text: /*
   * Freescale MPC5200 PSC in I2S mode
   * ALSA SoC Digital Audio Interface (DAI) driver
   *
   * Copyright (C) 2008 Secret Lab Technologies Ltd.
   * Copyright (C) 2009 Jon Smirl, Digispeaker
   */
  
  #include <linux/module.h>
  #include <linux/of_device.h>
  #include <linux/of_platform.h>
  
  #include <sound/pcm.h>
  #include <sound/pcm_params.h>
  #include <sound/soc.h>
  
  #include <asm/mpc52xx_psc.h>
  
  #include "mpc5200_dma.h"
  
  /**
   * PSC_I2S_RATES: sample rates supported by the I2S
   *
   * This driver currently only supports the PSC running in I2S slave mode,
   * which means the codec determines the sample rate.  Therefore, we tell
   * ALSA that we support all rates and let the codec driver decide what rates
   * are really supported.
   */
  #define PSC_I2S_RATES SNDRV_PCM_RATE_CONTINUOUS
  
  /**
   * PSC_I2S_FORMATS: audio formats supported by the PSC I2S mode
   */
  #define PSC_I2S_FORMATS (SNDRV_PCM_FMTBIT_S8 | SNDRV_PCM_FMTBIT_S16_BE | \
  			 SNDRV_PCM_FMTBIT_S24_BE | SNDRV_PCM_FMTBIT_S32_BE)
  
  static int psc_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 psc_dma *psc_dma = snd_soc_dai_get_drvdata(rtd->cpu_dai);
  	u32 mode;
  
  	dev_dbg(psc_dma->dev, "%s(substream=%p) p_size=%i p_bytes=%i"
  		" periods=%i buffer_size=%i  buffer_bytes=%i\n",
  		__func__, substream, params_period_size(params),
  		params_period_bytes(params), params_periods(params),
  		params_buffer_size(params), params_buffer_bytes(params));
  
  	switch (params_format(params)) {
  	case SNDRV_PCM_FORMAT_S8:
  		mode = MPC52xx_PSC_SICR_SIM_CODEC_8;
  		break;
  	case SNDRV_PCM_FORMAT_S16_BE:
  		mode = MPC52xx_PSC_SICR_SIM_CODEC_16;
  		break;
  	case SNDRV_PCM_FORMAT_S24_BE:
  		mode = MPC52xx_PSC_SICR_SIM_CODEC_24;
  		break;
  	case SNDRV_PCM_FORMAT_S32_BE:
  		mode = MPC52xx_PSC_SICR_SIM_CODEC_32;
  		break;
  	default:
  		dev_dbg(psc_dma->dev, "invalid format\n");
  		return -EINVAL;
  	}
  	out_be32(&psc_dma->psc_regs->sicr, psc_dma->sicr | mode);
  
  	return 0;
  }
  
  /**
   * psc_i2s_set_sysclk: set the clock frequency and direction
   *
   * This function is called by the machine driver to tell us what the clock
   * frequency and direction are.
   *
   * Currently, we only support operating as a clock slave (SND_SOC_CLOCK_IN),
   * and we don't care about the frequency.  Return an error if the direction
   * is not SND_SOC_CLOCK_IN.
   *
   * @clk_id: reserved, should be zero
   * @freq: the frequency of the given clock ID, currently ignored
   * @dir: SND_SOC_CLOCK_IN (clock slave) or SND_SOC_CLOCK_OUT (clock master)
   */
  static int psc_i2s_set_sysclk(struct snd_soc_dai *cpu_dai,
  			      int clk_id, unsigned int freq, int dir)
  {
  	struct psc_dma *psc_dma = snd_soc_dai_get_drvdata(cpu_dai);
  	dev_dbg(psc_dma->dev, "psc_i2s_set_sysclk(cpu_dai=%p, dir=%i)\n",
  				cpu_dai, dir);
  	return (dir == SND_SOC_CLOCK_IN) ? 0 : -EINVAL;
  }
  
  /**
   * psc_i2s_set_fmt: set the serial format.
   *
   * This function is called by the machine driver to tell us what serial
   * format to use.
   *
   * This driver only supports I2S mode.  Return an error if the format is
   * not SND_SOC_DAIFMT_I2S.
   *
   * @format: one of SND_SOC_DAIFMT_xxx
   */
  static int psc_i2s_set_fmt(struct snd_soc_dai *cpu_dai, unsigned int format)
  {
  	struct psc_dma *psc_dma = snd_soc_dai_get_drvdata(cpu_dai);
  	dev_dbg(psc_dma->dev, "psc_i2s_set_fmt(cpu_dai=%p, format=%i)\n",
  				cpu_dai, format);
  	return (format == SND_SOC_DAIFMT_I2S) ? 0 : -EINVAL;
  }
  
