3 files changed, 197 insertions, 10 deletions

diff --git a/include/sound/soc-dapm.h b/include/sound/soc-dapm.h
index bea0c8658aa0..e3833d9f1914 100644
--- a/include/sound/soc-dapm.h
+++ b/include/sound/soc-dapm.h
@@ -321,6 +321,7 @@ struct snd_soc_dapm_pin;
 struct snd_soc_dapm_route;
 struct snd_soc_dapm_context;
 struct regulator;
+struct snd_soc_dapm_widget_list;
 
 int dapm_reg_event(struct snd_soc_dapm_widget *w,
                    struct snd_kcontrol *kcontrol, int event);
@@ -403,6 +404,10 @@ void snd_soc_dapm_auto_nc_codec_pins(struct snd_soc_codec *codec);
 /* Mostly internal - should not normally be used */
 void dapm_mark_dirty(struct snd_soc_dapm_widget *w, const char *reason);
 
+/* dapm path query */
+int snd_soc_dapm_dai_get_connected_widgets(struct snd_soc_dai *dai, int stream,
+        struct snd_soc_dapm_widget_list **list);
+
 /* dapm widget types */
 enum snd_soc_dapm_type {
         snd_soc_dapm_input = 0,         /* input pin */
diff --git a/include/trace/events/asoc.h b/include/trace/events/asoc.h
index ab26f8aa3c78..6d8efb1cc8ce 100644
--- a/include/trace/events/asoc.h
+++ b/include/trace/events/asoc.h
@@ -7,6 +7,8 @@
 #include <linux/ktime.h>
 #include <linux/tracepoint.h>
 
+#define DAPM_DIRECT "(direct)"
+
 struct snd_soc_jack;
 struct snd_soc_codec;
 struct snd_soc_platform;
@@ -241,6 +243,84 @@ TRACE_EVENT(snd_soc_dapm_walk_done,
                   (int)__entry->path_checks, (int)__entry->neighbour_checks)
 );
 
+TRACE_EVENT(snd_soc_dapm_output_path,
+
+        TP_PROTO(struct snd_soc_dapm_widget *widget,
+                struct snd_soc_dapm_path *path),
+
+        TP_ARGS(widget, path),
+
+        TP_STRUCT__entry(
+                __string(       wname,  widget->name            )
+                __string(       pname,  path->name ? path->name : DAPM_DIRECT)
+                __string(       psname, path->sink->name        )
+                __field(        int,    path_sink               )
+                __field(        int,    path_connect            )
+        ),
+
+        TP_fast_assign(
+                __assign_str(wname, widget->name);
+                __assign_str(pname, path->name ? path->name : DAPM_DIRECT);
+                __assign_str(psname, path->sink->name);
+                __entry->path_connect = path->connect;
+                __entry->path_sink = (int)path->sink;
+        ),
+
+        TP_printk("%c%s -> %s -> %s\n",
+                (int) __entry->path_sink &&
+                (int) __entry->path_connect ? '*' : ' ',
+                __get_str(wname), __get_str(pname), __get_str(psname))
+);
+
+TRACE_EVENT(snd_soc_dapm_input_path,
+
+        TP_PROTO(struct snd_soc_dapm_widget *widget,
+                struct snd_soc_dapm_path *path),
+
+        TP_ARGS(widget, path),
+
+        TP_STRUCT__entry(
+                __string(       wname,  widget->name            )
+                __string(       pname,  path->name ? path->name : DAPM_DIRECT)
+                __string(       psname, path->source->name      )
+                __field(        int,    path_source             )
+                __field(        int,    path_connect            )
+        ),
+
+        TP_fast_assign(
+                __assign_str(wname, widget->name);
+                __assign_str(pname, path->name ? path->name : DAPM_DIRECT);
+                __assign_str(psname, path->source->name);
+                __entry->path_connect = path->connect;
+                __entry->path_source = (int)path->source;
+        ),
+
+        TP_printk("%c%s <- %s <- %s\n",
+                (int) __entry->path_source &&
+                (int) __entry->path_connect ? '*' : ' ',
+                __get_str(wname), __get_str(pname), __get_str(psname))
+);
+
+TRACE_EVENT(snd_soc_dapm_connected,
+
+        TP_PROTO(int paths, int stream),
+
+        TP_ARGS(paths, stream),
+
+        TP_STRUCT__entry(
+                __field(        int,    paths           )
+                __field(        int,    stream          )
+        ),
+
+        TP_fast_assign(
+                __entry->paths = paths;
+                __entry->stream = stream;
+        ),
+
+        TP_printk("%s: found %d paths\n",
+                __entry->stream ? "capture" : "playback", __entry->paths)
+);
+
 TRACE_EVENT(snd_soc_jack_irq,
 
