/*
   * 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/slab.h>
  #include <linux/module.h>
  #include <linux/dma-mapping.h>
  #include <linux/dmaengine.h>
  
  #include <sound/core.h>
  #include <sound/pcm.h>
  #include <sound/pcm_params.h>
  #include <sound/pxa2xx-lib.h>
  #include <sound/dmaengine_pcm.h>
  
  #include <mach/dma.h>
  
  #include "pxa2xx-pcm.h"
  
  static const struct snd_pcm_hardware pxa2xx_pcm_hardware = {
  	.info			= SNDRV_PCM_INFO_MMAP |
  				  SNDRV_PCM_INFO_MMAP_VALID |
  				  SNDRV_PCM_INFO_INTERLEAVED |
  				  SNDRV_PCM_INFO_PAUSE |
  				  SNDRV_PCM_INFO_RESUME,
  	.formats		= SNDRV_PCM_FMTBIT_S16_LE |
  					SNDRV_PCM_FMTBIT_S24_LE |
  					SNDRV_PCM_FMTBIT_S32_LE,
  	.period_bytes_min	= 32,
  	.period_bytes_max	= 8192 - 32,
  	.periods_min		= 1,
  	.periods_max		= PAGE_SIZE/sizeof(pxa_dma_desc),
  	.buffer_bytes_max	= 128 * 1024,
  	.fifo_size		= 32,
  };
  
  int __pxa2xx_pcm_hw_params(struct snd_pcm_substream *substream,
  				struct snd_pcm_hw_params *params)
  {
  	struct snd_pcm_runtime *runtime = substream->runtime;
  	struct pxa2xx_runtime_data *rtd = runtime->private_data;
  	size_t totsize = params_buffer_bytes(params);
  	size_t period = params_period_bytes(params);
  	pxa_dma_desc *dma_desc;
  	dma_addr_t dma_buff_phys, next_desc_phys;
  	u32 dcmd = DCMD_INCSRCADDR | DCMD_FLOWTRG;
  
  	/* temporary transition hack */
  	switch (rtd->params->addr_width) {
  	case DMA_SLAVE_BUSWIDTH_1_BYTE:
  		dcmd |= DCMD_WIDTH1;
  		break;
  	case DMA_SLAVE_BUSWIDTH_2_BYTES:
  		dcmd |= DCMD_WIDTH2;
  		break;
  	case DMA_SLAVE_BUSWIDTH_4_BYTES:
  		dcmd |= DCMD_WIDTH4;
  		break;
  	default:
  		/* can't happen */
  		break;
  	}
  
  	switch (rtd->params->maxburst) {
  	case 8:
  		dcmd |= DCMD_BURST8;
  		break;
  	case 16:
  		dcmd |= DCMD_BURST16;
  		break;
  	case 32:
  		dcmd |= DCMD_BURST32;
  		break;
  	}
  
  	snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
  	runtime->dma_bytes = totsize;
  
  	dma_desc = rtd->dma_desc_array;
  	next_desc_phys = rtd->dma_desc_array_phys;
  	dma_buff_phys = runtime->dma_addr;
  	do {
  		next_desc_phys += sizeof(pxa_dma_desc);
  		dma_desc->ddadr = next_desc_phys;
  		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
  			dma_desc->dsadr = dma_buff_phys;
  			dma_desc->dtadr = rtd->params->addr;
  		} else {
  			dma_desc->dsadr = rtd->params->addr;
  			dma_desc->dtadr = dma_buff_phys;
  		}
  		if (period > totsize)
  			period = totsize;
  		dma_desc->dcmd = dcmd | period | DCMD_ENDIRQEN;
  		dma_desc++;
  		dma_buff_phys += period;
  	} while (totsize -= period);
  	dma_desc[-1].ddadr = rtd->dma_desc_array_phys;
  
  	return 0;
  }
  EXPORT_SYMBOL(__pxa2xx_pcm_hw_params);
  
  int __pxa2xx_pcm_hw_free(struct snd_pcm_substream *substream)
  {
  	struct pxa2xx_runtime_data *rtd = substream->runtime->private_data;
  
