text: // SPDX-License-Identifier: GPL-2.0-or-later
  /*
   * atmel_ssc_dai.c  --  ALSA SoC ATMEL SSC Audio Layer Platform driver
   *
   * Copyright (C) 2005 SAN People
   * Copyright (C) 2008 Atmel
   *
   * Author: Sedji Gaouaou <sedji.gaouaou@atmel.com>
   *         ATMEL CORP.
   *
   * Based on at91-ssc.c by
   * Frank Mandarino <fmandarino@endrelia.com>
   * Based on pxa2xx Platform drivers by
   * Liam Girdwood <lrg@slimlogic.co.uk>
   */
  
  #include <linux/init.h>
  #include <linux/module.h>
  #include <linux/interrupt.h>
  #include <linux/device.h>
  #include <linux/delay.h>
  #include <linux/clk.h>
  #include <linux/atmel_pdc.h>
  
  #include <linux/atmel-ssc.h>
  #include <sound/core.h>
  #include <sound/pcm.h>
  #include <sound/pcm_params.h>
  #include <sound/initval.h>
  #include <sound/soc.h>
  
  #include "atmel-pcm.h"
  #include "atmel_ssc_dai.h"
  
  
  #define NUM_SSC_DEVICES		3
  
  /*
   * SSC PDC registers required by the PCM DMA engine.
   */
  static struct atmel_pdc_regs pdc_tx_reg = {
  	.xpr		= ATMEL_PDC_TPR,
  	.xcr		= ATMEL_PDC_TCR,
  	.xnpr		= ATMEL_PDC_TNPR,
  	.xncr		= ATMEL_PDC_TNCR,
  };
  
  static struct atmel_pdc_regs pdc_rx_reg = {
  	.xpr		= ATMEL_PDC_RPR,
  	.xcr		= ATMEL_PDC_RCR,
  	.xnpr		= ATMEL_PDC_RNPR,
  	.xncr		= ATMEL_PDC_RNCR,
  };
  
  /*
   * SSC & PDC status bits for transmit and receive.
   */
  static struct atmel_ssc_mask ssc_tx_mask = {
  	.ssc_enable	= SSC_BIT(CR_TXEN),
  	.ssc_disable	= SSC_BIT(CR_TXDIS),
  	.ssc_endx	= SSC_BIT(SR_ENDTX),
  	.ssc_endbuf	= SSC_BIT(SR_TXBUFE),
  	.ssc_error	= SSC_BIT(SR_OVRUN),
  	.pdc_enable	= ATMEL_PDC_TXTEN,
  	.pdc_disable	= ATMEL_PDC_TXTDIS,
  };
  
  static struct atmel_ssc_mask ssc_rx_mask = {
  	.ssc_enable	= SSC_BIT(CR_RXEN),
  	.ssc_disable	= SSC_BIT(CR_RXDIS),
  	.ssc_endx	= SSC_BIT(SR_ENDRX),
  	.ssc_endbuf	= SSC_BIT(SR_RXBUFF),
  	.ssc_error	= SSC_BIT(SR_OVRUN),
  	.pdc_enable	= ATMEL_PDC_RXTEN,
  	.pdc_disable	= ATMEL_PDC_RXTDIS,
  };
  
  
  /*
   * DMA parameters.
   */
  static struct atmel_pcm_dma_params ssc_dma_params[NUM_SSC_DEVICES][2] = {
  	{{
  	.name		= "SSC0 PCM out",
  	.pdc		= &pdc_tx_reg,
  	.mask		= &ssc_tx_mask,
  	},
  	{
  	.name		= "SSC0 PCM in",
  	.pdc		= &pdc_rx_reg,
  	.mask		= &ssc_rx_mask,
  	} },
  	{{
  	.name		= "SSC1 PCM out",
  	.pdc		= &pdc_tx_reg,
  	.mask		= &ssc_tx_mask,
  	},
  	{
  	.name		= "SSC1 PCM in",
  	.pdc		= &pdc_rx_reg,
  	.mask		= &ssc_rx_mask,
  	} },
  	{{
  	.name		= "SSC2 PCM out",
  	.pdc		= &pdc_tx_reg,
  	.mask		= &ssc_tx_mask,
  	},
  	{
  	.name		= "SSC2 PCM in",
  	.pdc		= &pdc_rx_reg,
  	.mask		= &ssc_rx_mask,
  	} },
  };
  
  
  static struct atmel_ssc_info ssc_info[NUM_SSC_DEVICES] = {
  	{
  	.name		= "ssc0",
  	.dir_mask	= SSC_DIR_MASK_UNUSED,
  	.initialized	= 0,
  	},
  	{
  	.name		= "ssc1",
  	.dir_mask	= SSC_DIR_MASK_UNUSED,
  	.initialized	= 0,
  	},
  	{
  	.name		= "ssc2",
  	.dir_mask	= SSC_DIR_MASK_UNUSED,
  	.initialized	= 0,
  	},
  };
  
