ASoC: Add utility to parse DAPM routes from device tree

Implement snd_soc_of_parse_audio_routing(), a utility function that can
parses a simple DAPM route table from device tree.The machine driver
specifies the DT property to use, since this is binding-specific.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

diff --git a/include/sound/soc.h b/include/sound/soc.h
index 278f3b8..db8acd2 100644 (file)
--- a/include/sound/soc.h
+++ b/include/sound/soc.h
@@ -963,6 +963,8 @@ void snd_soc_util_exit(void);
 
 int snd_soc_of_parse_card_name(struct snd_soc_card *card,
                               const char *propname);
+int snd_soc_of_parse_audio_routing(struct snd_soc_card *card,
+                                  const char *propname);
 
 #include <sound/soc-dai.h>
 

diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c
index 51eef9b..42ad2db 100644 (file)
--- a/sound/soc/soc-core.c
+++ b/sound/soc/soc-core.c
@@ -3342,6 +3342,63 @@ int snd_soc_of_parse_card_name(struct snd_soc_card *card,
 }
 EXPORT_SYMBOL_GPL(snd_soc_of_parse_card_name);
 
+int snd_soc_of_parse_audio_routing(struct snd_soc_card *card,
+                                  const char *propname)
+{
+       struct device_node *np = card->dev->of_node;
+       int num_routes;
+       struct snd_soc_dapm_route *routes;
+       int i, ret;
+
+       num_routes = of_property_count_strings(np, propname);
+       if (num_routes & 1) {
+               dev_err(card->dev,
+                       "Property '%s's length is not even\n",
+                       propname);
+               return -EINVAL;
+       }
+       num_routes /= 2;
+       if (!num_routes) {
+               dev_err(card->dev,
+                       "Property '%s's length is zero\n",
+                       propname);
+               return -EINVAL;
+       }
+
+       routes = devm_kzalloc(card->dev, num_routes * sizeof(*routes),
+                             GFP_KERNEL);
+       if (!routes) {
+               dev_err(card->dev,
+                       "Could not allocate DAPM route table\n");
+               return -EINVAL;
+       }
+
+       for (i = 0; i < num_routes; i++) {
+               ret = of_property_read_string_index(np, propname,
+                       2 * i, &routes[i].sink);
+               if (ret) {
+                       dev_err(card->dev,
+                               "Property '%s' index %d could not be read: %d\n",
+                               propname, 2 * i, ret);
+                       return -EINVAL;
+               }
+               ret = of_property_read_string_index(np, propname,
+                       (2 * i) + 1, &routes[i].source);
+               if (ret) {
+                       dev_err(card->dev,
+                               "Property '%s' index %d could not be read: %d\n",
+                               propname, (2 * i) + 1, ret);
+                       return -EINVAL;
+               }
+       }
+
+       card->num_dapm_routes = num_routes;
+       card->dapm_routes = routes;
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(snd_soc_of_parse_audio_routing);
+
 static int __init snd_soc_init(void)
 {
 #ifdef CONFIG_DEBUG_FS