midi.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 <linux/usb.h>
#include <sound/core.h>
#include <sound/rawmidi.h>

#include "audio.h"
#include "driver.h"
#include "midi.h"
#include "pod.h"
#include "usbdefs.h"

#define line6_rawmidi_substream_midi(substream) \
    ((struct snd_line6_midi *)((substream)->rmidi->private_data))

static int send_midi_async(struct usb_line6 *line6, unsigned char *data,
               int length);

/*
    Pass data received via USB to MIDI.
*/
void line6_midi_receive(struct usb_line6 *line6, unsigned char *data,
            int length)
{
    if (line6->line6midi->substream_receive)
        snd_rawmidi_receive(line6->line6midi->substream_receive,
                    data, length);
}

/*
    Read data from MIDI buffer and transmit them via USB.
*/
static void line6_midi_transmit(struct snd_rawmidi_substream *substream)
{
    struct usb_line6 *line6 =
        line6_rawmidi_substream_midi(substream)->line6;
    struct snd_line6_midi *line6midi = line6->line6midi;
    struct MidiBuffer *mb = &line6midi->midibuf_out;
    unsigned long flags;
    unsigned char chunk[line6->max_packet_size];
    int req, done;

    spin_lock_irqsave(&line6->line6midi->midi_transmit_lock, flags);

    for (;;) {
        req = min(line6_midibuf_bytes_free(mb), line6->max_packet_size);
        done = snd_rawmidi_transmit_peek(substream, chunk, req);

        if (done == 0)
            break;

#ifdef CONFIG_LINE6_USB_DUMP_MIDI
        line6_write_hexdump(line6, 's', chunk, done);
#endif
        line6_midibuf_write(mb, chunk, done);
        snd_rawmidi_transmit_ack(substream, done);
    }

    for (;;) {
        done = line6_midibuf_read(mb, chunk, line6->max_packet_size);

        if (done == 0)
            break;

        if (line6_midibuf_skip_message
            (mb, line6midi->midi_mask_transmit))
            continue;

        send_midi_async(line6, chunk, done);
    }

    spin_unlock_irqrestore(&line6->line6midi->midi_transmit_lock, flags);
}

/*
    Notification of completion of MIDI transmission.
*/
static void midi_sent(struct urb *urb)
{
    unsigned long flags;
    int status;
    int num;
    struct usb_line6 *line6 = (struct usb_line6 *)urb->context;

    status = urb->status;
    kfree(urb->transfer_buffer);
    usb_free_urb(urb);

    if (status == -ESHUTDOWN)
        return;

    spin_lock_irqsave(&line6->line6midi->send_urb_lock, flags);
    num = --line6->line6midi->num_active_send_urbs;

    if (num == 0) {
        line6_midi_transmit(line6->line6midi->substream_transmit);
        num = line6->line6midi->num_active_send_urbs;
    }

    if (num == 0)
        wake_up(&line6->line6midi->send_wait);

    spin_unlock_irqrestore(&line6->line6midi->send_urb_lock, flags);
}

/*
    Send an asynchronous MIDI message.
    Assumes that line6->line6midi->send_urb_lock is held
    (i.e., this function is serialized).
*/
static int send_midi_async(struct usb_line6 *line6, unsigned char *data,
               int length)
{
    struct urb *urb;
    int retval;
    unsigned char *transfer_buffer;

    urb = usb_alloc_urb(0, GFP_ATOMIC);

    if (urb == NULL) {
        dev_err(line6->ifcdev, "Out of memory\n");
        return -ENOMEM;
    }
#ifdef CONFIG_LINE6_USB_DUMP_CTRL
    line6_write_hexdump(line6, 'S', data, length);
#endif

    transfer_buffer = kmemdup(data, length, GFP_ATOMIC);

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

    usb_fill_int_urb(urb, line6->usbdev,
             usb_sndbulkpipe(line6->usbdev,
                     line6->ep_control_write),
             transfer_buffer, length, midi_sent, line6,
             line6->interval);
    urb->actual_length = 0;
    retval = usb_submit_urb(urb, GFP_ATOMIC);

    if (retval < 0) {
        dev_err(line6->ifcdev, "usb_submit_urb failed\n");
        usb_free_urb(urb);
        return -EINVAL;
    }

