target/linux/brcm2708/patches-4.4/0571-Revert-bcm2835-i2s-Changes-for-allowing-asymmetric-s.patch

   1 From ba1f22a0d2179a0201e764c341d9dbf8f1c27ffe Mon Sep 17 00:00:00 2001
   2 From: Phil Elwell <phil@raspberrypi.org>
   3 Date: Mon, 16 Jan 2017 20:58:18 +0000
   4 Subject: [PATCH] Revert "bcm2835-i2s: Changes for allowing asymmetric sample
   5  formats. (#1783)"
   6
   7 This reverts commit 4897c5c2f7adb4f77d638121e9959174dff87b9c.
   8
   9 Signed-off-by: Phil Elwell <phil@raspberrypi.org>
  10
  11 See: https://github.com/raspberrypi/linux/issues/1799
  12 ---
  13  sound/soc/bcm/bcm2835-i2s.c | 54 ++++++++++++++-------------------------------
  14  1 file changed, 16 insertions(+), 38 deletions(-)
  15
  16 diff --git a/sound/soc/bcm/bcm2835-i2s.c b/sound/soc/bcm/bcm2835-i2s.c
  17 index d2b0801..aedb01f 100644
  18 --- a/sound/soc/bcm/bcm2835-i2s.c
  19 +++ b/sound/soc/bcm/bcm2835-i2s.c
  20 @@ -310,7 +310,6 @@ static int bcm2835_i2s_hw_params(struct snd_pcm_substream *substream,
  21         unsigned int sampling_rate = params_rate(params);
  22         unsigned int data_length, data_delay, bclk_ratio;
  23         unsigned int ch1pos, ch2pos, mode, format;
  24 -       unsigned int previous_ftxp, previous_frxp;
  25         unsigned int mash = BCM2835_CLK_MASH_1;
  26         unsigned int divi, divf, target_frequency;
  27         int clk_src = -1;
  28 @@ -321,7 +320,6 @@ static int bcm2835_i2s_hw_params(struct snd_pcm_substream *substream,
  29         bool frame_master =     (master == SND_SOC_DAIFMT_CBS_CFS
  30                                         || master == SND_SOC_DAIFMT_CBM_CFS);
  31         uint32_t csreg;
  32 -       bool packed;
  33
  34         /*
  35          * If a stream is already enabled,
  36 @@ -467,46 +465,26 @@ static int bcm2835_i2s_hw_params(struct snd_pcm_substream *substream,
  37                 return -EINVAL;
  38         }
  39
  40 -       /* Set the format for the matching stream direction. */
  41 -       switch (substream->stream) {
  42 -       case SNDRV_PCM_STREAM_PLAYBACK:
  43 -               regmap_write(dev->i2s_regmap, BCM2835_I2S_TXC_A_REG, format);
  44 -               break;
  45 -       case SNDRV_PCM_STREAM_CAPTURE:
  46 -               regmap_write(dev->i2s_regmap, BCM2835_I2S_RXC_A_REG, format);
  47 -               break;
  48 -       default:
  49 -               return -EINVAL;
  50 -       }
  51 +       /*
  52 +        * Set format for both streams.
  53 +        * We cannot set another frame length
  54 +        * (and therefore word length) anyway,
  55 +        * so the format will be the same.
  56 +        */
  57 +       regmap_write(dev->i2s_regmap, BCM2835_I2S_RXC_A_REG, format);
  58 +       regmap_write(dev->i2s_regmap, BCM2835_I2S_TXC_A_REG, format);
  59
  60         /* Setup the I2S mode */
  61 -       /* Keep existing FTXP and FRXP values. */
  62 -       regmap_read(dev->i2s_regmap, BCM2835_I2S_MODE_A_REG, &mode);
  63 -
  64 -       previous_ftxp = mode & BCM2835_I2S_FTXP;
  65 -       previous_frxp = mode & BCM2835_I2S_FRXP;
  66 -
  67         mode = 0;
  68
  69 -       /*
  70 -        * Retain the frame packed mode (2 channels per 32 bit word)
  71 -        * of the other direction stream intact. The formats of each
  72 -        * direction can be different as long as the frame length is
  73 -        * shared for both.
  74 -        */
  75 -       packed = data_length <= 16;
  76 -
  77 -       switch (substream->stream) {
  78 -       case SNDRV_PCM_STREAM_PLAYBACK:
  79 -               mode |= previous_frxp;
  80 -               mode |= packed ? BCM2835_I2S_FTXP : 0;
  81 -               break;
  82 -       case SNDRV_PCM_STREAM_CAPTURE:
  83 -               mode |= previous_ftxp;
  84 -               mode |= packed ? BCM2835_I2S_FRXP : 0;
  85 -               break;
  86 -       default:
  87 -               return -EINVAL;
  88 +       if (data_length <= 16) {
  89 +               /*
  90 +                * Use frame packed mode (2 channels per 32 bit word)
  91 +                * We cannot set another frame length in the second stream
  92 +                * (and therefore word length) anyway,
  93 +                * so the format will be the same.
  94 +                */
  95 +               mode |= BCM2835_I2S_FTXP | BCM2835_I2S_FRXP;
  96         }
  97
  98         mode |= BCM2835_I2S_FLEN(bclk_ratio - 1);
  99 --
 100 2.1.4
 101