  
  /*
   * SSC interrupt handler.  Passes PDC interrupts to the DMA
   * interrupt handler in the PCM driver.
   */
  static irqreturn_t atmel_ssc_interrupt(int irq, void *dev_id)
  {
  	struct atmel_ssc_info *ssc_p = dev_id;
  	struct atmel_pcm_dma_params *dma_params;
  	u32 ssc_sr;
  	u32 ssc_substream_mask;
  	int i;
  
  	ssc_sr = (unsigned long)ssc_readl(ssc_p->ssc->regs, SR)
  			& (unsigned long)ssc_readl(ssc_p->ssc->regs, IMR);
  
  	/*
  	 * Loop through the substreams attached to this SSC.  If
  	 * a DMA-related interrupt occurred on that substream, call
  	 * the DMA interrupt handler function, if one has been
  	 * registered in the dma_params structure by the PCM driver.
  	 */
  	for (i = 0; i < ARRAY_SIZE(ssc_p->dma_params); i++) {
  		dma_params = ssc_p->dma_params[i];
  
  		if ((dma_params != NULL) &&
  			(dma_params->dma_intr_handler != NULL)) {
  			ssc_substream_mask = (dma_params->mask->ssc_endx |
  					dma_params->mask->ssc_endbuf);
  			if (ssc_sr & ssc_substream_mask) {
  				dma_params->dma_intr_handler(ssc_sr,
  						dma_params->
  						substream);
  			}
  		}
  	}
  
  	return IRQ_HANDLED;
  }
  
  /*
   * When the bit clock is input, limit the maximum rate according to the
   * Serial Clock Ratio Considerations section from the SSC documentation:
   *
   *   The Transmitter and the Receiver can be programmed to operate
   *   with the clock signals provided on either the TK or RK pins.
   *   This allows the SSC to support many slave-mode data transfers.
   *   In this case, the maximum clock speed allowed on the RK pin is:
   *   - Peripheral clock divided by 2 if Receiver Frame Synchro is input
   *   - Peripheral clock divided by 3 if Receiver Frame Synchro is output
   *   In addition, the maximum clock speed allowed on the TK pin is:
   *   - Peripheral clock divided by 6 if Transmit Frame Synchro is input
   *   - Peripheral clock divided by 2 if Transmit Frame Synchro is output
   *
   * When the bit clock is output, limit the rate according to the
   * SSC divider restrictions.
   */
  static int atmel_ssc_hw_rule_rate(struct snd_pcm_hw_params *params,
  				  struct snd_pcm_hw_rule *rule)
  {
  	struct atmel_ssc_info *ssc_p = rule->private;
  	struct ssc_device *ssc = ssc_p->ssc;
  	struct snd_interval *i = hw_param_interval(params, rule->var);
  	struct snd_interval t;
  	struct snd_ratnum r = {
  		.den_min = 1,
  		.den_max = 4095,
  		.den_step = 1,
  	};
  	unsigned int num = 0, den = 0;
  	int frame_size;
  	int mck_div = 2;
  	int ret;
  
  	frame_size = snd_soc_params_to_frame_size(params);
  	if (frame_size < 0)
  		return frame_size;
  
  	switch (ssc_p->daifmt & SND_SOC_DAIFMT_MASTER_MASK) {
  	case SND_SOC_DAIFMT_CBM_CFS:
  		if ((ssc_p->dir_mask & SSC_DIR_MASK_CAPTURE)
  		    && ssc->clk_from_rk_pin)
  			/* Receiver Frame Synchro (i.e. capture)
  			 * is output (format is _CFS) and the RK pin
  			 * is used for input (format is _CBM_).
  			 */
  			mck_div = 3;
  		break;
  
  	case SND_SOC_DAIFMT_CBM_CFM:
  		if ((ssc_p->dir_mask & SSC_DIR_MASK_PLAYBACK)
  		    && !ssc->clk_from_rk_pin)
  			/* Transmit Frame Synchro (i.e. playback)
  			 * is input (format is _CFM) and the TK pin
  			 * is used for input (format _CBM_ but not
  			 * using the RK pin).
  			 */
  			mck_div = 6;
  		break;
  	}
  
  	switch (ssc_p->daifmt & SND_SOC_DAIFMT_MASTER_MASK) {
  	case SND_SOC_DAIFMT_CBS_CFS:
  		r.num = ssc_p->mck_rate / mck_div / frame_size;
  
