sound/soc/at32/at32-pcm.c - maze/linux - Git at Google

 /* sound/soc/at32/at32-pcm.c
  * ASoC PCM interface for Atmel AT32 SoC
  *
  * Copyright (C) 2008 Long Range Systems
  *    Geoffrey Wossum <gwossum@acm.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.
  *
  * Note that this is basically a port of the sound/soc/at91-pcm.c to
  * the AVR32 kernel.  Thanks to Frank Mandarino for that code.
  */

 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/dma-mapping.h>
 #include <linux/atmel_pdc.h>

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

 #include "at32-pcm.h"


 /*--------------------------------------------------------------------------*\
  * Hardware definition
 \*--------------------------------------------------------------------------*/
 /* TODO: These values were taken from the AT91 platform driver, check
  *	 them against real values for AT32
  */
 static const struct snd_pcm_hardware at32_pcm_hardware = {
 	.info = (SNDRV_PCM_INFO_MMAP |
 		 SNDRV_PCM_INFO_MMAP_VALID |
 		 SNDRV_PCM_INFO_INTERLEAVED |
 		 SNDRV_PCM_INFO_BLOCK_TRANSFER |
 		 SNDRV_PCM_INFO_PAUSE),

 	.formats = SNDRV_PCM_FMTBIT_S16,
 	.period_bytes_min = 32,
 	.period_bytes_max = 8192,	/* 512 frames * 16 bytes / frame */
 	.periods_min = 2,
 	.periods_max = 1024,
 	.buffer_bytes_max = 32 * 1024,
 };


 /*--------------------------------------------------------------------------*\
  * Data types
 \*--------------------------------------------------------------------------*/
 struct at32_runtime_data {
 	struct at32_pcm_dma_params *params;
 	dma_addr_t dma_buffer;	/* physical address of DMA buffer */
 	dma_addr_t dma_buffer_end; /* first address beyond DMA buffer */
 	size_t period_size;

 	dma_addr_t period_ptr;	/* physical address of next period */
 	int periods;		/* period index of period_ptr */

 	/* Save PDC registers (for power management) */
 	u32 pdc_xpr_save;
 	u32 pdc_xcr_save;
 	u32 pdc_xnpr_save;
 	u32 pdc_xncr_save;
 };


 /*--------------------------------------------------------------------------*\
  * Helper functions
 \*--------------------------------------------------------------------------*/
 static int at32_pcm_preallocate_dma_buffer(struct snd_pcm *pcm, int stream)
 {
 	struct snd_pcm_substream *substream = pcm->streams[stream].substream;
 	struct snd_dma_buffer *dmabuf = &substream->dma_buffer;
 	size_t size = at32_pcm_hardware.buffer_bytes_max;

 	dmabuf->dev.type = SNDRV_DMA_TYPE_DEV;
 	dmabuf->dev.dev = pcm->card->dev;
 	dmabuf->private_data = NULL;
 	dmabuf->area = dma_alloc_coherent(pcm->card->dev, size,
 					  &dmabuf->addr, GFP_KERNEL);
 	pr_debug("at32_pcm: preallocate_dma_buffer: "
 		 "area=%p, addr=%p, size=%ld\n",
 		 (void *)dmabuf->area, (void *)dmabuf->addr, size);

 	if (!dmabuf->area)
 		return -ENOMEM;

 	dmabuf->bytes = size;
 	return 0;
 }


 /*--------------------------------------------------------------------------*\
  * ISR
 \*--------------------------------------------------------------------------*/
 static void at32_pcm_dma_irq(u32 ssc_sr, struct snd_pcm_substream *substream)
 {
 	struct snd_pcm_runtime *rtd = substream->runtime;
 	struct at32_runtime_data *prtd = rtd->private_data;
 	struct at32_pcm_dma_params *params = prtd->params;
 	static int count;

 	count++;
 	if (ssc_sr & params->mask->ssc_endbuf) {
 		pr_warning("at32-pcm: buffer %s on %s (SSC_SR=%#x, count=%d)\n",
 			   substream->stream == SNDRV_PCM_STREAM_PLAYBACK ?
 			   "underrun" : "overrun", params->name, ssc_sr, count);