    ++line6->line6midi->num_active_send_urbs;

    switch (line6->usbdev->descriptor.idProduct) {
    case LINE6_DEVID_BASSPODXT:
    case LINE6_DEVID_BASSPODXTLIVE:
    case LINE6_DEVID_BASSPODXTPRO:
    case LINE6_DEVID_PODXT:
    case LINE6_DEVID_PODXTLIVE:
    case LINE6_DEVID_PODXTPRO:
    case LINE6_DEVID_POCKETPOD:
        line6_pod_midi_postprocess((struct usb_line6_pod *)line6, data,
                       length);
        break;

    case LINE6_DEVID_VARIAX:
    case LINE6_DEVID_PODHD300:
    case LINE6_DEVID_PODHD500:
        break;

    default:
        MISSING_CASE;
    }

    return 0;
}

static int line6_midi_output_open(struct snd_rawmidi_substream *substream)
{
    return 0;
}

static int line6_midi_output_close(struct snd_rawmidi_substream *substream)
{
    return 0;
}

static void line6_midi_output_trigger(struct snd_rawmidi_substream *substream,
                      int up)
{
    unsigned long flags;
    struct usb_line6 *line6 =
        line6_rawmidi_substream_midi(substream)->line6;

    line6->line6midi->substream_transmit = substream;
    spin_lock_irqsave(&line6->line6midi->send_urb_lock, flags);

    if (line6->line6midi->num_active_send_urbs == 0)
        line6_midi_transmit(substream);

    spin_unlock_irqrestore(&line6->line6midi->send_urb_lock, flags);
}

static void line6_midi_output_drain(struct snd_rawmidi_substream *substream)
{
    struct usb_line6 *line6 =
        line6_rawmidi_substream_midi(substream)->line6;
    struct snd_line6_midi *midi = line6->line6midi;
    wait_event_interruptible(midi->send_wait,
                 midi->num_active_send_urbs == 0);
}

static int line6_midi_input_open(struct snd_rawmidi_substream *substream)
{
    return 0;
}

static int line6_midi_input_close(struct snd_rawmidi_substream *substream)
{
    return 0;
}

static void line6_midi_input_trigger(struct snd_rawmidi_substream *substream,
                     int up)
{
    struct usb_line6 *line6 =
        line6_rawmidi_substream_midi(substream)->line6;

    if (up)
        line6->line6midi->substream_receive = substream;
    else
        line6->line6midi->substream_receive = 0;
}

static struct snd_rawmidi_ops line6_midi_output_ops = {
    .open = line6_midi_output_open,
    .close = line6_midi_output_close,
    .trigger = line6_midi_output_trigger,
    .drain = line6_midi_output_drain,
};

static struct snd_rawmidi_ops line6_midi_input_ops = {
    .open = line6_midi_input_open,
    .close = line6_midi_input_close,
    .trigger = line6_midi_input_trigger,
};

/*
    Cleanup the Line6 MIDI device.
*/
static void line6_cleanup_midi(struct snd_rawmidi *rmidi)
{
}

/* Create a MIDI device */
static int snd_line6_new_midi(struct snd_line6_midi *line6midi)
{
    struct snd_rawmidi *rmidi;
    int err;

    err = snd_rawmidi_new(line6midi->line6->card, "Line6 MIDI", 0, 1, 1,
                  &rmidi);
    if (err < 0)
        return err;

    rmidi->private_data = line6midi;
    rmidi->private_free = line6_cleanup_midi;
    strcpy(rmidi->id, line6midi->line6->properties->id);
    strcpy(rmidi->name, line6midi->line6->properties->name);

    rmidi->info_flags =
        SNDRV_RAWMIDI_INFO_OUTPUT |
        SNDRV_RAWMIDI_INFO_INPUT | SNDRV_RAWMIDI_INFO_DUPLEX;

    snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
                &line6_midi_output_ops);
    snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
                &line6_midi_input_ops);
    return 0;
}

/*
    "read" request on "midi_mask_transmit" special file.
*/
static ssize_t midi_get_midi_mask_transmit(struct device *dev,
                       struct device_attribute *attr,
                       char *buf)
{
    struct usb_interface *interface = to_usb_interface(dev);
    struct usb_line6 *line6 = usb_get_intfdata(interface);
    return sprintf(buf, "%d\n", line6->line6midi->midi_mask_transmit);
}