  		ret = snd_interval_ratnum(i, 1, &r, &num, &den);
  		if (ret >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
  			params->rate_num = num;
  			params->rate_den = den;
  		}
  		break;
  
  	case SND_SOC_DAIFMT_CBM_CFS:
  	case SND_SOC_DAIFMT_CBM_CFM:
  		t.min = 8000;
  		t.max = ssc_p->mck_rate / mck_div / frame_size;
  		t.openmin = t.openmax = 0;
  		t.integer = 0;
  		ret = snd_interval_refine(i, &t);
  		break;
  
  	default:
  		ret = -EINVAL;
  		break;
  	}
  
  	return ret;
  }
  
  /*-------------------------------------------------------------------------*\
   * DAI functions
  \*-------------------------------------------------------------------------*/
  /*
   * Startup.  Only that one substream allowed in each direction.
   */
  static int atmel_ssc_startup(struct snd_pcm_substream *substream,
  			     struct snd_soc_dai *dai)
  {
  	struct platform_device *pdev = to_platform_device(dai->dev);
  	struct atmel_ssc_info *ssc_p = &ssc_info[pdev->id];
  	struct atmel_pcm_dma_params *dma_params;
  	int dir, dir_mask;
  	int ret;
  
  	pr_debug("atmel_ssc_startup: SSC_SR=0x%x\n",
  		ssc_readl(ssc_p->ssc->regs, SR));
  
  	/* Enable PMC peripheral clock for this SSC */
  	pr_debug("atmel_ssc_dai: Starting clock\n");
  	clk_enable(ssc_p->ssc->clk);
  	ssc_p->mck_rate = clk_get_rate(ssc_p->ssc->clk);
  
  	/* Reset the SSC unless initialized to keep it in a clean state */
  	if (!ssc_p->initialized)
  		ssc_writel(ssc_p->ssc->regs, CR, SSC_BIT(CR_SWRST));
  
  	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
  		dir = 0;
  		dir_mask = SSC_DIR_MASK_PLAYBACK;
  	} else {
  		dir = 1;
  		dir_mask = SSC_DIR_MASK_CAPTURE;
  	}
  
  	ret = snd_pcm_hw_rule_add(substream->runtime, 0,
  				  SNDRV_PCM_HW_PARAM_RATE,
  				  atmel_ssc_hw_rule_rate,
  				  ssc_p,
  				  SNDRV_PCM_HW_PARAM_FRAME_BITS,
  				  SNDRV_PCM_HW_PARAM_CHANNELS, -1);
  	if (ret < 0) {
  		dev_err(dai->dev, "Failed to specify rate rule: %d\n", ret);
  		return ret;
  	}
  
  	dma_params = &ssc_dma_params[pdev->id][dir];
  	dma_params->ssc = ssc_p->ssc;
  	dma_params->substream = substream;
  
  	ssc_p->dma_params[dir] = dma_params;
  
  	snd_soc_dai_set_dma_data(dai, substream, dma_params);
  
  	if (ssc_p->dir_mask & dir_mask)
  		return -EBUSY;
  
  	ssc_p->dir_mask |= dir_mask;
  
  	return 0;
  }
  
  /*
   * Shutdown.  Clear DMA parameters and shutdown the SSC if there
   * are no other substreams open.
   */
  static void atmel_ssc_shutdown(struct snd_pcm_substream *substream,
  			       struct snd_soc_dai *dai)
  {
  	struct platform_device *pdev = to_platform_device(dai->dev);
  	struct atmel_ssc_info *ssc_p = &ssc_info[pdev->id];
  	struct atmel_pcm_dma_params *dma_params;
  	int dir, dir_mask;
  
  	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
  		dir = 0;
  	else
  		dir = 1;
  
  	dma_params = ssc_p->dma_params[dir];
  
  	if (dma_params != NULL) {
  		dma_params->ssc = NULL;
  		dma_params->substream = NULL;
  		ssc_p->dma_params[dir] = NULL;
  	}
  
  	dir_mask = 1 << dir;
  
  	ssc_p->dir_mask &= ~dir_mask;
  	if (!ssc_p->dir_mask) {
  		if (ssc_p->initialized) {
  			free_irq(ssc_p->ssc->irq, ssc_p);
  			ssc_p->initialized = 0;
  		}
  
  		/* Reset the SSC */
  		ssc_writel(ssc_p->ssc->regs, CR, SSC_BIT(CR_SWRST));
  		/* Clear the SSC dividers */
  		ssc_p->cmr_div = ssc_p->tcmr_period = ssc_p->rcmr_period = 0;
  		ssc_p->forced_divider = 0;
  	}
  
  	/* Shutdown the SSC clock. */
  	pr_debug("atmel_ssc_dai: Stopping clock\n");
  	clk_disable(ssc_p->ssc->clk);
  }
  