 		/* re-start the PDC */
 		ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
 			   params->mask->pdc_disable);
 		prtd->period_ptr += prtd->period_size;
 		if (prtd->period_ptr >= prtd->dma_buffer_end)
 			prtd->period_ptr = prtd->dma_buffer;


 		ssc_writex(params->ssc->regs, params->pdc->xpr,
 			   prtd->period_ptr);
 		ssc_writex(params->ssc->regs, params->pdc->xcr,
 			   prtd->period_size / params->pdc_xfer_size);
 		ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
 			   params->mask->pdc_enable);
 	}


 	if (ssc_sr & params->mask->ssc_endx) {
 		/* Load the PDC next pointer and counter registers */
 		prtd->period_ptr += prtd->period_size;
 		if (prtd->period_ptr >= prtd->dma_buffer_end)
 			prtd->period_ptr = prtd->dma_buffer;
 		ssc_writex(params->ssc->regs, params->pdc->xnpr,
 			   prtd->period_ptr);
 		ssc_writex(params->ssc->regs, params->pdc->xncr,
 			   prtd->period_size / params->pdc_xfer_size);
 	}


 	snd_pcm_period_elapsed(substream);
 }


 /*--------------------------------------------------------------------------*\
  * PCM operations
 \*--------------------------------------------------------------------------*/
 static int at32_pcm_hw_params(struct snd_pcm_substream *substream,
 			      struct snd_pcm_hw_params *params)
 {
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct at32_runtime_data *prtd = runtime->private_data;
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;

 	/* this may get called several times by oss emulation
 	 * with different params
 	 */
 	snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
 	runtime->dma_bytes = params_buffer_bytes(params);

 	prtd->params = rtd->dai->cpu_dai->dma_data;
 	prtd->params->dma_intr_handler = at32_pcm_dma_irq;

 	prtd->dma_buffer = runtime->dma_addr;
 	prtd->dma_buffer_end = runtime->dma_addr + runtime->dma_bytes;
 	prtd->period_size = params_period_bytes(params);

 	pr_debug("hw_params: DMA for %s initialized "
 		 "(dma_bytes=%ld, period_size=%ld)\n",
 		 prtd->params->name, runtime->dma_bytes, prtd->period_size);

 	return 0;
 }


 static int at32_pcm_hw_free(struct snd_pcm_substream *substream)
 {
 	struct at32_runtime_data *prtd = substream->runtime->private_data;
 	struct at32_pcm_dma_params *params = prtd->params;

 	if (params != NULL) {
 		ssc_writex(params->ssc->regs, SSC_PDC_PTCR,
 			   params->mask->pdc_disable);
 		prtd->params->dma_intr_handler = NULL;
 	}

 	return 0;
 }


 static int at32_pcm_prepare(struct snd_pcm_substream *substream)
 {
 	struct at32_runtime_data *prtd = substream->runtime->private_data;
 	struct at32_pcm_dma_params *params = prtd->params;

 	ssc_writex(params->ssc->regs, SSC_IDR,
 		   params->mask->ssc_endx | params->mask->ssc_endbuf);
 	ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
 		   params->mask->pdc_disable);

 	return 0;
 }


 static int at32_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 {
 	struct snd_pcm_runtime *rtd = substream->runtime;
 	struct at32_runtime_data *prtd = rtd->private_data;
 	struct at32_pcm_dma_params *params = prtd->params;
 	int ret = 0;

 	pr_debug("at32_pcm_trigger: buffer_size = %ld, "
 		 "dma_area = %p, dma_bytes = %ld\n",
 		 rtd->buffer_size, rtd->dma_area, rtd->dma_bytes);

 	switch (cmd) {
 	case SNDRV_PCM_TRIGGER_START:
 		prtd->period_ptr = prtd->dma_buffer;

 		ssc_writex(params->ssc->regs, params->pdc->xpr,
 			   prtd->period_ptr);
 		ssc_writex(params->ssc->regs, params->pdc->xcr,
 			   prtd->period_size / params->pdc_xfer_size);

