capture.c

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/*
 * Line6 Linux USB driver - 0.9.1beta
 *
 * Copyright (C) 2004-2010 Markus Grabner ([email protected])
 *
 *  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, version 2.
 *
 */

#include <linux/slab.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>

#include "audio.h"
#include "capture.h"
#include "driver.h"
#include "pcm.h"
#include "pod.h"

/*
    Find a free URB and submit it.
*/
static int submit_audio_in_urb(struct snd_line6_pcm *line6pcm)
{
    int index;
    unsigned long flags;
    int i, urb_size;
    int ret;
    struct urb *urb_in;

    spin_lock_irqsave(&line6pcm->lock_audio_in, flags);
    index =
        find_first_zero_bit(&line6pcm->active_urb_in, LINE6_ISO_BUFFERS);

    if (index < 0 || index >= LINE6_ISO_BUFFERS) {
        spin_unlock_irqrestore(&line6pcm->lock_audio_in, flags);
        dev_err(line6pcm->line6->ifcdev, "no free URB found\n");
        return -EINVAL;
    }

    urb_in = line6pcm->urb_audio_in[index];
    urb_size = 0;

    for (i = 0; i < LINE6_ISO_PACKETS; ++i) {
        struct usb_iso_packet_descriptor *fin =
            &urb_in->iso_frame_desc[i];
        fin->offset = urb_size;
        fin->length = line6pcm->max_packet_size;
        urb_size += line6pcm->max_packet_size;
    }

    urb_in->transfer_buffer =
        line6pcm->buffer_in +
        index * LINE6_ISO_PACKETS * line6pcm->max_packet_size;
    urb_in->transfer_buffer_length = urb_size;
    urb_in->context = line6pcm;

    ret = usb_submit_urb(urb_in, GFP_ATOMIC);

    if (ret == 0)
        set_bit(index, &line6pcm->active_urb_in);
    else
        dev_err(line6pcm->line6->ifcdev,
            "URB in #%d submission failed (%d)\n", index, ret);

    spin_unlock_irqrestore(&line6pcm->lock_audio_in, flags);
    return 0;
}

/*
    Submit all currently available capture URBs.
*/
int line6_submit_audio_in_all_urbs(struct snd_line6_pcm *line6pcm)
{
    int ret, i;

    for (i = 0; i < LINE6_ISO_BUFFERS; ++i) {
        ret = submit_audio_in_urb(line6pcm);
        if (ret < 0)
            return ret;
    }

    return 0;
}

/*
    Unlink all currently active capture URBs.
*/
void line6_unlink_audio_in_urbs(struct snd_line6_pcm *line6pcm)
{
    unsigned int i;

    for (i = LINE6_ISO_BUFFERS; i--;) {
        if (test_bit(i, &line6pcm->active_urb_in)) {
            if (!test_and_set_bit(i, &line6pcm->unlink_urb_in)) {
                struct urb *u = line6pcm->urb_audio_in[i];
                usb_unlink_urb(u);
            }
        }
    }
}

/*
    Wait until unlinking of all currently active capture URBs has been
    finished.
*/
void line6_wait_clear_audio_in_urbs(struct snd_line6_pcm *line6pcm)
{
    int timeout = HZ;
    unsigned int i;
    int alive;

    do {
        alive = 0;
        for (i = LINE6_ISO_BUFFERS; i--;) {
            if (test_bit(i, &line6pcm->active_urb_in))
                alive++;
        }
        if (!alive)
            break;
        set_current_state(TASK_UNINTERRUPTIBLE);
        schedule_timeout(1);
    } while (--timeout > 0);
    if (alive)
        snd_printk(KERN_ERR "timeout: still %d active urbs..\n", alive);
}

/*
    Unlink all currently active capture URBs, and wait for finishing.
*/
void line6_unlink_wait_clear_audio_in_urbs(struct snd_line6_pcm *line6pcm)
{
    line6_unlink_audio_in_urbs(line6pcm);
    line6_wait_clear_audio_in_urbs(line6pcm);
}

