1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
4 *  Routines for control of EMU10K1 MPU-401 in UART mode
5 */
6
7#include <linux/time.h>
8#include <linux/init.h>
9#include <sound/core.h>
10#include <sound/emu10k1.h>
11
12#define EMU10K1_MIDI_MODE_INPUT		(1<<0)
13#define EMU10K1_MIDI_MODE_OUTPUT	(1<<1)
14
15static inline unsigned char mpu401_read(struct snd_emu10k1 *emu,
16					struct snd_emu10k1_midi *mpu, int idx)
17{
18	if (emu->audigy)
19		return (unsigned char)snd_emu10k1_ptr_read(emu, mpu->port + idx, 0);
20	else
21		return inb(emu->port + mpu->port + idx);
22}
23
24static inline void mpu401_write(struct snd_emu10k1 *emu,
25				struct snd_emu10k1_midi *mpu, int data, int idx)
26{
27	if (emu->audigy)
28		snd_emu10k1_ptr_write(emu, mpu->port + idx, 0, data);
29	else
30		outb(data, emu->port + mpu->port + idx);
31}
32
33#define mpu401_write_data(emu, mpu, data)	mpu401_write(emu, mpu, data, 0)
34#define mpu401_write_cmd(emu, mpu, data)	mpu401_write(emu, mpu, data, 1)
35#define mpu401_read_data(emu, mpu)		mpu401_read(emu, mpu, 0)
36#define mpu401_read_stat(emu, mpu)		mpu401_read(emu, mpu, 1)
37
38#define mpu401_input_avail(emu,mpu)	(!(mpu401_read_stat(emu,mpu) & 0x80))
39#define mpu401_output_ready(emu,mpu)	(!(mpu401_read_stat(emu,mpu) & 0x40))
40
41#define MPU401_RESET		0xff
42#define MPU401_ENTER_UART	0x3f
43#define MPU401_ACK		0xfe
44
45static void mpu401_clear_rx(struct snd_emu10k1 *emu, struct snd_emu10k1_midi *mpu)
46{
47	int timeout = 100000;
48	for (; timeout > 0 && mpu401_input_avail(emu, mpu); timeout--)
49		mpu401_read_data(emu, mpu);
50#ifdef CONFIG_SND_DEBUG
51	if (timeout <= 0)
52		dev_err(emu->card->dev,
53			"cmd: clear rx timeout (status = 0x%x)\n",
54			mpu401_read_stat(emu, mpu));
55#endif
56}
57
58/*
59
60 */
61
62static void do_emu10k1_midi_interrupt(struct snd_emu10k1 *emu, struct snd_emu10k1_midi *midi, unsigned int status)
63{
64	unsigned char byte;
65
66	if (midi->rmidi == NULL) {
67		snd_emu10k1_intr_disable(emu, midi->tx_enable | midi->rx_enable);
68		return;
69	}
70
71	spin_lock(&midi->input_lock);
72	if ((status & midi->ipr_rx) && mpu401_input_avail(emu, midi)) {
73		if (!(midi->midi_mode & EMU10K1_MIDI_MODE_INPUT)) {
74			mpu401_clear_rx(emu, midi);
75		} else {
76			byte = mpu401_read_data(emu, midi);
77			if (midi->substream_input)
78				snd_rawmidi_receive(midi->substream_input, &byte, 1);
79		}
80	}
81	spin_unlock(&midi->input_lock);
82
83	spin_lock(&midi->output_lock);
84	if ((status & midi->ipr_tx) && mpu401_output_ready(emu, midi)) {
85		if (midi->substream_output &&
86		    snd_rawmidi_transmit(midi->substream_output, &byte, 1) == 1) {
87			mpu401_write_data(emu, midi, byte);
88		} else {
89			snd_emu10k1_intr_disable(emu, midi->tx_enable);
90		}
91	}
92	spin_unlock(&midi->output_lock);
93}
94
95static void snd_emu10k1_midi_interrupt(struct snd_emu10k1 *emu, unsigned int status)
96{
97	do_emu10k1_midi_interrupt(emu, &emu->midi, status);
