Re: [linux-sunxi] [PATCH 01/16] ASoC: sun4i-i2s: Add support for H6 I2S

["Clément Péron" <peron.clem@gmail.com>]

Hi Samuel,

On Fri, 10 Jul 2020 at 07:44, Samuel Holland <samuel@sholland.org> wrote:
>
> On 7/4/20 6:38 AM, Clément Péron wrote:
> > From: Jernej Skrabec <jernej.skrabec@siol.net>
> >
> > H6 I2S is very similar to that in H3, except it supports up to 16
> > channels.
> >
> > Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
> > Signed-off-by: Marcus Cooper <codekipper@gmail.com>
> > Signed-off-by: Clément Péron <peron.clem@gmail.com>
> > ---
> >  sound/soc/sunxi/sun4i-i2s.c | 227 ++++++++++++++++++++++++++++++++++++
> >  1 file changed, 227 insertions(+)
> >
> > diff --git a/sound/soc/sunxi/sun4i-i2s.c b/sound/soc/sunxi/sun4i-i2s.c
> > index d0a8d5810c0a..9690389cb68e 100644
> > --- a/sound/soc/sunxi/sun4i-i2s.c
> > +++ b/sound/soc/sunxi/sun4i-i2s.c
> > @@ -124,6 +124,21 @@
> >  #define SUN8I_I2S_RX_CHAN_SEL_REG    0x54
> >  #define SUN8I_I2S_RX_CHAN_MAP_REG    0x58
> >
> > +/* Defines required for sun50i-h6 support */
> > +#define SUN50I_H6_I2S_TX_CHAN_SEL_OFFSET_MASK        GENMASK(21, 20)
> > +#define SUN50I_H6_I2S_TX_CHAN_SEL_OFFSET(offset)     ((offset) << 20)
> > +#define SUN50I_H6_I2S_TX_CHAN_SEL_MASK               GENMASK(19, 16)
> > +#define SUN50I_H6_I2S_TX_CHAN_SEL(chan)              ((chan - 1) << 16)
> > +#define SUN50I_H6_I2S_TX_CHAN_EN_MASK                GENMASK(15, 0)
> > +#define SUN50I_H6_I2S_TX_CHAN_EN(num_chan)   (((1 << num_chan) - 1))
> > +
> > +#define SUN50I_H6_I2S_TX_CHAN_MAP0_REG       0x44
> > +#define SUN50I_H6_I2S_TX_CHAN_MAP1_REG       0x48
> > +
> > +#define SUN50I_H6_I2S_RX_CHAN_SEL_REG        0x64
> > +#define SUN50I_H6_I2S_RX_CHAN_MAP0_REG       0x68
> > +#define SUN50I_H6_I2S_RX_CHAN_MAP1_REG       0x6C
> > +
> >  struct sun4i_i2s;
> >
> >  /**
> > @@ -466,6 +481,65 @@ static int sun8i_i2s_set_chan_cfg(const struct sun4i_i2s *i2s,
> >       return 0;
> >  }
> >
> > +static int sun50i_i2s_set_chan_cfg(const struct sun4i_i2s *i2s,
> > +                                const struct snd_pcm_hw_params *params)
> > +{
> > +     unsigned int channels = params_channels(params);
> > +     unsigned int slots = channels;
> > +     unsigned int lrck_period;
> > +
> > +     if (i2s->slots)
> > +             slots = i2s->slots;
> > +
> > +     /* Map the channels for playback and capture */
> > +     regmap_write(i2s->regmap, SUN50I_H6_I2S_TX_CHAN_MAP1_REG, 0x76543210);
> > +     regmap_write(i2s->regmap, SUN50I_H6_I2S_RX_CHAN_MAP1_REG, 0x76543210);
> > +
> > +     /* Configure the channels */
> > +     regmap_update_bits(i2s->regmap, SUN8I_I2S_TX_CHAN_SEL_REG,
> > +                        SUN50I_H6_I2S_TX_CHAN_SEL_MASK,
> > +                        SUN50I_H6_I2S_TX_CHAN_SEL(channels));
> > +     regmap_update_bits(i2s->regmap, SUN50I_H6_I2S_RX_CHAN_SEL_REG,
> > +                        SUN50I_H6_I2S_TX_CHAN_SEL_MASK,