/*
    "write" request on "midi_mask" special file.
*/
static ssize_t midi_set_midi_mask_transmit(struct device *dev,
                       struct device_attribute *attr,
                       const char *buf, size_t count)
{
    struct usb_interface *interface = to_usb_interface(dev);
    struct usb_line6 *line6 = usb_get_intfdata(interface);
    unsigned short value;
    int ret;

    ret = kstrtou16(buf, 10, &value);
    if (ret)
        return ret;

    line6->line6midi->midi_mask_transmit = value;
    return count;
}

/*
    "read" request on "midi_mask_receive" special file.
*/
static ssize_t midi_get_midi_mask_receive(struct device *dev,
                      struct device_attribute *attr,
                      char *buf)
{
    struct usb_interface *interface = to_usb_interface(dev);
    struct usb_line6 *line6 = usb_get_intfdata(interface);
    return sprintf(buf, "%d\n", line6->line6midi->midi_mask_receive);
}

/*
    "write" request on "midi_mask" special file.
*/
static ssize_t midi_set_midi_mask_receive(struct device *dev,
                      struct device_attribute *attr,
                      const char *buf, size_t count)
{
    struct usb_interface *interface = to_usb_interface(dev);
    struct usb_line6 *line6 = usb_get_intfdata(interface);
    unsigned short value;
    int ret;

    ret = kstrtou16(buf, 10, &value);
    if (ret)
        return ret;

    line6->line6midi->midi_mask_receive = value;
    return count;
}

static DEVICE_ATTR(midi_mask_transmit, S_IWUSR | S_IRUGO,
           midi_get_midi_mask_transmit, midi_set_midi_mask_transmit);
static DEVICE_ATTR(midi_mask_receive, S_IWUSR | S_IRUGO,
           midi_get_midi_mask_receive, midi_set_midi_mask_receive);

/* MIDI device destructor */
static int snd_line6_midi_free(struct snd_device *device)
{
    struct snd_line6_midi *line6midi = device->device_data;
    device_remove_file(line6midi->line6->ifcdev,
               &dev_attr_midi_mask_transmit);
    device_remove_file(line6midi->line6->ifcdev,
               &dev_attr_midi_mask_receive);
    line6_midibuf_destroy(&line6midi->midibuf_in);
    line6_midibuf_destroy(&line6midi->midibuf_out);
    return 0;
}

/*
    Initialize the Line6 MIDI subsystem.
*/
int line6_init_midi(struct usb_line6 *line6)
{
    static struct snd_device_ops midi_ops = {
        .dev_free = snd_line6_midi_free,
    };

    int err;
    struct snd_line6_midi *line6midi;

    if (!(line6->properties->capabilities & LINE6_BIT_CONTROL)) {
        /* skip MIDI initialization and report success */
        return 0;
    }

    line6midi = kzalloc(sizeof(struct snd_line6_midi), GFP_KERNEL);

    if (line6midi == NULL)
        return -ENOMEM;

    err = line6_midibuf_init(&line6midi->midibuf_in, MIDI_BUFFER_SIZE, 0);
    if (err < 0) {
        kfree(line6midi);
        return err;
    }

    err = line6_midibuf_init(&line6midi->midibuf_out, MIDI_BUFFER_SIZE, 1);
    if (err < 0) {
        kfree(line6midi->midibuf_in.buf);
        kfree(line6midi);
        return err;
    }

    line6midi->line6 = line6;

    switch (line6->product) {
    case LINE6_DEVID_PODHD300:
    case LINE6_DEVID_PODHD500:
        line6midi->midi_mask_transmit = 1;
        line6midi->midi_mask_receive = 1;
        break;

    default:
        line6midi->midi_mask_transmit = 1;
        line6midi->midi_mask_receive = 4;
    }

    line6->line6midi = line6midi;

    err = snd_device_new(line6->card, SNDRV_DEV_RAWMIDI, line6midi,
                 &midi_ops);
    if (err < 0)
        return err;

    snd_card_set_dev(line6->card, line6->ifcdev);

    err = snd_line6_new_midi(line6midi);
    if (err < 0)
        return err;

    err = device_create_file(line6->ifcdev, &dev_attr_midi_mask_transmit);
    if (err < 0)
        return err;

    err = device_create_file(line6->ifcdev, &dev_attr_midi_mask_receive);
    if (err < 0)
        return err;

    init_waitqueue_head(&line6midi->send_wait);
    spin_lock_init(&line6midi->send_urb_lock);
    spin_lock_init(&line6midi->midi_transmit_lock);
    return 0;
}