 		prtd->period_ptr += prtd->period_size;
 		ssc_writex(params->ssc->regs, params->pdc->xnpr,
 			   prtd->period_ptr);
 		ssc_writex(params->ssc->regs, params->pdc->xncr,
 			   prtd->period_size / params->pdc_xfer_size);

 		pr_debug("trigger: period_ptr=%lx, xpr=%x, "
 			 "xcr=%d, xnpr=%x, xncr=%d\n",
 			 (unsigned long)prtd->period_ptr,
 			 ssc_readx(params->ssc->regs, params->pdc->xpr),
 			 ssc_readx(params->ssc->regs, params->pdc->xcr),
 			 ssc_readx(params->ssc->regs, params->pdc->xnpr),
 			 ssc_readx(params->ssc->regs, params->pdc->xncr));

 		ssc_writex(params->ssc->regs, SSC_IER,
 			   params->mask->ssc_endx | params->mask->ssc_endbuf);
 		ssc_writex(params->ssc->regs, SSC_PDC_PTCR,
 			   params->mask->pdc_enable);

 		pr_debug("sr=%x, imr=%x\n",
 			 ssc_readx(params->ssc->regs, SSC_SR),
 			 ssc_readx(params->ssc->regs, SSC_IER));
 		break;		/* SNDRV_PCM_TRIGGER_START */


 	case SNDRV_PCM_TRIGGER_STOP:
 	case SNDRV_PCM_TRIGGER_SUSPEND:
 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 		ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
 			   params->mask->pdc_disable);
 		break;


 	case SNDRV_PCM_TRIGGER_RESUME:
 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 		ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
 			   params->mask->pdc_enable);
 		break;

 	default:
 		ret = -EINVAL;
 	}

 	return ret;
 }


 static snd_pcm_uframes_t at32_pcm_pointer(struct snd_pcm_substream *substream)
 {
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct at32_runtime_data *prtd = runtime->private_data;
 	struct at32_pcm_dma_params *params = prtd->params;
 	dma_addr_t ptr;
 	snd_pcm_uframes_t x;

 	ptr = (dma_addr_t) ssc_readx(params->ssc->regs, params->pdc->xpr);
 	x = bytes_to_frames(runtime, ptr - prtd->dma_buffer);

 	if (x == runtime->buffer_size)
 		x = 0;

 	return x;
 }


 static int at32_pcm_open(struct snd_pcm_substream *substream)
 {
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct at32_runtime_data *prtd;
 	int ret = 0;

 	snd_soc_set_runtime_hwparams(substream, &at32_pcm_hardware);

 	/* ensure that buffer size is a multiple of period size */
 	ret = snd_pcm_hw_constraint_integer(runtime,
 					    SNDRV_PCM_HW_PARAM_PERIODS);
 	if (ret < 0)
 		goto out;

 	prtd = kzalloc(sizeof(*prtd), GFP_KERNEL);
 	if (prtd == NULL) {
 		ret = -ENOMEM;
 		goto out;
 	}
 	runtime->private_data = prtd;


 out:
 	return ret;
 }


 static int at32_pcm_close(struct snd_pcm_substream *substream)
 {
 	struct at32_runtime_data *prtd = substream->runtime->private_data;

 	kfree(prtd);
 	return 0;
 }


 static int at32_pcm_mmap(struct snd_pcm_substream *substream,
 			 struct vm_area_struct *vma)
 {
 	return remap_pfn_range(vma, vma->vm_start,
 			       substream->dma_buffer.addr >> PAGE_SHIFT,
 			       vma->vm_end - vma->vm_start, vma->vm_page_prot);
 }


 static struct snd_pcm_ops at32_pcm_ops = {
 	.open = at32_pcm_open,
 	.close = at32_pcm_close,
 	.ioctl = snd_pcm_lib_ioctl,
 	.hw_params = at32_pcm_hw_params,
 	.hw_free = at32_pcm_hw_free,
 	.prepare = at32_pcm_prepare,
 	.trigger = at32_pcm_trigger,
 	.pointer = at32_pcm_pointer,
 	.mmap = at32_pcm_mmap,
 };