  
  /*
   * Record the DAI format for use in hw_params().
   */
  static int atmel_ssc_set_dai_fmt(struct snd_soc_dai *cpu_dai,
  		unsigned int fmt)
  {
  	struct platform_device *pdev = to_platform_device(cpu_dai->dev);
  	struct atmel_ssc_info *ssc_p = &ssc_info[pdev->id];
  
  	ssc_p->daifmt = fmt;
  	return 0;
  }
  
  /*
   * Record SSC clock dividers for use in hw_params().
   */
  static int atmel_ssc_set_dai_clkdiv(struct snd_soc_dai *cpu_dai,
  	int div_id, int div)
  {
  	struct platform_device *pdev = to_platform_device(cpu_dai->dev);
  	struct atmel_ssc_info *ssc_p = &ssc_info[pdev->id];
  
  	switch (div_id) {
  	case ATMEL_SSC_CMR_DIV:
  		/*
  		 * The same master clock divider is used for both
  		 * transmit and receive, so if a value has already
  		 * been set, it must match this value.
  		 */
  		if (ssc_p->dir_mask !=
  			(SSC_DIR_MASK_PLAYBACK | SSC_DIR_MASK_CAPTURE))
  			ssc_p->cmr_div = div;
  		else if (ssc_p->cmr_div == 0)
  			ssc_p->cmr_div = div;
  		else
  			if (div != ssc_p->cmr_div)
  				return -EBUSY;
  		ssc_p->forced_divider |= BIT(ATMEL_SSC_CMR_DIV);
  		break;
  
  	case ATMEL_SSC_TCMR_PERIOD:
  		ssc_p->tcmr_period = div;
  		ssc_p->forced_divider |= BIT(ATMEL_SSC_TCMR_PERIOD);
  		break;
  
  	case ATMEL_SSC_RCMR_PERIOD:
  		ssc_p->rcmr_period = div;
  		ssc_p->forced_divider |= BIT(ATMEL_SSC_RCMR_PERIOD);
  		break;
  
  	default:
  		return -EINVAL;
  	}
  
  	return 0;
  }
  
  /* Is the cpu-dai master of the frame clock? */
  static int atmel_ssc_cfs(struct atmel_ssc_info *ssc_p)
  {
  	switch (ssc_p->daifmt & SND_SOC_DAIFMT_MASTER_MASK) {
  	case SND_SOC_DAIFMT_CBM_CFS:
  	case SND_SOC_DAIFMT_CBS_CFS:
  		return 1;
  	}
  	return 0;
  }
  
  /* Is the cpu-dai master of the bit clock? */
  static int atmel_ssc_cbs(struct atmel_ssc_info *ssc_p)
  {
  	switch (ssc_p->daifmt & SND_SOC_DAIFMT_MASTER_MASK) {
  	case SND_SOC_DAIFMT_CBS_CFM:
  	case SND_SOC_DAIFMT_CBS_CFS:
  		return 1;
  	}
  	return 0;
  }
  
  /*
   * Configure the SSC.
   */
  static int atmel_ssc_hw_params(struct snd_pcm_substream *substream,
  	struct snd_pcm_hw_params *params,
  	struct snd_soc_dai *dai)
  {
  	struct platform_device *pdev = to_platform_device(dai->dev);
  	int id = pdev->id;
  	struct atmel_ssc_info *ssc_p = &ssc_info[id];
  	struct ssc_device *ssc = ssc_p->ssc;
  	struct atmel_pcm_dma_params *dma_params;
  	int dir, channels, bits;
  	u32 tfmr, rfmr, tcmr, rcmr;
  	int ret;
  	int fslen, fslen_ext, fs_osync, fs_edge;
  	u32 cmr_div;
  	u32 tcmr_period;
  	u32 rcmr_period;
  
  	/*
  	 * Currently, there is only one set of dma params for
  	 * each direction.  If more are added, this code will
  	 * have to be changed to select the proper set.
  	 */
  	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
  		dir = 0;
  	else
  		dir = 1;
  
