[RFC PATCH 5/7] ASoC: sunxi: sun4i-i2s: Detect TDM slots based on channel slots

[John Watts]

The current controller code assumes a 1:1 relationship between audio
channel and TDM slot. This may not be the case when slots are set
explicitly. Instead figure out how many slots we need based on the
number of slots used in the channel map.

This allows the case of reading multiple data pins on a single slot.

Signed-off-by: John Watts <contact@xxxxxxxxxx>
---
 sound/soc/sunxi/sun4i-i2s.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/sound/soc/sunxi/sun4i-i2s.c b/sound/soc/sunxi/sun4i-i2s.c
index 019a4856c90b..6347aaaed016 100644
--- a/sound/soc/sunxi/sun4i-i2s.c
+++ b/sound/soc/sunxi/sun4i-i2s.c
@@ -271,6 +271,7 @@ static int sun4i_i2s_read_channel_slots(struct device *dev, struct sun4i_i2s *i2
 {
 	struct device_node *np = dev->of_node;
 	int max_channels = ARRAY_SIZE(i2s->channel_dins);
+	int slot_max;
 	int ret;
 
 	/* Use a 1:1 mapping by default */
@@ -290,6 +291,16 @@ static int sun4i_i2s_read_channel_slots(struct device *dev, struct sun4i_i2s *i2
 	if (ret < 0)
 		return ret;
 
+	for (int i = 0; i < ret; ++i) {
+		int slot = i2s->channel_slots[i];
+
+		if (slot_max < slot)
+			slot_max = slot;
+	}
+
+	/* Add 1 to be inclusive of slot 0 */
+	i2s->slots = slot_max + 1;
+
 	return 0;
 }
 
-- 
2.41.0