Re: [alsa-devel] [PATCH v3 3/9] ASoc: sun4i-i2s: Add 20, 24 and 32 bit support

On Sat, Dec 22, 2018 at 12:48 AM Chen-Yu Tsai wens@csie.org wrote:

On Fri, Dec 21, 2018 at 11:21 PM codekipper@gmail.com wrote:

...

From: Marcus Cooper codekipper@gmail.com

Extend the functionality of the driver to include support of 20 and 24 bits per sample for the earlier SoCs.

Newer SoCs can also handle 32bit samples.

Signed-off-by: Marcus Cooper codekipper@gmail.com

sound/soc/sunxi/sun4i-i2s.c | 41 ++++++++++++++++++++++++++++++++++--- 1 file changed, 38 insertions(+), 3 deletions(-)

diff --git a/sound/soc/sunxi/sun4i-i2s.c b/sound/soc/sunxi/sun4i-i2s.c index 80bf29e0cc86..adb988ae9ac5 100644 --- a/sound/soc/sunxi/sun4i-i2s.c +++ b/sound/soc/sunxi/sun4i-i2s.c @@ -399,6 +399,11 @@ static int sun4i_i2s_hw_params(struct snd_pcm_substream *substream, case 16: width = DMA_SLAVE_BUSWIDTH_2_BYTES; break;

•   case 20:
  

•   case 24:
  

•   case 32:
  

•           width = DMA_SLAVE_BUSWIDTH_4_BYTES;
  

•           break;
    default:
            dev_err(dai->dev, "Unsupported physical sample width: %d\n",
                    params_physical_width(params));
  

@@ -411,7 +416,18 @@ static int sun4i_i2s_hw_params(struct snd_pcm_substream *substream, sr = 0; wss = 0; break;

•   case 20:
  

•           sr = 1;
  

•           wss = 1;
  

•           break;
  

•   case 24:
  

•           sr = 2;
  

•           wss = 2;
  

•           break;
  

•   case 32:
  

•           sr = 4;
  

•           wss = 4;
  

•           break;
    default:
            dev_err(dai->dev, "Unsupported sample width: %d\n",
                    params_width(params));
  

@@ -687,6 +703,13 @@ static int sun4i_i2s_dai_probe(struct snd_soc_dai *dai) return 0; }

+#define SUN4I_FORMATS (SNDRV_PCM_FMTBIT_S16_LE | \

•                    SNDRV_PCM_FMTBIT_S20_3LE | \
  

•                    SNDRV_PCM_FMTBIT_S24_LE)
  

IIRC SNDRV_PCM_FMTBIT_S24_LE and SNDRV_PCM_FMTBIT_S32_LE with .sig_bits = 24 are different things, in regards to how the sample is aligned in a 4 byte space. Have you checked that things actually work as expected? This was something that did not work using SNDRV_PCM_FMTBIT_S24_LE on sun4i-codec.

OK. I see the I2S driver is using FIFO mode 1, which expects the sample to be in the lower portion of the 4 bytes. However it looks like you would want SNDRV_PCM_FMTBIT_S20_LE (20 bits LSB justified in 4 bytes) instead of SNDRV_PCM_FMTBIT_S20_3LE (20 bits LSB justified in 3 bytes).

ChenYu

...

+#define SUN8I_FORMATS (SUN4I_FORMATS | \

•                    SNDRV_PCM_FMTBIT_S32_LE)
  

static struct snd_soc_dai_driver sun4i_i2s_dai = { .probe = sun4i_i2s_dai_probe, .capture = { @@ -694,14 +717,14 @@ static struct snd_soc_dai_driver sun4i_i2s_dai = { .channels_min = 2, .channels_max = 2, .rates = SNDRV_PCM_RATE_8000_192000,

•           .formats = SNDRV_PCM_FMTBIT_S16_LE,
  

•           .formats = SUN4I_FORMATS,
    },
    .playback = {
            .stream_name = "Playback",
            .channels_min = 2,
            .channels_max = 2,
            .rates = SNDRV_PCM_RATE_8000_192000,
  

•           .formats = SNDRV_PCM_FMTBIT_S16_LE,
  

•           .formats = SUN4I_FORMATS,
    },
    .ops = &sun4i_i2s_dai_ops,
    .symmetric_rates = 1,
  

@@ -1106,6 +1129,18 @@ static int sun4i_i2s_probe(struct platform_device *pdev) i2s->capture_dma_data.addr = res->start + SUN4I_I2S_FIFO_RX_REG; i2s->capture_dma_data.maxburst = 8;

•   soc_dai = devm_kmemdup(&pdev->dev, &sun4i_i2s_dai,
  

•                          sizeof(*soc_dai), GFP_KERNEL);
  

•   if (!soc_dai) {
  

•           ret = -ENOMEM;
  

•           goto err_pm_disable;
  

•   }
  

•   if (i2s->variant->has_fmt_set_lrck_period) {
  

This condition deserves a comment, particularly as to why you use it in place of having a separate quirk field to represent 32 bit support.

Regards ChenYu

...

•           soc_dai->playback.formats = SUN8I_FORMATS;
  

•           soc_dai->capture.formats = SUN8I_FORMATS;
  

•   }
  

•   pm_runtime_enable(&pdev->dev);
    if (!pm_runtime_enabled(&pdev->dev)) {
            ret = sun4i_i2s_runtime_resume(&pdev->dev);
  

-- 2.20.1