  	if (rtd && rtd->params && rtd->params->filter_data) {
  		unsigned long req = *(unsigned long *) rtd->params->filter_data;
  		DRCMR(req) = 0;
  	}
  
  	snd_pcm_set_runtime_buffer(substream, NULL);
  	return 0;
  }
  EXPORT_SYMBOL(__pxa2xx_pcm_hw_free);
  
  int pxa2xx_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
  {
  	struct pxa2xx_runtime_data *prtd = substream->runtime->private_data;
  	int ret = 0;
  
  	switch (cmd) {
  	case SNDRV_PCM_TRIGGER_START:
  		DDADR(prtd->dma_ch) = prtd->dma_desc_array_phys;
  		DCSR(prtd->dma_ch) = DCSR_RUN;
  		break;
  
  	case SNDRV_PCM_TRIGGER_STOP:
  	case SNDRV_PCM_TRIGGER_SUSPEND:
  	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
  		DCSR(prtd->dma_ch) &= ~DCSR_RUN;
  		break;
  
  	case SNDRV_PCM_TRIGGER_RESUME:
  		DCSR(prtd->dma_ch) |= DCSR_RUN;
  		break;
  	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
  		DDADR(prtd->dma_ch) = prtd->dma_desc_array_phys;
  		DCSR(prtd->dma_ch) |= DCSR_RUN;
  		break;
  
  	default:
  		ret = -EINVAL;
  	}
  
  	return ret;
  }
  EXPORT_SYMBOL(pxa2xx_pcm_trigger);
  
  snd_pcm_uframes_t
  pxa2xx_pcm_pointer(struct snd_pcm_substream *substream)
  {
  	struct snd_pcm_runtime *runtime = substream->runtime;
  	struct pxa2xx_runtime_data *prtd = runtime->private_data;
  
  	dma_addr_t ptr = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) ?
  			 DSADR(prtd->dma_ch) : DTADR(prtd->dma_ch);
  	snd_pcm_uframes_t x = bytes_to_frames(runtime, ptr - runtime->dma_addr);
  
  	if (x == runtime->buffer_size)
  		x = 0;
  	return x;
  }
  EXPORT_SYMBOL(pxa2xx_pcm_pointer);
  
  int __pxa2xx_pcm_prepare(struct snd_pcm_substream *substream)
  {
  	struct pxa2xx_runtime_data *prtd = substream->runtime->private_data;
  	unsigned long req;
  
  	if (!prtd || !prtd->params)
  		return 0;
  
  	if (prtd->dma_ch == -1)
  		return -EINVAL;
  
  	DCSR(prtd->dma_ch) &= ~DCSR_RUN;
  	DCSR(prtd->dma_ch) = 0;
  	DCMD(prtd->dma_ch) = 0;
  	req = *(unsigned long *) prtd->params->filter_data;
  	DRCMR(req) = prtd->dma_ch | DRCMR_MAPVLD;
  
  	return 0;
  }
  EXPORT_SYMBOL(__pxa2xx_pcm_prepare);
  
  void pxa2xx_pcm_dma_irq(int dma_ch, void *dev_id)
  {
  	struct snd_pcm_substream *substream = dev_id;
  	int dcsr;
  
  	dcsr = DCSR(dma_ch);
  	DCSR(dma_ch) = dcsr & ~DCSR_STOPIRQEN;
  
  	if (dcsr & DCSR_ENDINTR) {
  		snd_pcm_period_elapsed(substream);
  	} else {
  		printk(KERN_ERR "DMA error on channel %d (DCSR=%#x)
  ",
  			dma_ch, dcsr);
  		snd_pcm_stream_lock(substream);
  		snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
  		snd_pcm_stream_unlock(substream);
  	}
  }
  EXPORT_SYMBOL(pxa2xx_pcm_dma_irq);
  
  int __pxa2xx_pcm_open(struct snd_pcm_substream *substream)
  {
  	struct snd_pcm_runtime *runtime = substream->runtime;
  	struct pxa2xx_runtime_data *rtd;
  	int ret;
  
  	runtime->hw = pxa2xx_pcm_hardware;
  
