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ep93xx-i2s.c

/*
 * linux/sound/soc/ep93xx-i2s.c
 * EP93xx I2S driver
 *
 * Copyright (C) 2010 Ryan Mallon <ryan@bluewatersys.com>
 *
 * Based on the original driver by:
 *   Copyright (C) 2007 Chase Douglas <chasedouglas@gmail>
 *   Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/clk.h>
#include <linux/io.h>

#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/initval.h>
#include <sound/soc.h>

#include <mach/hardware.h>
#include <mach/ep93xx-regs.h>
#include <mach/dma.h>

#include "ep93xx-pcm.h"

#define EP93XX_I2S_TXCLKCFG         0x00
#define EP93XX_I2S_RXCLKCFG         0x04
#define EP93XX_I2S_GLCTRL           0x0C

#define EP93XX_I2S_TXLINCTRLDATA    0x28
#define EP93XX_I2S_TXCTRL           0x2C
#define EP93XX_I2S_TXWRDLEN         0x30
#define EP93XX_I2S_TX0EN            0x34

#define EP93XX_I2S_RXLINCTRLDATA    0x58
#define EP93XX_I2S_RXCTRL           0x5C
#define EP93XX_I2S_RXWRDLEN         0x60
#define EP93XX_I2S_RX0EN            0x64

#define EP93XX_I2S_WRDLEN_16        (0 << 0)
#define EP93XX_I2S_WRDLEN_24        (1 << 0)
#define EP93XX_I2S_WRDLEN_32        (2 << 0)

#define EP93XX_I2S_LINCTRLDATA_R_JUST     (1 << 2) /* Right justify */

#define EP93XX_I2S_CLKCFG_LRS       (1 << 0) /* lrclk polarity */
#define EP93XX_I2S_CLKCFG_CKP       (1 << 1) /* Bit clock polarity */
#define EP93XX_I2S_CLKCFG_REL       (1 << 2) /* First bit transition */
#define EP93XX_I2S_CLKCFG_MASTER    (1 << 3) /* Master mode */
#define EP93XX_I2S_CLKCFG_NBCG            (1 << 4) /* Not bit clock gating */

00061 struct ep93xx_i2s_info {
      struct clk              *mclk;
      struct clk              *sclk;
      struct clk              *lrclk;
      struct ep93xx_pcm_dma_params  *dma_params;
      struct resource               *mem;
      void __iomem                  *regs;
};

struct ep93xx_pcm_dma_params ep93xx_i2s_dma_params[] = {
      [SNDRV_PCM_STREAM_PLAYBACK] = {
            .name       = "i2s-pcm-out",
            .dma_port   = EP93XX_DMA_M2P_PORT_I2S1,
      },
      [SNDRV_PCM_STREAM_CAPTURE] = {
            .name       = "i2s-pcm-in",
            .dma_port   = EP93XX_DMA_M2P_PORT_I2S1,
      },
};

static inline void ep93xx_i2s_write_reg(struct ep93xx_i2s_info *info,
                              unsigned reg, unsigned val)
{
      __raw_writel(val, info->regs + reg);
}

static inline unsigned ep93xx_i2s_read_reg(struct ep93xx_i2s_info *info,
                                 unsigned reg)
{
      return __raw_readl(info->regs + reg);
}

static void ep93xx_i2s_enable(struct ep93xx_i2s_info *info, int stream)
{
      unsigned base_reg;
      int i;

      if ((ep93xx_i2s_read_reg(info, EP93XX_I2S_TX0EN) & 0x1) == 0 &&
          (ep93xx_i2s_read_reg(info, EP93XX_I2S_RX0EN) & 0x1) == 0) {
            /* Enable clocks */
            clk_enable(info->mclk);
            clk_enable(info->sclk);
            clk_enable(info->lrclk);

            /* Enable i2s */
            ep93xx_i2s_write_reg(info, EP93XX_I2S_GLCTRL, 1);
      }

      /* Enable fifos */
      if (stream == SNDRV_PCM_STREAM_PLAYBACK)
            base_reg = EP93XX_I2S_TX0EN;
      else
            base_reg = EP93XX_I2S_RX0EN;
      for (i = 0; i < 3; i++)
            ep93xx_i2s_write_reg(info, base_reg + (i * 4), 1);
}

static void ep93xx_i2s_disable(struct ep93xx_i2s_info *info, int stream)
{
      unsigned base_reg;
      int i;

