root/drivers/media/usb/go7007/snd-go7007.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2005-2006 Micronas USA Inc.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/spinlock.h>
#include <linux/delay.h>
#include <linux/sched.h>
#include <linux/time.h>
#include <linux/mm.h>
#include <linux/i2c.h>
#include <linux/mutex.h>
#include <linux/uaccess.h>
#include <linux/slab.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/initval.h>

#include "go7007-priv.h"

static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;
static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;
static bool enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE_PNP;

module_param_array(index, int, NULL, 0444);
module_param_array(id, charp, NULL, 0444);
module_param_array(enable, bool, NULL, 0444);
MODULE_PARM_DESC(index, "Index value for the go7007 audio driver");
MODULE_PARM_DESC(id, "ID string for the go7007 audio driver");
MODULE_PARM_DESC(enable, "Enable for the go7007 audio driver");

struct go7007_snd {
        struct snd_card *card;
        struct snd_pcm *pcm;
        struct snd_pcm_substream *substream;
        spinlock_t lock;
        int w_idx;
        int hw_ptr;
        int avail;
        int capturing;
};

static const struct snd_pcm_hardware go7007_snd_capture_hw = {
        .info                   = (SNDRV_PCM_INFO_MMAP |
                                        SNDRV_PCM_INFO_INTERLEAVED |
                                        SNDRV_PCM_INFO_BLOCK_TRANSFER |
                                        SNDRV_PCM_INFO_MMAP_VALID),
        .formats                = SNDRV_PCM_FMTBIT_S16_LE,
        .rates                  = SNDRV_PCM_RATE_48000,
        .rate_min               = 48000,
        .rate_max               = 48000,
        .channels_min           = 2,
        .channels_max           = 2,
        .buffer_bytes_max       = (128*1024),
        .period_bytes_min       = 4096,
        .period_bytes_max       = (128*1024),
        .periods_min            = 1,
        .periods_max            = 32,
};

static void parse_audio_stream_data(struct go7007 *go, u8 *buf, int length)
{
        struct go7007_snd *gosnd = go->snd_context;
        struct snd_pcm_runtime *runtime = gosnd->substream->runtime;
        int frames = bytes_to_frames(runtime, length);
        unsigned long flags;

        spin_lock_irqsave(&gosnd->lock, flags);
        gosnd->hw_ptr += frames;
        if (gosnd->hw_ptr >= runtime->buffer_size)
                gosnd->hw_ptr -= runtime->buffer_size;
        gosnd->avail += frames;
        spin_unlock_irqrestore(&gosnd->lock, flags);
        if (gosnd->w_idx + length > runtime->dma_bytes) {
                int cpy = runtime->dma_bytes - gosnd->w_idx;

                memcpy(runtime->dma_area + gosnd->w_idx, buf, cpy);
                length -= cpy;
                buf += cpy;
                gosnd->w_idx = 0;
        }
        memcpy(runtime->dma_area + gosnd->w_idx, buf, length);
        gosnd->w_idx += length;
        spin_lock_irqsave(&gosnd->lock, flags);
        if (gosnd->avail < runtime->period_size) {
                spin_unlock_irqrestore(&gosnd->lock, flags);
                return;
        }
        gosnd->avail -= runtime->period_size;
        spin_unlock_irqrestore(&gosnd->lock, flags);
        if (gosnd->capturing)
                snd_pcm_period_elapsed(gosnd->substream);
}

static int go7007_snd_hw_params(struct snd_pcm_substream *substream,
                                struct snd_pcm_hw_params *hw_params)
{
        struct go7007 *go = snd_pcm_substream_chip(substream);

        go->audio_deliver = parse_audio_stream_data;
        return 0;
}

static int go7007_snd_hw_free(struct snd_pcm_substream *substream)
{
        struct go7007 *go = snd_pcm_substream_chip(substream);

        go->audio_deliver = NULL;
        return 0;
}

static int go7007_snd_capture_open(struct snd_pcm_substream *substream)
{
        struct go7007 *go = snd_pcm_substream_chip(substream);
        struct go7007_snd *gosnd = go->snd_context;
        unsigned long flags;
        int r;

        spin_lock_irqsave(&gosnd->lock, flags);
        if (gosnd->substream == NULL) {
                gosnd->substream = substream;
                substream->runtime->hw = go7007_snd_capture_hw;
                r = 0;
        } else
                r = -EBUSY;
        spin_unlock_irqrestore(&gosnd->lock, flags);
        return r;
}