 /*--------------------------------------------------------------------------*\
  * ASoC platform driver
 \*--------------------------------------------------------------------------*/
 static u64 at32_pcm_dmamask = 0xffffffff;

 static int at32_pcm_new(struct snd_card *card,
 			struct snd_soc_dai *dai,
 			struct snd_pcm *pcm)
 {
 	int ret = 0;

 	if (!card->dev->dma_mask)
 		card->dev->dma_mask = &at32_pcm_dmamask;
 	if (!card->dev->coherent_dma_mask)
 		card->dev->coherent_dma_mask = 0xffffffff;

 	if (dai->playback.channels_min) {
 		ret = at32_pcm_preallocate_dma_buffer(
 			  pcm, SNDRV_PCM_STREAM_PLAYBACK);
 		if (ret)
 			goto out;
 	}

 	if (dai->capture.channels_min) {
 		pr_debug("at32-pcm: Allocating PCM capture DMA buffer\n");
 		ret = at32_pcm_preallocate_dma_buffer(
 			  pcm, SNDRV_PCM_STREAM_CAPTURE);
 		if (ret)
 			goto out;
 	}


 out:
 	return ret;
 }


 static void at32_pcm_free_dma_buffers(struct snd_pcm *pcm)
 {
 	struct snd_pcm_substream *substream;
 	struct snd_dma_buffer *buf;
 	int stream;

 	for (stream = 0; stream < 2; stream++) {
 		substream = pcm->streams[stream].substream;
 		if (substream == NULL)
 			continue;

 		buf = &substream->dma_buffer;
 		if (!buf->area)
 			continue;
 		dma_free_coherent(pcm->card->dev, buf->bytes,
 				  buf->area, buf->addr);
 		buf->area = NULL;
 	}
 }


 #ifdef CONFIG_PM
 static int at32_pcm_suspend(struct platform_device *pdev,
 			    struct snd_soc_dai *dai)
 {
 	struct snd_pcm_runtime *runtime = dai->runtime;
 	struct at32_runtime_data *prtd;
 	struct at32_pcm_dma_params *params;

 	if (runtime == NULL)
 		return 0;
 	prtd = runtime->private_data;
 	params = prtd->params;

 	/* Disable the PDC and save the PDC registers */
 	ssc_writex(params->ssc->regs, PDC_PTCR, params->mask->pdc_disable);

 	prtd->pdc_xpr_save = ssc_readx(params->ssc->regs, params->pdc->xpr);
 	prtd->pdc_xcr_save = ssc_readx(params->ssc->regs, params->pdc->xcr);
 	prtd->pdc_xnpr_save = ssc_readx(params->ssc->regs, params->pdc->xnpr);
 	prtd->pdc_xncr_save = ssc_readx(params->ssc->regs, params->pdc->xncr);

 	return 0;
 }


 static int at32_pcm_resume(struct platform_device *pdev,
 			   struct snd_soc_dai *dai)
 {
 	struct snd_pcm_runtime *runtime = dai->runtime;
 	struct at32_runtime_data *prtd;
 	struct at32_pcm_dma_params *params;

 	if (runtime == NULL)
 		return 0;
 	prtd = runtime->private_data;
 	params = prtd->params;

 	/* Restore the PDC registers and enable the PDC */
 	ssc_writex(params->ssc->regs, params->pdc->xpr, prtd->pdc_xpr_save);
 	ssc_writex(params->ssc->regs, params->pdc->xcr, prtd->pdc_xcr_save);
 	ssc_writex(params->ssc->regs, params->pdc->xnpr, prtd->pdc_xnpr_save);
 	ssc_writex(params->ssc->regs, params->pdc->xncr, prtd->pdc_xncr_save);

 	ssc_writex(params->ssc->regs, PDC_PTCR, params->mask->pdc_enable);
 	return 0;
 }
 #else /* CONFIG_PM */
 #  define at32_pcm_suspend	NULL
 #  define at32_pcm_resume	NULL
 #endif /* CONFIG_PM */


 struct snd_soc_platform at32_soc_platform = {
 	.name = "at32-audio",
 	.pcm_ops = &at32_pcm_ops,
 	.pcm_new = at32_pcm_new,
 	.pcm_free = at32_pcm_free_dma_buffers,
 	.suspend = at32_pcm_suspend,
 	.resume = at32_pcm_resume,
 };
 EXPORT_SYMBOL_GPL(at32_soc_platform);