      /* Disable fifos */
      if (stream == SNDRV_PCM_STREAM_PLAYBACK)
            base_reg = EP93XX_I2S_TX0EN;
      else
            base_reg = EP93XX_I2S_RX0EN;
      for (i = 0; i < 3; i++)
            ep93xx_i2s_write_reg(info, base_reg + (i * 4), 0);

      if ((ep93xx_i2s_read_reg(info, EP93XX_I2S_TX0EN) & 0x1) == 0 &&
          (ep93xx_i2s_read_reg(info, EP93XX_I2S_RX0EN) & 0x1) == 0) {
            /* Disable i2s */
            ep93xx_i2s_write_reg(info, EP93XX_I2S_GLCTRL, 0);

            /* Disable clocks */
            clk_disable(info->lrclk);
            clk_disable(info->sclk);
            clk_disable(info->mclk);
      }
}

static int ep93xx_i2s_startup(struct snd_pcm_substream *substream,
                        struct snd_soc_dai *dai)
{
      struct snd_soc_pcm_runtime *rtd = substream->private_data;
      struct ep93xx_i2s_info *info = snd_soc_dai_get_drvdata(dai);
      struct snd_soc_dai *cpu_dai = rtd->cpu_dai;

      snd_soc_dai_set_dma_data(cpu_dai, substream,
                         &info->dma_params[substream->stream]);
      return 0;
}

static void ep93xx_i2s_shutdown(struct snd_pcm_substream *substream,
                        struct snd_soc_dai *dai)
{
      struct ep93xx_i2s_info *info = snd_soc_dai_get_drvdata(dai);

      ep93xx_i2s_disable(info, substream->stream);
}

static int ep93xx_i2s_set_dai_fmt(struct snd_soc_dai *cpu_dai,
                          unsigned int fmt)
{
      struct ep93xx_i2s_info *info = snd_soc_dai_get_drvdata(cpu_dai);
      unsigned int clk_cfg, lin_ctrl;

      clk_cfg  = ep93xx_i2s_read_reg(info, EP93XX_I2S_RXCLKCFG);
      lin_ctrl = ep93xx_i2s_read_reg(info, EP93XX_I2S_RXLINCTRLDATA);

      switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
      case SND_SOC_DAIFMT_I2S:
            clk_cfg |= EP93XX_I2S_CLKCFG_REL;
            lin_ctrl &= ~EP93XX_I2S_LINCTRLDATA_R_JUST;
            break;

      case SND_SOC_DAIFMT_LEFT_J:
            clk_cfg &= ~EP93XX_I2S_CLKCFG_REL;
            lin_ctrl &= ~EP93XX_I2S_LINCTRLDATA_R_JUST;
            break;

      case SND_SOC_DAIFMT_RIGHT_J:
            clk_cfg &= ~EP93XX_I2S_CLKCFG_REL;
            lin_ctrl |= EP93XX_I2S_LINCTRLDATA_R_JUST;
            break;

      default:
            return -EINVAL;
      }

      switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
      case SND_SOC_DAIFMT_CBS_CFS:
            /* CPU is master */
            clk_cfg |= EP93XX_I2S_CLKCFG_MASTER;
            break;

      case SND_SOC_DAIFMT_CBM_CFM:
            /* Codec is master */
            clk_cfg &= ~EP93XX_I2S_CLKCFG_MASTER;
            break;

      default:
            return -EINVAL;
      }

      switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
      case SND_SOC_DAIFMT_NB_NF:
            /* Negative bit clock, lrclk low on left word */
            clk_cfg &= ~(EP93XX_I2S_CLKCFG_CKP | EP93XX_I2S_CLKCFG_REL);
            break;

      case SND_SOC_DAIFMT_NB_IF:
            /* Negative bit clock, lrclk low on right word */
            clk_cfg &= ~EP93XX_I2S_CLKCFG_CKP;
            clk_cfg |= EP93XX_I2S_CLKCFG_REL;
            break;

      case SND_SOC_DAIFMT_IB_NF:
            /* Positive bit clock, lrclk low on left word */
            clk_cfg |= EP93XX_I2S_CLKCFG_CKP;
            clk_cfg &= ~EP93XX_I2S_CLKCFG_REL;
            break;

      case SND_SOC_DAIFMT_IB_IF:
            /* Positive bit clock, lrclk low on right word */
            clk_cfg |= EP93XX_I2S_CLKCFG_CKP | EP93XX_I2S_CLKCFG_REL;
            break;
      }

