Re: [PATCH 1/2] Support internal I2S clock sources on MPC5200

["Jon Smirl" <jonsmirl@gmail.com>]

On 7/26/08, Grant Likely <grant.likely@secretlab.ca> wrote:
> On Tue, Jul 22, 2008 at 07:53:49PM -0400, Jon Smirl wrote:
>
> > Support internal I2S clock sources on MPC5200
>  >
>  > Signed-off-by: Jon Smirl <jonsmirl@gmail.com>
>
>
> I'll play with this when I get home.  In the mean time I've got some
>  comments below.  Overall, it looks right to me.
>
>  g.
>
>
>
>  > ---
>  >
>  >  sound/soc/fsl/mpc5200_psc_i2s.c |   58 ++++++++++++++++++++++++++++++++++-----
>  >  sound/soc/fsl/mpc5200_psc_i2s.h |   13 +++++++++
>  >  2 files changed, 64 insertions(+), 7 deletions(-)
>  >  create mode 100644 sound/soc/fsl/mpc5200_psc_i2s.h
>  >
>  > diff --git a/sound/soc/fsl/mpc5200_psc_i2s.c b/sound/soc/fsl/mpc5200_psc_i2s.c
>  > index 8692329..f028f61 100644
>  > --- a/sound/soc/fsl/mpc5200_psc_i2s.c
>  > +++ b/sound/soc/fsl/mpc5200_psc_i2s.c
>  > @@ -23,8 +23,12 @@
>  >
>  >  #include <sysdev/bestcomm/bestcomm.h>
>  >  #include <sysdev/bestcomm/gen_bd.h>
>  > +#include <asm/time.h>
>  > +#include <asm/mpc52xx.h>
>  >  #include <asm/mpc52xx_psc.h>
>  >
>  > +#include "mpc5200_psc_i2s.h"
>  > +
>  >  MODULE_AUTHOR("Grant Likely <grant.likely@secretlab.ca>");
>  >  MODULE_DESCRIPTION("Freescale MPC5200 PSC in I2S mode ASoC Driver");
>  >  MODULE_LICENSE("GPL");
>  > @@ -93,6 +97,7 @@ struct psc_i2s {
>  >       struct snd_soc_dai dai;
>  >       spinlock_t lock;
>  >       u32 sicr;
>  > +     uint sysclk;
>  >
>  >       /* per-stream data */
>  >       struct psc_i2s_stream playback;
>  > @@ -224,6 +229,7 @@ static int psc_i2s_hw_params(struct snd_pcm_substream *substream,
>  >  {
>  >       struct snd_soc_pcm_runtime *rtd = substream->private_data;
>  >       struct psc_i2s *psc_i2s = rtd->dai->cpu_dai->private_data;
>  > +     uint bits, framesync, bitclk, value;
>  >       u32 mode;
>  >
>  >       dev_dbg(psc_i2s->dev, "%s(substream=%p) p_size=%i p_bytes=%i"
>  > @@ -235,15 +241,19 @@ static int psc_i2s_hw_params(struct snd_pcm_substream *substream,
>  >       switch (params_format(params)) {
>  >       case SNDRV_PCM_FORMAT_S8:
>  >               mode = MPC52xx_PSC_SICR_SIM_CODEC_8;
>  > +             bits = 8;
>  >               break;
>  >       case SNDRV_PCM_FORMAT_S16_BE:
>  >               mode = MPC52xx_PSC_SICR_SIM_CODEC_16;
>  > +             bits = 16;
>  >               break;
>  >       case SNDRV_PCM_FORMAT_S24_BE:
>  >               mode = MPC52xx_PSC_SICR_SIM_CODEC_24;
>  > +             bits = 24;
>  >               break;
>  >       case SNDRV_PCM_FORMAT_S32_BE:
>  >               mode = MPC52xx_PSC_SICR_SIM_CODEC_32;
>  > +             bits = 32;
>  >               break;
>  >       default:
>  >               dev_dbg(psc_i2s->dev, "invalid format\n");
>  > @@ -251,7 +261,24 @@ static int psc_i2s_hw_params(struct snd_pcm_substream *substream,
>  >       }
>  >       out_be32(&psc_i2s->psc_regs->sicr, psc_i2s->sicr | mode);
>  >
>  > -     snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
>  > +     if (psc_i2s->sysclk) {
>  > +             framesync = bits * 2;
>  > +             bitclk = (psc_i2s->sysclk) / (params_rate(params) * framesync);
>  > +
>  > +             /* bitclk field is byte swapped due to mpc5200/b compatibility */
>  > +             value = ((framesync - 1) << 24) |
>  > +                     (((bitclk - 1) & 0xFF) << 16) | ((bitclk - 1) & 0xFF00);
>  > +
>  > +             dev_dbg(psc_i2s->dev, "%s(substream=%p) rate=%i sysclk=%i"
>  > +                     " framesync=%i bitclk=%i reg=%X\n",
>  > +                     __FUNCTION__, substream, params_rate(params), psc_i2s->sysclk,
>  > +                     framesync, bitclk, value);
>  > +
>  > +             out_be32(&psc_i2s->psc_regs->ccr, value);
>  > +             out_8(&psc_i2s->psc_regs->ctur, bits - 1);
>  > +     }
>
>
> This should probably only be executed if the psc is the clock master;
>  just like you've done in psc_i2s_set_sysclk()
>

psc_i2s->sysclk can only get set if there is a clock master. Note that
there are two ways to be a clock master, internal and cellslave.

i2s_set_sysclk() is dynamically called from my fabric driver to adjust
the timebase to match the music.