 MODULE_AUTHOR("Geoffrey Wossum <gwossum@acm.org>");
 MODULE_DESCRIPTION("Atmel AT32 PCM module");
 MODULE_LICENSE("GPL");
	/* sound/soc/at32/at32-pcm.c
	* ASoC PCM interface for Atmel AT32 SoC
	*
	* Copyright (C) 2008 Long Range Systems
	* Geoffrey Wossum <gwossum@acm.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.
	*
	* Note that this is basically a port of the sound/soc/at91-pcm.c to
	* the AVR32 kernel. Thanks to Frank Mandarino for that code.
	*/

	#include <linux/module.h>
	#include <linux/init.h>
	#include <linux/platform_device.h>
	#include <linux/slab.h>
	#include <linux/dma-mapping.h>
	#include <linux/atmel_pdc.h>

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

	#include "at32-pcm.h"



	/--------------------------------------------------------------------------\
	* Hardware definition
	\--------------------------------------------------------------------------/
	/* TODO: These values were taken from the AT91 platform driver, check
	* them against real values for AT32
	*/
	static const struct snd_pcm_hardware at32_pcm_hardware = {
	.info = (SNDRV_PCM_INFO_MMAP \|
	SNDRV_PCM_INFO_MMAP_VALID \|
	SNDRV_PCM_INFO_INTERLEAVED \|
	SNDRV_PCM_INFO_BLOCK_TRANSFER \|
	SNDRV_PCM_INFO_PAUSE),

	.formats = SNDRV_PCM_FMTBIT_S16,
	.period_bytes_min = 32,
	.period_bytes_max = 8192, /* 512 frames * 16 bytes / frame */
	.periods_min = 2,
	.periods_max = 1024,
	.buffer_bytes_max = 32 * 1024,
	};



	/--------------------------------------------------------------------------\
	* Data types
	\--------------------------------------------------------------------------/
	struct at32_runtime_data {
	struct at32_pcm_dma_params *params;
	dma_addr_t dma_buffer; /* physical address of DMA buffer */
	dma_addr_t dma_buffer_end; /* first address beyond DMA buffer */
	size_t period_size;

	dma_addr_t period_ptr; /* physical address of next period */
	int periods; /* period index of period_ptr */

	/* Save PDC registers (for power management) */
	u32 pdc_xpr_save;
	u32 pdc_xcr_save;
	u32 pdc_xnpr_save;
	u32 pdc_xncr_save;
	};



	/--------------------------------------------------------------------------\
	* Helper functions
	\--------------------------------------------------------------------------/
	static int at32_pcm_preallocate_dma_buffer(struct snd_pcm *pcm, int stream)
	{
	struct snd_pcm_substream *substream = pcm->streams[stream].substream;
	struct snd_dma_buffer *dmabuf = &substream->dma_buffer;
	size_t size = at32_pcm_hardware.buffer_bytes_max;

	dmabuf->dev.type = SNDRV_DMA_TYPE_DEV;
	dmabuf->dev.dev = pcm->card->dev;
	dmabuf->private_data = NULL;
	dmabuf->area = dma_alloc_coherent(pcm->card->dev, size,
	&dmabuf->addr, GFP_KERNEL);
	pr_debug("at32_pcm: preallocate_dma_buffer: "
	"area=%p, addr=%p, size=%ld\n",
	(void )dmabuf->area, (void )dmabuf->addr, size);

	if (!dmabuf->area)
	return -ENOMEM;

	dmabuf->bytes = size;
	return 0;
	}



	/--------------------------------------------------------------------------\
	* ISR
	\--------------------------------------------------------------------------/
	static void at32_pcm_dma_irq(u32 ssc_sr, struct snd_pcm_substream *substream)
	{
	struct snd_pcm_runtime *rtd = substream->runtime;
	struct at32_runtime_data *prtd = rtd->private_data;
	struct at32_pcm_dma_params *params = prtd->params;
	static int count;

	count++;
	if (ssc_sr & params->mask->ssc_endbuf) {
	pr_warning("at32-pcm: buffer %s on %s (SSC_SR=%#x, count=%d)\n",
	substream->stream == SNDRV_PCM_STREAM_PLAYBACK ?
	"underrun" : "overrun", params->name, ssc_sr, count);

