1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Line 6 Linux USB driver 4 * 5 * Copyright (C) 2004-2010 Markus Grabner (grabner@icg.tugraz.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 20 static 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 */ 26 void 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 */ 37 static 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 = min(line6_midibuf_bytes_free(mb), line6->max_packet_size); 48 done = snd_rawmidi_transmit_peek(substream, chunk, req); 49 50 if (done == 0) 51 break; 52 53 line6_midibuf_write(mb, chunk, done); 54 snd_rawmidi_transmit_ack(substream, done); 55 } 56 57 for (;;) { 58 done = line6_midibuf_read(mb, chunk, 59 LINE6_FALLBACK_MAXPACKETSIZE); 60 61 if (done == 0) 62 break; 63 64 send_midi_async(line6, chunk, done); 65 } 66 } 67 68 /* 69 Notification of completion of MIDI transmission. 70 */ 71 static void midi_sent(struct urb *urb) 72 { 73 unsigned long flags; 74 int status; 75 int num; 76 struct usb_line6 *line6 = (struct usb_line6 *)urb->context; 77 78 status = urb->status; 79 kfree(urb->transfer_buffer); 80 usb_free_urb(urb); 81 82 if (status == -ESHUTDOWN) 83 return; 84 85 spin_lock_irqsave(&line6->line6midi->lock, flags); 86 num = --line6->line6midi->num_active_send_urbs; 87 88 if (num == 0) { 89 line6_midi_transmit(line6->line6midi->substream_transmit); 90 num = line6->line6midi->num_active_send_urbs; 91 } 92 93 if (num == 0) 94 wake_up(&line6->line6midi->send_wait); 95 96 spin_unlock_irqrestore(&line6->line6midi->lock, flags); 97 } 98 99 /* 100 Send an asynchronous MIDI message. 101 Assumes that line6->line6midi->lock is held 102 (i.e., this function is serialized). 103 */ 104 static int send_midi_async(struct usb_line6 *line6, unsigned char *data, 105 int length) 106 { 107 struct urb *urb; 108 int retval; 109 unsigned char *transfer_buffer; 110 111 urb = usb_alloc_urb(0, GFP_ATOMIC); 112 113 if (urb == NULL) 114 return -ENOMEM; 115 116 transfer_buffer = kmemdup(data, length, GFP_ATOMIC); 117 118 if (transfer_buffer == NULL) { 119 usb_free_urb(urb); 120 return -ENOMEM; 121 } 122 123 usb_fill_int_urb(urb, line6->usbdev, 124 usb_sndintpipe(line6->usbdev, 125 line6->properties->ep_ctrl_w), 126 transfer_buffer, length, midi_sent, line6, 127 line6->interval); 128 urb->actual_length = 0; 129 retval = usb_urb_ep_type_check(urb); 130 if (retval < 0) 131 goto error; 132 133 retval = usb_submit_urb(urb, GFP_ATOMIC); 134 if (retval < 0) 135 goto error; 136 137 ++line6->line6midi->num_active_send_urbs; 138 return 0; 139 140 error: 141 dev_err(line6->ifcdev, "usb_submit_urb failed\n"); 142 usb_free_urb(urb); 143 return retval; 144 } 145 146 static int line6_midi_output_open(struct snd_rawmidi_substream *substream) 147 { 148 return 0; 149 } 150 151 static int line6_midi_output_close(struct snd_rawmidi_substream *substream) 152 { 153 return 0; 154 } 155 156 static void line6_midi_output_trigger(struct snd_rawmidi_substream *substream, 157 int up) 158 { 159 unsigned long flags; 160 struct usb_line6 *line6 = 161 line6_rawmidi_substream_midi(substream)->line6; 162 163 line6->line6midi->substream_transmit = substream; 164 spin_lock_irqsave(&line6->line6midi->lock, flags); 165 166 if (line6->line6midi->num_active_send_urbs == 0) 167 line6_midi_transmit(substream); 168 169 spin_unlock_irqrestore(&line6->line6midi->lock, flags); 170 } 171 172 static