/*
 * File:         sound/soc/blackfin/bf5xx-ac97-pcm.c
 * Author:       Cliff Cai <Cliff.Cai@analog.com>
 *
 * Created:      Tue June 06 2008
 * Description:  DMA Driver for AC97 sound chip
 *
 * Modified:
 *               Copyright 2008 Analog Devices Inc.
 *
 * Bugs:         Enter bugs at http://blackfin.uclinux.org/
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see the file COPYING, or write
 * to the Free Software Foundation, Inc.,
 * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

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

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

#include <asm/dma.h>

#include "bf5xx-ac97-pcm.h"
#include "bf5xx-ac97.h"
#include "bf5xx-sport.h"

#if defined(CONFIG_SND_MMAP_SUPPORT)
static void bf5xx_mmap_copy(struct snd_pcm_substream *substream,
	 snd_pcm_uframes_t count)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct sport_device *sport = runtime->private_data;
	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
		bf5xx_pcm_to_ac97(
			(struct ac97_frame *)sport->tx_dma_buf + sport->tx_pos,
			(__u32 *)runtime->dma_area + sport->tx_pos, count);
		sport->tx_pos += runtime->period_size;
		if (sport->tx_pos >= runtime->buffer_size)
			sport->tx_pos %= runtime->buffer_size;
		sport->tx_delay_pos = sport->tx_pos;
	} else {
		bf5xx_ac97_to_pcm(
			(struct ac97_frame *)sport->rx_dma_buf + sport->rx_pos,
			(__u32 *)runtime->dma_area + sport->rx_pos, count);
		sport->rx_pos += runtime->period_size;
		if (sport->rx_pos >= runtime->buffer_size)
			sport->rx_pos %= runtime->buffer_size;
	}
}
#endif

static void bf5xx_dma_irq(void *data)
{
	struct snd_pcm_substream *pcm = data;
#if defined(CONFIG_SND_MMAP_SUPPORT)
	struct snd_pcm_runtime *runtime = pcm->runtime;
	struct sport_device *sport = runtime->private_data;
	bf5xx_mmap_copy(pcm, runtime->period_size);
	if (pcm->stream == SNDRV_PCM_STREAM_PLAYBACK) {
		if (sport->once == 0) {
			snd_pcm_period_elapsed(pcm);
			bf5xx_mmap_copy(pcm, runtime->period_size);
			sport->once = 1;
		}
	}
#endif
	snd_pcm_period_elapsed(pcm);
}

/* The memory size for pure pcm data is 128*1024 = 0x20000 bytes.
 * The total rx/tx buffer is for ac97 frame to hold all pcm data
 * is  0x20000 * sizeof(struct ac97_frame) / 4.
 */
#ifdef CONFIG_SND_MMAP_SUPPORT
static const struct snd_pcm_hardware bf5xx_pcm_hardware = {
	.info			= SNDRV_PCM_INFO_INTERLEAVED |
				   SNDRV_PCM_INFO_MMAP |
				   SNDRV_PCM_INFO_MMAP_VALID |
				   SNDRV_PCM_INFO_BLOCK_TRANSFER,
#else
static const struct snd_pcm_hardware bf5xx_pcm_hardware = {
	.info			= SNDRV_PCM_INFO_INTERLEAVED |
				  SNDRV_PCM_INFO_BLOCK_TRANSFER,
#endif
	.formats		= SNDRV_PCM_FMTBIT_S16_LE,
	.period_bytes_min	= 32,
	.period_bytes_max	= 0x10000,
	.periods_min		= 1,
	.periods_max		= PAGE_SIZE/32,
	.buffer_bytes_max	= 0x20000, /* 128 kbytes */
	.fifo_size		= 16,
};

static int bf5xx_pcm_hw_params(struct snd_pcm_substream *substream,
	struct snd_pcm_hw_params *params)
{
	size_t size = bf5xx_pcm_hardware.buffer_bytes_max
			* sizeof(struct ac97_frame) / 4;

	snd_pcm_lib_malloc_pages(substream, size);

	return 0;
}

static int bf5xx_pcm_hw_free(struct snd_pcm_substream *substream)
{
	struct snd_pcm_runtime *runtime = substream->runtime;

	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
	memset(runtime->dma_area, 0, runtime->buffer_size);
	snd_pcm_lib_free_pages(substream);
	return 0;
}

static int bf5xx_pcm_prepare(struct snd_pcm_substream *substream)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct sport_device *sport = runtime->private_data;

