ASoC: simple-card: Support for selecting system clocks by ID

Most CPU and codec drivers can select their system clock from different
sources. They rely on snd_soc_dai_set_sysclk(x, sysclk_id, x, x) to do so.
Add support for selecting which clock need to be selected along with the
rate.

Signed-off-by: Jyri Sarha <jsarha@ti.com>
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>

Documentation/devicetree/bindings/sound/simple-card.txt

@@ -94,6 +94,8 @@ Optional CPU/CODEC subnodes properties:
 - system-clock-direction-out		: specifies clock direction as 'out' on
 					  initialization. It is useful for some aCPUs with
 					  fixed clocks.
+- system-clock-id			: Numberic ID of the system clock to
+					  select within the dai, default is 0.
 
 Example 1 - single DAI link:
 

include/sound/simple_card_utils.h

@@ -19,6 +19,7 @@ struct asoc_simple_dai {
 	const char *name;
 	unsigned int sysclk;
 	int clk_direction;
+	int sysclk_id;
 	int slots;
 	int slot_width;
 	unsigned int tx_slot_mask;

sound/soc/generic/simple-card-utils.c

@@ -200,8 +200,12 @@ int asoc_simple_card_parse_clk(struct device *dev,
 	if (of_property_read_bool(node, "system-clock-direction-out"))
 		simple_dai->clk_direction = SND_SOC_CLOCK_OUT;
 
-	dev_dbg(dev, "%s : sysclk = %d, direction %d\n", name,
-		simple_dai->sysclk, simple_dai->clk_direction);
+	if (!of_property_read_u32(node, "system-clock-id", &val))
+		simple_dai->sysclk_id = val;
+
+	dev_dbg(dev, "%s : sysclk-%d = %d, direction %d\n", name,
+		simple_dai->sysclk_id, simple_dai->sysclk,
+		simple_dai->clk_direction);
 
 	return 0;
 }
@@ -313,7 +317,8 @@ int asoc_simple_card_init_dai(struct snd_soc_dai *dai,
 	int ret;
 
 	if (simple_dai->sysclk) {
-		ret = snd_soc_dai_set_sysclk(dai, 0, simple_dai->sysclk,
+		ret = snd_soc_dai_set_sysclk(dai, simple_dai->sysclk_id,
+					     simple_dai->sysclk,
 					     simple_dai->clk_direction);
 		if (ret && ret != -ENOTSUPP) {
 			dev_err(dai->dev, "simple-card: set_sysclk error\n");