	/* re-start the PDC */
	ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
	params->mask->pdc_disable);
	prtd->period_ptr += prtd->period_size;
	if (prtd->period_ptr >= prtd->dma_buffer_end)
	prtd->period_ptr = prtd->dma_buffer;


	ssc_writex(params->ssc->regs, params->pdc->xpr,
	prtd->period_ptr);
	ssc_writex(params->ssc->regs, params->pdc->xcr,
	prtd->period_size / params->pdc_xfer_size);
	ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
	params->mask->pdc_enable);
	}


	if (ssc_sr & params->mask->ssc_endx) {
	/* Load the PDC next pointer and counter registers */
	prtd->period_ptr += prtd->period_size;
	if (prtd->period_ptr >= prtd->dma_buffer_end)
	prtd->period_ptr = prtd->dma_buffer;
	ssc_writex(params->ssc->regs, params->pdc->xnpr,
	prtd->period_ptr);
	ssc_writex(params->ssc->regs, params->pdc->xncr,
	prtd->period_size / params->pdc_xfer_size);
	}


	snd_pcm_period_elapsed(substream);
	}



	/--------------------------------------------------------------------------\
	* PCM operations
	\--------------------------------------------------------------------------/
	static int at32_pcm_hw_params(struct snd_pcm_substream *substream,
	struct snd_pcm_hw_params *params)
	{
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct at32_runtime_data *prtd = runtime->private_data;
	struct snd_soc_pcm_runtime *rtd = substream->private_data;

	/* this may get called several times by oss emulation
	* with different params
	*/
	snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
	runtime->dma_bytes = params_buffer_bytes(params);

	prtd->params = rtd->dai->cpu_dai->dma_data;
	prtd->params->dma_intr_handler = at32_pcm_dma_irq;

	prtd->dma_buffer = runtime->dma_addr;
	prtd->dma_buffer_end = runtime->dma_addr + runtime->dma_bytes;
	prtd->period_size = params_period_bytes(params);

	pr_debug("hw_params: DMA for %s initialized "
	"(dma_bytes=%ld, period_size=%ld)\n",
	prtd->params->name, runtime->dma_bytes, prtd->period_size);

	return 0;
	}



	static int at32_pcm_hw_free(struct snd_pcm_substream *substream)
	{
	struct at32_runtime_data *prtd = substream->runtime->private_data;
	struct at32_pcm_dma_params *params = prtd->params;

	if (params != NULL) {
	ssc_writex(params->ssc->regs, SSC_PDC_PTCR,
	params->mask->pdc_disable);
	prtd->params->dma_intr_handler = NULL;
	}

	return 0;
	}



	static int at32_pcm_prepare(struct snd_pcm_substream *substream)
	{
	struct at32_runtime_data *prtd = substream->runtime->private_data;
	struct at32_pcm_dma_params *params = prtd->params;

	ssc_writex(params->ssc->regs, SSC_IDR,
	params->mask->ssc_endx \| params->mask->ssc_endbuf);
	ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
	params->mask->pdc_disable);

	return 0;
	}


	static int at32_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
	{
	struct snd_pcm_runtime *rtd = substream->runtime;
	struct at32_runtime_data *prtd = rtd->private_data;
	struct at32_pcm_dma_params *params = prtd->params;
	int ret = 0;

	pr_debug("at32_pcm_trigger: buffer_size = %ld, "
	"dma_area = %p, dma_bytes = %ld\n",
	rtd->buffer_size, rtd->dma_area, rtd->dma_bytes);

	switch (cmd) {
	case SNDRV_PCM_TRIGGER_START:
	prtd->period_ptr = prtd->dma_buffer;

	ssc_writex(params->ssc->regs, params->pdc->xpr,
	prtd->period_ptr);
	ssc_writex(params->ssc->regs, params->pdc->xcr,
	prtd->period_size / params->pdc_xfer_size);

