1/*
2 *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
3 *  Copyright (c) 2009 by Krzysztof Helt
4 *  Routines for control of MPU-401 in UART mode
5 *
6 *  MPU-401 supports UART mode which is not capable generate transmit
7 *  interrupts thus output is done via polling. Also, if irq < 0, then
8 *  input is done also via polling. Do not expect good performance.
9 *
10 *
11 *   This program is free software; you can redistribute it and/or modify
12 *   it under the terms of the GNU General Public License as published by
13 *   the Free Software Foundation; either version 2 of the License, or
14 *   (at your option) any later version.
15 *
16 *   This program is distributed in the hope that it will be useful,
17 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
18 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19 *   GNU General Public License for more details.
20 *
21 *   You should have received a copy of the GNU General Public License
22 *   along with this program; if not, write to the Free Software
23 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
24 *
25 */
26
27#include <linux/io.h>
28#include <linux/slab.h>
29#include <linux/delay.h>
30#include <linux/ioport.h>
31#include <linux/errno.h>
32#include <linux/export.h>
33#include <sound/core.h>
34#include <sound/rawmidi.h>
35
36#include "msnd.h"
37
38#define MSNDMIDI_MODE_BIT_INPUT		0
39#define MSNDMIDI_MODE_BIT_OUTPUT		1
40#define MSNDMIDI_MODE_BIT_INPUT_TRIGGER	2
41#define MSNDMIDI_MODE_BIT_OUTPUT_TRIGGER	3
42
43struct snd_msndmidi {
44	struct snd_msnd *dev;
45
46	unsigned long mode;		/* MSNDMIDI_MODE_XXXX */
47
48	struct snd_rawmidi_substream *substream_input;
49
50	spinlock_t input_lock;
51};
52
53/*
54 * input/output open/close - protected by open_mutex in rawmidi.c
55 */
56static int snd_msndmidi_input_open(struct snd_rawmidi_substream *substream)
57{
58	struct snd_msndmidi *mpu;
59
60	snd_printdd("snd_msndmidi_input_open()\n");
61
62	mpu = substream->rmidi->private_data;
63
64	mpu->substream_input = substream;
65
66	snd_msnd_enable_irq(mpu->dev);
67
68	snd_msnd_send_dsp_cmd(mpu->dev, HDEX_MIDI_IN_START);
69	set_bit(MSNDMIDI_MODE_BIT_INPUT, &mpu->mode);
70	return 0;
71}
72
73static int snd_msndmidi_input_close(struct snd_rawmidi_substream *substream)
74{
75	struct snd_msndmidi *mpu;
76
77	mpu = substream->rmidi->private_data;
78	snd_msnd_send_dsp_cmd(mpu->dev, HDEX_MIDI_IN_STOP);
79	clear_bit(MSNDMIDI_MODE_BIT_INPUT, &mpu->mode);
80	mpu->substream_input = NULL;
81	snd_msnd_disable_irq(mpu->dev);
82	return 0;
83}
84
85static void snd_msndmidi_input_drop(struct snd_msndmidi *mpu)
86{
87	u16 tail;
88
89	tail = readw(mpu->dev->MIDQ + JQS_wTail);
90	writew(tail, mpu->dev->MIDQ + JQS_wHead);
91}
92
93/*
94 * trigger input
95 */
96static void snd_msndmidi_input_trigger(struct snd_rawmidi_substream *substream,
97					int up)
98{
99	unsigned long flags;
100	struct snd_msndmidi *mpu;
101
102	snd_printdd("snd_msndmidi_input_trigger(, %i)\n", up);
103
104	mpu = substream->rmidi->private_data;
105	spin_lock_irqsave(&mpu->input_lock, flags);
106	if (up) {
107		if (!test_and_set_bit(MSNDMIDI_MODE_BIT_INPUT_TRIGGER,
108				      &mpu->mode))
109			snd_msndmidi_input_drop(mpu);
110	} else {
111		clear_bit(MSNDMIDI_MODE_BIT_INPUT_TRIGGER, &mpu->mode);
112	}
113	spin_unlock_irqrestore(&mpu->input_lock, flags);
114	if (up)
115		snd_msndmidi_input_read(mpu);
116}
117
118void snd_msndmidi_input_read(void *mpuv)
119{
120	unsigned long flags;
121	struct snd_msndmidi *mpu = mpuv;
122	void *pwMIDQData = mpu->dev->mappedbase + MIDQ_DATA_BUFF;
123
124	spin_lock_irqsave(&mpu->input_lock, flags);
125	while (readw(mpu->dev->MIDQ + JQS_wTail) !=
126	       readw(mpu->dev->MIDQ + JQS_wHead)) {
127		u16 wTmp, val;
128		val = readw(pwMIDQData + 2 * readw(mpu->dev->MIDQ + JQS_wHead));
129
130			if (test_bit(MSNDMIDI_MODE_BIT_INPUT_TRIGGER,
131				     &mpu->mode))
132				snd_rawmidi_receive(mpu->substream_input,
133						    (unsigned char *)&val, 1);
134
135		wTmp = readw(mpu->dev->MIDQ + JQS_wHead) + 1;
136		if (wTmp > readw(mpu->dev->MIDQ + JQS_wSize))
137			writew(0,  mpu->dev->MIDQ + JQS_wHead);
138		else
139			writew(wTmp,  mpu->dev->MIDQ + JQS_wHead);
140	}
141	spin_unlock_irqrestore(&mpu->input_lock, flags);
142}
143EXPORT_SYMBOL(snd_msndmidi_input_read);
144
145static struct snd_rawmidi_ops snd_msndmidi_input = {
146	.open =		snd_msndmidi_input_open,
147	.close =	snd_msndmidi_input_close,
148	.trigger =	snd_msndmidi_input_trigger,
149};
150
151static void snd_msndmidi_free(struct snd_rawmidi *rmidi)
152{
153	struct snd_msndmidi *mpu = rmidi->private_data;
154	kfree(mpu);
155}
156
157int snd_msndmidi_new(struct snd_card *card, int device)
158{
159	struct snd_msnd *chip = card->private_data;
160	struct snd_msndmidi *mpu;
161	struct snd_rawmidi *rmidi;
162	int err;
163
164	err = snd_rawmidi_new(card, "MSND-MIDI", device, 1, 1, &rmidi);
165	if (err < 0)
166		return err;
167	mpu = kzalloc(sizeof(*mpu), GFP_KERNEL);
168	if (mpu == NULL) {
169		snd_device_free(card, rmidi);
170		return -ENOMEM;
171	}
172	mpu->dev = chip;
173	chip->msndmidi_mpu = mpu;
174	rmidi->private_data = mpu;
175	rmidi->private_free = snd_msndmidi_free;
176	spin_lock_init(&mpu->input_lock);
177	strcpy(rmidi->name, "MSND MIDI");
178	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
179			    &snd_msndmidi_input);
180	rmidi->info_flags |= SNDRV_RAWMIDI_INFO_INPUT;
181	return 0;
182}
183