoring control for weak route %s->%s\n",
+                         route->source, route->sink);
+
+        list_for_each_entry(path, &source->sinks, list_source) {
+                if (path->sink == sink) {
+                        path->weak = 1;
+                        count++;
+                }
+        }
+
+        if (count == 0)
+                dev_err(dapm->dev, "No path found for weak route %s->%s\n",
+                        route->source, route->sink);
+        if (count > 1)
+                dev_warn(dapm->dev, "%d paths found for weak route %s->%s\n",
+                         count, route->source, route->sink);
+
+        return 0;
+}
+
+/**
+ * snd_soc_dapm_weak_routes - Mark routes between DAPM widgets as weak
+ * @dapm: DAPM context
+ * @route: audio routes
+ * @num: number of routes
+ *
+ * Mark existing routes matching those specified in the passed array
+ * as being weak, meaning that they are ignored for the purpose of
+ * power decisions.  The main intended use case is for sidetone paths
+ * which couple audio between other independent paths if they are both
+ * active in order to make the combination work better at the user
+ * level but which aren't intended to be "used".
+ *
+ * Note that CODEC drivers should not use this as sidetone type paths
+ * can frequently also be used as bypass paths.
+ */
+int snd_soc_dapm_weak_routes(struct snd_soc_dapm_context *dapm,
+                             const struct snd_soc_dapm_route *route, int num)
+{
+        int i, err;
+        int ret = 0;
+
+        for (i = 0; i < num; i++) {
+                err = snd_soc_dapm_weak_route(dapm, route);
+                if (err)
+                        ret = err;
+                route++;
+        }
+
+        return ret;
+}
+EXPORT_SYMBOL_GPL(snd_soc_dapm_weak_routes);
+
 /**
  * snd_soc_dapm_new_widgets - add new dapm widgets
  * @dapm: DAPM context