static int go7007_snd_capture_close(struct snd_pcm_substream *substream)
{
        struct go7007 *go = snd_pcm_substream_chip(substream);
        struct go7007_snd *gosnd = go->snd_context;

        gosnd->substream = NULL;
        return 0;
}

static int go7007_snd_pcm_prepare(struct snd_pcm_substream *substream)
{
        return 0;
}

static int go7007_snd_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
{
        struct go7007 *go = snd_pcm_substream_chip(substream);
        struct go7007_snd *gosnd = go->snd_context;

        switch (cmd) {
        case SNDRV_PCM_TRIGGER_START:
                /* Just set a flag to indicate we should signal ALSA when
                 * sound comes in */
                gosnd->capturing = 1;
                return 0;
        case SNDRV_PCM_TRIGGER_STOP:
                gosnd->hw_ptr = gosnd->w_idx = gosnd->avail = 0;
                gosnd->capturing = 0;
                return 0;
        default:
                return -EINVAL;
        }
}

static snd_pcm_uframes_t go7007_snd_pcm_pointer(struct snd_pcm_substream *substream)
{
        struct go7007 *go = snd_pcm_substream_chip(substream);
        struct go7007_snd *gosnd = go->snd_context;

        return gosnd->hw_ptr;
}

static const struct snd_pcm_ops go7007_snd_capture_ops = {
        .open           = go7007_snd_capture_open,
        .close          = go7007_snd_capture_close,
        .hw_params      = go7007_snd_hw_params,
        .hw_free        = go7007_snd_hw_free,
        .prepare        = go7007_snd_pcm_prepare,
        .trigger        = go7007_snd_pcm_trigger,
        .pointer        = go7007_snd_pcm_pointer,
};

static int go7007_snd_free(struct snd_device *device)
{
        struct go7007 *go = device->device_data;

        kfree(go->snd_context);
        go->snd_context = NULL;
        return 0;
}

static const struct snd_device_ops go7007_snd_device_ops = {
        .dev_free       = go7007_snd_free,
};

int go7007_snd_init(struct go7007 *go)
{
        static int dev;
        struct go7007_snd *gosnd;
        int ret;

        if (dev >= SNDRV_CARDS)
                return -ENODEV;
        if (!enable[dev]) {
                dev++;
                return -ENOENT;
        }
        gosnd = kmalloc_obj(struct go7007_snd);
        if (gosnd == NULL)
                return -ENOMEM;
        spin_lock_init(&gosnd->lock);
        gosnd->hw_ptr = gosnd->w_idx = gosnd->avail = 0;
        gosnd->capturing = 0;
        ret = snd_card_new(go->dev, index[dev], id[dev], THIS_MODULE, 0,
                           &gosnd->card);
        if (ret < 0)
                goto free_snd;

        ret = snd_device_new(gosnd->card, SNDRV_DEV_LOWLEVEL, go,
                        &go7007_snd_device_ops);
        if (ret < 0)
                goto free_card;

        ret = snd_pcm_new(gosnd->card, "go7007", 0, 0, 1, &gosnd->pcm);
        if (ret < 0)
                goto free_card;

        strscpy(gosnd->card->driver, "go7007", sizeof(gosnd->card->driver));
        strscpy(gosnd->card->shortname, go->name, sizeof(gosnd->card->shortname));
        strscpy(gosnd->card->longname, gosnd->card->shortname,
                sizeof(gosnd->card->longname));

        gosnd->pcm->private_data = go;
        snd_pcm_set_ops(gosnd->pcm, SNDRV_PCM_STREAM_CAPTURE,
                        &go7007_snd_capture_ops);
        snd_pcm_set_managed_buffer_all(gosnd->pcm, SNDRV_DMA_TYPE_VMALLOC,
                                       NULL, 0, 0);

        ret = snd_card_register(gosnd->card);
        if (ret < 0)
                goto free_card;

        gosnd->substream = NULL;
        go->snd_context = gosnd;
        v4l2_device_get(&go->v4l2_dev);
        ++dev;

        return 0;

free_card:
        snd_card_free(gosnd->card);
free_snd:
        kfree(gosnd);
        return ret;
}
EXPORT_SYMBOL(go7007_snd_init);

int go7007_snd_remove(struct go7007 *go)
{
        struct go7007_snd *gosnd = go->snd_context;

        snd_card_disconnect(gosnd->card);
        snd_card_free_when_closed(gosnd->card);
        v4l2_device_put(&go->v4l2_dev);
        return 0;
}
EXPORT_SYMBOL(go7007_snd_remove);

MODULE_LICENSE("GPL v2");