diff options
Diffstat (limited to 'kernel/sound/usb/line6/midi.c')
| -rw-r--r-- | kernel/sound/usb/line6/midi.c | 292 |
1 files changed, 292 insertions, 0 deletions
diff --git a/kernel/sound/usb/line6/midi.c b/kernel/sound/usb/line6/midi.c new file mode 100644 index 000000000..cebea9b7f --- /dev/null +++ b/kernel/sound/usb/line6/midi.c @@ -0,0 +1,292 @@ +/* + * Line 6 Linux USB driver + * + * Copyright (C) 2004-2010 Markus Grabner (grabner@icg.tugraz.at) + * + * 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 <linux/export.h> +#include <sound/core.h> +#include <sound/rawmidi.h> + +#include "driver.h" +#include "midi.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 midi_buffer *mb = &line6midi->midibuf_out; + unsigned char chunk[LINE6_FALLBACK_MAXPACKETSIZE]; + int req, done; + + for (;;) { + req = min(line6_midibuf_bytes_free(mb), line6->max_packet_size); + done = snd_rawmidi_transmit_peek(substream, chunk, req); + + if (done == 0) + break; + + line6_midibuf_write(mb, chunk, done); + snd_rawmidi_transmit_ack(substream, done); + } + + for (;;) { + done = line6_midibuf_read(mb, chunk, + LINE6_FALLBACK_MAXPACKETSIZE); + + if (done == 0) + break; + + send_midi_async(line6, chunk, done); + } +} + +/* + 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->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->lock, flags); +} + +/* + Send an asynchronous MIDI message. + Assumes that line6->line6midi->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) + return -ENOMEM; + + transfer_buffer = kmemdup(data, length, GFP_ATOMIC); + + if (transfer_buffer == NULL) { + usb_free_urb(urb); + return -ENOMEM; + } + + usb_fill_int_urb(urb, line6->usbdev, + usb_sndbulkpipe(line6->usbdev, + line6->properties->ep_ctrl_w), + 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 retval; + } + + ++line6->line6midi->num_active_send_urbs; + 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->lock, flags); + + if (line6->line6midi->num_active_send_urbs == 0) + line6_midi_transmit(substream); + + spin_unlock_irqrestore(&line6->line6midi->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 = NULL; +} + +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, +}; + +/* Create a MIDI device */ +static int snd_line6_new_midi(struct usb_line6 *line6, + struct snd_rawmidi **rmidi_ret) +{ + struct snd_rawmidi *rmidi; + int err; + + err = snd_rawmidi_new(line6->card, "Line 6 MIDI", 0, 1, 1, rmidi_ret); + if (err < 0) + return err; + + rmidi = *rmidi_ret; + strcpy(rmidi->id, line6->properties->id); + strcpy(rmidi->name, 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; +} + +/* MIDI device destructor */ +static void snd_line6_midi_free(struct snd_rawmidi *rmidi) +{ + struct snd_line6_midi *line6midi = rmidi->private_data; + + line6_midibuf_destroy(&line6midi->midibuf_in); + line6_midibuf_destroy(&line6midi->midibuf_out); + kfree(line6midi); +} + +/* + Initialize the Line 6 MIDI subsystem. +*/ +int line6_init_midi(struct usb_line6 *line6) +{ + int err; + struct snd_rawmidi *rmidi; + struct snd_line6_midi *line6midi; + + if (!(line6->properties->capabilities & LINE6_CAP_CONTROL)) { + /* skip MIDI initialization and report success */ + return 0; + } + + err = snd_line6_new_midi(line6, &rmidi); + if (err < 0) + return err; + + line6midi = kzalloc(sizeof(struct snd_line6_midi), GFP_KERNEL); + if (!line6midi) + return -ENOMEM; + + rmidi->private_data = line6midi; + rmidi->private_free = snd_line6_midi_free; + + init_waitqueue_head(&line6midi->send_wait); + spin_lock_init(&line6midi->lock); + line6midi->line6 = line6; + + err = line6_midibuf_init(&line6midi->midibuf_in, MIDI_BUFFER_SIZE, 0); + if (err < 0) + return err; + + err = line6_midibuf_init(&line6midi->midibuf_out, MIDI_BUFFER_SIZE, 1); + if (err < 0) + return err; + + line6->line6midi = line6midi; + return 0; +} +EXPORT_SYMBOL_GPL(line6_init_midi); |