Re: [linux-sunxi] [PATCH v5 15/15] ASoC: sun4i-i2s: Adjust regmap settings

[Code Kipper]

On Wed, 14 Aug 2019 at 10:38, Jernej Åkrabec <jernej.skrabec@xxxxxxxxx> wrote:
>
> Hi!
>
> Dne sreda, 14. avgust 2019 ob 08:08:54 CEST je codekipper@xxxxxxxxx
> napisal(a):
> > From: Marcus Cooper <codekipper@xxxxxxxxx>
> >
> > Bypass the regmap cache when flushing the i2s FIFOs and modify the tables
> > to reflect this.
> >
> > Signed-off-by: Marcus Cooper <codekipper@xxxxxxxxx>
> > ---
> >  sound/soc/sunxi/sun4i-i2s.c | 31 ++++++++++---------------------
> >  1 file changed, 10 insertions(+), 21 deletions(-)
> >
> > diff --git a/sound/soc/sunxi/sun4i-i2s.c b/sound/soc/sunxi/sun4i-i2s.c
> > index d3c8789f70bb..ecfc1ed79379 100644
> > --- a/sound/soc/sunxi/sun4i-i2s.c
> > +++ b/sound/soc/sunxi/sun4i-i2s.c
> > @@ -876,9 +876,11 @@ static int sun4i_i2s_set_fmt(struct snd_soc_dai *dai,
> > unsigned int fmt) static void sun4i_i2s_start_capture(struct sun4i_i2s
> > *i2s)
> >  {
> >       /* Flush RX FIFO */
> > +     regcache_cache_bypass(i2s->regmap, true);
> >       regmap_update_bits(i2s->regmap, SUN4I_I2S_FIFO_CTRL_REG,
> >                          SUN4I_I2S_FIFO_CTRL_FLUSH_RX,
> >                          SUN4I_I2S_FIFO_CTRL_FLUSH_RX);
> > +     regcache_cache_bypass(i2s->regmap, false);
>
> Did you try with regmap_write_bits() instead? This function will
> unconditionally write bits so it's nicer solution, because you don't have to
> use regcache_cache_bypass().

I didn't....with all the rework I've avoided messing with this change.
Now that the dust
has settled, I can go back to look at this.
Thanks,
CK
>
> >
> >       /* Clear RX counter */
> >       regmap_write(i2s->regmap, SUN4I_I2S_RX_CNT_REG, 0);
> > @@ -897,9 +899,11 @@ static void sun4i_i2s_start_capture(struct sun4i_i2s
> > *i2s) static void sun4i_i2s_start_playback(struct sun4i_i2s *i2s)
> >  {
> >       /* Flush TX FIFO */
> > +     regcache_cache_bypass(i2s->regmap, true);
> >       regmap_update_bits(i2s->regmap, SUN4I_I2S_FIFO_CTRL_REG,
> >                          SUN4I_I2S_FIFO_CTRL_FLUSH_TX,
> >                          SUN4I_I2S_FIFO_CTRL_FLUSH_TX);
> > +     regcache_cache_bypass(i2s->regmap, false);
>
> Ditto.
>
> >
> >       /* Clear TX counter */
> >       regmap_write(i2s->regmap, SUN4I_I2S_TX_CNT_REG, 0);
> > @@ -1053,13 +1057,7 @@ static const struct snd_soc_component_driver
> > sun4i_i2s_component = {
> >
> >  static bool sun4i_i2s_rd_reg(struct device *dev, unsigned int reg)
> >  {
> > -     switch (reg) {
> > -     case SUN4I_I2S_FIFO_TX_REG:
> > -             return false;
> > -
> > -     default:
> > -             return true;
> > -     }
> > +     return true;
>
> Why did you change this? Manual mentions that SUN4I_I2S_FIFO_TX_REG is write-
> only register. Even if it can be read, then it's better to remove whole
> function, which will automatically mean that all registers can be read.
>
>
> >  }
> >
> >  static bool sun4i_i2s_wr_reg(struct device *dev, unsigned int reg)
> > @@ -1078,6 +1076,8 @@ static bool sun4i_i2s_volatile_reg(struct device *dev,
> > unsigned int reg) {
> >       switch (reg) {
> >       case SUN4I_I2S_FIFO_RX_REG:
> > +     case SUN4I_I2S_FIFO_TX_REG:
> > +     case SUN4I_I2S_FIFO_STA_REG:
> >       case SUN4I_I2S_INT_STA_REG:
> >       case SUN4I_I2S_RX_CNT_REG:
> >       case SUN4I_I2S_TX_CNT_REG:
>
> SUN4I_I2S_FIFO_CTRL_REG should be put here, because it has two bits which
> returns to 0 immediately after they are set to 1.
>
> Best regards,
> Jernej
>
> > @@ -1088,23 +1088,12 @@ static bool sun4i_i2s_volatile_reg(struct device
> > *dev, unsigned int reg) }
> >  }
> >
> > -static bool sun8i_i2s_rd_reg(struct device *dev, unsigned int reg)
> > -{
> > -     switch (reg) {
> > -     case SUN8I_I2S_FIFO_TX_REG:
> > -             return false;
> > -
> > -     default:
> > -             return true;
> > -     }
> > -}
> > -
> >  static bool sun8i_i2s_volatile_reg(struct device *dev, unsigned int reg)
> >  {
> >       if (reg == SUN8I_I2S_INT_STA_REG)
> >               return true;
> >       if (reg == SUN8I_I2S_FIFO_TX_REG)
> > -             return false;
> > +             return true;
> >
> >       return sun4i_i2s_volatile_reg(dev, reg);
> >  }
> > @@ -1175,7 +1164,7 @@ static const struct regmap_config
> > sun8i_i2s_regmap_config = { .reg_defaults     = sun8i_i2s_reg_defaults,
> >       .num_reg_defaults       = ARRAY_SIZE(sun8i_i2s_reg_defaults),
> >       .writeable_reg  = sun4i_i2s_wr_reg,
> > -     .readable_reg   = sun8i_i2s_rd_reg,
> > +     .readable_reg   = sun4i_i2s_rd_reg,
> >       .volatile_reg   = sun8i_i2s_volatile_reg,
> >  };
> >
> > @@ -1188,7 +1177,7 @@ static const struct regmap_config
> > sun50i_i2s_regmap_config = { .reg_defaults    = sun50i_i2s_reg_defaults,
> >       .num_reg_defaults       = ARRAY_SIZE(sun50i_i2s_reg_defaults),
> >       .writeable_reg  = sun4i_i2s_wr_reg,
> > -     .readable_reg   = sun8i_i2s_rd_reg,
> > +     .readable_reg   = sun4i_i2s_rd_reg,
> >       .volatile_reg   = sun8i_i2s_volatile_reg,
> >  };
>
>
>
>