playback.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"
#include "playback.h"

/*
    Software stereo volume control.
*/
static void change_volume(struct urb *urb_out, int volume[],
              int bytes_per_frame)
{
    int chn = 0;

    if (volume[0] == 256 && volume[1] == 256)
        return;     /* maximum volume - no change */

    if (bytes_per_frame == 4) {
        short *p, *buf_end;
        p = (short *)urb_out->transfer_buffer;
        buf_end = p + urb_out->transfer_buffer_length / sizeof(*p);

        for (; p < buf_end; ++p) {
            *p = (*p * volume[chn & 1]) >> 8;
            ++chn;
        }
    } else if (bytes_per_frame == 6) {
        unsigned char *p, *buf_end;
        p = (unsigned char *)urb_out->transfer_buffer;
        buf_end = p + urb_out->transfer_buffer_length;

        for (; p < buf_end; p += 3) {
            int val;
            val = p[0] + (p[1] << 8) + ((signed char)p[2] << 16);
            val = (val * volume[chn & 1]) >> 8;
            p[0] = val;
            p[1] = val >> 8;
            p[2] = val >> 16;
            ++chn;
        }
    }
}

#ifdef CONFIG_LINE6_USB_IMPULSE_RESPONSE

/*
    Create signal for impulse response test.
*/
static void create_impulse_test_signal(struct snd_line6_pcm *line6pcm,
                       struct urb *urb_out, int bytes_per_frame)
{
    int frames = urb_out->transfer_buffer_length / bytes_per_frame;

    if (bytes_per_frame == 4) {
        int i;
        short *pi = (short *)line6pcm->prev_fbuf;
        short *po = (short *)urb_out->transfer_buffer;

        for (i = 0; i < frames; ++i) {
            po[0] = pi[0];
            po[1] = 0;
            pi += 2;
            po += 2;
        }
    } else if (bytes_per_frame == 6) {
        int i, j;
        unsigned char *pi = line6pcm->prev_fbuf;
        unsigned char *po = urb_out->transfer_buffer;

        for (i = 0; i < frames; ++i) {
            for (j = 0; j < bytes_per_frame / 2; ++j)
                po[j] = pi[j];

            for (; j < bytes_per_frame; ++j)
                po[j] = 0;

            pi += bytes_per_frame;
            po += bytes_per_frame;
        }
    }
    if (--line6pcm->impulse_count <= 0) {
        ((unsigned char *)(urb_out->transfer_buffer))[bytes_per_frame -
                                  1] =
            line6pcm->impulse_volume;
        line6pcm->impulse_count = line6pcm->impulse_period;
    }
}

#endif

/*
    Add signal to buffer for software monitoring.
*/
static void add_monitor_signal(struct urb *urb_out, unsigned char *signal,
                   int volume, int bytes_per_frame)
{
    if (volume == 0)
        return;     /* zero volume - no change */

    if (bytes_per_frame == 4) {
        short *pi, *po, *buf_end;
        pi = (short *)signal;
        po = (short *)urb_out->transfer_buffer;
        buf_end = po + urb_out->transfer_buffer_length / sizeof(*po);

        for (; po < buf_end; ++pi, ++po)
            *po += (*pi * volume) >> 8;
    }

    /*
       We don't need to handle devices with 6 bytes per frame here
       since they all support hardware monitoring.
     */
}

/*
    Find a free URB, prepare audio data, and submit URB.
*/
static int submit_audio_out_urb(struct snd_line6_pcm *line6pcm)
{
    int index;
    unsigned long flags;
    int i, urb_size, urb_frames;
    int ret;
    const int bytes_per_frame = line6pcm->properties->bytes_per_frame;
    const int frame_increment =
        line6pcm->properties->snd_line6_rates.rats[0].num_min;
    const int frame_factor =
        line6pcm->properties->snd_line6_rates.rats[0].den *
        (USB_INTERVALS_PER_SECOND / LINE6_ISO_INTERVAL);
    struct urb *urb_out;

    spin_lock_irqsave(&line6pcm->lock_audio_out, flags);
    index =
        find_first_zero_bit(&line6pcm->active_urb_out, LINE6_ISO_BUFFERS);