  	/*
  	 * If the cpu dai should provide BCLK, but noone has provided the
  	 * divider needed for that to work, fall back to something sensible.
  	 */
  	cmr_div = ssc_p->cmr_div;
  	if (!(ssc_p->forced_divider & BIT(ATMEL_SSC_CMR_DIV)) &&
  	    atmel_ssc_cbs(ssc_p)) {
  		int bclk_rate = snd_soc_params_to_bclk(params);
  
  		if (bclk_rate < 0) {
  			dev_err(dai->dev, "unable to calculate cmr_div: %d\n",
  				bclk_rate);
  			return bclk_rate;
  		}
  
  		cmr_div = DIV_ROUND_CLOSEST(ssc_p->mck_rate, 2 * bclk_rate);
  	}
  
  	/*
  	 * If the cpu dai should provide LRCLK, but noone has provided the
  	 * dividers needed for that to work, fall back to something sensible.
  	 */
  	tcmr_period = ssc_p->tcmr_period;
  	rcmr_period = ssc_p->rcmr_period;
  	if (atmel_ssc_cfs(ssc_p)) {
  		int frame_size = snd_soc_params_to_frame_size(params);
  
  		if (frame_size < 0) {
  			dev_err(dai->dev,
  				"unable to calculate tx/rx cmr_period: %d\n",
  				frame_size);
  			return frame_size;
  		}
  
  		if (!(ssc_p->forced_divider & BIT(ATMEL_SSC_TCMR_PERIOD)))
  			tcmr_period = frame_size / 2 - 1;
  		if (!(ssc_p->forced_divider & BIT(ATMEL_SSC_RCMR_PERIOD)))
  			rcmr_period = frame_size / 2 - 1;
  	}
  
  	dma_params = ssc_p->dma_params[dir];
  
  	channels = params_channels(params);
  
  	/*
  	 * Determine sample size in bits and the PDC increment.
  	 */
  	switch (params_format(params)) {
  	case SNDRV_PCM_FORMAT_S8:
  		bits = 8;
  		dma_params->pdc_xfer_size = 1;
  		break;
  	case SNDRV_PCM_FORMAT_S16_LE:
  		bits = 16;
  		dma_params->pdc_xfer_size = 2;
  		break;
  	case SNDRV_PCM_FORMAT_S24_LE:
  		bits = 24;
  		dma_params->pdc_xfer_size = 4;
  		break;
  	case SNDRV_PCM_FORMAT_S32_LE:
  		bits = 32;
  		dma_params->pdc_xfer_size = 4;
  		break;
  	default:
  		printk(KERN_WARNING "atmel_ssc_dai: unsupported PCM format");
  		return -EINVAL;
  	}
  
  	/*
  	 * Compute SSC register settings.
  	 */
  
  	fslen_ext = (bits - 1) / 16;
  	fslen = (bits - 1) % 16;
  
  	switch (ssc_p->daifmt & SND_SOC_DAIFMT_FORMAT_MASK) {
  
  	case SND_SOC_DAIFMT_LEFT_J:
  		fs_osync = SSC_FSOS_POSITIVE;
  		fs_edge = SSC_START_RISING_RF;
  
  		rcmr =	  SSC_BF(RCMR_STTDLY, 0);
  		tcmr =	  SSC_BF(TCMR_STTDLY, 0);
  
  		break;
  
  	case SND_SOC_DAIFMT_I2S:
  		fs_osync = SSC_FSOS_NEGATIVE;
  		fs_edge = SSC_START_FALLING_RF;
  
  		rcmr =	  SSC_BF(RCMR_STTDLY, 1);
  		tcmr =	  SSC_BF(TCMR_STTDLY, 1);
  
  		break;
  
  	case SND_SOC_DAIFMT_DSP_A:
  		/*
  		 * DSP/PCM Mode A format
  		 *
  		 * Data is transferred on first BCLK after LRC pulse rising
  		 * edge.If stereo, the right channel data is contiguous with
  		 * the left channel data.
  		 */
  		fs_osync = SSC_FSOS_POSITIVE;
  		fs_edge = SSC_START_RISING_RF;
  		fslen = fslen_ext = 0;
  
  		rcmr =	  SSC_BF(RCMR_STTDLY, 1);
  		tcmr =	  SSC_BF(TCMR_STTDLY, 1);
  
  		break;
  
  	default:
  		printk(KERN_WARNING "atmel_ssc_dai: unsupported DAI format 0x%x\n",
  			ssc_p->daifmt);
  		return -EINVAL;
  	}
  
  	if (!atmel_ssc_cfs(ssc_p)) {
  		fslen = fslen_ext = 0;
  		rcmr_period = tcmr_period = 0;
  		fs_osync = SSC_FSOS_NONE;
  	}
  
  	rcmr |=	  SSC_BF(RCMR_START, fs_edge);
  	tcmr |=	  SSC_BF(TCMR_START, fs_edge);
  
  	if (atmel_ssc_cbs(ssc_p)) {
  		/*
  		 * SSC provides BCLK
  		 *
  		 * The SSC transmit and receive clocks are generated from the
  		 * MCK divider, and the BCLK signal is output
  		 * on the SSC TK line.
  		 */
  		rcmr |=	  SSC_BF(RCMR_CKS, SSC_CKS_DIV)
  			| SSC_BF(RCMR_CKO, SSC_CKO_NONE);
  
