On R329 I2S variants with multiple pins it's useful to read from multiple devices within a single TDM slot. Allow changing the assignment of slots through a device tree property.
As an example:
&i2s2 { channel-dins = /bits/ 8 <0 0 1 1 2 2>; channel-slots = /bits/ 8 <0 1 0 1 0 1>; };
In addition to configuring the first 6 channels to use different DIN pins for three separate ADCs, the addition of channel-slots allows all three ADCs to be sampled within the first two TDM slots.
Signed-off-by: John Watts contact@jookia.org --- sound/soc/sunxi/sun4i-i2s.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+)
diff --git a/sound/soc/sunxi/sun4i-i2s.c b/sound/soc/sunxi/sun4i-i2s.c index 627bf319e1cc..019a4856c90b 100644 --- a/sound/soc/sunxi/sun4i-i2s.c +++ b/sound/soc/sunxi/sun4i-i2s.c @@ -269,12 +269,27 @@ static int sun4i_i2s_read_channel_dins(struct device *dev, struct sun4i_i2s *i2s
static int sun4i_i2s_read_channel_slots(struct device *dev, struct sun4i_i2s *i2s) { + struct device_node *np = dev->of_node; int max_channels = ARRAY_SIZE(i2s->channel_dins); + int ret;
/* Use a 1:1 mapping by default */ for (int i = 0; i < max_channels; ++i) i2s->channel_slots[i] = i;
+ if (!np) + return 0; + + ret = of_property_read_variable_u8_array(np, "channel-slots", + i2s->channel_slots, + 1, max_channels); + + if (ret == -EINVAL) + return 0; + + if (ret < 0) + return ret; + return 0; }