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root/sound/soc/davinci/davinci-pcm.c

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DEFINITIONS

This source file includes following definitions.
  1. davinci_pcm_enqueue_dma
  2. davinci_pcm_dma_irq
  3. davinci_pcm_dma_request
  4. davinci_pcm_trigger
  5. davinci_pcm_prepare
  6. davinci_pcm_pointer
  7. davinci_pcm_open
  8. davinci_pcm_close
  9. davinci_pcm_hw_params
  10. davinci_pcm_hw_free
  11. davinci_pcm_mmap
  12. davinci_pcm_preallocate_dma_buffer
  13. davinci_pcm_free
  14. davinci_pcm_new

/*
 * ALSA PCM interface for the TI DAVINCI processor
 *
 * Author:      Vladimir Barinov, <vbarinov@embeddedalley.com>
 * Copyright:   (C) 2007 MontaVista Software, Inc., <source@mvista.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.
 */

#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 "davinci-pcm.h"

#define DAVINCI_PCM_DEBUG 0
#if DAVINCI_PCM_DEBUG
#define DPRINTK(x...) printk(KERN_DEBUG x)
#else
#define DPRINTK(x...)
#endif

static struct snd_pcm_hardware davinci_pcm_hardware = {
        .info = (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER |
                 SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
                 SNDRV_PCM_INFO_PAUSE),
        .formats = (SNDRV_PCM_FMTBIT_S16_LE),
        .rates = (SNDRV_PCM_RATE_8000 | SNDRV_PCM_RATE_16000 |
                  SNDRV_PCM_RATE_22050 | SNDRV_PCM_RATE_32000 |
                  SNDRV_PCM_RATE_44100 | SNDRV_PCM_RATE_48000 |
                  SNDRV_PCM_RATE_88200 | SNDRV_PCM_RATE_96000 |
                  SNDRV_PCM_RATE_KNOT),
        .rate_min = 8000,
        .rate_max = 96000,
        .channels_min = 2,
        .channels_max = 2,
        .buffer_bytes_max = 128 * 1024,
        .period_bytes_min = 32,
        .period_bytes_max = 8 * 1024,
        .periods_min = 16,
        .periods_max = 255,
        .fifo_size = 0,
};

struct davinci_runtime_data {
        spinlock_t lock;
        int period;             /* current DMA period */
        int master_lch;         /* Master DMA channel */
        int slave_lch;          /* Slave DMA channel */
        struct davinci_pcm_dma_params *params;  /* DMA params */
};

static void davinci_pcm_enqueue_dma(struct snd_pcm_substream *substream)
{
        struct davinci_runtime_data *prtd = substream->runtime->private_data;
        struct snd_pcm_runtime *runtime = substream->runtime;
        int lch = prtd->slave_lch;
        unsigned int period_size;
        unsigned int dma_offset;
        dma_addr_t dma_pos;
        dma_addr_t src, dst;
        unsigned short src_bidx, dst_bidx;
        unsigned int data_type;
        unsigned int count;

        period_size = snd_pcm_lib_period_bytes(substream);
        dma_offset = prtd->period * period_size;
        dma_pos = runtime->dma_addr + dma_offset;

        DPRINTK("audio_set_dma_params_play channel = %d dma_ptr = %x "
                "period_size=%x\n", lch, dma_pos, period_size);

        data_type = prtd->params->data_type;
        count = period_size / data_type;

        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
                src = dma_pos;
                dst = prtd->params->dma_addr;
                src_bidx = data_type;
                dst_bidx = 0;
        } else {
                src = prtd->params->dma_addr;
                dst = dma_pos;
                src_bidx = 0;
                dst_bidx = data_type;
        }

        davinci_set_dma_src_params(lch, src, INCR, W8BIT);
        davinci_set_dma_dest_params(lch, dst, INCR, W8BIT);
        davinci_set_dma_src_index(lch, src_bidx, 0);
        davinci_set_dma_dest_index(lch, dst_bidx, 0);
        davinci_set_dma_transfer_params(lch, data_type, count, 1, 0, ASYNC);

        prtd->period++;
        if (unlikely(prtd->period >= runtime->periods))
                prtd->period = 0;
}

static void davinci_pcm_dma_irq(int lch, u16 ch_status, void *data)
{
        struct snd_pcm_substream *substream = data;
        struct davinci_runtime_data *prtd = substream->runtime->private_data;

        DPRINTK("lch=%d, status=0x%x\n", lch, ch_status);

        if (unlikely(ch_status != DMA_COMPLETE))
                return;

        if (snd_pcm_running(substream)) {
                snd_pcm_period_elapsed(substream);

                spin_lock(&prtd->lock);
                davinci_pcm_enqueue_dma(substream);
                spin_unlock(&prtd->lock);
        }
}

static int davinci_pcm_dma_request(struct snd_pcm_substream *substream)
{
        struct davinci_runtime_data *prtd = substream->runtime->private_data;
        struct snd_soc_pcm_runtime *rtd = substream->private_data;
        struct davinci_pcm_dma_params *dma_data = rtd->dai->cpu_dai->dma_data;
        int tcc = TCC_ANY;
        int ret;

        if (!dma_data)
                return -ENODEV;

        prtd->params = dma_data;

        /* Request master DMA channel */
        ret = davinci_request_dma(prtd->params->channel, prtd->params->name,
                                  davinci_pcm_dma_irq, substream,
                                  &prtd->master_lch, &tcc, EVENTQ_0);
        if (ret)
                return ret;

        /* Request slave DMA channel */
        ret = davinci_request_dma(PARAM_ANY, "Link",
                                  NULL, NULL, &prtd->slave_lch, &tcc, EVENTQ_0);
        if (ret) {
                davinci_free_dma(prtd->master_lch);
                return ret;
        }