      /* Write new register values */
      ep93xx_i2s_write_reg(info, EP93XX_I2S_RXCLKCFG, clk_cfg);
      ep93xx_i2s_write_reg(info, EP93XX_I2S_TXCLKCFG, clk_cfg);
      ep93xx_i2s_write_reg(info, EP93XX_I2S_RXLINCTRLDATA, lin_ctrl);
      ep93xx_i2s_write_reg(info, EP93XX_I2S_TXLINCTRLDATA, lin_ctrl);
      return 0;
}

static int ep93xx_i2s_hw_params(struct snd_pcm_substream *substream,
                        struct snd_pcm_hw_params *params,
                        struct snd_soc_dai *dai)
{
      struct ep93xx_i2s_info *info = snd_soc_dai_get_drvdata(dai);
      unsigned word_len, div, sdiv, lrdiv;
      int found = 0, err;

      switch (params_format(params)) {
      case SNDRV_PCM_FORMAT_S16_LE:
            word_len = EP93XX_I2S_WRDLEN_16;
            break;

      case SNDRV_PCM_FORMAT_S24_LE:
            word_len = EP93XX_I2S_WRDLEN_24;
            break;

      case SNDRV_PCM_FORMAT_S32_LE:
            word_len = EP93XX_I2S_WRDLEN_32;
            break;

      default:
            return -EINVAL;
      }

      if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
            ep93xx_i2s_write_reg(info, EP93XX_I2S_TXWRDLEN, word_len);
      else
            ep93xx_i2s_write_reg(info, EP93XX_I2S_RXWRDLEN, word_len);

      /*
       * EP93xx I2S module can be setup so SCLK / LRCLK value can be
       * 32, 64, 128. MCLK / SCLK value can be 2 and 4.
       * We set LRCLK equal to `rate' and minimum SCLK / LRCLK 
       * value is 64, because our sample size is 32 bit * 2 channels.
       * I2S standard permits us to transmit more bits than
       * the codec uses.
       */
      div = clk_get_rate(info->mclk) / params_rate(params);
      for (sdiv = 2; sdiv <= 4; sdiv += 2)
            for (lrdiv = 64; lrdiv <= 128; lrdiv <<= 1)
                  if (sdiv * lrdiv == div) {
                        found = 1;
                        goto out;
                  }
out:
      if (!found)
            return -EINVAL;

      err = clk_set_rate(info->sclk, clk_get_rate(info->mclk) / sdiv);
      if (err)
            return err;

      err = clk_set_rate(info->lrclk, clk_get_rate(info->sclk) / lrdiv);
      if (err)
            return err;

      ep93xx_i2s_enable(info, substream->stream);
      return 0;
}

static int ep93xx_i2s_set_sysclk(struct snd_soc_dai *cpu_dai, int clk_id,
                         unsigned int freq, int dir)
{
      struct ep93xx_i2s_info *info = snd_soc_dai_get_drvdata(cpu_dai);

      if (dir == SND_SOC_CLOCK_IN || clk_id != 0)
            return -EINVAL;

      return clk_set_rate(info->mclk, freq);
}

#ifdef CONFIG_PM
static int ep93xx_i2s_suspend(struct snd_soc_dai *dai)
{
      struct ep93xx_i2s_info *info = snd_soc_dai_get_drvdata(dai);

      if (!dai->active)
            return;

      ep93xx_i2s_disable(info, SNDRV_PCM_STREAM_PLAYBACK);
      ep93xx_i2s_disable(info, SNDRV_PCM_STREAM_CAPTURE);
}

static int ep93xx_i2s_resume(struct snd_soc_dai *dai)
{
      struct ep93xx_i2s_info *info = snd_soc_dai_get_drvdata(dai);

      if (!dai->active)
            return;

      ep93xx_i2s_enable(info, SNDRV_PCM_STREAM_PLAYBACK);
      ep93xx_i2s_enable(info, SNDRV_PCM_STREAM_CAPTURE);
}
#else
#define ep93xx_i2s_suspend    NULL
#define ep93xx_i2s_resume     NULL
#endif

static struct snd_soc_dai_ops ep93xx_i2s_dai_ops = {
      .startup    = ep93xx_i2s_startup,
      .shutdown   = ep93xx_i2s_shutdown,
      .hw_params  = ep93xx_i2s_hw_params,
      .set_sysclk = ep93xx_i2s_set_sysclk,
      .set_fmt    = ep93xx_i2s_set_dai_fmt,
};