  		tcmr |=	  SSC_BF(TCMR_CKS, SSC_CKS_DIV)
  			| SSC_BF(TCMR_CKO, SSC_CKO_CONTINUOUS);
  	} else {
  		rcmr |=	  SSC_BF(RCMR_CKS, ssc->clk_from_rk_pin ?
  					SSC_CKS_PIN : SSC_CKS_CLOCK)
  			| SSC_BF(RCMR_CKO, SSC_CKO_NONE);
  
  		tcmr |=	  SSC_BF(TCMR_CKS, ssc->clk_from_rk_pin ?
  					SSC_CKS_CLOCK : SSC_CKS_PIN)
  			| SSC_BF(TCMR_CKO, SSC_CKO_NONE);
  	}
  
  	rcmr |=	  SSC_BF(RCMR_PERIOD, rcmr_period)
  		| SSC_BF(RCMR_CKI, SSC_CKI_RISING);
  
  	tcmr |=   SSC_BF(TCMR_PERIOD, tcmr_period)
  		| SSC_BF(TCMR_CKI, SSC_CKI_FALLING);
  
  	rfmr =    SSC_BF(RFMR_FSLEN_EXT, fslen_ext)
  		| SSC_BF(RFMR_FSEDGE, SSC_FSEDGE_POSITIVE)
  		| SSC_BF(RFMR_FSOS, fs_osync)
  		| SSC_BF(RFMR_FSLEN, fslen)
  		| SSC_BF(RFMR_DATNB, (channels - 1))
  		| SSC_BIT(RFMR_MSBF)
  		| SSC_BF(RFMR_LOOP, 0)
  		| SSC_BF(RFMR_DATLEN, (bits - 1));
  
  	tfmr =    SSC_BF(TFMR_FSLEN_EXT, fslen_ext)
  		| SSC_BF(TFMR_FSEDGE, SSC_FSEDGE_POSITIVE)
  		| SSC_BF(TFMR_FSDEN, 0)
  		| SSC_BF(TFMR_FSOS, fs_osync)
  		| SSC_BF(TFMR_FSLEN, fslen)
  		| SSC_BF(TFMR_DATNB, (channels - 1))
  		| SSC_BIT(TFMR_MSBF)
  		| SSC_BF(TFMR_DATDEF, 0)
  		| SSC_BF(TFMR_DATLEN, (bits - 1));
  
  	if (fslen_ext && !ssc->pdata->has_fslen_ext) {
  		dev_err(dai->dev, "sample size %d is too large for SSC device\n",
  			bits);
  		return -EINVAL;
  	}
  
  	pr_debug("atmel_ssc_hw_params: "
  			"RCMR=%08x RFMR=%08x TCMR=%08x TFMR=%08x\n",
  			rcmr, rfmr, tcmr, tfmr);
  
  	if (!ssc_p->initialized) {
  		if (!ssc_p->ssc->pdata->use_dma) {
  			ssc_writel(ssc_p->ssc->regs, PDC_RPR, 0);
  			ssc_writel(ssc_p->ssc->regs, PDC_RCR, 0);
  			ssc_writel(ssc_p->ssc->regs, PDC_RNPR, 0);
  			ssc_writel(ssc_p->ssc->regs, PDC_RNCR, 0);
  
  			ssc_writel(ssc_p->ssc->regs, PDC_TPR, 0);
  			ssc_writel(ssc_p->ssc->regs, PDC_TCR, 0);
  			ssc_writel(ssc_p->ssc->regs, PDC_TNPR, 0);
  			ssc_writel(ssc_p->ssc->regs, PDC_TNCR, 0);
  		}
  
  		ret = request_irq(ssc_p->ssc->irq, atmel_ssc_interrupt, 0,
  				ssc_p->name, ssc_p);
  		if (ret < 0) {
  			printk(KERN_WARNING
  					"atmel_ssc_dai: request_irq failure\n");
  			pr_debug("Atmel_ssc_dai: Stopping clock\n");
  			clk_disable(ssc_p->ssc->clk);
  			return ret;
  		}
  
  		ssc_p->initialized = 1;
  	}
  
  	/* set SSC clock mode register */
  	ssc_writel(ssc_p->ssc->regs, CMR, cmr_div);
  
  	/* set receive clock mode and format */
  	ssc_writel(ssc_p->ssc->regs, RCMR, rcmr);
  	ssc_writel(ssc_p->ssc->regs, RFMR, rfmr);
  