        /* Link slave DMA channel in loopback */
        davinci_dma_link_lch(prtd->slave_lch, prtd->slave_lch);

        return 0;
}

static int davinci_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
{
        struct davinci_runtime_data *prtd = substream->runtime->private_data;
        int ret = 0;

        spin_lock(&prtd->lock);

        switch (cmd) {
        case SNDRV_PCM_TRIGGER_START:
        case SNDRV_PCM_TRIGGER_RESUME:
        case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
                davinci_start_dma(prtd->master_lch);
                break;
        case SNDRV_PCM_TRIGGER_STOP:
        case SNDRV_PCM_TRIGGER_SUSPEND:
        case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
                davinci_stop_dma(prtd->master_lch);
                break;
        default:
                ret = -EINVAL;
                break;
        }

        spin_unlock(&prtd->lock);

        return ret;
}

static int davinci_pcm_prepare(struct snd_pcm_substream *substream)
{
        struct davinci_runtime_data *prtd = substream->runtime->private_data;
        struct paramentry_descriptor temp;

        prtd->period = 0;
        davinci_pcm_enqueue_dma(substream);

        /* Get slave channel dma params for master channel startup */
        davinci_get_dma_params(prtd->slave_lch, &temp);
        davinci_set_dma_params(prtd->master_lch, &temp);

        return 0;
}

static snd_pcm_uframes_t
davinci_pcm_pointer(struct snd_pcm_substream *substream)
{
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct davinci_runtime_data *prtd = runtime->private_data;
        unsigned int offset;
        dma_addr_t count;
        dma_addr_t src, dst;

        spin_lock(&prtd->lock);

        davinci_dma_getposition(prtd->master_lch, &src, &dst);
        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
                count = src - runtime->dma_addr;
        else
                count = dst - runtime->dma_addr;;

        spin_unlock(&prtd->lock);

        offset = bytes_to_frames(runtime, count);
        if (offset >= runtime->buffer_size)
                offset = 0;

        return offset;
}

static int davinci_pcm_open(struct snd_pcm_substream *substream)
{
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct davinci_runtime_data *prtd;
        int ret = 0;

        snd_soc_set_runtime_hwparams(substream, &davinci_pcm_hardware);

        prtd = kzalloc(sizeof(struct davinci_runtime_data), GFP_KERNEL);
        if (prtd == NULL)
                return -ENOMEM;

        spin_lock_init(&prtd->lock);

        runtime->private_data = prtd;

        ret = davinci_pcm_dma_request(substream);
        if (ret) {
                printk(KERN_ERR "davinci_pcm: Failed to get dma channels\n");
                kfree(prtd);
        }

        return ret;
}

static int davinci_pcm_close(struct snd_pcm_substream *substream)
{
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct davinci_runtime_data *prtd = runtime->private_data;

        davinci_dma_unlink_lch(prtd->slave_lch, prtd->slave_lch);

        davinci_free_dma(prtd->slave_lch);
        davinci_free_dma(prtd->master_lch);

        kfree(prtd);

        return 0;
}

static int davinci_pcm_hw_params(struct snd_pcm_substream *substream,
                                 struct snd_pcm_hw_params *hw_params)
{
        return snd_pcm_lib_malloc_pages(substream,
                                        params_buffer_bytes(hw_params));
}

static int davinci_pcm_hw_free(struct snd_pcm_substream *substream)
{
        return snd_pcm_lib_free_pages(substream);
}

static int davinci_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);
}

struct snd_pcm_ops davinci_pcm_ops = {
        .open =         davinci_pcm_open,
        .close =        davinci_pcm_close,
        .ioctl =        snd_pcm_lib_ioctl,
        .hw_params =    davinci_pcm_hw_params,
        .hw_free =      davinci_pcm_hw_free,
        .prepare =      davinci_pcm_prepare,
        .trigger =      davinci_pcm_trigger,
        .pointer =      davinci_pcm_pointer,
        .mmap =         davinci_pcm_mmap,
};

static int davinci_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 = davinci_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);

        DPRINTK("preallocate_dma_buffer: area=%p, addr=%p, size=%d\n",
                (void *) buf->area, (void *) buf->addr, size);

        if (!buf->area)
                return -ENOMEM;

        buf->bytes = size;
        return 0;
}

static void davinci_pcm_free(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 u64 davinci_pcm_dmamask = 0xffffffff;

static int davinci_pcm_new(struct snd_card *card,
                           struct snd_soc_dai *dai, struct snd_pcm *pcm)
{
        int ret;

        if (!card->dev->dma_mask)
                card->dev->dma_mask = &davinci_pcm_dmamask;
        if (!card->dev->coherent_dma_mask)
                card->dev->coherent_dma_mask = 0xffffffff;

        if (dai->playback.channels_min) {
                ret = davinci_pcm_preallocate_dma_buffer(pcm,
                        SNDRV_PCM_STREAM_PLAYBACK);
                if (ret)
                        return ret;
        }

        if (dai->capture.channels_min) {
                ret = davinci_pcm_preallocate_dma_buffer(pcm,
                        SNDRV_PCM_STREAM_CAPTURE);
                if (ret)
                        return ret;
        }

        return 0;
}

struct snd_soc_platform davinci_soc_platform = {
        .name =         "davinci-audio",
        .pcm_ops =      &davinci_pcm_ops,
        .pcm_new =      davinci_pcm_new,
        .pcm_free =     davinci_pcm_free,
};
EXPORT_SYMBOL_GPL(davinci_soc_platform);

MODULE_AUTHOR("Vladimir Barinov");
MODULE_DESCRIPTION("TI DAVINCI PCM DMA module");
MODULE_LICENSE("GPL");

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