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pxa2xx-i2s.c

/*
 * pxa2xx-i2s.c  --  ALSA Soc Audio Layer
 *
 * Copyright 2005 Wolfson Microelectronics PLC.
 * Author: Liam Girdwood
 *         lrg@slimlogic.co.uk
 *
 *  This program is free software; you can redistribute  it and/or modify it
 *  under  the terms of  the GNU General  Public License as published by the
 *  Free Software Foundation;  either version 2 of the  License, or (at your
 *  option) any later version.
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/delay.h>
#include <linux/clk.h>
#include <linux/platform_device.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/initval.h>
#include <sound/soc.h>
#include <sound/pxa2xx-lib.h>

#include <mach/hardware.h>
#include <mach/dma.h>
#include <mach/audio.h>

#include "pxa2xx-pcm.h"
#include "pxa2xx-i2s.h"

/*
 * I2S Controller Register and Bit Definitions
 */
#define SACR0           __REG(0x40400000)  /* Global Control Register */
#define SACR1           __REG(0x40400004)  /* Serial Audio I 2 S/MSB-Justified Control Register */
#define SASR0           __REG(0x4040000C)  /* Serial Audio I 2 S/MSB-Justified Interface and FIFO Status Register */
#define SAIMR           __REG(0x40400014)  /* Serial Audio Interrupt Mask Register */
#define SAICR           __REG(0x40400018)  /* Serial Audio Interrupt Clear Register */
#define SADIV           __REG(0x40400060)  /* Audio Clock Divider Register. */
#define SADR            __REG(0x40400080)  /* Serial Audio Data Register (TX and RX FIFO access Register). */

#define SACR0_RFTH(x)   ((x) << 12) /* Rx FIFO Interrupt or DMA Trigger Threshold */
#define SACR0_TFTH(x)   ((x) << 8)  /* Tx FIFO Interrupt or DMA Trigger Threshold */
#define SACR0_STRF      (1 << 5)    /* FIFO Select for EFWR Special Function */
#define SACR0_EFWR      (1 << 4)    /* Enable EFWR Function  */
#define SACR0_RST (1 << 3)    /* FIFO, i2s Register Reset */
#define SACR0_BCKD      (1 << 2)    /* Bit Clock Direction */
#define SACR0_ENB (1 << 0)    /* Enable I2S Link */
#define SACR1_ENLBF     (1 << 5)    /* Enable Loopback */
#define SACR1_DRPL      (1 << 4)    /* Disable Replaying Function */
#define SACR1_DREC      (1 << 3)    /* Disable Recording Function */
#define SACR1_AMSL      (1 << 0)    /* Specify Alternate Mode */

#define SASR0_I2SOFF    (1 << 7)    /* Controller Status */
#define SASR0_ROR (1 << 6)    /* Rx FIFO Overrun */
#define SASR0_TUR (1 << 5)    /* Tx FIFO Underrun */
#define SASR0_RFS (1 << 4)    /* Rx FIFO Service Request */
#define SASR0_TFS (1 << 3)    /* Tx FIFO Service Request */
#define SASR0_BSY (1 << 2)    /* I2S Busy */
#define SASR0_RNE (1 << 1)    /* Rx FIFO Not Empty */
#define SASR0_TNF (1 << 0)    /* Tx FIFO Not Empty */

#define SAICR_ROR (1 << 6)    /* Clear Rx FIFO Overrun Interrupt */
#define SAICR_TUR (1 << 5)    /* Clear Tx FIFO Underrun Interrupt */

#define SAIMR_ROR (1 << 6)    /* Enable Rx FIFO Overrun Condition Interrupt */
#define SAIMR_TUR (1 << 5)    /* Enable Tx FIFO Underrun Condition Interrupt */
#define SAIMR_RFS (1 << 4)    /* Enable Rx FIFO Service Interrupt */
#define SAIMR_TFS (1 << 3)    /* Enable Tx FIFO Service Interrupt */

struct pxa_i2s_port {
      u32 sadiv;
      u32 sacr0;
      u32 sacr1;
      u32 saimr;
      int master;
      u32 fmt;
};
static struct pxa_i2s_port pxa_i2s;
static struct clk *clk_i2s;

static struct pxa2xx_pcm_dma_params pxa2xx_i2s_pcm_stereo_out = {
      .name             = "I2S PCM Stereo out",
      .dev_addr         = __PREG(SADR),
      .drcmr                  = &DRCMR(3),
      .dcmd             = DCMD_INCSRCADDR | DCMD_FLOWTRG |
                          DCMD_BURST32 | DCMD_WIDTH4,
};

static struct pxa2xx_pcm_dma_params pxa2xx_i2s_pcm_stereo_in = {
      .name             = "I2S PCM Stereo in",
      .dev_addr         = __PREG(SADR),
      .drcmr                  = &DRCMR(2),
      .dcmd             = DCMD_INCTRGADDR | DCMD_FLOWSRC |
                          DCMD_BURST32 | DCMD_WIDTH4,
};

static int pxa2xx_i2s_startup(struct snd_pcm_substream *substream,
                        struct snd_soc_dai *dai)
{
      struct snd_soc_pcm_runtime *rtd = substream->private_data;
      struct snd_soc_dai *cpu_dai = rtd->dai->cpu_dai;

      if (IS_ERR(clk_i2s))
            return PTR_ERR(clk_i2s);

      if (!cpu_dai->active)
            SACR0 = 0;

      return 0;
}

/* wait for I2S controller to be ready */
static int pxa_i2s_wait(void)
{
      int i;