	prtd->period_ptr += prtd->period_size;
	ssc_writex(params->ssc->regs, params->pdc->xnpr,
	prtd->period_ptr);
	ssc_writex(params->ssc->regs, params->pdc->xncr,
	prtd->period_size / params->pdc_xfer_size);

	pr_debug("trigger: period_ptr=%lx, xpr=%x, "
	"xcr=%d, xnpr=%x, xncr=%d\n",
	(unsigned long)prtd->period_ptr,
	ssc_readx(params->ssc->regs, params->pdc->xpr),
	ssc_readx(params->ssc->regs, params->pdc->xcr),
	ssc_readx(params->ssc->regs, params->pdc->xnpr),
	ssc_readx(params->ssc->regs, params->pdc->xncr));

	ssc_writex(params->ssc->regs, SSC_IER,
	params->mask->ssc_endx \| params->mask->ssc_endbuf);
	ssc_writex(params->ssc->regs, SSC_PDC_PTCR,
	params->mask->pdc_enable);

	pr_debug("sr=%x, imr=%x\n",
	ssc_readx(params->ssc->regs, SSC_SR),
	ssc_readx(params->ssc->regs, SSC_IER));
	break; /* SNDRV_PCM_TRIGGER_START */



	case SNDRV_PCM_TRIGGER_STOP:
	case SNDRV_PCM_TRIGGER_SUSPEND:
	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
	ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
	params->mask->pdc_disable);
	break;


	case SNDRV_PCM_TRIGGER_RESUME:
	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
	ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
	params->mask->pdc_enable);
	break;

	default:
	ret = -EINVAL;
	}

	return ret;
	}



	static snd_pcm_uframes_t at32_pcm_pointer(struct snd_pcm_substream *substream)
	{
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct at32_runtime_data *prtd = runtime->private_data;
	struct at32_pcm_dma_params *params = prtd->params;
	dma_addr_t ptr;
	snd_pcm_uframes_t x;

	ptr = (dma_addr_t) ssc_readx(params->ssc->regs, params->pdc->xpr);
	x = bytes_to_frames(runtime, ptr - prtd->dma_buffer);

	if (x == runtime->buffer_size)
	x = 0;

	return x;
	}



	static int at32_pcm_open(struct snd_pcm_substream *substream)
	{
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct at32_runtime_data *prtd;
	int ret = 0;

	snd_soc_set_runtime_hwparams(substream, &at32_pcm_hardware);

	/* ensure that buffer size is a multiple of period size */
	ret = snd_pcm_hw_constraint_integer(runtime,
	SNDRV_PCM_HW_PARAM_PERIODS);
	if (ret < 0)
	goto out;

	prtd = kzalloc(sizeof(*prtd), GFP_KERNEL);
	if (prtd == NULL) {
	ret = -ENOMEM;
	goto out;
	}
	runtime->private_data = prtd;


	out:
	return ret;
	}



	static int at32_pcm_close(struct snd_pcm_substream *substream)
	{
	struct at32_runtime_data *prtd = substream->runtime->private_data;

	kfree(prtd);
	return 0;
	}


	static int at32_pcm_mmap(struct snd_pcm_substream *substream,
	struct vm_area_struct *vma)
	{
	return remap_pfn_range(vma, vma->vm_start,
	substream->dma_buffer.addr >> PAGE_SHIFT,
	vma->vm_end - vma->vm_start, vma->vm_page_prot);
	}



	static struct snd_pcm_ops at32_pcm_ops = {
	.open = at32_pcm_open,
	.close = at32_pcm_close,
	.ioctl = snd_pcm_lib_ioctl,
	.hw_params = at32_pcm_hw_params,
	.hw_free = at32_pcm_hw_free,
	.prepare = at32_pcm_prepare,
	.trigger = at32_pcm_trigger,
	.pointer = at32_pcm_pointer,
	.mmap = at32_pcm_mmap,
	};