98}
99
100static void snd_emu10k1_midi_interrupt2(struct snd_emu10k1 *emu, unsigned int status)
101{
102	do_emu10k1_midi_interrupt(emu, &emu->midi2, status);
103}
104
105static int snd_emu10k1_midi_cmd(struct snd_emu10k1 * emu, struct snd_emu10k1_midi *midi, unsigned char cmd, int ack)
106{
107	unsigned long flags;
108	int timeout, ok;
109
110	spin_lock_irqsave(&midi->input_lock, flags);
111	mpu401_write_data(emu, midi, 0x00);
112	/* mpu401_clear_rx(emu, midi); */
113
114	mpu401_write_cmd(emu, midi, cmd);
115	if (ack) {
116		ok = 0;
117		timeout = 10000;
118		while (!ok && timeout-- > 0) {
119			if (mpu401_input_avail(emu, midi)) {
120				if (mpu401_read_data(emu, midi) == MPU401_ACK)
121					ok = 1;
122			}
123		}
124		if (!ok && mpu401_read_data(emu, midi) == MPU401_ACK)
125			ok = 1;
126	} else {
127		ok = 1;
128	}
129	spin_unlock_irqrestore(&midi->input_lock, flags);
130	if (!ok) {
131		dev_err(emu->card->dev,
132			"midi_cmd: 0x%x failed at 0x%lx (status = 0x%x, data = 0x%x)!!!\n",
133			   cmd, emu->port,
134			   mpu401_read_stat(emu, midi),
135			   mpu401_read_data(emu, midi));
136		return 1;
137	}
138	return 0;
139}
140
141static int snd_emu10k1_midi_input_open(struct snd_rawmidi_substream *substream)
142{
143	struct snd_emu10k1 *emu;
144	struct snd_emu10k1_midi *midi = (struct snd_emu10k1_midi *)substream->rmidi->private_data;
145	unsigned long flags;
146
147	emu = midi->emu;
148	if (snd_BUG_ON(!emu))
149		return -ENXIO;
150	spin_lock_irqsave(&midi->open_lock, flags);
151	midi->midi_mode |= EMU10K1_MIDI_MODE_INPUT;
152	midi->substream_input = substream;
153	if (!(midi->midi_mode & EMU10K1_MIDI_MODE_OUTPUT)) {
154		spin_unlock_irqrestore(&midi->open_lock, flags);
155		if (snd_emu10k1_midi_cmd(emu, midi, MPU401_RESET, 1))
156			goto error_out;
157		if (snd_emu10k1_midi_cmd(emu, midi, MPU401_ENTER_UART, 1))
158			goto error_out;
159	} else {
160		spin_unlock_irqrestore(&midi->open_lock, flags);
161	}
162	return 0;
163
164error_out:
165	return -EIO;
166}
167
168static int snd_emu10k1_midi_output_open(struct snd_rawmidi_substream *substream)
169{
170	struct snd_emu10k1 *emu;
171	struct snd_emu10k1_midi *midi = (struct snd_emu10k1_midi *)substream->rmidi->private_data;
172	unsigned long flags;
173
174	emu = midi->emu;
175	if (snd_BUG_ON(!emu))
176		return -ENXIO;
177	spin_lock_irqsave(&midi->open_lock, flags);
178	midi->midi_mode |= EMU10K1_MIDI_MODE_OUTPUT;
179	midi->substream_output = substream;
180	if (!(midi->midi_mode & EMU10K1_MIDI_MODE_INPUT)) {
181		spin_unlock_irqrestore(&midi->open_lock, flags);
182		if (snd_emu10k1_midi_cmd(emu, midi, MPU401_RESET, 1))
183			goto error_out;
184		if (snd_emu10k1_midi_cmd(emu, midi, MPU401_ENTER_UART, 1))
185			goto error_out;
186	} else {
187		spin_unlock_irqrestore(&midi->open_lock, flags);
188	}
189	return 0;
190
191error_out:
192	return -EIO;
193}
194
195static int snd_emu10k1_midi_input_close(struct snd_rawmidi_substream *substream)
