/*
 * 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 <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/pxa2xx-lib.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;

	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->dev_addr;
		} else {
			dma_desc->dsadr = rtd->params->dev_addr;
			dma_desc->dtadr = dma_buff_phys;
		}
		if (period > totsize)
			period = totsize;
		dma_desc->dcmd = rtd->params->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->drcmr)
		*rtd->params->drcmr = 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;

	if (!prtd || !prtd->params)
		return 0;

	DCSR(prtd->dma_ch) &= ~DCSR_RUN;
	DCSR(prtd->dma_ch) = 0;
	DCMD(prtd->dma_ch) = 0;
	*prtd->params->drcmr = 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;
	struct pxa2xx_runtime_data *rtd = substream->runtime->private_data;
	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 "%s: DMA error on channel %d (DCSR=%#x)\n",
			rtd->params->name, dma_ch, dcsr);
		snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
	}
}
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");
