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 */
enable_midi_input(struct echoaudio * chip,char enable)37 static int enable_midi_input(struct echoaudio *chip, char enable)
38 {
39 DE_MID(("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
59 Returns how many actually written or < 0 on error */
write_midi(struct echoaudio * chip,u8 * data,int bytes)60 static 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 DE_MID(("write_midi: %d\n", bytes));
78 return bytes;
79 }
80
81
82
83 /* Run the state machine for MIDI input data
84 MIDI time code sync isn't supported by this code right now, but you still need
85 this state machine to parse the incoming MIDI data stream. Every time the DSP
86 sees a 0xF1 byte come in, it adds the DSP sample position to the MIDI data
87 stream. The DSP sample position is represented as a 32 bit unsigned value,
88 with the high 16 bits first, followed by the low 16 bits. Since these aren't
89 real MIDI bytes, the following logic is needed to skip them. */
mtc_process_data(struct echoaudio * chip,short midi_byte)90 static 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
115 from the DSP's buffer. It returns the number of bytes received. */
midi_service_irq(struct echoaudio * chip)116 static 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
snd_echo_midi_input_open(struct snd_rawmidi_substream * substream)155 static 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 DE_MID(("rawmidi_iopen\n"));
161 return 0;
162 }
163
164
165
snd_echo_midi_input_trigger(struct snd_rawmidi_substream * substream,int up)166 static void snd_echo_midi_input_trigger(struct snd_rawmidi_substream *substream,
167 int up)
168 {
169 struct echoaudio *chip = substream->rmidi->private_data;
170
171 if (up != chip->midi_input_enabled) {
172 spin_lock_irq(&chip->lock);
173 enable_midi_input(chip, up);
174 spin_unlock_irq(&chip->lock);
175 chip->midi_input_enabled = up;
176 }
177 }
178
179
180
snd_echo_midi_input_close(struct snd_rawmidi_substream * substream)181 static int snd_echo_midi_input_close(struct snd_rawmidi_substream *substream)
182 {
183 struct echoaudio *chip = substream->rmidi->private_data;
184
185 chip->midi_in = NULL;
186 DE_MID(("rawmidi_iclose\n"));
187 return 0;
188 }
189
190
191
snd_echo_midi_output_open(struct snd_rawmidi_substream * substream)192 static int snd_echo_midi_output_open(struct snd_rawmidi_substream *substream)
193 {
194 struct echoaudio *chip = substream->rmidi->private_data;
195
196 chip->tinuse = 0;
197 chip->midi_full = 0;
198 chip->midi_out = substream;
199 DE_MID(("rawmidi_oopen\n"));
200 return 0;
201 }
202
203
204
snd_echo_midi_output_write(unsigned long data)205 static void snd_echo_midi_output_write(unsigned long data)
206 {
207 struct echoaudio *chip = (struct echoaudio *)data;
208 unsigned long flags;
209 int bytes, sent, time;
210 unsigned char buf[MIDI_OUT_BUFFER_SIZE - 1];
211
212 DE_MID(("snd_echo_midi_output_write\n"));
213 /* No interrupts are involved: we have to check at regular intervals
214 if the card's output buffer has room for new data. */
215 sent = bytes = 0;
216 spin_lock_irqsave(&chip->lock, flags);
217 chip->midi_full = 0;
218 if (!snd_rawmidi_transmit_empty(chip->midi_out)) {
219 bytes = snd_rawmidi_transmit_peek(chip->midi_out, buf,
220 MIDI_OUT_BUFFER_SIZE - 1);
221 DE_MID(("Try to send %d bytes...\n", bytes));
222 sent = write_midi(chip, buf, bytes);
223 if (sent < 0) {
224 dev_err(chip->card->dev,
225 "write_midi() error %d\n", sent);
226 /* retry later */
227 sent = 9000;
228 chip->midi_full = 1;
229 } else if (sent > 0) {
230 DE_MID(("%d bytes sent\n", sent));
231 snd_rawmidi_transmit_ack(chip->midi_out, sent);
232 } else {
233 /* Buffer is full. DSP's internal buffer is 64 (128 ?)