#define EP93XX_I2S_FORMATS (SNDRV_PCM_FMTBIT_S32_LE)

static struct snd_soc_dai_driver ep93xx_i2s_dai = {
      .symmetric_rates= 1,
      .suspend    = ep93xx_i2s_suspend,
      .resume           = ep93xx_i2s_resume,
      .playback   = {
            .channels_min     = 2,
            .channels_max     = 2,
            .rates            = SNDRV_PCM_RATE_8000_96000,
            .formats    = EP93XX_I2S_FORMATS,
      },
      .capture    = {
             .channels_min    = 2,
             .channels_max    = 2,
             .rates           = SNDRV_PCM_RATE_8000_96000,
             .formats   = EP93XX_I2S_FORMATS,
      },
      .ops        = &ep93xx_i2s_dai_ops,
};

static int ep93xx_i2s_probe(struct platform_device *pdev)
{
      struct ep93xx_i2s_info *info;
      struct resource *res;
      int err;

      info = kzalloc(sizeof(struct ep93xx_i2s_info), GFP_KERNEL);
      if (!info) {
            err = -ENOMEM;
            goto fail;
      }

      dev_set_drvdata(&pdev->dev, info);
      info->dma_params = ep93xx_i2s_dma_params;

      res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
      if (!res) {
            err = -ENODEV;
            goto fail;
      }

      info->mem = request_mem_region(res->start, resource_size(res),
                               pdev->name);
      if (!info->mem) {
            err = -EBUSY;
            goto fail;
      }

      info->regs = ioremap(info->mem->start, resource_size(info->mem));
      if (!info->regs) {
            err = -ENXIO;
            goto fail_release_mem;
      }

      info->mclk = clk_get(&pdev->dev, "mclk");
      if (IS_ERR(info->mclk)) {
            err = PTR_ERR(info->mclk);
            goto fail_unmap_mem;
      }

      info->sclk = clk_get(&pdev->dev, "sclk");
      if (IS_ERR(info->sclk)) {
            err = PTR_ERR(info->sclk);
            goto fail_put_mclk;
      }

      info->lrclk = clk_get(&pdev->dev, "lrclk");
      if (IS_ERR(info->lrclk)) {
            err = PTR_ERR(info->lrclk);
            goto fail_put_sclk;
      }

      err = snd_soc_register_dai(&pdev->dev, &ep93xx_i2s_dai);
      if (err)
            goto fail_put_lrclk;

      return 0;

fail_put_lrclk:
      clk_put(info->lrclk);
fail_put_sclk:
      clk_put(info->sclk);
fail_put_mclk:
      clk_put(info->mclk);
fail_unmap_mem:
      iounmap(info->regs);
fail_release_mem:
      release_mem_region(info->mem->start, resource_size(info->mem));
      kfree(info);
fail:
      return err;
}

static int __devexit ep93xx_i2s_remove(struct platform_device *pdev)
{
      struct ep93xx_i2s_info *info = dev_get_drvdata(&pdev->dev);

      snd_soc_unregister_dai(&pdev->dev);
      clk_put(info->lrclk);
      clk_put(info->sclk);
      clk_put(info->mclk);
      iounmap(info->regs);
      release_mem_region(info->mem->start, resource_size(info->mem));
      kfree(info);
      return 0;
}

static struct platform_driver ep93xx_i2s_driver = {
      .probe      = ep93xx_i2s_probe,
      .remove     = __devexit_p(ep93xx_i2s_remove),
      .driver     = {
            .name = "ep93xx-i2s",
            .owner      = THIS_MODULE,
      },
};

static int __init ep93xx_i2s_init(void)
{
      return platform_driver_register(&ep93xx_i2s_driver);
}

static void __exit ep93xx_i2s_exit(void)
{
      platform_driver_unregister(&ep93xx_i2s_driver);
}

module_init(ep93xx_i2s_init);
module_exit(ep93xx_i2s_exit);

MODULE_ALIAS("platform:ep93xx-i2s");
MODULE_AUTHOR("Ryan Mallon <ryan@bluewatersys.com>");
MODULE_DESCRIPTION("EP93XX I2S driver");
MODULE_LICENSE("GPL");

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