1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
4 * Routines for the GF1 MIDI interface - like UART 6850
5 */
6
7 #include <linux/delay.h>
8 #include <linux/interrupt.h>
9 #include <linux/time.h>
10 #include <sound/core.h>
11 #include <sound/gus.h>
12
snd_gf1_interrupt_midi_in(struct snd_gus_card * gus)13 static void snd_gf1_interrupt_midi_in(struct snd_gus_card * gus)
14 {
15 int count;
16 unsigned char stat, byte;
17 __always_unused unsigned char data;
18 unsigned long flags;
19
20 count = 10;
21 while (count) {
22 spin_lock_irqsave(&gus->uart_cmd_lock, flags);
23 stat = snd_gf1_uart_stat(gus);
24 if (!(stat & 0x01)) { /* data in Rx FIFO? */
25 spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
26 count--;
27 continue;
28 }
29 count = 100; /* arm counter to new value */
30 data = snd_gf1_uart_get(gus);
31 if (!(gus->gf1.uart_cmd & 0x80)) {
32 spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
33 continue;
34 }
35 if (stat & 0x10) { /* framing error */
36 gus->gf1.uart_framing++;
37 spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
38 continue;
39 }
40 byte = snd_gf1_uart_get(gus);
41 spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
42 snd_rawmidi_receive(gus->midi_substream_input, &byte, 1);
43 if (stat & 0x20) {
44 gus->gf1.uart_overrun++;
45 }
46 }
47 }
48
snd_gf1_interrupt_midi_out(struct snd_gus_card * gus)49 static void snd_gf1_interrupt_midi_out(struct snd_gus_card * gus)
50 {
51 char byte;
52 unsigned long flags;
53
54 /* try unlock output */
55 if (snd_gf1_uart_stat(gus) & 0x01)
56 snd_gf1_interrupt_midi_in(gus);
57
58 spin_lock_irqsave(&gus->uart_cmd_lock, flags);
59 if (snd_gf1_uart_stat(gus) & 0x02) { /* Tx FIFO free? */
60 if (snd_rawmidi_transmit(gus->midi_substream_output, &byte, 1) != 1) { /* no other bytes or error */
61 snd_gf1_uart_cmd(gus, gus->gf1.uart_cmd & ~0x20); /* disable Tx interrupt */
62 } else {
63 snd_gf1_uart_put(gus, byte);
64 }
65 }
66 spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
67 }
68
snd_gf1_uart_reset(struct snd_gus_card * gus,int close)69 static void snd_gf1_uart_reset(struct snd_gus_card * gus, int close)
70 {
71 snd_gf1_uart_cmd(gus, 0x03); /* reset */
72 if (!close && gus->uart_enable) {
73 udelay(160);
74 snd_gf1_uart_cmd(gus, 0x00); /* normal operations */
75 }
76 }
77
snd_gf1_uart_output_open(struct snd_rawmidi_substream * substream)78 static int snd_gf1_uart_output_open(struct snd_rawmidi_substream *substream)
79 {
80 unsigned long flags;
81 struct snd_gus_card *gus;
82
83 gus = substream->rmidi->private_data;
84 spin_lock_irqsave(&gus->uart_cmd_lock, flags);
85 if (!(gus->gf1.uart_cmd & 0x80)) { /* input active? */
86 snd_gf1_uart_reset(gus, 0);
87 }
88 gus->gf1.interrupt_handler_midi_out = snd_gf1_interrupt_midi_out;
89 gus->midi_substream_output = substream;
90 spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
91 #if 0
92 snd_printk(KERN_DEBUG "write init - cmd = 0x%x, stat = 0x%x\n", gus->gf1.uart_cmd, snd_gf1_uart_stat(gus));
93 #endif
94 return 0;
95 }
96
snd_gf1_uart_input_open(struct snd_rawmidi_substream * substream)97 static int snd_gf1_uart_input_open(struct snd_rawmidi_substream *substream)
98 {
99 unsigned long flags;
100 struct snd_gus_card *gus;
101 int i;
102
103 gus = substream->rmidi->private_data;
104 spin_lock_irqsave(&gus->uart_cmd_lock, flags);
105 if (gus->gf1.interrupt_handler_midi_out != snd_gf1_interrupt_midi_out) {
106 snd_gf1_uart_reset(gus, 0);
107 }
108 gus->gf1.interrupt_handler_midi_in = snd_gf1_interrupt_midi_in;
109 gus->midi_substream_input = substream;
110 if (gus->uart_enable) {
111 for (i = 0; i < 1000 && (snd_gf1_uart_stat(gus) & 0x01); i++)
112 snd_gf1_uart_get(gus); /* clean Rx */
113 if (i >= 1000)
114 snd_printk(KERN_ERR "gus midi uart init read - cleanup error\n");
115 }
116 spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
117 #if 0
118 snd_printk(KERN_DEBUG
119 "read init - enable = %i, cmd = 0x%x, stat = 0x%x\n",
120 gus->uart_enable, gus->gf1.uart_cmd, snd_gf1_uart_stat(gus));
121 snd_printk(KERN_DEBUG
122 "[0x%x] reg (ctrl/status) = 0x%x, reg (data) = 0x%x "
123 "(page = 0x%x)\n",
124 gus->gf1.port + 0x100, inb(gus->gf1.port + 0x100),
125 inb(gus->gf1.port + 0x101), inb(gus->gf1.port + 0x102));
126 #endif
127 return 0;
128 }
129
