xref: /linux/sound/isa/gus/gus_uart.c (revision 2f27fce67173bbb05d5a0ee03dae5c021202c912)
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 
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 
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 
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 
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 	dev_dbg(gus->card->dev,
93 		"write init - cmd = 0x%x, stat = 0x%x\n",
94 		gus->gf1.uart_cmd, snd_gf1_uart_stat(gus));
95 #endif
96 	return 0;
97 }
98 
99 static int snd_gf1_uart_input_open(struct snd_rawmidi_substream *substream)
100 {
101 	unsigned long flags;
102 	struct snd_gus_card *gus;
103 	int i;
104 
105 	gus = substream->rmidi->private_data;
106 	spin_lock_irqsave(&gus->uart_cmd_lock, flags);
107 	if (gus->gf1.interrupt_handler_midi_out != snd_gf1_interrupt_midi_out) {
108 		snd_gf1_uart_reset(gus, 0);
109 	}
110 	gus->gf1.interrupt_handler_midi_in = snd_gf1_interrupt_midi_in;
111 	gus->midi_substream_input = substream;
112 	if (gus->uart_enable) {
113 		for (i = 0; i < 1000 && (snd_gf1_uart_stat(gus) & 0x01); i++)
114 			snd_gf1_uart_get(gus);	/* clean Rx */
115 		if (i >= 1000)
116 			dev_err(gus->card->dev, "gus midi uart init read - cleanup error\n");
117 	}
118 	spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
119 #if 0
120 	dev_dbg(gus->card->dev,
121 		"read init - enable = %i, cmd = 0x%x, stat = 0x%x\n",
122 		gus->uart_enable, gus->gf1.uart_cmd, snd_gf1_uart_stat(gus));
123 	dev_dbg(gus->card->dev,
124 		"[0x%x] reg (ctrl/status) = 0x%x, reg (data) = 0x%x (page = 0x%x)\n",
125 		gus->gf1.port + 0x100, inb(gus->gf1.port + 0x100),
126 		inb(gus->gf1.port + 0x101), inb(gus->gf1.port + 0x102));
127 #endif
128 	return 0;
129 }
130 
131 static int snd_gf1_uart_output_close(struct snd_rawmidi_substream *substream)
132 {
133 	unsigned long flags;
134 	struct snd_gus_card *gus;
135 
136 	gus = substream->rmidi->private_data;
137 	spin_lock_irqsave(&gus->uart_cmd_lock, flags);
138 	if (gus->gf1.interrupt_handler_midi_in != snd_gf1_interrupt_midi_in)
139 		snd_gf1_uart_reset(gus, 1);
140 	snd_gf1_set_default_handlers(gus, SNDRV_GF1_HANDLER_MIDI_OUT);
141 	gus->midi_substream_output = NULL;
142 	spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
143 	return 0;
144 }
145 
146 static int snd_gf1_uart_input_close(struct snd_rawmidi_substream *substream)
147 {
148 	unsigned long flags;
149 	struct snd_gus_card *gus;
150 
151 	gus = substream->rmidi->private_data;
152 	spin_lock_irqsave(&gus->uart_cmd_lock, flags);
153 	if (gus->gf1.interrupt_handler_midi_out != snd_gf1_interrupt_midi_out)
154 		snd_gf1_uart_reset(gus, 1);
155 	snd_gf1_set_default_handlers(gus, SNDRV_GF1_HANDLER_MIDI_IN);
156 	gus->midi_substream_input = NULL;
157 	spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
158 	return 0;
159 }
160 
161 static void snd_gf1_uart_input_trigger(struct snd_rawmidi_substream *substream, int up)
162 {
163 	struct snd_gus_card *gus;
164 	unsigned long flags;
165 
166 	gus = substream->rmidi->private_data;
167 
168 	spin_lock_irqsave(&gus->uart_cmd_lock, flags);
169 	if (up) {
170 		if ((gus->gf1.uart_cmd & 0x80) == 0)
171 			snd_gf1_uart_cmd(gus, gus->gf1.uart_cmd | 0x80); /* enable Rx interrupts */
172 	} else {
173 		if (gus->gf1.uart_cmd & 0x80)
174 			snd_gf1_uart_cmd(gus, gus->gf1.uart_cmd & ~0x80); /* disable Rx interrupts */
175 	}
176 	spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
177 }
178 
179 static void snd_gf1_uart_output_trigger(struct snd_rawmidi_substream *substream, int up)
180 {
181 	unsigned long flags;
182 	struct snd_gus_card *gus;
183 	char byte;
184 	int timeout;
185 
186 	gus = substream->rmidi->private_data;
187 
188 	spin_lock_irqsave(&gus->uart_cmd_lock, flags);
189 	if (up) {
190 		if ((gus->gf1.uart_cmd & 0x20) == 0) {
191 			spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
192 			/* wait for empty Rx - Tx is probably unlocked */
193 			timeout = 10000;
194 			while (timeout-- > 0 && snd_gf1_uart_stat(gus) & 0x01);
195 			/* Tx FIFO free? */
196 			spin_lock_irqsave(&gus->uart_cmd_lock, flags);
197 			if (gus->gf1.uart_cmd & 0x20) {
198 				spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
199 				return;
200 			}
201 			if (snd_gf1_uart_stat(gus) & 0x02) {
202 				if (snd_rawmidi_transmit(substream, &byte, 1) != 1) {
203 					spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
204 					return;
205 				}
206 				snd_gf1_uart_put(gus, byte);
207 			}
208 			snd_gf1_uart_cmd(gus, gus->gf1.uart_cmd | 0x20);	/* enable Tx interrupt */
209 		}
210 	} else {
211 		if (gus->gf1.uart_cmd & 0x20)
212 			snd_gf1_uart_cmd(gus, gus->gf1.uart_cmd & ~0x20);
213 	}
214 	spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
215 }
216 
217 static const struct snd_rawmidi_ops snd_gf1_uart_output =
218 {
219 	.open =		snd_gf1_uart_output_open,
220 	.close =	snd_gf1_uart_output_close,
221 	.trigger =	snd_gf1_uart_output_trigger,
222 };
223 
224 static const struct snd_rawmidi_ops snd_gf1_uart_input =
225 {
226 	.open =		snd_gf1_uart_input_open,
227 	.close =	snd_gf1_uart_input_close,
228 	.trigger =	snd_gf1_uart_input_trigger,
229 };
230 
231 int snd_gf1_rawmidi_new(struct snd_gus_card *gus, int device)
232 {
233 	struct snd_rawmidi *rmidi;
234 	int err;
235 
236 	err = snd_rawmidi_new(gus->card, "GF1", device, 1, 1, &rmidi);
237 	if (err < 0)
238 		return err;
239 	strcpy(rmidi->name, gus->interwave ? "AMD InterWave" : "GF1");
240 	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT, &snd_gf1_uart_output);
241 	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT, &snd_gf1_uart_input);
242 	rmidi->info_flags |= SNDRV_RAWMIDI_INFO_OUTPUT | SNDRV_RAWMIDI_INFO_INPUT | SNDRV_RAWMIDI_INFO_DUPLEX;
243 	rmidi->private_data = gus;
244 	gus->midi_uart = rmidi;
245 	return err;
246 }
247