1/****************************************************************************
2
3   Copyright Echo Digital Audio Corporation (c) 1998 - 2004
4   All rights reserved
5   www.echoaudio.com
6
7   This file is part of Echo Digital Audio's generic driver library.
8
9   Echo Digital Audio's generic driver library is free software;
10   you can redistribute it and/or modify it under the terms of
11   the GNU General Public License as published by the Free Software
12   Foundation.
13
14   This program is distributed in the hope that it will be useful,
15   but WITHOUT ANY WARRANTY; without even the implied warranty of
16   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17   GNU General Public License for more details.
18
19   You should have received a copy of the GNU General Public License
20   along with this program; if not, write to the Free Software
21   Foundation, Inc., 59 Temple Place - Suite 330, Boston,
22   MA  02111-1307, USA.
23
24   *************************************************************************
25
26 Translation from C++ and adaptation for use in ALSA-Driver
27 were made by Giuliano Pochini <pochini@shiny.it>
28
29****************************************************************************/
30
31
32/******************************************************************************
33	MIDI lowlevel code
34******************************************************************************/
35
36/* Start and stop Midi input */
37static int enable_midi_input(struct echoaudio *chip, char enable)
38{
39	dev_dbg(chip->card->dev, "enable_midi_input(%d)\n", enable);
40
41	if (wait_handshake(chip))
42		return -EIO;
43
44	if (enable) {
45		chip->mtc_state = MIDI_IN_STATE_NORMAL;
46		chip->comm_page->flags |=
47			cpu_to_le32(DSP_FLAG_MIDI_INPUT);
48	} else
49		chip->comm_page->flags &=
50			~cpu_to_le32(DSP_FLAG_MIDI_INPUT);
51
52	clear_handshake(chip);
53	return send_vector(chip, DSP_VC_UPDATE_FLAGS);
54}
55
56
57
58/* Send a buffer full of MIDI data to the DSP
59Returns how many actually written or < 0 on error */
60static int write_midi(struct echoaudio *chip, u8 *data, int bytes)
61{
62	if (snd_BUG_ON(bytes <= 0 || bytes >= MIDI_OUT_BUFFER_SIZE))
63		return -EINVAL;
64
65	if (wait_handshake(chip))
66		return -EIO;
67
68	/* HF4 indicates that it is safe to write MIDI output data */
69	if (! (get_dsp_register(chip, CHI32_STATUS_REG) & CHI32_STATUS_REG_HF4))
70		return 0;
71
72	chip->comm_page->midi_output[0] = bytes;
73	memcpy(&chip->comm_page->midi_output[1], data, bytes);
74	chip->comm_page->midi_out_free_count = 0;
75	clear_handshake(chip);
76	send_vector(chip, DSP_VC_MIDI_WRITE);
77	dev_dbg(chip->card->dev, "write_midi: %d\n", bytes);
78	return bytes;
79}
80
81
82
83/* Run the state machine for MIDI input data
84MIDI time code sync isn't supported by this code right now, but you still need
85this state machine to parse the incoming MIDI data stream.  Every time the DSP
86sees a 0xF1 byte come in, it adds the DSP sample position to the MIDI data
87stream. The DSP sample position is represented as a 32 bit unsigned value,
88with the high 16 bits first, followed by the low 16 bits. Since these aren't
89real MIDI bytes, the following logic is needed to skip them. */
90static inline int mtc_process_data(struct echoaudio *chip, short midi_byte)
91{
92	switch (chip->mtc_state) {
93	case MIDI_IN_STATE_NORMAL:
94		if (midi_byte == 0xF1)
95			chip->mtc_state = MIDI_IN_STATE_TS_HIGH;
96		break;
97	case MIDI_IN_STATE_TS_HIGH:
98		chip->mtc_state = MIDI_IN_STATE_TS_LOW;
99		return MIDI_IN_SKIP_DATA;
100		break;
101	case MIDI_IN_STATE_TS_LOW:
102		chip->mtc_state = MIDI_IN_STATE_F1_DATA;
103		return MIDI_IN_SKIP_DATA;
