1. 根目录:
2. sound
3. soc
4. blackfin
5. bf5xx-tdm-pcm.c

/*
 * File:         sound/soc/blackfin/bf5xx-tdm-pcm.c
 * Author:       Barry Song <Barry.Song@analog.com>
 *
 * Created:      Tue June 06 2009
 * Description:  DMA driver for tdm codec
 *
 * Modified:
 *               Copyright 2009 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/dma-mapping.h>
#include <linux/gfp.h>

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

#include <asm/dma.h>

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

#define PCM_BUFFER_MAX  0x8000
#define FRAGMENT_SIZE_MIN  (4*1024)
#define FRAGMENTS_MIN  2
#define FRAGMENTS_MAX  32

static void bf5xx_dma_irq(void *data)
{
	struct snd_pcm_substream *pcm = data;
	snd_pcm_period_elapsed(pcm);
}

static const struct snd_pcm_hardware bf5xx_pcm_hardware = {
	.info = (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER |
		SNDRV_PCM_INFO_RESUME),
	.formats =          SNDRV_PCM_FMTBIT_S32_LE,
	.rates =            SNDRV_PCM_RATE_48000,
	.channels_min =     2,
	.channels_max =     8,
	.buffer_bytes_max = PCM_BUFFER_MAX,
	.period_bytes_min = FRAGMENT_SIZE_MIN,
	.period_bytes_max = PCM_BUFFER_MAX/2,
	.periods_min =      FRAGMENTS_MIN,
	.periods_max =      FRAGMENTS_MAX,
};

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;
	snd_pcm_lib_malloc_pages(substream, size * 4);

	return 0;
}

static int bf5xx_pcm_hw_free(struct snd_pcm_substream *substream)
{
	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;
	int fragsize_bytes = frames_to_bytes(runtime, runtime->period_size);

	fragsize_bytes /= runtime->channels;
	/* inflate the fragsize to match the dma width of SPORT */
	fragsize_bytes *= 8;

	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, fragsize_bytes);
	} else {
		sport_set_rx_callback(sport, bf5xx_dma_irq, substream);
		sport_config_rx_dma(sport, runtime->dma_area,
			runtime->periods, fragsize_bytes);
	}

	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;

	switch (cmd) {
	case SNDRV_PCM_TRIGGER_START:
		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
			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)
			sport_tx_stop(sport);
		else
			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 diff;
	snd_pcm_uframes_t frames;

	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
		diff = sport_curr_offset_tx(sport);
		frames = diff / (8*4); /* 32 bytes per frame */
	} else {
		diff = sport_curr_offset_rx(sport);
		frames = diff / (8*4);
	}
	return frames;
}

static int bf5xx_pcm_open(struct snd_pcm_substream *substream)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
	struct sport_device *sport_handle = snd_soc_dai_get_drvdata(cpu_dai);
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct snd_dma_buffer *buf = &substream->dma_buffer;

	int ret = 0;

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

		runtime->private_data = sport_handle;
	} else {
		pr_err("sport_handle is NULL\n");
		ret = -ENODEV;
	}
out:
	return ret;
}

static int bf5xx_pcm_copy(struct snd_pcm_substream *substream, int channel,
	snd_pcm_uframes_t pos, void *buf, snd_pcm_uframes_t count)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct sport_device *sport = runtime->private_data;
	struct bf5xx_tdm_port *tdm_port = sport->private_data;
	unsigned int *src;
	unsigned int *dst;
	int i;

	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
		src = buf;
		dst = (unsigned int *)substream->runtime->dma_area;

		dst += pos * 8;
		while (count--) {
			for (i = 0; i < substream->runtime->channels; i++)
				*(dst + tdm_port->tx_map[i]) = *src++;
			dst += 8;
		}
	} else {
		src = (unsigned int *)substream->runtime->dma_area;
		dst = buf;

		src += pos * 8;
		while (count--) {
			for (i = 0; i < substream->runtime->channels; i++)
				*dst++ = *(src + tdm_port->rx_map[i]);
			src += 8;
		}
	}

	return 0;
}

static int bf5xx_pcm_silence(struct snd_pcm_substream *substream,
	int channel, snd_pcm_uframes_t pos, snd_pcm_uframes_t count)
{
	unsigned char *buf = substream->runtime->dma_area;
	buf += pos * 8 * 4;
	memset(buf, '\0', count * 8 * 4);

	return 0;
}


struct snd_pcm_ops bf5xx_pcm_tdm_ops = {
	.open           = bf5xx_pcm_open,
	.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,
	.copy           = bf5xx_pcm_copy,
	.silence        = bf5xx_pcm_silence,
};

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;

	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 * 4,
		&buf->addr, GFP_KERNEL);
	if (!buf->area) {
		pr_err("Failed to allocate dma memory - Please increase uncached DMA memory region\n");
		return -ENOMEM;
	}
	buf->bytes = size;

	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;

	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;
	}
}

static u64 bf5xx_pcm_dmamask = DMA_BIT_MASK(32);

static int bf5xx_pcm_tdm_new(struct snd_soc_pcm_runtime *rtd)
{
	struct snd_card *card = rtd->card->snd_card;
	struct snd_pcm *pcm = rtd->pcm;
	int ret = 0;

	if (!card->dev->dma_mask)
		card->dev->dma_mask = &bf5xx_pcm_dmamask;
	if (!card->dev->coherent_dma_mask)
		card->dev->coherent_dma_mask = DMA_BIT_MASK(32);

	if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream) {
		ret = bf5xx_pcm_preallocate_dma_buffer(pcm,
			SNDRV_PCM_STREAM_PLAYBACK);
		if (ret)
			goto out;
	}

	if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream) {
		ret = bf5xx_pcm_preallocate_dma_buffer(pcm,
			SNDRV_PCM_STREAM_CAPTURE);
		if (ret)
			goto out;
	}
out:
	return ret;
}

static struct snd_soc_platform_driver bf5xx_tdm_soc_platform = {
	.ops        = &bf5xx_pcm_tdm_ops,
	.pcm_new        = bf5xx_pcm_tdm_new,
	.pcm_free       = bf5xx_pcm_free_dma_buffers,
};

static int bf5xx_soc_platform_probe(struct platform_device *pdev)
{
	return snd_soc_register_platform(&pdev->dev, &bf5xx_tdm_soc_platform);
}

static int bf5xx_soc_platform_remove(struct platform_device *pdev)
{
	snd_soc_unregister_platform(&pdev->dev);
	return 0;
}

static struct platform_driver bfin_tdm_driver = {
	.driver = {
			.name = "bfin-tdm-pcm-audio",
			.owner = THIS_MODULE,
	},

	.probe = bf5xx_soc_platform_probe,
	.remove = bf5xx_soc_platform_remove,
};

module_platform_driver(bfin_tdm_driver);

MODULE_AUTHOR("Barry Song");
MODULE_DESCRIPTION("ADI Blackfin TDM PCM DMA module");
MODULE_LICENSE("GPL");