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

    urb_out = line6pcm->urb_audio_out[index];
    urb_size = 0;

    for (i = 0; i < LINE6_ISO_PACKETS; ++i) {
        /* compute frame size for given sampling rate */
        int fsize = 0;
        struct usb_iso_packet_descriptor *fout =
            &urb_out->iso_frame_desc[i];

        if (line6pcm->flags & LINE6_BITS_CAPTURE_STREAM)
            fsize = line6pcm->prev_fsize;

        if (fsize == 0) {
            int n;
            line6pcm->count_out += frame_increment;
            n = line6pcm->count_out / frame_factor;
            line6pcm->count_out -= n * frame_factor;
            fsize = n * bytes_per_frame;
        }

        fout->offset = urb_size;
        fout->length = fsize;
        urb_size += fsize;
    }

    if (urb_size == 0) {
        /* can't determine URB size */
        spin_unlock_irqrestore(&line6pcm->lock_audio_out, flags);
        dev_err(line6pcm->line6->ifcdev, "driver bug: urb_size = 0\n"); /* this is somewhat paranoid */
        return -EINVAL;
    }

    urb_frames = urb_size / bytes_per_frame;
    urb_out->transfer_buffer =
        line6pcm->buffer_out +
        index * LINE6_ISO_PACKETS * line6pcm->max_packet_size;
    urb_out->transfer_buffer_length = urb_size;
    urb_out->context = line6pcm;

    if (test_bit(LINE6_INDEX_PCM_ALSA_PLAYBACK_STREAM, &line6pcm->flags) &&
        !test_bit(LINE6_INDEX_PAUSE_PLAYBACK, &line6pcm->flags)) {
        struct snd_pcm_runtime *runtime =
            get_substream(line6pcm, SNDRV_PCM_STREAM_PLAYBACK)->runtime;

        if (line6pcm->pos_out + urb_frames > runtime->buffer_size) {
            /*
               The transferred area goes over buffer boundary,
               copy the data to the temp buffer.
             */
            int len;
            len = runtime->buffer_size - line6pcm->pos_out;

            if (len > 0) {
                memcpy(urb_out->transfer_buffer,
                       runtime->dma_area +
                       line6pcm->pos_out * bytes_per_frame,
                       len * bytes_per_frame);
                memcpy(urb_out->transfer_buffer +
                       len * bytes_per_frame, runtime->dma_area,
                       (urb_frames - len) * bytes_per_frame);
            } else
                dev_err(line6pcm->line6->ifcdev, "driver bug: len = %d\n", len);    /* this is somewhat paranoid */
        } else {
            memcpy(urb_out->transfer_buffer,
                   runtime->dma_area +
                   line6pcm->pos_out * bytes_per_frame,
                   urb_out->transfer_buffer_length);
        }

        line6pcm->pos_out += urb_frames;
        if (line6pcm->pos_out >= runtime->buffer_size)
            line6pcm->pos_out -= runtime->buffer_size;
    } else {
        memset(urb_out->transfer_buffer, 0,
               urb_out->transfer_buffer_length);
    }

    change_volume(urb_out, line6pcm->volume_playback, bytes_per_frame);

    if (line6pcm->prev_fbuf != NULL) {
#ifdef CONFIG_LINE6_USB_IMPULSE_RESPONSE
        if (line6pcm->flags & LINE6_BITS_PCM_IMPULSE) {
            create_impulse_test_signal(line6pcm, urb_out,
                           bytes_per_frame);
            if (line6pcm->flags & LINE6_BIT_PCM_ALSA_CAPTURE_STREAM) {
                line6_capture_copy(line6pcm,
                           urb_out->transfer_buffer,
                           urb_out->
                           transfer_buffer_length);
                line6_capture_check_period(line6pcm,
                               urb_out->transfer_buffer_length);
            }
        } else {
#endif
            if (!
                (line6pcm->line6->
                 properties->capabilities & LINE6_BIT_HWMON)
                && (line6pcm->flags & LINE6_BITS_PLAYBACK_STREAM)
                && (line6pcm->flags & LINE6_BITS_CAPTURE_STREAM))
                add_monitor_signal(urb_out, line6pcm->prev_fbuf,
                           line6pcm->volume_monitor,
                           bytes_per_frame);
#ifdef CONFIG_LINE6_USB_IMPULSE_RESPONSE
        }
#endif
    }
#ifdef CONFIG_LINE6_USB_DUMP_PCM
    for (i = 0; i < LINE6_ISO_PACKETS; ++i) {
        struct usb_iso_packet_descriptor *fout =
            &urb_out->iso_frame_desc[i];
        line6_write_hexdump(line6pcm->line6, 'P',
                    urb_out->transfer_buffer + fout->offset,
                    fout->length);
    }
#endif

    ret = usb_submit_urb(urb_out, GFP_ATOMIC);

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

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

/*
    Submit all currently available playback URBs.
*/
int line6_submit_audio_out_all_urbs(struct snd_line6_pcm *line6pcm)
{
    int ret, i;