104		break;
105	case MIDI_IN_STATE_F1_DATA:
106		chip->mtc_state = MIDI_IN_STATE_NORMAL;
107		break;
108	}
109	return 0;
110}
111
112
113
114/* This function is called from the IRQ handler and it reads the midi data
115from the DSP's buffer.  It returns the number of bytes received. */
116static int midi_service_irq(struct echoaudio *chip)
117{
118	short int count, midi_byte, i, received;
119
120	/* The count is at index 0, followed by actual data */
121	count = le16_to_cpu(chip->comm_page->midi_input[0]);
122
123	if (snd_BUG_ON(count >= MIDI_IN_BUFFER_SIZE))
124		return 0;
125
126	/* Get the MIDI data from the comm page */
127	i = 1;
128	received = 0;
129	for (i = 1; i <= count; i++) {
130		/* Get the MIDI byte */
131		midi_byte = le16_to_cpu(chip->comm_page->midi_input[i]);
132
133		/* Parse the incoming MIDI stream. The incoming MIDI data
134		consists of MIDI bytes and timestamps for the MIDI time code
135		0xF1 bytes. mtc_process_data() is a little state machine that
136		parses the stream. If you get MIDI_IN_SKIP_DATA back, then
137		this is a timestamp byte, not a MIDI byte, so don't store it
138		in the MIDI input buffer. */
139		if (mtc_process_data(chip, midi_byte) == MIDI_IN_SKIP_DATA)
140			continue;
141
142		chip->midi_buffer[received++] = (u8)midi_byte;
143	}
144
145	return received;
146}
147
148
149
150
151/******************************************************************************
152	MIDI interface
153******************************************************************************/
154
155static int snd_echo_midi_input_open(struct snd_rawmidi_substream *substream)
156{
157	struct echoaudio *chip = substream->rmidi->private_data;
158
159	chip->midi_in = substream;
160	return 0;
161}
162
163
164
165static void snd_echo_midi_input_trigger(struct snd_rawmidi_substream *substream,
166					int up)
167{
168	struct echoaudio *chip = substream->rmidi->private_data;
169
170	if (up != chip->midi_input_enabled) {
171		spin_lock_irq(&chip->lock);
172		enable_midi_input(chip, up);
173		spin_unlock_irq(&chip->lock);
174		chip->midi_input_enabled = up;
175	}
176}
177
178
179
180static int snd_echo_midi_input_close(struct snd_rawmidi_substream *substream)
181{
182	struct echoaudio *chip = substream->rmidi->private_data;
183
184	chip->midi_in = NULL;
185	return 0;
186}
187
188
189
190static int snd_echo_midi_output_open(struct snd_rawmidi_substream *substream)
191{
192	struct echoaudio *chip = substream->rmidi->private_data;
193
194	chip->tinuse = 0;
195	chip->midi_full = 0;
196	chip->midi_out = substream;
197	return 0;
198}
199
200
201
202static void snd_echo_midi_output_write(unsigned long data)
203{
204	struct echoaudio *chip = (struct echoaudio *)data;
205	unsigned long flags;
206	int bytes, sent, time;
207	unsigned char buf[MIDI_OUT_BUFFER_SIZE - 1];
208
209	/* No interrupts are involved: we have to check at regular intervals
210	if the card's output buffer has room for new data. */
211	sent = bytes = 0;
212	spin_lock_irqsave(&chip->lock, flags);
213	chip->midi_full = 0;
214	if (!snd_rawmidi_transmit_empty(chip->midi_out)) {
215		bytes = snd_rawmidi_transmit_peek(chip->midi_out, buf,
216						  MIDI_OUT_BUFFER_SIZE - 1);
217		dev_dbg(chip->card->dev, "Try to send %d bytes...\n", bytes);
218		sent = write_midi(chip, buf, bytes);
219		if (sent < 0) {
220			dev_err(chip->card->dev,
221				"write_midi() error %d\n", sent);
222			/* retry later */
223			sent = 9000;
224			chip->midi_full = 1;
225		} else if (sent > 0) {
226			dev_dbg(chip->card->dev, "%d bytes sent\n", sent);
227			snd_rawmidi_transmit_ack(chip->midi_out, sent);
228		} else {
229			/* Buffer is full. DSP's internal buffer is 64 (128 ?)
