ASoC: rockchip: Fix mono capture

[ Upstream commit 789e162a6255325325bd321ab0cd51dc7e285054 ]

This reverts commit db51707b9c9aeedd310ebce60f15d5bb006567e0.
Revert "ASoC: rockchip: i2s: Support mono capture"

Previous discussion in

https://patchwork.kernel.org/patch/10147153/

explains the issue of the patch.
While device is configured as 1-ch, hardware is still
generating a 2-ch stream.
When user space reads the data and assumes it is a 1-ch stream,
the rate will be slower by 2x.

Revert the change so 1-ch is not supported.
User space can selectively take one channel data out of two channel
if 1-ch is preferred.
Currently, both channels record identical data.

Signed-off-by: Cheng-Yi Chiang <cychiang@chromium.org>
Link: https://lore.kernel.org/r/20190726044202.26866-1-cychiang@chromium.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/sound/soc/rockchip/rockchip_i2s.c b/sound/soc/rockchip/rockchip_i2s.c
index 60d43d5..11399f8 100644 (file)
--- a/sound/soc/rockchip/rockchip_i2s.c
+++ b/sound/soc/rockchip/rockchip_i2s.c
@@ -329,7 +329,6 @@ static int rockchip_i2s_hw_params(struct snd_pcm_substream *substream,
                val |= I2S_CHN_4;
                break;
        case 2:
-       case 1:
                val |= I2S_CHN_2;
                break;
        default:
@@ -462,7 +461,7 @@ static struct snd_soc_dai_driver rockchip_i2s_dai = {
        },
        .capture = {
                .stream_name = "Capture",
-               .channels_min = 1,
+               .channels_min = 2,
                .channels_max = 2,
                .rates = SNDRV_PCM_RATE_8000_192000,
                .formats = (SNDRV_PCM_FMTBIT_S8 |
@@ -662,7 +661,7 @@ static int rockchip_i2s_probe(struct platform_device *pdev)
        }
 
        if (!of_property_read_u32(node, "rockchip,capture-channels", &val)) {
-               if (val >= 1 && val <= 8)
+               if (val >= 2 && val <= 8)
                        soc_dai->capture.channels_max = val;
        }