  	/* set transmit clock mode and format */
  	ssc_writel(ssc_p->ssc->regs, TCMR, tcmr);
  	ssc_writel(ssc_p->ssc->regs, TFMR, tfmr);
  
  	pr_debug("atmel_ssc_dai,hw_params: SSC initialized\n");
  	return 0;
  }
  
  
  static int atmel_ssc_prepare(struct snd_pcm_substream *substream,
  			     struct snd_soc_dai *dai)
  {
  	struct platform_device *pdev = to_platform_device(dai->dev);
  	struct atmel_ssc_info *ssc_p = &ssc_info[pdev->id];
  	struct atmel_pcm_dma_params *dma_params;
  	int dir;
  
  	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
  		dir = 0;
  	else
  		dir = 1;
  
  	dma_params = ssc_p->dma_params[dir];
  
  	ssc_writel(ssc_p->ssc->regs, CR, dma_params->mask->ssc_disable);
  	ssc_writel(ssc_p->ssc->regs, IDR, dma_params->mask->ssc_error);
  
  	pr_debug("%s enabled SSC_SR=0x%08x\n",
  			dir ? "receive" : "transmit",
  			ssc_readl(ssc_p->ssc->regs, SR));
  	return 0;
  }
  
  static int atmel_ssc_trigger(struct snd_pcm_substream *substream,
  			     int cmd, struct snd_soc_dai *dai)
  {
  	struct platform_device *pdev = to_platform_device(dai->dev);
  	struct atmel_ssc_info *ssc_p = &ssc_info[pdev->id];
  	struct atmel_pcm_dma_params *dma_params;
  	int dir;
  
  	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
  		dir = 0;
  	else
  		dir = 1;
  
  	dma_params = ssc_p->dma_params[dir];
  
  	switch (cmd) {
  	case SNDRV_PCM_TRIGGER_START:
  	case SNDRV_PCM_TRIGGER_RESUME:
  	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
  		ssc_writel(ssc_p->ssc->regs, CR, dma_params->mask->ssc_enable);
  		break;
  	default:
  		ssc_writel(ssc_p->ssc->regs, CR, dma_params->mask->ssc_disable);
  		break;
  	}
  
  	return 0;
  }
  
  #ifdef CONFIG_PM
  static int atmel_ssc_suspend(struct snd_soc_component *component)
  {
  	struct atmel_ssc_info *ssc_p;
  	struct platform_device *pdev = to_platform_device(component->dev);
  
  	if (!snd_soc_component_active(component))
  		return 0;
  
  	ssc_p = &ssc_info[pdev->id];
  
  	/* Save the status register before disabling transmit and receive */
  	ssc_p->ssc_state.ssc_sr = ssc_readl(ssc_p->ssc->regs, SR);
  	ssc_writel(ssc_p->ssc->regs, CR, SSC_BIT(CR_TXDIS) | SSC_BIT(CR_RXDIS));
  
  	/* Save the current interrupt mask, then disable unmasked interrupts */
  	ssc_p->ssc_state.ssc_imr = ssc_readl(ssc_p->ssc->regs, IMR);
  	ssc_writel(ssc_p->ssc->regs, IDR, ssc_p->ssc_state.ssc_imr);
  
  	ssc_p->ssc_state.ssc_cmr = ssc_readl(ssc_p->ssc->regs, CMR);
  	ssc_p->ssc_state.ssc_rcmr = ssc_readl(ssc_p->ssc->regs, RCMR);
  	ssc_p->ssc_state.ssc_rfmr = ssc_readl(ssc_p->ssc->regs, RFMR);
  	ssc_p->ssc_state.ssc_tcmr = ssc_readl(ssc_p->ssc->regs, TCMR);
  	ssc_p->ssc_state.ssc_tfmr = ssc_readl(ssc_p->ssc->regs, TFMR);
  
  	return 0;
  }
  
  static int atmel_ssc_resume(struct snd_soc_component *component)
  {
  	struct atmel_ssc_info *ssc_p;
  	struct platform_device *pdev = to_platform_device(component->dev);
  	u32 cr;
  
  	if (!snd_soc_component_active(component))
  		return 0;
  
  	ssc_p = &ssc_info[pdev->id];
  
  	/* restore SSC register settings */
  	ssc_writel(ssc_p->ssc->regs, TFMR, ssc_p->ssc_state.ssc_tfmr);
  	ssc_writel(ssc_p->ssc->regs, TCMR, ssc_p->ssc_state.ssc_tcmr);
  	ssc_writel(ssc_p->ssc->regs, RFMR, ssc_p->ssc_state.ssc_rfmr);
  	ssc_writel(ssc_p->ssc->regs, RCMR, ssc_p->ssc_state.ssc_rcmr);
  	ssc_writel(ssc_p->ssc->regs, CMR, ssc_p->ssc_state.ssc_cmr);
  
