296 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Line 6 Linux USB driver4 *5 * Copyright (C) 2004-2010 Markus Grabner (line6@grabner-graz.at)6 */7 8#include <linux/slab.h>9#include <linux/usb.h>10#include <linux/export.h>11#include <sound/core.h>12#include <sound/rawmidi.h>13 14#include "driver.h"15#include "midi.h"16 17#define line6_rawmidi_substream_midi(substream) \18 ((struct snd_line6_midi *)((substream)->rmidi->private_data))19 20static int send_midi_async(struct usb_line6 *line6, unsigned char *data,21 int length);22 23/*24 Pass data received via USB to MIDI.25*/26void line6_midi_receive(struct usb_line6 *line6, unsigned char *data,27 int length)28{29 if (line6->line6midi->substream_receive)30 snd_rawmidi_receive(line6->line6midi->substream_receive,31 data, length);32}33 34/*35 Read data from MIDI buffer and transmit them via USB.36*/37static void line6_midi_transmit(struct snd_rawmidi_substream *substream)38{39 struct usb_line6 *line6 =40 line6_rawmidi_substream_midi(substream)->line6;41 struct snd_line6_midi *line6midi = line6->line6midi;42 struct midi_buffer *mb = &line6midi->midibuf_out;43 unsigned char chunk[LINE6_FALLBACK_MAXPACKETSIZE];44 int req, done;45 46 for (;;) {47 req = min3(line6_midibuf_bytes_free(mb), line6->max_packet_size,48 LINE6_FALLBACK_MAXPACKETSIZE);49 done = snd_rawmidi_transmit_peek(substream, chunk, req);50 51 if (done == 0)52 break;53 54 line6_midibuf_write(mb, chunk, done);55 snd_rawmidi_transmit_ack(substream, done);56 }57 58 for (;;) {59 done = line6_midibuf_read(mb, chunk,60 LINE6_FALLBACK_MAXPACKETSIZE,61 LINE6_MIDIBUF_READ_TX);62 63 if (done == 0)64 break;65 66 send_midi_async(line6, chunk, done);67 }68}69 70/*71 Notification of completion of MIDI transmission.72*/73static void midi_sent(struct urb *urb)74{75 unsigned long flags;76 int status;77 int num;78 struct usb_line6 *line6 = (struct usb_line6 *)urb->context;79 80 status = urb->status;81 kfree(urb->transfer_buffer);82 usb_free_urb(urb);83 84 if (status == -ESHUTDOWN)85 return;86 87 spin_lock_irqsave(&line6->line6midi->lock, flags);88 num = --line6->line6midi->num_active_send_urbs;89 90 if (num == 0) {91 line6_midi_transmit(line6->line6midi->substream_transmit);92 num = line6->line6midi->num_active_send_urbs;93 }94 95 if (num == 0)96 wake_up(&line6->line6midi->send_wait);97 98 spin_unlock_irqrestore(&line6->line6midi->lock, flags);99}100 101/*102 Send an asynchronous MIDI message.103 Assumes that line6->line6midi->lock is held104 (i.e., this function is serialized).105*/106static int send_midi_async(struct usb_line6 *line6, unsigned char *data,107 int length)108{109 struct urb *urb;110 int retval;111 unsigned char *transfer_buffer;112 113 urb = usb_alloc_urb(0, GFP_ATOMIC);114 115 if (urb == NULL)116 return -ENOMEM;117 118 transfer_buffer = kmemdup(data, length, GFP_ATOMIC);119 120 if (transfer_buffer == NULL) {121 usb_free_urb(urb);122 return -ENOMEM;123 }124 125 usb_fill_int_urb(urb, line6->usbdev,126 usb_sndintpipe(line6->usbdev,127 line6->properties->ep_ctrl_w),128 transfer_buffer, length, midi_sent, line6,129 line6->interval);130 urb->actual_length = 0;131 retval = usb_urb_ep_type_check(urb);132 if (retval < 0)133 goto error;134 135 retval = usb_submit_urb(urb, GFP_ATOMIC);136 if (retval < 0)137 goto error;138 139 ++line6->line6midi->num_active_send_urbs;140 return 0;141 142 error:143 dev_err(line6->ifcdev, "usb_submit_urb failed\n");144 usb_free_urb(urb);145 return retval;146}147 148static int line6_midi_output_open(struct snd_rawmidi_substream *substream)149{150 return 0;151}152 153static int line6_midi_output_close(struct snd_rawmidi_substream *substream)154{155 return 0;156}157 158static void line6_midi_output_trigger(struct