/*
    Copy data into ALSA capture buffer.
*/
void line6_capture_copy(struct snd_line6_pcm *line6pcm, char *fbuf, int fsize)
{
    struct snd_pcm_substream *substream =
        get_substream(line6pcm, SNDRV_PCM_STREAM_CAPTURE);
    struct snd_pcm_runtime *runtime = substream->runtime;
    const int bytes_per_frame = line6pcm->properties->bytes_per_frame;
    int frames = fsize / bytes_per_frame;

    if (runtime == NULL)
        return;

    if (line6pcm->pos_in_done + frames > runtime->buffer_size) {
        /*
           The transferred area goes over buffer boundary,
           copy two separate chunks.
         */
        int len;
        len = runtime->buffer_size - line6pcm->pos_in_done;

        if (len > 0) {
            memcpy(runtime->dma_area +
                   line6pcm->pos_in_done * bytes_per_frame, fbuf,
                   len * bytes_per_frame);
            memcpy(runtime->dma_area, fbuf + len * bytes_per_frame,
                   (frames - len) * bytes_per_frame);
        } else {
            /* this is somewhat paranoid */
            dev_err(line6pcm->line6->ifcdev,
                "driver bug: len = %d\n", len);
        }
    } else {
        /* copy single chunk */
        memcpy(runtime->dma_area +
               line6pcm->pos_in_done * bytes_per_frame, fbuf, fsize);
    }

    line6pcm->pos_in_done += frames;
    if (line6pcm->pos_in_done >= runtime->buffer_size)
        line6pcm->pos_in_done -= runtime->buffer_size;
}

void line6_capture_check_period(struct snd_line6_pcm *line6pcm, int length)
{
    struct snd_pcm_substream *substream =
        get_substream(line6pcm, SNDRV_PCM_STREAM_CAPTURE);

    line6pcm->bytes_in += length;
    if (line6pcm->bytes_in >= line6pcm->period_in) {
        line6pcm->bytes_in %= line6pcm->period_in;
        snd_pcm_period_elapsed(substream);
    }
}

void line6_free_capture_buffer(struct snd_line6_pcm *line6pcm)
{
    kfree(line6pcm->buffer_in);
    line6pcm->buffer_in = NULL;
}

/*
 * Callback for completed capture URB.
 */
static void audio_in_callback(struct urb *urb)
{
    int i, index, length = 0, shutdown = 0;
    unsigned long flags;

    struct snd_line6_pcm *line6pcm = (struct snd_line6_pcm *)urb->context;

    line6pcm->last_frame_in = urb->start_frame;

    /* find index of URB */
    for (index = 0; index < LINE6_ISO_BUFFERS; ++index)
        if (urb == line6pcm->urb_audio_in[index])
            break;

#ifdef CONFIG_LINE6_USB_DUMP_PCM
    for (i = 0; i < LINE6_ISO_PACKETS; ++i) {
        struct usb_iso_packet_descriptor *fout =
            &urb->iso_frame_desc[i];
        line6_write_hexdump(line6pcm->line6, 'C',
                    urb->transfer_buffer + fout->offset,
                    fout->length);
    }
#endif

    spin_lock_irqsave(&line6pcm->lock_audio_in, flags);

    for (i = 0; i < LINE6_ISO_PACKETS; ++i) {
        char *fbuf;
        int fsize;
        struct usb_iso_packet_descriptor *fin = &urb->iso_frame_desc[i];

        if (fin->status == -EXDEV) {
            shutdown = 1;
            break;
        }

        fbuf = urb->transfer_buffer + fin->offset;
        fsize = fin->actual_length;

        if (fsize > line6pcm->max_packet_size) {
            dev_err(line6pcm->line6->ifcdev,
                "driver and/or device bug: packet too large (%d > %d)\n",
                fsize, line6pcm->max_packet_size);
        }

        length += fsize;

        /* the following assumes LINE6_ISO_PACKETS == 1: */
        line6pcm->prev_fbuf = fbuf;
        line6pcm->prev_fsize = fsize;

#ifdef CONFIG_LINE6_USB_IMPULSE_RESPONSE
        if (!(line6pcm->flags & LINE6_BITS_PCM_IMPULSE))
#endif
            if (test_bit(LINE6_INDEX_PCM_ALSA_CAPTURE_STREAM, &line6pcm->flags)
                && (fsize > 0))
                line6_capture_copy(line6pcm, fbuf, fsize);
    }

    clear_bit(index, &line6pcm->active_urb_in);

    if (test_and_clear_bit(index, &line6pcm->unlink_urb_in))
        shutdown = 1;

    spin_unlock_irqrestore(&line6pcm->lock_audio_in, flags);

    if (!shutdown) {
        submit_audio_in_urb(line6pcm);

#ifdef CONFIG_LINE6_USB_IMPULSE_RESPONSE
        if (!(line6pcm->flags & LINE6_BITS_PCM_IMPULSE))
#endif
            if (test_bit(LINE6_INDEX_PCM_ALSA_CAPTURE_STREAM, &line6pcm->flags))
                line6_capture_check_period(line6pcm, length);
    }
}