	/--------------------------------------------------------------------------\
	* ASoC platform driver
	\--------------------------------------------------------------------------/
	static u64 at32_pcm_dmamask = 0xffffffff;

	static int at32_pcm_new(struct snd_card *card,
	struct snd_soc_dai *dai,
	struct snd_pcm *pcm)
	{
	int ret = 0;

	if (!card->dev->dma_mask)
	card->dev->dma_mask = &at32_pcm_dmamask;
	if (!card->dev->coherent_dma_mask)
	card->dev->coherent_dma_mask = 0xffffffff;

	if (dai->playback.channels_min) {
	ret = at32_pcm_preallocate_dma_buffer(
	pcm, SNDRV_PCM_STREAM_PLAYBACK);
	if (ret)
	goto out;
	}

	if (dai->capture.channels_min) {
	pr_debug("at32-pcm: Allocating PCM capture DMA buffer\n");
	ret = at32_pcm_preallocate_dma_buffer(
	pcm, SNDRV_PCM_STREAM_CAPTURE);
	if (ret)
	goto out;
	}


	out:
	return ret;
	}



	static void at32_pcm_free_dma_buffers(struct snd_pcm *pcm)
	{
	struct snd_pcm_substream *substream;
	struct snd_dma_buffer *buf;
	int stream;

	for (stream = 0; stream < 2; stream++) {
	substream = pcm->streams[stream].substream;
	if (substream == NULL)
	continue;

	buf = &substream->dma_buffer;
	if (!buf->area)
	continue;
	dma_free_coherent(pcm->card->dev, buf->bytes,
	buf->area, buf->addr);
	buf->area = NULL;
	}
	}



	#ifdef CONFIG_PM
	static int at32_pcm_suspend(struct platform_device *pdev,
	struct snd_soc_dai *dai)
	{
	struct snd_pcm_runtime *runtime = dai->runtime;
	struct at32_runtime_data *prtd;
	struct at32_pcm_dma_params *params;

	if (runtime == NULL)
	return 0;
	prtd = runtime->private_data;
	params = prtd->params;

	/* Disable the PDC and save the PDC registers */
	ssc_writex(params->ssc->regs, PDC_PTCR, params->mask->pdc_disable);

	prtd->pdc_xpr_save = ssc_readx(params->ssc->regs, params->pdc->xpr);
	prtd->pdc_xcr_save = ssc_readx(params->ssc->regs, params->pdc->xcr);
	prtd->pdc_xnpr_save = ssc_readx(params->ssc->regs, params->pdc->xnpr);
	prtd->pdc_xncr_save = ssc_readx(params->ssc->regs, params->pdc->xncr);

	return 0;
	}



	static int at32_pcm_resume(struct platform_device *pdev,
	struct snd_soc_dai *dai)
	{
	struct snd_pcm_runtime *runtime = dai->runtime;
	struct at32_runtime_data *prtd;
	struct at32_pcm_dma_params *params;

	if (runtime == NULL)
	return 0;
	prtd = runtime->private_data;
	params = prtd->params;

	/* Restore the PDC registers and enable the PDC */
	ssc_writex(params->ssc->regs, params->pdc->xpr, prtd->pdc_xpr_save);
	ssc_writex(params->ssc->regs, params->pdc->xcr, prtd->pdc_xcr_save);
	ssc_writex(params->ssc->regs, params->pdc->xnpr, prtd->pdc_xnpr_save);
	ssc_writex(params->ssc->regs, params->pdc->xncr, prtd->pdc_xncr_save);

	ssc_writex(params->ssc->regs, PDC_PTCR, params->mask->pdc_enable);
	return 0;
	}
	#else /* CONFIG_PM */
	# define at32_pcm_suspend NULL
	# define at32_pcm_resume NULL
	#endif /* CONFIG_PM */



	struct snd_soc_platform at32_soc_platform = {
	.name = "at32-audio",
	.pcm_ops = &at32_pcm_ops,
	.pcm_new = at32_pcm_new,
	.pcm_free = at32_pcm_free_dma_buffers,
	.suspend = at32_pcm_suspend,
	.resume = at32_pcm_resume,
	};
	EXPORT_SYMBOL_GPL(at32_soc_platform);



	MODULE_AUTHOR("Geoffrey Wossum <gwossum@acm.org>");
	MODULE_DESCRIPTION("Atmel AT32 PCM module");
	MODULE_LICENSE("GPL");