234 bytes long. Let's wait until half of them are sent */
235 DE_MID(("Full\n"));
236 sent = 32;
237 chip->midi_full = 1;
238 }
239 }
240
241 /* We restart the timer only if there is some data left to send */
242 if (!snd_rawmidi_transmit_empty(chip->midi_out) && chip->tinuse) {
243 /* The timer will expire slightly after the data has been
244 sent */
245 time = (sent << 3) / 25 + 1; /* 8/25=0.32ms to send a byte */
246 mod_timer(&chip->timer, jiffies + (time * HZ + 999) / 1000);
247 DE_MID(("Timer armed(%d)\n", ((time * HZ + 999) / 1000)));
248 }
249 spin_unlock_irqrestore(&chip->lock, flags);
250 }
251
252
253
snd_echo_midi_output_trigger(struct snd_rawmidi_substream * substream,int up)254 static void snd_echo_midi_output_trigger(struct snd_rawmidi_substream *substream,
255 int up)
256 {
257 struct echoaudio *chip = substream->rmidi->private_data;
258
259 DE_MID(("snd_echo_midi_output_trigger(%d)\n", up));
260 spin_lock_irq(&chip->lock);
261 if (up) {
262 if (!chip->tinuse) {
263 init_timer(&chip->timer);
264 chip->timer.function = snd_echo_midi_output_write;
265 chip->timer.data = (unsigned long)chip;
266 chip->tinuse = 1;
267 }
268 } else {
269 if (chip->tinuse) {
270 chip->tinuse = 0;
271 spin_unlock_irq(&chip->lock);
272 del_timer_sync(&chip->timer);
273 DE_MID(("Timer removed\n"));
274 return;
275 }
276 }
277 spin_unlock_irq(&chip->lock);
278
279 if (up && !chip->midi_full)
280 snd_echo_midi_output_write((unsigned long)chip);
281 }
282
283
284
snd_echo_midi_output_close(struct snd_rawmidi_substream * substream)285 static int snd_echo_midi_output_close(struct snd_rawmidi_substream *substream)
286 {
287 struct echoaudio *chip = substream->rmidi->private_data;
288
289 chip->midi_out = NULL;
290 DE_MID(("rawmidi_oclose\n"));
291 return 0;
292 }
293
294
295
296 static struct snd_rawmidi_ops snd_echo_midi_input = {
297 .open = snd_echo_midi_input_open,
298 .close = snd_echo_midi_input_close,
299 .trigger = snd_echo_midi_input_trigger,
300 };
301
302 static struct snd_rawmidi_ops snd_echo_midi_output = {
303 .open = snd_echo_midi_output_open,
304 .close = snd_echo_midi_output_close,
305 .trigger = snd_echo_midi_output_trigger,
306 };
307
308
309
310 /* <--snd_echo_probe() */
snd_echo_midi_create(struct snd_card * card,struct echoaudio * chip)311 static int snd_echo_midi_create(struct snd_card *card,
312 struct echoaudio *chip)
313 {
314 int err;
315
316 if ((err = snd_rawmidi_new(card, card->shortname, 0, 1, 1,
317 &chip->rmidi)) < 0)
318 return err;
319
320 strcpy(chip->rmidi->name, card->shortname);
321 chip->rmidi->private_data = chip;
322
323 snd_rawmidi_set_ops(chip->rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
324 &snd_echo_midi_input);
325 snd_rawmidi_set_ops(chip->rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
326 &snd_echo_midi_output);
327
328 chip->rmidi->info_flags |= SNDRV_RAWMIDI_INFO_OUTPUT |
329 SNDRV_RAWMIDI_INFO_INPUT | SNDRV_RAWMIDI_INFO_DUPLEX;
330 DE_INIT(("MIDI ok\n"));
331 return 0;
332 }
333