         TP_PROTO(const char *name),
diff --git a/sound/soc/soc-dapm.c b/sound/soc/soc-dapm.c
index d7ee73a60ca5..214323f53956 100644
--- a/sound/soc/soc-dapm.c
+++ b/sound/soc/soc-dapm.c
@@ -705,11 +705,51 @@ static int snd_soc_dapm_suspend_check(struct snd_soc_dapm_widget *widget)
         }
 }
 
+/* add widget to list if it's not already in the list */
+static int dapm_list_add_widget(struct snd_soc_dapm_widget_list **list,
+        struct snd_soc_dapm_widget *w)
+{
+        struct snd_soc_dapm_widget_list *wlist;
+        int wlistsize, wlistentries, i;
+
+        if (*list == NULL)
+                return -EINVAL;
+
+        wlist = *list;
+
+        /* is this widget already in the list */
+        for (i = 0; i < wlist->num_widgets; i++) {
+                if (wlist->widgets[i] == w)
+                        return 0;
+        }
+
+        /* allocate some new space */
+        wlistentries = wlist->num_widgets + 1;
+        wlistsize = sizeof(struct snd_soc_dapm_widget_list) +
+                        wlistentries * sizeof(struct snd_soc_dapm_widget *);
+        *list = krealloc(wlist, wlistsize, GFP_KERNEL);
+        if (*list == NULL) {
+                dev_err(w->dapm->dev, "can't allocate widget list for %s\n",
+                        w->name);
+                return -ENOMEM;
+        }
+        wlist = *list;
+
+        /* insert the widget */
+        dev_dbg(w->dapm->dev, "added %s in widget list pos %d\n",
+                        w->name, wlist->num_widgets);
+
+        wlist->widgets[wlist->num_widgets] = w;
+        wlist->num_widgets++;
+        return 1;
+}
+
 /*
  * Recursively check for a completed path to an active or physically connected
  * output widget. Returns number of complete paths.
  */
-static int is_connected_output_ep(struct snd_soc_dapm_widget *widget)
+static int is_connected_output_ep(struct snd_soc_dapm_widget *widget,
+        struct snd_soc_dapm_widget_list **list)
 {
         struct snd_soc_dapm_path *path;
         int con = 0;
@@ -765,9 +805,23 @@ static int is_connected_output_ep(struct snd_soc_dapm_widget *widget)
                 if (path->walked)
                         continue;
 
+                trace_snd_soc_dapm_output_path(widget, path);
+
                 if (path->sink && path->connect) {
                         path->walked = 1;
-                        con += is_connected_output_ep(path->sink);
+
+                        /* do we need to add this widget to the list ? */
+                        if (list) {
+                                int err;
+                                err = dapm_list_add_widget(list, path->sink);
+                                if (err < 0) {
+                                        dev_err(widget->dapm->dev, "could not add widget %s\n",
+                                                widget->name);
+                                        return con;
+                                }
+                        }
+
+                        con += is_connected_output_ep(path->sink, list);
                 }
         }
 
@@ -780,7 +834,8 @@ static int is_connected_output_ep(struct snd_soc_dapm_widget *widget)
  * Recursively check for a completed path to an active or physically connected
  * input widget. Returns number of complete paths.
  */
-static int is_connected_input_ep(struct snd_soc_dapm_widget *widget)
+static int is_connected_input_ep(struct snd_soc_dapm_widget *widget,
+        struct snd_soc_dapm_widget_list **list)
 {
         struct snd_soc_dapm_path *path;
         int con = 0;
@@ -848,9 +903,23 @@ static int is_connected_input_ep(struct snd_soc_dapm_widget *widget)
                 if (path->walked)
                         continue;
 