void line6_midi_output_drain(struct snd_rawmidi_substream *substream) 173 { 174 struct usb_line6 *line6 = 175 line6_rawmidi_substream_midi(substream)->line6; 176 struct snd_line6_midi *midi = line6->line6midi; 177 178 wait_event_interruptible(midi->send_wait, 179 midi->num_active_send_urbs == 0); 180 } 181 182 static int line6_midi_input_open(struct snd_rawmidi_substream *substream) 183 { 184 return 0; 185 } 186 187 static int line6_midi_input_close(struct snd_rawmidi_substream *substream) 188 { 189 return 0; 190 } 191 192 static void line6_midi_input_trigger(struct snd_rawmidi_substream *substream, 193 int up) 194 { 195 struct usb_line6 *line6 = 196 line6_rawmidi_substream_midi(substream)->line6; 197 198 if (up) 199 line6->line6midi->substream_receive = substream; 200 else 201 line6->line6midi->substream_receive = NULL; 202 } 203 204 static const struct snd_rawmidi_ops line6_midi_output_ops = { 205 .open = line6_midi_output_open, 206 .close = line6_midi_output_close, 207 .trigger = line6_midi_output_trigger, 208 .drain = line6_midi_output_drain, 209 }; 210 211 static const struct snd_rawmidi_ops line6_midi_input_ops = { 212 .open = line6_midi_input_open, 213 .close = line6_midi_input_close, 214 .trigger = line6_midi_input_trigger, 215 }; 216 217 /* Create a MIDI device */ 218 static int snd_line6_new_midi(struct usb_line6 *line6, 219 struct snd_rawmidi **rmidi_ret) 220 { 221 struct snd_rawmidi *rmidi; 222 int err; 223 224 err = snd_rawmidi_new(line6->card, "Line 6 MIDI", 0, 1, 1, rmidi_ret); 225 if (err < 0) 226 return err; 227 228 rmidi = *rmidi_ret; 229 strcpy(rmidi->id, line6->properties->id); 230 strcpy(rmidi->name, line6->properties->name); 231 232 rmidi->info_flags = 233 SNDRV_RAWMIDI_INFO_OUTPUT | 234 SNDRV_RAWMIDI_INFO_INPUT | SNDRV_RAWMIDI_INFO_DUPLEX; 235 236 snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT, 237 &line6_midi_output_ops); 238 snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT, 239 &line6_midi_input_ops); 240 return 0; 241 } 242 243 /* MIDI device destructor */ 244 static void snd_line6_midi_free(struct snd_rawmidi *rmidi) 245 { 246 struct snd_line6_midi *line6midi = rmidi->private_data; 247 248 line6_midibuf_destroy(&line6midi->midibuf_in); 249 line6_midibuf_destroy(&line6midi->midibuf_out); 250 kfree(line6midi); 251 } 252 253 /* 254 Initialize the Line 6 MIDI subsystem. 255 */ 256 int line6_init_midi(struct usb_line6 *line6) 257 { 258 int err; 259 struct snd_rawmidi *rmidi; 260 struct snd_line6_midi *line6midi; 261 262 if (!(line6->properties->capabilities & LINE6_CAP_CONTROL_MIDI)) { 263 /* skip MIDI initialization and report success */ 264 return 0; 265 } 266 267 err = snd_line6_new_midi(line6, &rmidi); 268 if (err < 0) 269 return err; 270 271 line6midi = kzalloc(sizeof(struct snd_line6_midi), GFP_KERNEL); 272 if (!line6midi) 273 return -ENOMEM; 274 275 rmidi->private_data = line6midi; 276 rmidi->private_free = snd_line6_midi_free; 277 278 init_waitqueue_head(&line6midi->send_wait); 279 spin_lock_init(&line6midi->lock); 280 line6midi->line6 = line6; 281 282 err = line6_midibuf_init(&line6midi->midibuf_in, MIDI_BUFFER_SIZE, 0); 283 if (err < 0) 284 return err; 285 286 err = line6_midibuf_init(&line6midi->midibuf_out, MIDI_BUFFER_SIZE, 1); 287 if (err < 0) 288 return err; 289 290 line6->line6midi = line6midi; 291 return 0; 292 } 293 EXPORT_SYMBOL_GPL(line6_init_midi); 294