snd_rawmidi_substream *substream,159 int up)160{161 unsigned long flags;162 struct usb_line6 *line6 =163 line6_rawmidi_substream_midi(substream)->line6;164 165 line6->line6midi->substream_transmit = substream;166 spin_lock_irqsave(&line6->line6midi->lock, flags);167 168 if (line6->line6midi->num_active_send_urbs == 0)169 line6_midi_transmit(substream);170 171 spin_unlock_irqrestore(&line6->line6midi->lock, flags);172}173 174static void line6_midi_output_drain(struct snd_rawmidi_substream *substream)175{176 struct usb_line6 *line6 =177 line6_rawmidi_substream_midi(substream)->line6;178 struct snd_line6_midi *midi = line6->line6midi;179 180 wait_event_interruptible(midi->send_wait,181 midi->num_active_send_urbs == 0);182}183 184static int line6_midi_input_open(struct snd_rawmidi_substream *substream)185{186 return 0;187}188 189static int line6_midi_input_close(struct snd_rawmidi_substream *substream)190{191 return 0;192}193 194static void line6_midi_input_trigger(struct snd_rawmidi_substream *substream,195 int up)196{197 struct usb_line6 *line6 =198 line6_rawmidi_substream_midi(substream)->line6;199 200 if (up)201 line6->line6midi->substream_receive = substream;202 else203 line6->line6midi->substream_receive = NULL;204}205 206static const struct snd_rawmidi_ops line6_midi_output_ops = {207 .open = line6_midi_output_open,208 .close = line6_midi_output_close,209 .trigger = line6_midi_output_trigger,210 .drain = line6_midi_output_drain,211};212 213static const struct snd_rawmidi_ops line6_midi_input_ops = {214 .open = line6_midi_input_open,215 .close = line6_midi_input_close,216 .trigger = line6_midi_input_trigger,217};218 219/* Create a MIDI device */220static int snd_line6_new_midi(struct usb_line6 *line6,221 struct snd_rawmidi **rmidi_ret)222{223 struct snd_rawmidi *rmidi;224 int err;225 226 err = snd_rawmidi_new(line6->card, "Line 6 MIDI", 0, 1, 1, rmidi_ret);227 if (err < 0)228 return err;229 230 rmidi = *rmidi_ret;231 strcpy(rmidi->id, line6->properties->id);232 strcpy(rmidi->name, line6->properties->name);233 234 rmidi->info_flags =235 SNDRV_RAWMIDI_INFO_OUTPUT |236 SNDRV_RAWMIDI_INFO_INPUT | SNDRV_RAWMIDI_INFO_DUPLEX;237 238 snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,239 &line6_midi_output_ops);240 snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT,241 &line6_midi_input_ops);242 return 0;243}244 245/* MIDI device destructor */246static void snd_line6_midi_free(struct snd_rawmidi *rmidi)247{248 struct snd_line6_midi *line6midi = rmidi->private_data;249 250 line6_midibuf_destroy(&line6midi->midibuf_in);251 line6_midibuf_destroy(&line6midi->midibuf_out);252 kfree(line6midi);253}254 255/*256 Initialize the Line 6 MIDI subsystem.257*/258int line6_init_midi(struct usb_line6 *line6)259{260 int err;261 struct snd_rawmidi *rmidi;262 struct snd_line6_midi *line6midi;263 264 if (!(line6->properties->capabilities & LINE6_CAP_CONTROL_MIDI)) {265 /* skip MIDI initialization and report success */266 return 0;267 }268 269 err = snd_line6_new_midi(line6, &rmidi);270 if (err < 0)271 return err;272 273 line6midi = kzalloc(sizeof(struct snd_line6_midi), GFP_KERNEL);274 if (!line6midi)275 return -ENOMEM;276 277 rmidi->private_data = line6midi;278 rmidi->private_free = snd_line6_midi_free;279 280 init_waitqueue_head(&line6midi->send_wait);281 spin_lock_init(&line6midi->lock);282 line6midi->line6 = line6;283 284 err = line6_midibuf_init(&line6midi->midibuf_in, MIDI_BUFFER_SIZE, 0);285 if (err < 0)286 return err;287 288 err = line6_midibuf_init(&line6midi->midibuf_out, MIDI_BUFFER_SIZE, 1);289 if (err < 0)290 return err;291 292 line6->line6midi = line6midi;293 return 0;294}295EXPORT_SYMBOL_GPL(line6_init_midi);296