	/* An intermediate buffer is introduced for implementing mmap for
	 * SPORT working in TMD mode(include AC97).
	 */
#if defined(CONFIG_SND_MMAP_SUPPORT)
	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
		sport_set_tx_callback(sport, bf5xx_dma_irq, substream);
		sport_config_tx_dma(sport, sport->tx_dma_buf, runtime->periods,
			runtime->period_size * sizeof(struct ac97_frame));
	} else {
		sport_set_rx_callback(sport, bf5xx_dma_irq, substream);
		sport_config_rx_dma(sport, sport->rx_dma_buf, runtime->periods,
			runtime->period_size * sizeof(struct ac97_frame));
	}
#else
	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
		sport_set_tx_callback(sport, bf5xx_dma_irq, substream);
		sport_config_tx_dma(sport, runtime->dma_area, runtime->periods,
			runtime->period_size * sizeof(struct ac97_frame));
	} else {
		sport_set_rx_callback(sport, bf5xx_dma_irq, substream);
		sport_config_rx_dma(sport, runtime->dma_area, runtime->periods,
			runtime->period_size * sizeof(struct ac97_frame));
	}
#endif
	return 0;
}

static int bf5xx_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct sport_device *sport = runtime->private_data;
	int ret = 0;

	pr_debug("%s enter\n", __func__);
	switch (cmd) {
	case SNDRV_PCM_TRIGGER_START:
		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
			bf5xx_mmap_copy(substream, runtime->period_size);
			snd_pcm_period_elapsed(substream);
			sport->tx_delay_pos = 0;
			sport_tx_start(sport);
		}
		else
			sport_rx_start(sport);
		break;
	case SNDRV_PCM_TRIGGER_STOP:
	case SNDRV_PCM_TRIGGER_SUSPEND:
	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
#if defined(CONFIG_SND_MMAP_SUPPORT)
			sport->tx_pos = 0;
#endif
			sport_tx_stop(sport);
		} else {
#if defined(CONFIG_SND_MMAP_SUPPORT)
			sport->rx_pos = 0;
#endif
			sport_rx_stop(sport);
		}
		break;
	default:
		ret = -EINVAL;
	}
	return ret;
}

static snd_pcm_uframes_t bf5xx_pcm_pointer(struct snd_pcm_substream *substream)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct sport_device *sport = runtime->private_data;
	unsigned int curr;

#if defined(CONFIG_SND_MMAP_SUPPORT)
	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
		curr = sport->tx_delay_pos;
	else
		curr = sport->rx_pos;
#else

	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
		curr = sport_curr_offset_tx(sport) / sizeof(struct ac97_frame);
	else
		curr = sport_curr_offset_rx(sport) / sizeof(struct ac97_frame);

#endif
	return curr;
}

static int bf5xx_pcm_open(struct snd_pcm_substream *substream)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	int ret;

	pr_debug("%s enter\n", __func__);
	snd_soc_set_runtime_hwparams(substream, &bf5xx_pcm_hardware);

	ret = snd_pcm_hw_constraint_integer(runtime,
					    SNDRV_PCM_HW_PARAM_PERIODS);
	if (ret < 0)
		goto out;

	if (sport_handle != NULL)
		runtime->private_data = sport_handle;
	else {
		pr_err("sport_handle is NULL\n");
		return -1;
	}
	return 0;

 out:
	return ret;
}

static int bf5xx_pcm_close(struct snd_pcm_substream *substream)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct sport_device *sport = runtime->private_data;

	pr_debug("%s enter\n", __func__);
	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
		sport->once = 0;
		memset(sport->tx_dma_buf, 0, runtime->buffer_size * sizeof(struct ac97_frame));
	} else
		memset(sport->rx_dma_buf, 0, runtime->buffer_size * sizeof(struct ac97_frame));

	return 0;
}

#ifdef CONFIG_SND_MMAP_SUPPORT
static int bf5xx_pcm_mmap(struct snd_pcm_substream *substream,
	struct vm_area_struct *vma)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	size_t size = vma->vm_end - vma->vm_start;
	vma->vm_start = (unsigned long)runtime->dma_area;
	vma->vm_end = vma->vm_start + size;
	vma->vm_flags |=  VM_SHARED;
	return 0 ;
}
#else
static	int bf5xx_pcm_copy(struct snd_pcm_substream *substream, int channel,
		    snd_pcm_uframes_t pos,
		    void __user *buf, snd_pcm_uframes_t count)
{
	struct snd_pcm_runtime *runtime = substream->runtime;

	pr_debug("%s copy pos:0x%lx count:0x%lx\n",
			substream->stream ? "Capture" : "Playback", pos, count);

	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
		bf5xx_pcm_to_ac97(
				(struct ac97_frame *)runtime->dma_area + pos,
				buf, count);
	else
		bf5xx_ac97_to_pcm(
				(struct ac97_frame *)runtime->dma_area + pos,
				buf, count);
	return 0;
}
#endif

struct snd_pcm_ops bf5xx_pcm_ac97_ops = {
	.open		= bf5xx_pcm_open,
	.close		= bf5xx_pcm_close,
	.ioctl		= snd_pcm_lib_ioctl,
	.hw_params	= bf5xx_pcm_hw_params,
	.hw_free	= bf5xx_pcm_hw_free,
	.prepare	= bf5xx_pcm_prepare,
	.trigger	= bf5xx_pcm_trigger,
	.pointer	= bf5xx_pcm_pointer,
#ifdef CONFIG_SND_MMAP_SUPPORT
	.mmap		= bf5xx_pcm_mmap,
#else
	.copy		= bf5xx_pcm_copy,
#endif
};

