target/linux/bcm27xx/patches-6.1/950-0895-ASOC-dwc-Fix-16-bit-audio-handling.patch

   1 From 9c6694c24f26ea435165431d41c72451fadbd753 Mon Sep 17 00:00:00 2001
   2 From: Phil Elwell <phil@raspberrypi.com>
   3 Date: Fri, 21 Jul 2023 12:07:16 +0100
   4 Subject: [PATCH] ASOC: dwc: Fix 16-bit audio handling
   5
   6 IMO the Synopsys datasheet could be clearer in this area, but it seems
   7 that the DMA data ports (DMATX and DMARX) expect left and right samples
   8 in alternate writes; if a stereo pair is pushed in a single 32-bit
   9 write, the upper half is ignored, leading to double speed audio with a
  10 confused stereo image. Make sure the necessary changes happen by
  11 updating the DMA configuration data in the hw_params method.
  12
  13 The set_bclk_ratio change was made at a time when it looked like it
  14 could be causing an error, but I think the division of responsibilities
  15 is clearer this way (and the kernel log clearer without the info-level
  16 message).
  17
  18 Signed-off-by: Phil Elwell <phil@raspberrypi.com>
  19 ---
  20  sound/soc/dwc/dwc-i2s.c | 22 +++++++++++++++-------
  21  1 file changed, 15 insertions(+), 7 deletions(-)
  22
  23 --- a/sound/soc/dwc/dwc-i2s.c
  24 +++ b/sound/soc/dwc/dwc-i2s.c
  25 @@ -223,23 +223,34 @@ static int dw_i2s_hw_params(struct snd_p
  26  {
  27         struct dw_i2s_dev *dev = snd_soc_dai_get_drvdata(dai);
  28         struct i2s_clk_config_data *config = &dev->config;
  29 +       union dw_i2s_snd_dma_data *dma_data = NULL;
  30         int ret;
  31
  32 +       if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
  33 +               dma_data = &dev->play_dma_data;
  34 +       else if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
  35 +               dma_data = &dev->capture_dma_data;
  36 +       else
  37 +               return -1;
  38 +
  39         switch (params_format(params)) {
  40         case SNDRV_PCM_FORMAT_S16_LE:
  41                 config->data_width = 16;
  42 +               dma_data->dt.addr_width = 2;
  43                 dev->ccr = 0x00;
  44                 dev->xfer_resolution = 0x02;
  45                 break;
  46
  47         case SNDRV_PCM_FORMAT_S24_LE:
  48                 config->data_width = 24;
  49 +               dma_data->dt.addr_width = 4;
  50                 dev->ccr = 0x08;
  51                 dev->xfer_resolution = 0x04;
  52                 break;
  53
  54         case SNDRV_PCM_FORMAT_S32_LE:
  55                 config->data_width = 32;
  56 +               dma_data->dt.addr_width = 4;
  57                 dev->ccr = 0x10;
  58                 dev->xfer_resolution = 0x05;
  59                 break;
  60 @@ -418,24 +429,21 @@ static int dw_i2s_set_bclk_ratio(struct
  61         struct dw_i2s_dev *dev = snd_soc_dai_get_drvdata(cpu_dai);
  62         struct i2s_clk_config_data *config = &dev->config;
  63
  64 -       dev_err(dev->dev, "%s(%d)\n", __func__, ratio);
  65 +       dev_dbg(dev->dev, "%s(%d)\n", __func__, ratio);
  66 +       if (ratio < config->data_width * 2)
  67 +               return -EINVAL;
  68 +
  69         switch (ratio) {
  70         case 32:
  71 -               config->data_width = 16;
  72                 dev->ccr = 0x00;
  73 -               dev->xfer_resolution = 0x02;
  74                 break;
  75
  76         case 48:
  77 -               config->data_width = 24;
  78                 dev->ccr = 0x08;
  79 -               dev->xfer_resolution = 0x04;
  80                 break;
  81
  82         case 64:
  83 -               config->data_width = 32;
  84                 dev->ccr = 0x10;
  85 -               dev->xfer_resolution = 0x05;
  86                 break;
  87         default:
  88                 return -EINVAL;