196{
197	struct snd_emu10k1 *emu;
198	struct snd_emu10k1_midi *midi = (struct snd_emu10k1_midi *)substream->rmidi->private_data;
199	unsigned long flags;
200	int err = 0;
201
202	emu = midi->emu;
203	if (snd_BUG_ON(!emu))
204		return -ENXIO;
205	spin_lock_irqsave(&midi->open_lock, flags);
206	snd_emu10k1_intr_disable(emu, midi->rx_enable);
207	midi->midi_mode &= ~EMU10K1_MIDI_MODE_INPUT;
208	midi->substream_input = NULL;
209	if (!(midi->midi_mode & EMU10K1_MIDI_MODE_OUTPUT)) {
210		spin_unlock_irqrestore(&midi->open_lock, flags);
211		err = snd_emu10k1_midi_cmd(emu, midi, MPU401_RESET, 0);
212	} else {
213		spin_unlock_irqrestore(&midi->open_lock, flags);
214	}
215	return err;
216}
217
218static int snd_emu10k1_midi_output_close(struct snd_rawmidi_substream *substream)
219{
220	struct snd_emu10k1 *emu;
221	struct snd_emu10k1_midi *midi = (struct snd_emu10k1_midi *)substream->rmidi->private_data;
222	unsigned long flags;
223	int err = 0;
224
225	emu = midi->emu;
226	if (snd_BUG_ON(!emu))
227		return -ENXIO;
228	spin_lock_irqsave(&midi->open_lock, flags);
229	snd_emu10k1_intr_disable(emu, midi->tx_enable);
230	midi->midi_mode &= ~EMU10K1_MIDI_MODE_OUTPUT;
231	midi->substream_output = NULL;
232	if (!(midi->midi_mode & EMU10K1_MIDI_MODE_INPUT)) {
233		spin_unlock_irqrestore(&midi->open_lock, flags);
234		err = snd_emu10k1_midi_cmd(emu, midi, MPU401_RESET, 0);
235	} else {
236		spin_unlock_irqrestore(&midi->open_lock, flags);
237	}
238	return err;
239}
240
241static void snd_emu10k1_midi_input_trigger(struct snd_rawmidi_substream *substream, int up)
242{
243	struct snd_emu10k1 *emu;
244	struct snd_emu10k1_midi *midi = (struct snd_emu10k1_midi *)substream->rmidi->private_data;
245	emu = midi->emu;
246	if (snd_BUG_ON(!emu))
247		return;
248
249	if (up)
250		snd_emu10k1_intr_enable(emu, midi->rx_enable);
251	else
252		snd_emu10k1_intr_disable(emu, midi->rx_enable);
253}
254
255static void snd_emu10k1_midi_output_trigger(struct snd_rawmidi_substream *substream, int up)
256{
257	struct snd_emu10k1 *emu;
258	struct snd_emu10k1_midi *midi = (struct snd_emu10k1_midi *)substream->rmidi->private_data;
259	unsigned long flags;
260
261	emu = midi->emu;
262	if (snd_BUG_ON(!emu))
263		return;
264
265	if (up) {
266		int max = 4;
267		unsigned char byte;
268
269		/* try to send some amount of bytes here before interrupts */
270		spin_lock_irqsave(&midi->output_lock, flags);
271		while (max > 0) {
272			if (mpu401_output_ready(emu, midi)) {
273				if (!(midi->midi_mode & EMU10K1_MIDI_MODE_OUTPUT) ||
274				    snd_rawmidi_transmit(substream, &byte, 1) != 1) {
275					/* no more data */
276					spin_unlock_irqrestore(&midi->output_lock, flags);
277					return;
278				}
279				mpu401_write_data(emu, midi, byte);
280				max--;
281			} else {
282				break;
283			}
284		}
285		spin_unlock_irqrestore(&midi->output_lock, flags);
286		snd_emu10k1_intr_enable(emu, midi->tx_enable);
287	} else {