>
>  > +
>  > +     snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
>  >
>  >       return 0;
>  >  }
>  > @@ -429,9 +456,29 @@ static int psc_i2s_set_sysclk(struct snd_soc_dai *cpu_dai,
>  >                             int clk_id, unsigned int freq, int dir)
>  >  {
>  >       struct psc_i2s *psc_i2s = cpu_dai->private_data;
>  > -     dev_dbg(psc_i2s->dev, "psc_i2s_set_sysclk(cpu_dai=%p, dir=%i)\n",
>  > -                             cpu_dai, dir);
>  > -     return (dir == SND_SOC_CLOCK_IN) ? 0 : -EINVAL;
>  > +     int clkdiv, err;
>  > +     dev_dbg(psc_i2s->dev, "psc_i2s_set_sysclk(cpu_dai=%p, freq=%u, dir=%i)\n",
>  > +                             cpu_dai, freq, dir);
>  > +     if (dir == SND_SOC_CLOCK_OUT) {
>  > +             psc_i2s->sysclk = freq;
>  > +             if (clk_id == MPC52xx_CLK_CELLSLAVE) {
>  > +                     psc_i2s->sicr |= MPC52xx_PSC_SICR_CELLSLAVE | MPC52xx_PSC_SICR_GENCLK;
>  > +             } else { /* MPC52xx_CLK_INTERNAL */
>  > +                     psc_i2s->sicr &= ~MPC52xx_PSC_SICR_CELLSLAVE;
>  > +                     psc_i2s->sicr |= MPC52xx_PSC_SICR_GENCLK;
>  > +
>  > +                     clkdiv = ppc_proc_freq / freq;
>  > +                     err = ppc_proc_freq % freq;
>  > +                     if (err > freq / 2)
>  > +                             clkdiv++;
>  > +
>  > +                     dev_dbg(psc_i2s->dev, "psc_i2s_set_sysclk(clkdiv %d freq error=%ldHz)\n",
>  > +                                     clkdiv, (ppc_proc_freq / clkdiv - freq));
>  > +
>  > +                     return mpc52xx_set_psc_clkdiv(psc_i2s->dai.id + 1, clkdiv);
>  > +             }
>  > +     }
>  > +     return 0;
>  >  }
>  >
>  >  /**
>  > @@ -784,9 +831,6 @@ static int __devinit psc_i2s_of_probe(struct of_device *op,
>  >       /* Configure the serial interface mode; defaulting to CODEC8 mode */
>  >       psc_i2s->sicr = MPC52xx_PSC_SICR_DTS1 | MPC52xx_PSC_SICR_I2S |
>  >                       MPC52xx_PSC_SICR_CLKPOL;
>  > -     if (of_get_property(op->node, "fsl,cellslave", NULL))
>  > -             psc_i2s->sicr |= MPC52xx_PSC_SICR_CELLSLAVE |
>  > -                              MPC52xx_PSC_SICR_GENCLK;
>  >       out_be32(&psc_i2s->psc_regs->sicr,
>  >                psc_i2s->sicr | MPC52xx_PSC_SICR_SIM_CODEC_8);
>  >
>  > diff --git a/sound/soc/fsl/mpc5200_psc_i2s.h b/sound/soc/fsl/mpc5200_psc_i2s.h
>  > new file mode 100644
>  > index 0000000..0e0a84e
>  > --- /dev/null
>  > +++ b/sound/soc/fsl/mpc5200_psc_i2s.h
>  > @@ -0,0 +1,13 @@
>  > +/*
>  > + * Freescale MPC5200 PSC in I2S mode
>  > + * ALSA SoC Digital Audio Interface (DAI) driver
>  > + *
>  > + */
>  > +
>  > +#ifndef __SOUND_SOC_FSL_MPC52xx_PSC_I2S_H__
>  > +#define __SOUND_SOC_FSL_MPC52xx_PSC_I2S_H__
>  > +
>  > +#define MPC52xx_CLK_INTERNAL 0
>  > +#define MPC52xx_CLK_CELLSLAVE 1
>  > +
>  > +#endif /* __SOUND_SOC_FSL_MPC52xx_PSC_I2S_H__ */
>  >
>
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>


-- 
Jon Smirl
jonsmirl@gmail.com