ASoC: dwc: Correct channel count reporting

The DWC I2S driver treats the channel count register values as if they
encode a power of two (2, 4, 8, 16), but they actually encode a
multiple of 2 (2, 4, 6, 8).

Also improve the error message when asked for an unsupported number
of channels.

Signed-off-by: Phil Elwell <[email protected]>

Author: pelwell

sound/soc/dwc/dwc-i2s.c

@@ -320,7 +320,7 @@ static int dw_i2s_hw_params(struct snd_pcm_substream *substream,
 	case TWO_CHANNEL_SUPPORT:
 		break;
 	default:
-		dev_err(dev->dev, "channel not supported\n");
+		dev_err(dev->dev, "channel count %d not supported\n", config->chan_nr);
 		return -EINVAL;
 	}
 
@@ -708,7 +708,7 @@ static int dw_configure_dai(struct dw_i2s_dev *dev,
 			idx = 1;
 		dw_i2s_dai->playback.channels_min = MIN_CHANNEL_NUM;
 		dw_i2s_dai->playback.channels_max =
-				1 << (COMP1_TX_CHANNELS(comp1) + 1);
+				2 * (COMP1_TX_CHANNELS(comp1) + 1);
 		dw_i2s_dai->playback.formats = formats[idx];
 		dw_i2s_dai->playback.rates = rates;
 	}
@@ -722,7 +722,7 @@ static int dw_configure_dai(struct dw_i2s_dev *dev,
 			idx = 1;
 		dw_i2s_dai->capture.channels_min = MIN_CHANNEL_NUM;
 		dw_i2s_dai->capture.channels_max =
-				1 << (COMP1_RX_CHANNELS(comp1) + 1);
+				2 * (COMP1_RX_CHANNELS(comp1) + 1);
 		dw_i2s_dai->capture.formats = formats[idx];
 		dw_i2s_dai->capture.rates = rates;
 	}