288		snd_emu10k1_intr_disable(emu, midi->tx_enable);
289	}
290}
291
292/*
293
294 */
295
296static const struct snd_rawmidi_ops snd_emu10k1_midi_output =
297{
298	.open =		snd_emu10k1_midi_output_open,
299	.close =	snd_emu10k1_midi_output_close,
300	.trigger =	snd_emu10k1_midi_output_trigger,
301};
302
303static const struct snd_rawmidi_ops snd_emu10k1_midi_input =
304{
305	.open =		snd_emu10k1_midi_input_open,
306	.close =	snd_emu10k1_midi_input_close,
307	.trigger =	snd_emu10k1_midi_input_trigger,
308};
309
310static void snd_emu10k1_midi_free(struct snd_rawmidi *rmidi)
311{
312	struct snd_emu10k1_midi *midi = rmidi->private_data;
313	midi->interrupt = NULL;
314	midi->rmidi = NULL;
315}
316
317static int emu10k1_midi_init(struct snd_emu10k1 *emu, struct snd_emu10k1_midi *midi, int device, char *name)
318{
319	struct snd_rawmidi *rmidi;
320	int err;
321
322	if ((err = snd_rawmidi_new(emu->card, name, device, 1, 1, &rmidi)) < 0)
323		return err;
324	midi->emu = emu;
325	spin_lock_init(&midi->open_lock);
326	spin_lock_init(&midi->input_lock);
327	spin_lock_init(&midi->output_lock);
328	strcpy(rmidi->name, name);
329	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT, &snd_emu10k1_midi_output);
330	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT, &snd_emu10k1_midi_input);
331	rmidi->info_flags |= SNDRV_RAWMIDI_INFO_OUTPUT |
332	                     SNDRV_RAWMIDI_INFO_INPUT |
333	                     SNDRV_RAWMIDI_INFO_DUPLEX;
334	rmidi->private_data = midi;
335	rmidi->private_free = snd_emu10k1_midi_free;
336	midi->rmidi = rmidi;
337	return 0;
338}
339
340int snd_emu10k1_midi(struct snd_emu10k1 *emu)
341{
342	struct snd_emu10k1_midi *midi = &emu->midi;
343	int err;
344
345	if ((err = emu10k1_midi_init(emu, midi, 0, "EMU10K1 MPU-401 (UART)")) < 0)
346		return err;
347
348	midi->tx_enable = INTE_MIDITXENABLE;
349	midi->rx_enable = INTE_MIDIRXENABLE;
350	midi->port = MUDATA;
351	midi->ipr_tx = IPR_MIDITRANSBUFEMPTY;
352	midi->ipr_rx = IPR_MIDIRECVBUFEMPTY;
353	midi->interrupt = snd_emu10k1_midi_interrupt;
354	return 0;
355}
356
357int snd_emu10k1_audigy_midi(struct snd_emu10k1 *emu)
358{
359	struct snd_emu10k1_midi *midi;
360	int err;
361
362	midi = &emu->midi;
363	if ((err = emu10k1_midi_init(emu, midi, 0, "Audigy MPU-401 (UART)")) < 0)
364		return err;
365
366	midi->tx_enable = INTE_MIDITXENABLE;
367	midi->rx_enable = INTE_MIDIRXENABLE;
368	midi->port = A_MUDATA1;
369	midi->ipr_tx = IPR_MIDITRANSBUFEMPTY;
370	midi->ipr_rx = IPR_MIDIRECVBUFEMPTY;
371	midi->interrupt = snd_emu10k1_midi_interrupt;
372
373	midi = &emu->midi2;
374	if ((err = emu10k1_midi_init(emu, midi, 1, "Audigy MPU-401 #2")) < 0)
375		return err;
376
377	midi->tx_enable = INTE_A_MIDITXENABLE2;
378	midi->rx_enable = INTE_A_MIDIRXENABLE2;
379	midi->port = A_MUDATA2;
380	midi->ipr_tx = IPR_A_MIDITRANSBUFEMPTY2;
381	midi->ipr_rx = IPR_A_MIDIRECVBUFEMPTY2;
382	midi->interrupt = snd_emu10k1_midi_interrupt2;
383	return 0;
384}
385