snd_gf1_uart_output_close(struct snd_rawmidi_substream * substream)130 static int snd_gf1_uart_output_close(struct snd_rawmidi_substream *substream)
131 {
132 unsigned long flags;
133 struct snd_gus_card *gus;
134
135 gus = substream->rmidi->private_data;
136 spin_lock_irqsave(&gus->uart_cmd_lock, flags);
137 if (gus->gf1.interrupt_handler_midi_in != snd_gf1_interrupt_midi_in)
138 snd_gf1_uart_reset(gus, 1);
139 snd_gf1_set_default_handlers(gus, SNDRV_GF1_HANDLER_MIDI_OUT);
140 gus->midi_substream_output = NULL;
141 spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
142 return 0;
143 }
144
snd_gf1_uart_input_close(struct snd_rawmidi_substream * substream)145 static int snd_gf1_uart_input_close(struct snd_rawmidi_substream *substream)
146 {
147 unsigned long flags;
148 struct snd_gus_card *gus;
149
150 gus = substream->rmidi->private_data;
151 spin_lock_irqsave(&gus->uart_cmd_lock, flags);
152 if (gus->gf1.interrupt_handler_midi_out != snd_gf1_interrupt_midi_out)
153 snd_gf1_uart_reset(gus, 1);
154 snd_gf1_set_default_handlers(gus, SNDRV_GF1_HANDLER_MIDI_IN);
155 gus->midi_substream_input = NULL;
156 spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
157 return 0;
158 }
159
snd_gf1_uart_input_trigger(struct snd_rawmidi_substream * substream,int up)160 static void snd_gf1_uart_input_trigger(struct snd_rawmidi_substream *substream, int up)
161 {
162 struct snd_gus_card *gus;
163 unsigned long flags;
164
165 gus = substream->rmidi->private_data;
166
167 spin_lock_irqsave(&gus->uart_cmd_lock, flags);
168 if (up) {
169 if ((gus->gf1.uart_cmd & 0x80) == 0)
170 snd_gf1_uart_cmd(gus, gus->gf1.uart_cmd | 0x80); /* enable Rx interrupts */
171 } else {
172 if (gus->gf1.uart_cmd & 0x80)
173 snd_gf1_uart_cmd(gus, gus->gf1.uart_cmd & ~0x80); /* disable Rx interrupts */
174 }
175 spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
176 }
177
snd_gf1_uart_output_trigger(struct snd_rawmidi_substream * substream,int up)178 static void snd_gf1_uart_output_trigger(struct snd_rawmidi_substream *substream, int up)
179 {
180 unsigned long flags;
181 struct snd_gus_card *gus;
182 char byte;
183 int timeout;
184
185 gus = substream->rmidi->private_data;
186
187 spin_lock_irqsave(&gus->uart_cmd_lock, flags);
188 if (up) {
189 if ((gus->gf1.uart_cmd & 0x20) == 0) {
190 spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
191 /* wait for empty Rx - Tx is probably unlocked */
192 timeout = 10000;
193 while (timeout-- > 0 && snd_gf1_uart_stat(gus) & 0x01);
194 /* Tx FIFO free? */
195 spin_lock_irqsave(&gus->uart_cmd_lock, flags);
196 if (gus->gf1.uart_cmd & 0x20) {
197 spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
198 return;
199 }
200 if (snd_gf1_uart_stat(gus) & 0x02) {
201 if (snd_rawmidi_transmit(substream, &byte, 1) != 1) {
202 spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
203 return;
204 }
205 snd_gf1_uart_put(gus, byte);
206 }
207 snd_gf1_uart_cmd(gus, gus->gf1.uart_cmd | 0x20); /* enable Tx interrupt */
208 }
209 } else {
210 if (gus->gf1.uart_cmd & 0x20)
211 snd_gf1_uart_cmd(gus, gus->gf1.uart_cmd & ~0x20);
212 }
213 spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
214 }
215
216 static const struct snd_rawmidi_ops snd_gf1_uart_output =
217 {
218 .open = snd_gf1_uart_output_open,
219 .close = snd_gf1_uart_output_close,
220 .trigger = snd_gf1_uart_output_trigger,
221 };
222
223 static const struct snd_rawmidi_ops snd_gf1_uart_input =
224 {
225 .open = snd_gf1_uart_input_open,
226 .close = snd_gf1_uart_input_close,
227 .trigger = snd_gf1_uart_input_trigger,
228 };
229
snd_gf1_rawmidi_new(struct snd_gus_card * gus,int device)230 int snd_gf1_rawmidi_new(struct snd_gus_card *gus, int device)
231 {
232 struct snd_rawmidi *rmidi;
233 int err;
234
235 err = snd_rawmidi_new(gus->card, "GF1", device, 1, 1, &rmidi);
236 if (err < 0)
237 return err;
238 strcpy(rmidi->name, gus->interwave ? "AMD InterWave" : "GF1");
239 snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT, &snd_gf1_uart_output);
240 snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT, &snd_gf1_uart_input);
241 rmidi->info_flags |= SNDRV_RAWMIDI_INFO_OUTPUT | SNDRV_RAWMIDI_INFO_INPUT | SNDRV_RAWMIDI_INFO_DUPLEX;
242 rmidi->private_data = gus;
243 gus->midi_uart = rmidi;
244 return err;
245 }
246