  	/*
  	 * For mysterious reasons (and despite what the manual says)
  	 * playback samples are lost if the DMA count is not a multiple
  	 * of the DMA burst size.  Let's add a rule to enforce that.
  	 */
  	ret = snd_pcm_hw_constraint_step(runtime, 0,
  		SNDRV_PCM_HW_PARAM_PERIOD_BYTES, 32);
  	if (ret)
  		goto out;
  
  	ret = snd_pcm_hw_constraint_step(runtime, 0,
  		SNDRV_PCM_HW_PARAM_BUFFER_BYTES, 32);
  	if (ret)
  		goto out;
  
  	ret = snd_pcm_hw_constraint_integer(runtime,
  					    SNDRV_PCM_HW_PARAM_PERIODS);
  	if (ret < 0)
  		goto out;
  
  	ret = -ENOMEM;
  	rtd = kzalloc(sizeof(*rtd), GFP_KERNEL);
  	if (!rtd)
  		goto out;
  	rtd->dma_desc_array =
  		dma_alloc_writecombine(substream->pcm->card->dev, PAGE_SIZE,
  				       &rtd->dma_desc_array_phys, GFP_KERNEL);
  	if (!rtd->dma_desc_array)
  		goto err1;
  
  	rtd->dma_ch = -1;
  	runtime->private_data = rtd;
  	return 0;
  
   err1:
  	kfree(rtd);
   out:
  	return ret;
  }
  EXPORT_SYMBOL(__pxa2xx_pcm_open);
  
  int __pxa2xx_pcm_close(struct snd_pcm_substream *substream)
  {
  	struct snd_pcm_runtime *runtime = substream->runtime;
  	struct pxa2xx_runtime_data *rtd = runtime->private_data;
  
  	dma_free_writecombine(substream->pcm->card->dev, PAGE_SIZE,
  			      rtd->dma_desc_array, rtd->dma_desc_array_phys);
  	kfree(rtd);
  	return 0;
  }
  EXPORT_SYMBOL(__pxa2xx_pcm_close);
  
  int pxa2xx_pcm_mmap(struct snd_pcm_substream *substream,
  	struct vm_area_struct *vma)
  {
  	struct snd_pcm_runtime *runtime = substream->runtime;
  	return dma_mmap_writecombine(substream->pcm->card->dev, vma,
  				     runtime->dma_area,
  				     runtime->dma_addr,
  				     runtime->dma_bytes);
  }
  EXPORT_SYMBOL(pxa2xx_pcm_mmap);
  
  int pxa2xx_pcm_preallocate_dma_buffer(struct snd_pcm *pcm, int stream)
  {
  	struct snd_pcm_substream *substream = pcm->streams[stream].substream;
  	struct snd_dma_buffer *buf = &substream->dma_buffer;
  	size_t size = pxa2xx_pcm_hardware.buffer_bytes_max;
  	buf->dev.type = SNDRV_DMA_TYPE_DEV;
  	buf->dev.dev = pcm->card->dev;
  	buf->private_data = NULL;
  	buf->area = dma_alloc_writecombine(pcm->card->dev, size,
  					   &buf->addr, GFP_KERNEL);
  	if (!buf->area)
  		return -ENOMEM;
  	buf->bytes = size;
  	return 0;
  }
  EXPORT_SYMBOL(pxa2xx_pcm_preallocate_dma_buffer);
  
  void pxa2xx_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)
  			continue;
  		buf = &substream->dma_buffer;
  		if (!buf->area)
  			continue;
  		dma_free_writecombine(pcm->card->dev, buf->bytes,
  				      buf->area, buf->addr);
  		buf->area = NULL;
  	}
  }
  EXPORT_SYMBOL(pxa2xx_pcm_free_dma_buffers);
  
  MODULE_AUTHOR("Nicolas Pitre");
  MODULE_DESCRIPTION("Intel PXA2xx sound library");
  MODULE_LICENSE("GPL");