/* open capture callback */
static int snd_line6_capture_open(struct snd_pcm_substream *substream)
{
    int err;
    struct snd_pcm_runtime *runtime = substream->runtime;
    struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);

    err = snd_pcm_hw_constraint_ratdens(runtime, 0,
                        SNDRV_PCM_HW_PARAM_RATE,
                        (&line6pcm->
                         properties->snd_line6_rates));
    if (err < 0)
        return err;

    runtime->hw = line6pcm->properties->snd_line6_capture_hw;
    return 0;
}

/* close capture callback */
static int snd_line6_capture_close(struct snd_pcm_substream *substream)
{
    return 0;
}

/* hw_params capture callback */
static int snd_line6_capture_hw_params(struct snd_pcm_substream *substream,
                       struct snd_pcm_hw_params *hw_params)
{
    int ret;
    struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);

    /* -- Florian Demski [FD] */
    /* don't ask me why, but this fixes the bug on my machine */
    if (line6pcm == NULL) {
        if (substream->pcm == NULL)
            return -ENOMEM;
        if (substream->pcm->private_data == NULL)
            return -ENOMEM;
        substream->private_data = substream->pcm->private_data;
        line6pcm = snd_pcm_substream_chip(substream);
    }
    /* -- [FD] end */

    ret = line6_pcm_acquire(line6pcm, LINE6_BIT_PCM_ALSA_CAPTURE_BUFFER);

    if (ret < 0)
        return ret;

    ret = snd_pcm_lib_malloc_pages(substream,
                       params_buffer_bytes(hw_params));
    if (ret < 0) {
        line6_pcm_release(line6pcm, LINE6_BIT_PCM_ALSA_CAPTURE_BUFFER);
        return ret;
    }

    line6pcm->period_in = params_period_bytes(hw_params);
    return 0;
}

/* hw_free capture callback */
static int snd_line6_capture_hw_free(struct snd_pcm_substream *substream)
{
    struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
    line6_pcm_release(line6pcm, LINE6_BIT_PCM_ALSA_CAPTURE_BUFFER);
    return snd_pcm_lib_free_pages(substream);
}

/* trigger callback */
int snd_line6_capture_trigger(struct snd_line6_pcm *line6pcm, int cmd)
{
    int err;

    switch (cmd) {
    case SNDRV_PCM_TRIGGER_START:
#ifdef CONFIG_PM
    case SNDRV_PCM_TRIGGER_RESUME:
#endif
        err = line6_pcm_acquire(line6pcm, LINE6_BIT_PCM_ALSA_CAPTURE_STREAM);

        if (err < 0)
            return err;

        break;

    case SNDRV_PCM_TRIGGER_STOP:
#ifdef CONFIG_PM
    case SNDRV_PCM_TRIGGER_SUSPEND:
#endif
        err = line6_pcm_release(line6pcm, LINE6_BIT_PCM_ALSA_CAPTURE_STREAM);

        if (err < 0)
            return err;

        break;

    default:
        return -EINVAL;
    }

    return 0;
}

/* capture pointer callback */
static snd_pcm_uframes_t
snd_line6_capture_pointer(struct snd_pcm_substream *substream)
{
    struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
    return line6pcm->pos_in_done;
}

/* capture operators */
struct snd_pcm_ops snd_line6_capture_ops = {
    .open = snd_line6_capture_open,
    .close = snd_line6_capture_close,
    .ioctl = snd_pcm_lib_ioctl,
    .hw_params = snd_line6_capture_hw_params,
    .hw_free = snd_line6_capture_hw_free,
    .prepare = snd_line6_prepare,
    .trigger = snd_line6_trigger,
    .pointer = snd_line6_capture_pointer,
};

int line6_create_audio_in_urbs(struct snd_line6_pcm *line6pcm)
{
    int i;

    /* create audio URBs and fill in constant values: */
    for (i = 0; i < LINE6_ISO_BUFFERS; ++i) {
        struct urb *urb;

        /* URB for audio in: */
        urb = line6pcm->urb_audio_in[i] =
            usb_alloc_urb(LINE6_ISO_PACKETS, GFP_KERNEL);

        if (urb == NULL) {
            dev_err(line6pcm->line6->ifcdev, "Out of memory\n");
            return -ENOMEM;
        }

        urb->dev = line6pcm->line6->usbdev;
        urb->pipe =
            usb_rcvisocpipe(line6pcm->line6->usbdev,
                    line6pcm->ep_audio_read &
                    USB_ENDPOINT_NUMBER_MASK);
        urb->transfer_flags = URB_ISO_ASAP;
        urb->start_frame = -1;
        urb->number_of_packets = LINE6_ISO_PACKETS;
        urb->interval = LINE6_ISO_INTERVAL;
        urb->error_count = 0;
        urb->complete = audio_in_callback;
    }

    return 0;
}