  	/* re-enable interrupts */
  	ssc_writel(ssc_p->ssc->regs, IER, ssc_p->ssc_state.ssc_imr);
  
  	/* Re-enable receive and transmit as appropriate */
  	cr = 0;
  	cr |=
  	    (ssc_p->ssc_state.ssc_sr & SSC_BIT(SR_RXEN)) ? SSC_BIT(CR_RXEN) : 0;
  	cr |=
  	    (ssc_p->ssc_state.ssc_sr & SSC_BIT(SR_TXEN)) ? SSC_BIT(CR_TXEN) : 0;
  	ssc_writel(ssc_p->ssc->regs, CR, cr);
  
  	return 0;
  }
  #else /* CONFIG_PM */
  #  define atmel_ssc_suspend	NULL
  #  define atmel_ssc_resume	NULL
  #endif /* CONFIG_PM */
  
  #define ATMEL_SSC_FORMATS (SNDRV_PCM_FMTBIT_S8     | SNDRV_PCM_FMTBIT_S16_LE |\
  			  SNDRV_PCM_FMTBIT_S24_LE | SNDRV_PCM_FMTBIT_S32_LE)
  
  static const struct snd_soc_dai_ops atmel_ssc_dai_ops = {
  	.startup	= atmel_ssc_startup,
  	.shutdown	= atmel_ssc_shutdown,
  	.prepare	= atmel_ssc_prepare,
  	.trigger	= atmel_ssc_trigger,
  	.hw_params	= atmel_ssc_hw_params,
  	.set_fmt	= atmel_ssc_set_dai_fmt,
  	.set_clkdiv	= atmel_ssc_set_dai_clkdiv,
  };
  
  static struct snd_soc_dai_driver atmel_ssc_dai = {
  		.playback = {
  			.channels_min = 1,
  			.channels_max = 2,
  			.rates = SNDRV_PCM_RATE_CONTINUOUS,
  			.rate_min = 8000,
  			.rate_max = 384000,
  			.formats = ATMEL_SSC_FORMATS,},
  		.capture = {
  			.channels_min = 1,
  			.channels_max = 2,
  			.rates = SNDRV_PCM_RATE_CONTINUOUS,
  			.rate_min = 8000,
  			.rate_max = 384000,
  			.formats = ATMEL_SSC_FORMATS,},
  		.ops = &atmel_ssc_dai_ops,
  };
  
  static const struct snd_soc_component_driver atmel_ssc_component = {
  	.name		= "atmel-ssc",
  	.suspend	= atmel_ssc_suspend,
  	.resume		= atmel_ssc_resume,
  };
  
  static int asoc_ssc_init(struct device *dev)
  {
  	struct ssc_device *ssc = dev_get_drvdata(dev);
  	int ret;
  
  	ret = devm_snd_soc_register_component(dev, &atmel_ssc_component,
  					 &atmel_ssc_dai, 1);
  	if (ret) {
  		dev_err(dev, "Could not register DAI: %d\n", ret);
  		return ret;
  	}
  
  	if (ssc->pdata->use_dma)
  		ret = atmel_pcm_dma_platform_register(dev);
  	else
  		ret = atmel_pcm_pdc_platform_register(dev);
  
  	if (ret) {
  		dev_err(dev, "Could not register PCM: %d\n", ret);
  		return ret;
  	}
  
  	return 0;
  }
  
  /**
   * atmel_ssc_set_audio - Allocate the specified SSC for audio use.
   */
  int atmel_ssc_set_audio(int ssc_id)
  {
  	struct ssc_device *ssc;
  	int ret;
  
  	/* If we can grab the SSC briefly to parent the DAI device off it */
  	ssc = ssc_request(ssc_id);
  	if (IS_ERR(ssc)) {
  		pr_err("Unable to parent ASoC SSC DAI on SSC: %ld\n",
  			PTR_ERR(ssc));
  		return PTR_ERR(ssc);
  	} else {
  		ssc_info[ssc_id].ssc = ssc;
  	}
  
  	ret = asoc_ssc_init(&ssc->pdev->dev);
  
  	return ret;
  }
  EXPORT_SYMBOL_GPL(atmel_ssc_set_audio);
  
  void atmel_ssc_put_audio(int ssc_id)
  {
  	struct ssc_device *ssc = ssc_info[ssc_id].ssc;
  
  	ssc_free(ssc);
  }
  EXPORT_SYMBOL_GPL(atmel_ssc_put_audio);
  
  /* Module information */
  MODULE_AUTHOR("Sedji Gaouaou, sedji.gaouaou@atmel.com, www.atmel.com");
  MODULE_DESCRIPTION("ATMEL SSC ASoC Interface");
  MODULE_LICENSE("GPL");
  