> > +                        SUN50I_H6_I2S_TX_CHAN_SEL(channels));
> > +
> > +     regmap_update_bits(i2s->regmap, SUN8I_I2S_CHAN_CFG_REG,
> > +                        SUN8I_I2S_CHAN_CFG_TX_SLOT_NUM_MASK,
> > +                        SUN8I_I2S_CHAN_CFG_TX_SLOT_NUM(channels));
> > +     regmap_update_bits(i2s->regmap, SUN8I_I2S_CHAN_CFG_REG,
> > +                        SUN8I_I2S_CHAN_CFG_RX_SLOT_NUM_MASK,
> > +                        SUN8I_I2S_CHAN_CFG_RX_SLOT_NUM(channels));
> > +
> > +     switch (i2s->format & SND_SOC_DAIFMT_FORMAT_MASK) {
> > +     case SND_SOC_DAIFMT_DSP_A:
> > +     case SND_SOC_DAIFMT_DSP_B:
> > +     case SND_SOC_DAIFMT_LEFT_J:
> > +     case SND_SOC_DAIFMT_RIGHT_J:
>
> According to the manual, LEFT_J and RIGHT_J should use the same calculation as
> I2S, not the one for PCM/DSP.
>
> > +             lrck_period = params_physical_width(params) * slots;
> > +             break;
> > +
> > +     case SND_SOC_DAIFMT_I2S:
> > +             lrck_period = params_physical_width(params);
> > +             break;
> > +
> > +     default:
> > +             return -EINVAL;
> > +     }
> > +
> > +     if (i2s->slot_width)
> > +             lrck_period = i2s->slot_width;
> > +
> > +     regmap_update_bits(i2s->regmap, SUN4I_I2S_FMT0_REG,
> > +                        SUN8I_I2S_FMT0_LRCK_PERIOD_MASK,
> > +                        SUN8I_I2S_FMT0_LRCK_PERIOD(lrck_period));
>
> From the description in the manual, this looks off by one. The number of BCLKs
> per LRCK is LRCK_PERIOD + 1.
>
> > +
> > +     regmap_update_bits(i2s->regmap, SUN8I_I2S_TX_CHAN_SEL_REG,
> > +                        SUN50I_H6_I2S_TX_CHAN_EN_MASK,
> > +                        SUN50I_H6_I2S_TX_CHAN_EN(channels));
> > +
> > +     return 0;
> > +}
> > +
> >  static int sun4i_i2s_hw_params(struct snd_pcm_substream *substream,
> >                              struct snd_pcm_hw_params *params,
> >                              struct snd_soc_dai *dai)
> > @@ -691,6 +765,108 @@ static int sun8i_i2s_set_soc_fmt(const struct sun4i_i2s *i2s,
> >       return 0;
> >  }
> >
> > +static int sun50i_i2s_set_soc_fmt(const struct sun4i_i2s *i2s,
> > +                               unsigned int fmt)
> > +{
> > +     u32 mode, val;
> > +     u8 offset;
> > +
> > +     /*
> > +      * DAI clock polarity
> > +      *
> > +      * The setup for LRCK contradicts the datasheet, but under a
> > +      * scope it's clear that the LRCK polarity is reversed
> > +      * compared to the expected polarity on the bus.
> > +      */
>
> This comment makes us sound a lot more confident than I think we actually are.

That's a comment that needs to be checked using a Logic analyzer (that
I don't have).
It's a copy paste from the previous generation.
But this seems wrong as we need to specify
"simple-audio-card,frame-inversion;" in the device-tree.

Regards,
Clement

>
> Regards,
> Samuel