  /* ---------------------------------------------------------------------
   * ALSA SoC Bindings
   *
   * - Digital Audio Interface (DAI) template
   * - create/destroy dai hooks
   */
  
  /**
   * psc_i2s_dai_template: template CPU Digital Audio Interface
   */
  static const struct snd_soc_dai_ops psc_i2s_dai_ops = {
  	.hw_params	= psc_i2s_hw_params,
  	.set_sysclk	= psc_i2s_set_sysclk,
  	.set_fmt	= psc_i2s_set_fmt,
  };
  
  static struct snd_soc_dai_driver psc_i2s_dai[] = {{
  	.name = "mpc5200-psc-i2s.0",
  	.playback = {
  		.stream_name = "I2S Playback",
  		.channels_min = 2,
  		.channels_max = 2,
  		.rates = PSC_I2S_RATES,
  		.formats = PSC_I2S_FORMATS,
  	},
  	.capture = {
  		.stream_name = "I2S Capture",
  		.channels_min = 2,
  		.channels_max = 2,
  		.rates = PSC_I2S_RATES,
  		.formats = PSC_I2S_FORMATS,
  	},
  	.ops = &psc_i2s_dai_ops,
  } };
  
  static const struct snd_soc_component_driver psc_i2s_component = {
  	.name		= "mpc5200-i2s",
  };
  
  /* ---------------------------------------------------------------------
   * OF platform bus binding code:
   * - Probe/remove operations
   * - OF device match table
   */
  static int psc_i2s_of_probe(struct platform_device *op)
  {
  	int rc;
  	struct psc_dma *psc_dma;
  	struct mpc52xx_psc __iomem *regs;
  
  	rc = mpc5200_audio_dma_create(op);
  	if (rc != 0)
  		return rc;
  
  	rc = snd_soc_register_component(&op->dev, &psc_i2s_component,
  					psc_i2s_dai, ARRAY_SIZE(psc_i2s_dai));
  	if (rc != 0) {
  		pr_err("Failed to register DAI\n");
  		return rc;
  	}
  
  	psc_dma = dev_get_drvdata(&op->dev);
  	regs = psc_dma->psc_regs;
  
  	/* Configure the serial interface mode; defaulting to CODEC8 mode */
  	psc_dma->sicr = MPC52xx_PSC_SICR_DTS1 | MPC52xx_PSC_SICR_I2S |
  			MPC52xx_PSC_SICR_CLKPOL;
  	out_be32(&psc_dma->psc_regs->sicr,
  		 psc_dma->sicr | MPC52xx_PSC_SICR_SIM_CODEC_8);
  
  	/* Check for the codec handle.  If it is not present then we
  	 * are done */
  	if (!of_get_property(op->dev.of_node, "codec-handle", NULL))
  		return 0;
  
  	/* Due to errata in the dma mode; need to line up enabling
  	 * the transmitter with a transition on the frame sync
  	 * line */
  
  	/* first make sure it is low */
  	while ((in_8(&regs->ipcr_acr.ipcr) & 0x80) != 0)
  		;
  	/* then wait for the transition to high */
  	while ((in_8(&regs->ipcr_acr.ipcr) & 0x80) == 0)
  		;
  	/* Finally, enable the PSC.
  	 * Receiver must always be enabled; even when we only want
  	 * transmit.  (see 15.3.2.3 of MPC5200B User's Guide) */
  
  	/* Go */
  	out_8(&psc_dma->psc_regs->command,
  			MPC52xx_PSC_TX_ENABLE | MPC52xx_PSC_RX_ENABLE);
  
  	return 0;
  
  }
  
  static int psc_i2s_of_remove(struct platform_device *op)
  {
  	mpc5200_audio_dma_destroy(op);
  	snd_soc_unregister_component(&op->dev);
  	return 0;
  }
  
  /* Match table for of_platform binding */
  static const struct of_device_id psc_i2s_match[] = {
  	{ .compatible = "fsl,mpc5200-psc-i2s", },
  	{ .compatible = "fsl,mpc5200b-psc-i2s", },
  	{}
  };
  MODULE_DEVICE_TABLE(of, psc_i2s_match);
  
  static struct platform_driver psc_i2s_driver = {
  	.probe = psc_i2s_of_probe,
  	.remove = psc_i2s_of_remove,
  	.driver = {
  		.name = "mpc5200-psc-i2s",
  		.of_match_table = psc_i2s_match,
  	},
  };
  
  module_platform_driver(psc_i2s_driver);
  
  MODULE_AUTHOR("Grant Likely <grant.likely@secretlab.ca>");
  MODULE_DESCRIPTION("Freescale MPC5200 PSC in I2S mode ASoC Driver");
  MODULE_LICENSE("GPL");
  
  