ASoC: simple-card: add support for aux devices

Add device tree property to define auxiliary devices to be added to
simle-audio-card.

Together with proper audio routing definition, this allows to use
simple-card in setups where separate amplifier chip is connected to
codec's output.

Signed-off-by: Nikita Yushchenko <nikita.yoush@cogentembedded.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

2 files changed, 71 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/sound/simple-card.txt b/Documentation/devicetree/bindings/sound/simple-card.txt
index cf3979eb3578..5ecdde6d9f63 100644
--- a/Documentation/devicetree/bindings/sound/simple-card.txt
+++ b/Documentation/devicetree/bindings/sound/simple-card.txt
@@ -22,6 +22,8 @@ Optional properties:
                                           headphones are attached.
 - simple-audio-card,mic-det-gpio        : Reference to GPIO that signals when
                                           a microphone is attached.
+- simple-audio-card,aux-devs            : List of phandles pointing to auxiliary devices, such
+                                          as amplifiers, to be added to the sound card.
 
 Optional subnodes:
 
@@ -162,3 +164,38 @@ sound {
                 };
         };
 };
+
+Example 3 - route audio from IMX6 SSI2 through TLV320DAC3100 codec
+through TPA6130A2 amplifier to headphones:
+
+&i2c0 {
+        codec: tlv320dac3100@18 {
+                compatible = "ti,tlv320dac3100";
+                ...
+        }
+
+        amp: tpa6130a2@60 {
+                compatible = "ti,tpa6130a2";
+                ...
+        }
+}
+
+sound {
+        compatible = "simple-audio-card";
+        ...
+        simple-audio-card,widgets =
+                "Headphone", "Headphone Jack";
+        simple-audio-card,routing =
+                "Headphone Jack", "HPLEFT",
+                "Headphone Jack", "HPRIGHT",
+                "LEFTIN", "HPL",
+                "RIGHTIN", "HPR";
+        simple-audio-card,aux-devs = <&amp>;
+        simple-audio-card,cpu {
+                sound-dai = <&ssi2>;
+        };
+        simple-audio-card,codec {
+                sound-dai = <&codec>;
+                clocks = ...
+        };
+};
diff --git a/sound/soc/generic/simple-card.c b/sound/soc/generic/simple-card.c
index fe0bc5c469e2..f608f8d23f3d 100644
--- a/sound/soc/generic/simple-card.c
+++ b/sound/soc/generic/simple-card.c
@@ -318,6 +318,36 @@ dai_link_of_err:
         return ret;
 }
 
+static int asoc_simple_card_parse_aux_devs(struct device_node *node,
+                                           struct simple_card_data *priv)
+{
+        struct device *dev = simple_priv_to_dev(priv);
+        struct device_node *aux_node;
+        int i, n, len;
+
+        if (!of_find_property(node, PREFIX "aux-devs", &len))
+                return 0;               /* Ok to have no aux-devs */
+
+        n = len / sizeof(__be32);
+        if (n <= 0)
+                return -EINVAL;
+
+        priv->snd_card.aux_dev = devm_kzalloc(dev,
+                        n * sizeof(*priv->snd_card.aux_dev), GFP_KERNEL);
+        if (!priv->snd_card.aux_dev)
+                return -ENOMEM;
+
+        for (i = 0; i < n; i++) {
+                aux_node = of_parse_phandle(node, PREFIX "aux-devs", i);
+                if (!aux_node)
+                        return -EINVAL;
+                priv->snd_card.aux_dev[i].codec_of_node = aux_node;
+        }
+
+        priv->snd_card.num_aux_devs = n;
+        return 0;
+}
+
 static int asoc_simple_card_parse_of(struct device_node *node,
                                      struct simple_card_data *priv)
 {
@@ -372,6 +402,10 @@ static int asoc_simple_card_parse_of(struct device_node *node,
         }
 
         ret = asoc_simple_card_parse_card_name(&priv->snd_card, PREFIX);
+        if (ret < 0)
+                goto card_parse_end;
+
+        ret = asoc_simple_card_parse_aux_devs(node, priv);
 
 card_parse_end:
         of_node_put(dai_link);