230			bytes long. Let's wait until half of them are sent */
231			dev_dbg(chip->card->dev, "Full\n");
232			sent = 32;
233			chip->midi_full = 1;
234		}
235	}
236
237	/* We restart the timer only if there is some data left to send */
238	if (!snd_rawmidi_transmit_empty(chip->midi_out) && chip->tinuse) {
239		/* The timer will expire slightly after the data has been
240		   sent */
241		time = (sent << 3) / 25 + 1;	/* 8/25=0.32ms to send a byte */
242		mod_timer(&chip->timer, jiffies + (time * HZ + 999) / 1000);
243		dev_dbg(chip->card->dev,
244			"Timer armed(%d)\n", ((time * HZ + 999) / 1000));
245	}
246	spin_unlock_irqrestore(&chip->lock, flags);
247}
248
249
250
251static void snd_echo_midi_output_trigger(struct snd_rawmidi_substream *substream,
252					 int up)
253{
254	struct echoaudio *chip = substream->rmidi->private_data;
255
256	dev_dbg(chip->card->dev, "snd_echo_midi_output_trigger(%d)\n", up);
257	spin_lock_irq(&chip->lock);
258	if (up) {
259		if (!chip->tinuse) {
260			setup_timer(&chip->timer, snd_echo_midi_output_write,
261				    (unsigned long)chip);
262			chip->tinuse = 1;
263		}
264	} else {
265		if (chip->tinuse) {
266			chip->tinuse = 0;
267			spin_unlock_irq(&chip->lock);
268			del_timer_sync(&chip->timer);
269			dev_dbg(chip->card->dev, "Timer removed\n");
270			return;
271		}
272	}
273	spin_unlock_irq(&chip->lock);
274
275	if (up && !chip->midi_full)
276		snd_echo_midi_output_write((unsigned long)chip);
277}
278
279
280
281static int snd_echo_midi_output_close(struct snd_rawmidi_substream *substream)
282{
283	struct echoaudio *chip = substream->rmidi->private_data;
284
285	chip->midi_out = NULL;
286	return 0;
287}
288
289
290
291static struct snd_rawmidi_ops snd_echo_midi_input = {
292	.open = snd_echo_midi_input_open,
293	.close = snd_echo_midi_input_close,
294	.trigger = snd_echo_midi_input_trigger,
295};
296
297static struct snd_rawmidi_ops snd_echo_midi_output = {
298	.open = snd_echo_midi_output_open,
299	.close = snd_echo_midi_output_close,
300	.trigger = snd_echo_midi_output_trigger,
301};
302
303
304
305/* <--snd_echo_probe() */
306static int snd_echo_midi_create(struct snd_card *card,
307				struct echoaudio *chip)
308{
309	int err;
310
311	if ((err = snd_rawmidi_new(card, card->shortname, 0, 1, 1,
312				   &chip->rmidi)) < 0)
313		return err;
314
315	strcpy(chip->rmidi->name, card->shortname);
316	chip->rmidi->private_data = chip;
317
318	snd_rawmidi_set_ops(chip->rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
319			    &snd_echo_midi_input);
320	snd_rawmidi_set_ops(chip->rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
321			    &snd_echo_midi_output);
322
323	chip->rmidi->info_flags |= SNDRV_RAWMIDI_INFO_OUTPUT |
324		SNDRV_RAWMIDI_INFO_INPUT | SNDRV_RAWMIDI_INFO_DUPLEX;
325	return 0;
326}
327