/*
 * omap-pcm.c  --  ALSA PCM interface for the OMAP SoC
 *
 * Copyright (C) 2008 Nokia Corporation
 *
 * Contact: Jarkko Nikula <jarkko.nikula@bitmer.com>
 *          Peter Ujfalusi <peter.ujfalusi@ti.com>
 *
 * 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.
 *
 * 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, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 *
 */

#include <linux/dma-mapping.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/omap-dma.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/dmaengine_pcm.h>
#include <sound/soc.h>
#include <sound/omap-pcm.h>

#ifdef CONFIG_ARCH_OMAP1
#define pcm_omap1510()  cpu_is_omap1510()
#else
#define pcm_omap1510()  0
#endif

static struct snd_pcm_hardware omap_pcm_hardware = {
        .info                   = SNDRV_PCM_INFO_MMAP |
                                  SNDRV_PCM_INFO_MMAP_VALID |
                                  SNDRV_PCM_INFO_INTERLEAVED |
                                  SNDRV_PCM_INFO_PAUSE |
                                  SNDRV_PCM_INFO_RESUME |
                                  SNDRV_PCM_INFO_NO_PERIOD_WAKEUP,
        .period_bytes_min       = 32,
        .period_bytes_max       = 64 * 1024,
        .periods_min            = 2,
        .periods_max            = 255,
        .buffer_bytes_max       = 128 * 1024,
};

/* sDMA supports only 1, 2, and 4 byte transfer elements. */
static void omap_pcm_limit_supported_formats(void)
{
        int i;

        for (i = 0; i < SNDRV_PCM_FORMAT_LAST; i++) {
                switch (snd_pcm_format_physical_width(i)) {
                case 8:
                case 16:
                case 32:
                        omap_pcm_hardware.formats |= (1LL << i);
                        break;
                default:
                        break;
                }
        }
}

/* this may get called several times by oss emulation */
static int omap_pcm_hw_params(struct snd_pcm_substream *substream,
                              struct snd_pcm_hw_params *params)
{
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct snd_soc_pcm_runtime *rtd = substream->private_data;
        struct omap_pcm_dma_data *dma_data;
        struct dma_slave_config config;
        struct dma_chan *chan;
        int err = 0;

        dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);

        /* return if this is a bufferless transfer e.g.
         * codec <--> BT codec or GSM modem -- lg FIXME */
        if (!dma_data)
                return 0;

        snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
        runtime->dma_bytes = params_buffer_bytes(params);

        chan = snd_dmaengine_pcm_get_chan(substream);
        if (!chan)
                return -EINVAL;

        /* fills in addr_width and direction */
        err = snd_hwparams_to_dma_slave_config(substream, params, &config);
        if (err)
                return err;

        snd_dmaengine_pcm_set_config_from_dai_data(substream,
                        snd_soc_dai_get_dma_data(rtd->cpu_dai, substream),
                        &config);

        return dmaengine_slave_config(chan, &config);
}

static int omap_pcm_hw_free(struct snd_pcm_substream *substream)
{
        snd_pcm_set_runtime_buffer(substream, NULL);
        return 0;
}

static snd_pcm_uframes_t omap_pcm_pointer(struct snd_pcm_substream *substream)
{
        snd_pcm_uframes_t offset;

        if (pcm_omap1510())
                offset = snd_dmaengine_pcm_pointer_no_residue(substream);
        else
                offset = snd_dmaengine_pcm_pointer(substream);

        return offset;
}

static int omap_pcm_open(struct snd_pcm_substream *substream)
{
        struct snd_soc_pcm_runtime *rtd = substream->private_data;
        struct snd_dmaengine_dai_dma_data *dma_data;
        int ret;

        snd_soc_set_runtime_hwparams(substream, &omap_pcm_hardware);

        dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);

        /* DT boot: filter_data is the DMA name */
        if (rtd->cpu_dai->dev->of_node) {
                struct dma_chan *chan;

                chan = dma_request_slave_channel(rtd->cpu_dai->dev,
                                                 dma_data->filter_data);
                ret = snd_dmaengine_pcm_open(substream, chan);
        } else {
                ret = snd_dmaengine_pcm_open_request_chan(substream,
                                                          omap_dma_filter_fn,
                                                          dma_data->filter_data);
        }
        return ret;
}

static int omap_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);
}

static struct snd_pcm_ops omap_pcm_ops = {
        .open           = omap_pcm_open,
        .close          = snd_dmaengine_pcm_close_release_chan,
        .ioctl          = snd_pcm_lib_ioctl,
        .hw_params      = omap_pcm_hw_params,
        .hw_free        = omap_pcm_hw_free,
        .trigger        = snd_dmaengine_pcm_trigger,
        .pointer        = omap_pcm_pointer,
        .mmap           = omap_pcm_mmap,
};

static int omap_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 = omap_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;
}

static void omap_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;
        }
}

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

        ret = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(32));
        if (ret)
                return ret;

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

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

out:
        /* free preallocated buffers in case of error */
        if (ret)
                omap_pcm_free_dma_buffers(pcm);

        return ret;
}

static struct snd_soc_platform_driver omap_soc_platform = {
        .ops            = &omap_pcm_ops,
        .pcm_new        = omap_pcm_new,
        .pcm_free       = omap_pcm_free_dma_buffers,
};

int omap_pcm_platform_register(struct device *dev)
{
        omap_pcm_limit_supported_formats();
        return devm_snd_soc_register_platform(dev, &omap_soc_platform);
}
EXPORT_SYMBOL_GPL(omap_pcm_platform_register);

MODULE_AUTHOR("Jarkko Nikula <jarkko.nikula@bitmer.com>");
MODULE_DESCRIPTION("OMAP PCM DMA module");
MODULE_LICENSE("GPL");