static int bf5xx_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 = bf5xx_pcm_hardware.buffer_bytes_max
			* sizeof(struct ac97_frame) / 4;

	buf->dev.type = SNDRV_DMA_TYPE_DEV;
	buf->dev.dev = pcm->card->dev;
	buf->private_data = NULL;
	buf->area = dma_alloc_coherent(pcm->card->dev, size,
			&buf->addr, GFP_KERNEL);
	if (!buf->area) {
		pr_err("Failed to allocate dma memory\n");
		pr_err("Please increase uncached DMA memory region\n");
		return -ENOMEM;
	}
	buf->bytes = size;

	pr_debug("%s, area:%p, size:0x%08lx\n", __func__,
			buf->area, buf->bytes);

	if (stream == SNDRV_PCM_STREAM_PLAYBACK)
		sport_handle->tx_buf = buf->area;
	else
		sport_handle->rx_buf = buf->area;

/*
 * Need to allocate local buffer when enable
 * MMAP for SPORT working in TMD mode (include AC97).
 */
#if defined(CONFIG_SND_MMAP_SUPPORT)
	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
		if (!sport_handle->tx_dma_buf) {
			sport_handle->tx_dma_buf = dma_alloc_coherent(NULL, \
				size, &sport_handle->tx_dma_phy, GFP_KERNEL);
			if (!sport_handle->tx_dma_buf) {
				pr_err("Failed to allocate memory for tx dma \
					buf - Please increase uncached DMA \
					memory region\n");
				return -ENOMEM;
			} else
				memset(sport_handle->tx_dma_buf, 0, size);
		} else
			memset(sport_handle->tx_dma_buf, 0, size);
	} else {
		if (!sport_handle->rx_dma_buf) {
			sport_handle->rx_dma_buf = dma_alloc_coherent(NULL, \
				size, &sport_handle->rx_dma_phy, GFP_KERNEL);
			if (!sport_handle->rx_dma_buf) {
				pr_err("Failed to allocate memory for rx dma \
					buf - Please increase uncached DMA \
					memory region\n");
				return -ENOMEM;
			} else
				memset(sport_handle->rx_dma_buf, 0, size);
		} else
			memset(sport_handle->rx_dma_buf, 0, size);
	}
#endif
	return 0;
}

static void bf5xx_pcm_free_dma_buffers(struct snd_pcm *pcm)
{
	struct snd_pcm_substream *substream;
	struct snd_dma_buffer *buf;
	int stream;
#if defined(CONFIG_SND_MMAP_SUPPORT)
	size_t size = bf5xx_pcm_hardware.buffer_bytes_max *
		sizeof(struct ac97_frame) / 4;
#endif
	for (stream = 0; stream < 2; stream++) {
		substream = pcm->streams[stream].substream;
		if (!substream)
			continue;

		buf = &substream->dma_buffer;
		if (!buf->area)
			continue;
		dma_free_coherent(NULL, buf->bytes, buf->area, 0);
		buf->area = NULL;
#if defined(CONFIG_SND_MMAP_SUPPORT)
	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
		if (sport_handle->tx_dma_buf)
			dma_free_coherent(NULL, size, \
				sport_handle->tx_dma_buf, 0);
		sport_handle->tx_dma_buf = NULL;
	} else {

		if (sport_handle->rx_dma_buf)
			dma_free_coherent(NULL, size, \
				sport_handle->rx_dma_buf, 0);
		sport_handle->rx_dma_buf = NULL;
	}
#endif
	}
	if (sport_handle)
		sport_done(sport_handle);
}

static u64 bf5xx_pcm_dmamask = DMA_32BIT_MASK;

int bf5xx_pcm_ac97_new(struct snd_card *card, struct snd_soc_dai *dai,
	struct snd_pcm *pcm)
{
	int ret = 0;

	pr_debug("%s enter\n", __func__);
	if (!card->dev->dma_mask)
		card->dev->dma_mask = &bf5xx_pcm_dmamask;
	if (!card->dev->coherent_dma_mask)
		card->dev->coherent_dma_mask = DMA_32BIT_MASK;

	if (dai->playback.channels_min) {
		ret = bf5xx_pcm_preallocate_dma_buffer(pcm,
			SNDRV_PCM_STREAM_PLAYBACK);
		if (ret)
			goto out;
	}

	if (dai->capture.channels_min) {
		ret = bf5xx_pcm_preallocate_dma_buffer(pcm,
			SNDRV_PCM_STREAM_CAPTURE);
		if (ret)
			goto out;
	}
 out:
	return ret;
}

struct snd_soc_platform bf5xx_ac97_soc_platform = {
	.name		= "bf5xx-audio",
	.pcm_ops 	= &bf5xx_pcm_ac97_ops,
	.pcm_new	= bf5xx_pcm_ac97_new,
	.pcm_free	= bf5xx_pcm_free_dma_buffers,
};
EXPORT_SYMBOL_GPL(bf5xx_ac97_soc_platform);

MODULE_AUTHOR("Cliff Cai");
MODULE_DESCRIPTION("ADI Blackfin AC97 PCM DMA module");
MODULE_LICENSE("GPL");