      /* flush the Rx FIFO */
      for(i = 0; i < 16; i++)
            SADR;
      return 0;
}

static int pxa2xx_i2s_set_dai_fmt(struct snd_soc_dai *cpu_dai,
            unsigned int fmt)
{
      /* interface format */
      switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
      case SND_SOC_DAIFMT_I2S:
            pxa_i2s.fmt = 0;
            break;
      case SND_SOC_DAIFMT_LEFT_J:
            pxa_i2s.fmt = SACR1_AMSL;
            break;
      }

      switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
      case SND_SOC_DAIFMT_CBS_CFS:
            pxa_i2s.master = 1;
            break;
      case SND_SOC_DAIFMT_CBM_CFS:
            pxa_i2s.master = 0;
            break;
      default:
            break;
      }
      return 0;
}

static int pxa2xx_i2s_set_dai_sysclk(struct snd_soc_dai *cpu_dai,
            int clk_id, unsigned int freq, int dir)
{
      if (clk_id != PXA2XX_I2S_SYSCLK)
            return -ENODEV;

      return 0;
}

static int pxa2xx_i2s_hw_params(struct snd_pcm_substream *substream,
                        struct snd_pcm_hw_params *params,
                        struct snd_soc_dai *dai)
{
      struct snd_soc_pcm_runtime *rtd = substream->private_data;
      struct snd_soc_dai *cpu_dai = rtd->dai->cpu_dai;

      BUG_ON(IS_ERR(clk_i2s));
      clk_enable(clk_i2s);
      dai->private_data = dai;
      pxa_i2s_wait();

      if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
            cpu_dai->dma_data = &pxa2xx_i2s_pcm_stereo_out;
      else
            cpu_dai->dma_data = &pxa2xx_i2s_pcm_stereo_in;

      /* is port used by another stream */
      if (!(SACR0 & SACR0_ENB)) {
            SACR0 = 0;
            if (pxa_i2s.master)
                  SACR0 |= SACR0_BCKD;

            SACR0 |= SACR0_RFTH(14) | SACR0_TFTH(1);
            SACR1 |= pxa_i2s.fmt;
      }
      if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
            SAIMR |= SAIMR_TFS;
      else
            SAIMR |= SAIMR_RFS;

      switch (params_rate(params)) {
      case 8000:
            SADIV = 0x48;
            break;
      case 11025:
            SADIV = 0x34;
            break;
      case 16000:
            SADIV = 0x24;
            break;
      case 22050:
            SADIV = 0x1a;
            break;
      case 44100:
            SADIV = 0xd;
            break;
      case 48000:
            SADIV = 0xc;
            break;
      case 96000: /* not in manual and possibly slightly inaccurate */
            SADIV = 0x6;
            break;
      }

      return 0;
}

static int pxa2xx_i2s_trigger(struct snd_pcm_substream *substream, int cmd,
                        struct snd_soc_dai *dai)
{
      int ret = 0;

      switch (cmd) {
      case SNDRV_PCM_TRIGGER_START:
            if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
                  SACR1 &= ~SACR1_DRPL;
            else
                  SACR1 &= ~SACR1_DREC;
            SACR0 |= SACR0_ENB;
            break;
      case SNDRV_PCM_TRIGGER_RESUME:
      case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
      case SNDRV_PCM_TRIGGER_STOP:
      case SNDRV_PCM_TRIGGER_SUSPEND:
      case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
            break;
      default:
            ret = -EINVAL;
      }

      return ret;
}

static void pxa2xx_i2s_shutdown(struct snd_pcm_substream *substream,
                        struct snd_soc_dai *dai)
{
      if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
            SACR1 |= SACR1_DRPL;
            SAIMR &= ~SAIMR_TFS;
      } else {
            SACR1 |= SACR1_DREC;
            SAIMR &= ~SAIMR_RFS;
      }

      if ((SACR1 & (SACR1_DREC | SACR1_DRPL)) == (SACR1_DREC | SACR1_DRPL)) {
            SACR0 &= ~SACR0_ENB;
            pxa_i2s_wait();
            if (dai->private_data != NULL) {
                  clk_disable(clk_i2s);
                  dai->private_data = NULL;
            }
      }
}