+                trace_snd_soc_dapm_input_path(widget, path);
+
                 if (path->source && path->connect) {
                         path->walked = 1;
-                        con += is_connected_input_ep(path->source);
+
+                        /* do we need to add this widget to the list ? */
+                        if (list) {
+                                int err;
+                                err = dapm_list_add_widget(list, path->sink);
+                                if (err < 0) {
+                                        dev_err(widget->dapm->dev, "could not add widget %s\n",
+                                                widget->name);
+                                        return con;
+                                }
+                        }
+
+                        con += is_connected_input_ep(path->source, list);
                 }
         }
 
@@ -859,6 +928,39 @@ static int is_connected_input_ep(struct snd_soc_dapm_widget *widget)
         return con;
 }
 
+/**
+ * snd_soc_dapm_get_connected_widgets - query audio path and it's widgets.
+ * @dai: the soc DAI.
+ * @stream: stream direction.
+ * @list: list of active widgets for this stream.
+ *
+ * Queries DAPM graph as to whether an valid audio stream path exists for
+ * the initial stream specified by name. This takes into account
+ * current mixer and mux kcontrol settings. Creates list of valid widgets.
+ *
+ * Returns the number of valid paths or negative error.
+ */
+int snd_soc_dapm_dai_get_connected_widgets(struct snd_soc_dai *dai, int stream,
+        struct snd_soc_dapm_widget_list **list)
+{
+        struct snd_soc_card *card = dai->card;
+        int paths;
+
+        mutex_lock_nested(&card->dapm_mutex, SND_SOC_DAPM_CLASS_RUNTIME);
+        dapm_reset(card);
+
+        if (stream == SNDRV_PCM_STREAM_PLAYBACK)
+                paths = is_connected_output_ep(dai->playback_widget, list);
+        else
+                paths = is_connected_input_ep(dai->playback_widget, list);
+
+        trace_snd_soc_dapm_connected(paths, stream);
+        dapm_clear_walk(&card->dapm);
+        mutex_unlock(&card->dapm_mutex);
+
+        return paths;
+}
+
 /*
  * Handler for generic register modifier widget.
  */
@@ -915,9 +1017,9 @@ static int dapm_generic_check_power(struct snd_soc_dapm_widget *w)
 
         DAPM_UPDATE_STAT(w, power_checks);
 
-        in = is_connected_input_ep(w);
+        in = is_connected_input_ep(w, NULL);
         dapm_clear_walk(w->dapm);
-        out = is_connected_output_ep(w);
+        out = is_connected_output_ep(w, NULL);
         dapm_clear_walk(w->dapm);
         return out != 0 && in != 0;
 }
@@ -940,7 +1042,7 @@ static int dapm_adc_check_power(struct snd_soc_dapm_widget *w)
         DAPM_UPDATE_STAT(w, power_checks);
 
         if (w->active) {
-                in = is_connected_input_ep(w);
+                in = is_connected_input_ep(w, NULL);
                 dapm_clear_walk(w->dapm);
                 return in != 0;
         } else {
@@ -956,7 +1058,7 @@ static int dapm_dac_check_power(struct snd_soc_dapm_widget *w)
         DAPM_UPDATE_STAT(w, power_checks);
 
         if (w->active) {
-                out = is_connected_output_ep(w);
+                out = is_connected_output_ep(w, NULL);
                 dapm_clear_walk(w->dapm);
                 return out != 0;
         } else {
@@ -1558,9 +1660,9 @@ static ssize_t dapm_widget_power_read_file(struct file *file,
         if (!buf)
                 return -ENOMEM;
 
-        in = is_connected_input_ep(w);
+        in = is_connected_input_ep(w, NULL);
         dapm_clear_walk(w->dapm);
-        out = is_connected_output_ep(w);
+        out = is_connected_output_ep(w, NULL);
         dapm_clear_walk(w->dapm);
 
         ret = snprintf(buf, PAGE_SIZE, "%s: %s%s  in %d out %d",