target/linux/brcm2708/patches-4.9/0132-Revert-bcm2835-i2s-Changes-for-allowing-asymmetric-s.patch

   1 From db51b292d97ecb021831ed380ce4e1152b1bd235 Mon Sep 17 00:00:00 2001
   2 From: Phil Elwell <phil@raspberrypi.org>
   3 Date: Mon, 16 Jan 2017 21:02:26 +0000
   4 Subject: [PATCH] Revert "bcm2835-i2s: Changes for allowing asymmetric sample
   5  formats."
   6
   7 This reverts commit f5a6236a32e82068122301d246a94ca755d61704.
   8
   9 See: https://github.com/raspberrypi/linux/issues/1799
  10
  11 Signed-off-by: Phil Elwell <phil@raspberrypi.org>
  12 ---
  13  sound/soc/bcm/bcm2835-i2s.c | 54 ++++++++++++++-------------------------------
  14  1 file changed, 16 insertions(+), 38 deletions(-)
  15
  16 --- a/sound/soc/bcm/bcm2835-i2s.c
  17 +++ b/sound/soc/bcm/bcm2835-i2s.c
  18 @@ -237,9 +237,7 @@ static int bcm2835_i2s_hw_params(struct
  19         unsigned int sampling_rate = params_rate(params);
  20         unsigned int data_length, data_delay, bclk_ratio;
  21         unsigned int ch1pos, ch2pos, mode, format;
  22 -       unsigned int previous_ftxp, previous_frxp;
  23         uint32_t csreg;
  24 -       bool packed;
  25
  26         /*
  27          * If a stream is already enabled,
  28 @@ -322,46 +320,26 @@ static int bcm2835_i2s_hw_params(struct
  29                 return -EINVAL;
  30         }
  31
  32 -       /* Set the format for the matching stream direction. */
  33 -       switch (substream->stream) {
  34 -       case SNDRV_PCM_STREAM_PLAYBACK:
  35 -               regmap_write(dev->i2s_regmap, BCM2835_I2S_TXC_A_REG, format);
  36 -               break;
  37 -       case SNDRV_PCM_STREAM_CAPTURE:
  38 -               regmap_write(dev->i2s_regmap, BCM2835_I2S_RXC_A_REG, format);
  39 -               break;
  40 -       default:
  41 -               return -EINVAL;
  42 -       }
  43 +       /*
  44 +        * Set format for both streams.
  45 +        * We cannot set another frame length
  46 +        * (and therefore word length) anyway,
  47 +        * so the format will be the same.
  48 +        */
  49 +       regmap_write(dev->i2s_regmap, BCM2835_I2S_RXC_A_REG, format);
  50 +       regmap_write(dev->i2s_regmap, BCM2835_I2S_TXC_A_REG, format);
  51
  52         /* Setup the I2S mode */
  53 -       /* Keep existing FTXP and FRXP values. */
  54 -       regmap_read(dev->i2s_regmap, BCM2835_I2S_MODE_A_REG, &mode);
  55 -
  56 -       previous_ftxp = mode & BCM2835_I2S_FTXP;
  57 -       previous_frxp = mode & BCM2835_I2S_FRXP;
  58 -
  59         mode = 0;
  60
  61 -       /*
  62 -        * Retain the frame packed mode (2 channels per 32 bit word)
  63 -        * of the other direction stream intact. The formats of each
  64 -        * direction can be different as long as the frame length is
  65 -        * shared for both.
  66 -        */
  67 -       packed = data_length <= 16;
  68 -
  69 -       switch (substream->stream) {
  70 -       case SNDRV_PCM_STREAM_PLAYBACK:
  71 -               mode |= previous_frxp;
  72 -               mode |= packed ? BCM2835_I2S_FTXP : 0;
  73 -               break;
  74 -       case SNDRV_PCM_STREAM_CAPTURE:
  75 -               mode |= previous_ftxp;
  76 -               mode |= packed ? BCM2835_I2S_FRXP : 0;
  77 -               break;
  78 -       default:
  79 -               return -EINVAL;
  80 +       if (data_length <= 16) {
  81 +               /*
  82 +                * Use frame packed mode (2 channels per 32 bit word)
  83 +                * We cannot set another frame length in the second stream
  84 +                * (and therefore word length) anyway,
  85 +                * so the format will be the same.
  86 +                */
  87 +               mode |= BCM2835_I2S_FTXP | BCM2835_I2S_FRXP;
  88         }
  89
  90         mode |= BCM2835_I2S_FLEN(bclk_ratio - 1);