#ifdef CONFIG_PM
static int pxa2xx_i2s_suspend(struct snd_soc_dai *dai)
{
      /* store registers */
      pxa_i2s.sacr0 = SACR0;
      pxa_i2s.sacr1 = SACR1;
      pxa_i2s.saimr = SAIMR;
      pxa_i2s.sadiv = SADIV;

      /* deactivate link */
      SACR0 &= ~SACR0_ENB;
      pxa_i2s_wait();
      return 0;
}

static int pxa2xx_i2s_resume(struct snd_soc_dai *dai)
{
      pxa_i2s_wait();

      SACR0 = pxa_i2s.sacr0 & ~SACR0_ENB;
      SACR1 = pxa_i2s.sacr1;
      SAIMR = pxa_i2s.saimr;
      SADIV = pxa_i2s.sadiv;

      SACR0 = pxa_i2s.sacr0;

      return 0;
}

#else
#define pxa2xx_i2s_suspend    NULL
#define pxa2xx_i2s_resume     NULL
#endif

#define PXA2XX_I2S_RATES (SNDRV_PCM_RATE_8000 | SNDRV_PCM_RATE_11025 |\
            SNDRV_PCM_RATE_16000 | SNDRV_PCM_RATE_22050 | SNDRV_PCM_RATE_44100 | \
            SNDRV_PCM_RATE_48000 | SNDRV_PCM_RATE_96000)

static struct snd_soc_dai_ops pxa_i2s_dai_ops = {
      .startup    = pxa2xx_i2s_startup,
      .shutdown   = pxa2xx_i2s_shutdown,
      .trigger    = pxa2xx_i2s_trigger,
      .hw_params  = pxa2xx_i2s_hw_params,
      .set_fmt    = pxa2xx_i2s_set_dai_fmt,
      .set_sysclk = pxa2xx_i2s_set_dai_sysclk,
};

struct snd_soc_dai pxa_i2s_dai = {
      .name = "pxa2xx-i2s",
      .id = 0,
      .suspend = pxa2xx_i2s_suspend,
      .resume = pxa2xx_i2s_resume,
      .playback = {
            .channels_min = 2,
            .channels_max = 2,
            .rates = PXA2XX_I2S_RATES,
            .formats = SNDRV_PCM_FMTBIT_S16_LE,},
      .capture = {
            .channels_min = 2,
            .channels_max = 2,
            .rates = PXA2XX_I2S_RATES,
            .formats = SNDRV_PCM_FMTBIT_S16_LE,},
      .ops = &pxa_i2s_dai_ops,
      .symmetric_rates = 1,
};

EXPORT_SYMBOL_GPL(pxa_i2s_dai);

static int pxa2xx_i2s_probe(struct platform_device *dev)
{
      int ret;

      clk_i2s = clk_get(&dev->dev, "I2SCLK");
      if (IS_ERR(clk_i2s))
            return PTR_ERR(clk_i2s);

      pxa_i2s_dai.dev = &dev->dev;
      pxa_i2s_dai.private_data = NULL;
      ret = snd_soc_register_dai(&pxa_i2s_dai);
      if (ret != 0)
            clk_put(clk_i2s);

      /*
       * PXA Developer's Manual:
       * If SACR0[ENB] is toggled in the middle of a normal operation,
       * the SACR0[RST] bit must also be set and cleared to reset all
       * I2S controller registers.
       */
      SACR0 = SACR0_RST;
      SACR0 = 0;
      /* Make sure RPL and REC are disabled */
      SACR1 = SACR1_DRPL | SACR1_DREC;
      /* Along with FIFO servicing */
      SAIMR &= ~(SAIMR_RFS | SAIMR_TFS);

      return ret;
}

static int __devexit pxa2xx_i2s_remove(struct platform_device *dev)
{
      snd_soc_unregister_dai(&pxa_i2s_dai);
      clk_put(clk_i2s);
      clk_i2s = ERR_PTR(-ENOENT);
      return 0;
}

static struct platform_driver pxa2xx_i2s_driver = {
      .probe = pxa2xx_i2s_probe,
      .remove = __devexit_p(pxa2xx_i2s_remove),

      .driver = {
            .name = "pxa2xx-i2s",
            .owner = THIS_MODULE,
      },
};

static int __init pxa2xx_i2s_init(void)
{
      clk_i2s = ERR_PTR(-ENOENT);
      return platform_driver_register(&pxa2xx_i2s_driver);
}

static void __exit pxa2xx_i2s_exit(void)
{
      platform_driver_unregister(&pxa2xx_i2s_driver);
}

module_init(pxa2xx_i2s_init);
module_exit(pxa2xx_i2s_exit);

/* Module information */
MODULE_AUTHOR("Liam Girdwood, lrg@slimlogic.co.uk");
MODULE_DESCRIPTION("pxa2xx I2S SoC Interface");
MODULE_LICENSE("GPL");

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