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

    return 0;
}

/*
    Unlink all currently active playback URBs.
*/
void line6_unlink_audio_out_urbs(struct snd_line6_pcm *line6pcm)
{
    unsigned int i;

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

/*
    Wait until unlinking of all currently active playback URBs has been finished.
*/
void line6_wait_clear_audio_out_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_out))
                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 playback URBs, and wait for finishing.
*/
void line6_unlink_wait_clear_audio_out_urbs(struct snd_line6_pcm *line6pcm)
{
    line6_unlink_audio_out_urbs(line6pcm);
    line6_wait_clear_audio_out_urbs(line6pcm);
}

void line6_free_playback_buffer(struct snd_line6_pcm *line6pcm)
{
    kfree(line6pcm->buffer_out);
    line6pcm->buffer_out = NULL;
}

/*
    Callback for completed playback URB.
*/
static void audio_out_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;
    struct snd_pcm_substream *substream =
        get_substream(line6pcm, SNDRV_PCM_STREAM_PLAYBACK);

#if USE_CLEAR_BUFFER_WORKAROUND
    memset(urb->transfer_buffer, 0, urb->transfer_buffer_length);
#endif

    line6pcm->last_frame_out = urb->start_frame;

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

    if (index < 0)
        return;     /* URB has been unlinked asynchronously */

    for (i = LINE6_ISO_PACKETS; i--;)
        length += urb->iso_frame_desc[i].length;

    spin_lock_irqsave(&line6pcm->lock_audio_out, flags);

    if (test_bit(LINE6_INDEX_PCM_ALSA_PLAYBACK_STREAM, &line6pcm->flags)) {
        struct snd_pcm_runtime *runtime = substream->runtime;
        line6pcm->pos_out_done +=
            length / line6pcm->properties->bytes_per_frame;

        if (line6pcm->pos_out_done >= runtime->buffer_size)
            line6pcm->pos_out_done -= runtime->buffer_size;
    }

    clear_bit(index, &line6pcm->active_urb_out);

    for (i = LINE6_ISO_PACKETS; i--;)
        if (urb->iso_frame_desc[i].status == -EXDEV) {
            shutdown = 1;
            break;
        }

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

    spin_unlock_irqrestore(&line6pcm->lock_audio_out, flags);

    if (!shutdown) {
        submit_audio_out_urb(line6pcm);

        if (test_bit(LINE6_INDEX_PCM_ALSA_PLAYBACK_STREAM, &line6pcm->flags)) {
            line6pcm->bytes_out += length;
            if (line6pcm->bytes_out >= line6pcm->period_out) {
                line6pcm->bytes_out %= line6pcm->period_out;
                snd_pcm_period_elapsed(substream);
            }
        }
    }
}

/* open playback callback */
static int snd_line6_playback_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_playback_hw;
    return 0;
}

/* close playback callback */
static int snd_line6_playback_close(struct snd_pcm_substream *substream)
{
    return 0;
}

/* hw_params playback callback */
static int snd_line6_playback_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_PLAYBACK_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_PLAYBACK_BUFFER);
        return ret;
    }

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

/* hw_free playback callback */
static int snd_line6_playback_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_PLAYBACK_BUFFER);
    return snd_pcm_lib_free_pages(substream);
}

/* trigger playback callback */
int snd_line6_playback_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_PLAYBACK_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_PLAYBACK_STREAM);

        if (err < 0)
            return err;

        break;

    case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
        set_bit(LINE6_INDEX_PAUSE_PLAYBACK, &line6pcm->flags);
        break;

    case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
        clear_bit(LINE6_INDEX_PAUSE_PLAYBACK, &line6pcm->flags);
        break;

    default:
        return -EINVAL;
    }

    return 0;
}

/* playback pointer callback */
static snd_pcm_uframes_t
snd_line6_playback_pointer(struct snd_pcm_substream *substream)
{
    struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
    return line6pcm->pos_out_done;
}

/* playback operators */
struct snd_pcm_ops snd_line6_playback_ops = {
    .open = snd_line6_playback_open,
    .close = snd_line6_playback_close,
    .ioctl = snd_pcm_lib_ioctl,
    .hw_params = snd_line6_playback_hw_params,
    .hw_free = snd_line6_playback_hw_free,
    .prepare = snd_line6_prepare,
    .trigger = snd_line6_trigger,
    .pointer = snd_line6_playback_pointer,
};

int line6_create_audio_out_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 out: */
        urb = line6pcm->urb_audio_out[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_sndisocpipe(line6pcm->line6->usbdev,
                    line6pcm->ep_audio_write &
                    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_out_callback;
    }

    return 0;
}