midi.c

  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * Linux driver for TerraTec DMX 6Fire USB
  4 *
  5 * Rawmidi driver
  6 *
  7 * Author:	Torsten Schenk <torsten.schenk@zoho.com>
  8 * Created:	Jan 01, 2011
  9 * Copyright:	(C) Torsten Schenk
 10 */
 11
 12#include <sound/rawmidi.h>
 13
 14#include "midi.h"
 15#include "chip.h"
 16#include "comm.h"
 17
 18enum {
 19	MIDI_BUFSIZE = 64
 20};
 21
 22static void usb6fire_midi_out_handler(struct urb *urb)
 23{
 24	struct midi_runtime *rt = urb->context;
 25	int ret;
 26
 27	guard(spinlock_irqsave)(&rt->out_lock);
 28
 29	if (rt->out) {
 30		ret = snd_rawmidi_transmit(rt->out, rt->out_buffer + 4,
 31				MIDI_BUFSIZE - 4);
 32		if (ret > 0) { /* more data available, send next packet */
 33			rt->out_buffer[1] = ret + 2;
 34			rt->out_buffer[3] = rt->out_serial++;
 35			urb->transfer_buffer_length = ret + 4;
 36
 37			ret = usb_submit_urb(urb, GFP_ATOMIC);
 38			if (ret < 0)
 39				dev_err(&urb->dev->dev,
 40					"midi out urb submit failed: %d\n",
 41					ret);
 42		} else /* no more data to transmit */
 43			rt->out = NULL;
 44	}
 45}
 46
 47static void usb6fire_midi_in_received(
 48		struct midi_runtime *rt, u8 *data, int length)
 49{
 50	guard(spinlock_irqsave)(&rt->in_lock);
 51	if (rt->in)
 52		snd_rawmidi_receive(rt->in, data, length);
 53}
 54
 55static int usb6fire_midi_out_open(struct snd_rawmidi_substream *alsa_sub)
 56{
 57	return 0;
 58}
 59
 60static int usb6fire_midi_out_close(struct snd_rawmidi_substream *alsa_sub)
 61{
 62	return 0;
 63}
 64
 65static void usb6fire_midi_out_trigger(
 66		struct snd_rawmidi_substream *alsa_sub, int up)
 67{
 68	struct midi_runtime *rt = alsa_sub->rmidi->private_data;
 69	struct urb *urb = &rt->out_urb;
 70	__s8 ret;
 71
 72	guard(spinlock_irqsave)(&rt->out_lock);
 73	if (up) { /* start transfer */
 74		if (rt->out) /* we are already transmitting so just return */
 75			return;
 76
 77		ret = snd_rawmidi_transmit(alsa_sub, rt->out_buffer + 4,
 78				MIDI_BUFSIZE - 4);
 79		if (ret > 0) {
 80			rt->out_buffer[1] = ret + 2;
 81			rt->out_buffer[3] = rt->out_serial++;
 82			urb->transfer_buffer_length = ret + 4;
 83
 84			ret = usb_submit_urb(urb, GFP_ATOMIC);
 85			if (ret < 0)
 86				dev_err(&urb->dev->dev,
 87					"midi out urb submit failed: %d\n",
 88					ret);
 89			else
 90				rt->out = alsa_sub;
 91		}
 92	} else if (rt->out == alsa_sub)
 93		rt->out = NULL;
 94}
 95
 96static void usb6fire_midi_out_drain(struct snd_rawmidi_substream *alsa_sub)
 97{
 98	struct midi_runtime *rt = alsa_sub->rmidi->private_data;
 99	int retry = 0;
100
101	while (rt->out && retry++ < 100)
102		msleep(10);
103}
104
105static int usb6fire_midi_in_open(struct snd_rawmidi_substream *alsa_sub)
106{
107	return 0;
108}
109
110static int usb6fire_midi_in_close(struct snd_rawmidi_substream *alsa_sub)
111{
112	return 0;
113}
114
115static void usb6fire_midi_in_trigger(
116		struct snd_rawmidi_substream *alsa_sub, int up)
117{
118	struct midi_runtime *rt = alsa_sub->rmidi->private_data;
119
120	guard(spinlock_irqsave)(&rt->in_lock);
121	if (up)
122		rt->in = alsa_sub;
123	else
124		rt->in = NULL;
125}
126
127static const struct snd_rawmidi_ops out_ops = {
128	.open = usb6fire_midi_out_open,
129	.close = usb6fire_midi_out_close,
130	.trigger = usb6fire_midi_out_trigger,
131	.drain = usb6fire_midi_out_drain
132};
133
134static const struct snd_rawmidi_ops in_ops = {
135	.open = usb6fire_midi_in_open,
136	.close = usb6fire_midi_in_close,
137	.trigger = usb6fire_midi_in_trigger
138};
139
140int usb6fire_midi_init(struct sfire_chip *chip)
141{
142	int ret;
143	struct midi_runtime *rt = kzalloc(sizeof(struct midi_runtime),
144			GFP_KERNEL);
145	struct comm_runtime *comm_rt = chip->comm;
146
147	if (!rt)
148		return -ENOMEM;
149
150	rt->out_buffer = kzalloc(MIDI_BUFSIZE, GFP_KERNEL);
151	if (!rt->out_buffer) {
152		kfree(rt);
153		return -ENOMEM;
154	}
155
156	rt->chip = chip;
157	rt->in_received = usb6fire_midi_in_received;
158	rt->out_buffer[0] = 0x80; /* 'send midi' command */
159	rt->out_buffer[1] = 0x00; /* size of data */
160	rt->out_buffer[2] = 0x00; /* always 0 */
161	spin_lock_init(&rt->in_lock);
162	spin_lock_init(&rt->out_lock);
163
164	comm_rt->init_urb(comm_rt, &rt->out_urb, rt->out_buffer, rt,
165			usb6fire_midi_out_handler);
166
167	ret = snd_rawmidi_new(chip->card, "6FireUSB", 0, 1, 1, &rt->instance);
168	if (ret < 0) {
169		kfree(rt->out_buffer);
170		kfree(rt);
171		dev_err(&chip->dev->dev, "unable to create midi.\n");
172		return ret;
173	}
174	rt->instance->private_data = rt;
175	strscpy(rt->instance->name, "DMX6FireUSB MIDI");
176	rt->instance->info_flags = SNDRV_RAWMIDI_INFO_OUTPUT |
177			SNDRV_RAWMIDI_INFO_INPUT |
178			SNDRV_RAWMIDI_INFO_DUPLEX;
179	snd_rawmidi_set_ops(rt->instance, SNDRV_RAWMIDI_STREAM_OUTPUT,
180			&out_ops);
181	snd_rawmidi_set_ops(rt->instance, SNDRV_RAWMIDI_STREAM_INPUT,
182			&in_ops);
183
184	chip->midi = rt;
185	return 0;
186}
187
188void usb6fire_midi_abort(struct sfire_chip *chip)
189{
190	struct midi_runtime *rt = chip->midi;
191
192	if (rt)
193		usb_poison_urb(&rt->out_urb);
194}
195
196void usb6fire_midi_destroy(struct sfire_chip *chip)
197{
198	struct midi_runtime *rt = chip->midi;
199
200	kfree(rt->out_buffer);
201	kfree(rt);
202	chip->midi = NULL;
203}