xref: /openbmc/linux/sound/isa/gus/gus_uart.c (revision e2c75e76)
1 /*
2  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
3  *  Routines for the GF1 MIDI interface - like UART 6850
4  *
5  *
6  *   This program is free software; you can redistribute it and/or modify
7  *   it under the terms of the GNU General Public License as published by
8  *   the Free Software Foundation; either version 2 of the License, or
9  *   (at your option) any later version.
10  *
11  *   This program is distributed in the hope that it will be useful,
12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  *   GNU General Public License for more details.
15  *
16  *   You should have received a copy of the GNU General Public License
17  *   along with this program; if not, write to the Free Software
18  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
19  *
20  */
21 
22 #include <linux/delay.h>
23 #include <linux/interrupt.h>
24 #include <linux/time.h>
25 #include <sound/core.h>
26 #include <sound/gus.h>
27 
28 static void snd_gf1_interrupt_midi_in(struct snd_gus_card * gus)
29 {
30 	int count;
31 	unsigned char stat, data, byte;
32 	unsigned long flags;
33 
34 	count = 10;
35 	while (count) {
36 		spin_lock_irqsave(&gus->uart_cmd_lock, flags);
37 		stat = snd_gf1_uart_stat(gus);
38 		if (!(stat & 0x01)) {	/* data in Rx FIFO? */
39 			spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
40 			count--;
41 			continue;
42 		}
43 		count = 100;	/* arm counter to new value */
44 		data = snd_gf1_uart_get(gus);
45 		if (!(gus->gf1.uart_cmd & 0x80)) {
46 			spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
47 			continue;
48 		}
49 		if (stat & 0x10) {	/* framing error */
50 			gus->gf1.uart_framing++;
51 			spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
52 			continue;
53 		}
54 		byte = snd_gf1_uart_get(gus);
55 		spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
56 		snd_rawmidi_receive(gus->midi_substream_input, &byte, 1);
57 		if (stat & 0x20) {
58 			gus->gf1.uart_overrun++;
59 		}
60 	}
61 }
62 
63 static void snd_gf1_interrupt_midi_out(struct snd_gus_card * gus)
64 {
65 	char byte;
66 	unsigned long flags;
67 
68 	/* try unlock output */
69 	if (snd_gf1_uart_stat(gus) & 0x01)
70 		snd_gf1_interrupt_midi_in(gus);
71 
72 	spin_lock_irqsave(&gus->uart_cmd_lock, flags);
73 	if (snd_gf1_uart_stat(gus) & 0x02) {	/* Tx FIFO free? */
74 		if (snd_rawmidi_transmit(gus->midi_substream_output, &byte, 1) != 1) {	/* no other bytes or error */
75 			snd_gf1_uart_cmd(gus, gus->gf1.uart_cmd & ~0x20); /* disable Tx interrupt */
76 		} else {
77 			snd_gf1_uart_put(gus, byte);
78 		}
79 	}
80 	spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
81 }
82 
83 static void snd_gf1_uart_reset(struct snd_gus_card * gus, int close)
84 {
85 	snd_gf1_uart_cmd(gus, 0x03);	/* reset */
86 	if (!close && gus->uart_enable) {
87 		udelay(160);
88 		snd_gf1_uart_cmd(gus, 0x00);	/* normal operations */
89 	}
90 }
91 
92 static int snd_gf1_uart_output_open(struct snd_rawmidi_substream *substream)
93 {
94 	unsigned long flags;
95 	struct snd_gus_card *gus;
96 
97 	gus = substream->rmidi->private_data;
98 	spin_lock_irqsave(&gus->uart_cmd_lock, flags);
99 	if (!(gus->gf1.uart_cmd & 0x80)) {	/* input active? */
100 		snd_gf1_uart_reset(gus, 0);
101 	}
102 	gus->gf1.interrupt_handler_midi_out = snd_gf1_interrupt_midi_out;
103 	gus->midi_substream_output = substream;
104 	spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
105 #if 0
106 	snd_printk(KERN_DEBUG "write init - cmd = 0x%x, stat = 0x%x\n", gus->gf1.uart_cmd, snd_gf1_uart_stat(gus));
107 #endif
108 	return 0;
109 }
110 
111 static int snd_gf1_uart_input_open(struct snd_rawmidi_substream *substream)
112 {
113 	unsigned long flags;
114 	struct snd_gus_card *gus;
115 	int i;
116 
117 	gus = substream->rmidi->private_data;
118 	spin_lock_irqsave(&gus->uart_cmd_lock, flags);
119 	if (gus->gf1.interrupt_handler_midi_out != snd_gf1_interrupt_midi_out) {
120 		snd_gf1_uart_reset(gus, 0);
121 	}
122 	gus->gf1.interrupt_handler_midi_in = snd_gf1_interrupt_midi_in;
123 	gus->midi_substream_input = substream;
124 	if (gus->uart_enable) {
125 		for (i = 0; i < 1000 && (snd_gf1_uart_stat(gus) & 0x01); i++)
126 			snd_gf1_uart_get(gus);	/* clean Rx */
127 		if (i >= 1000)
128 			snd_printk(KERN_ERR "gus midi uart init read - cleanup error\n");
129 	}
130 	spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
131 #if 0
132 	snd_printk(KERN_DEBUG
133 		   "read init - enable = %i, cmd = 0x%x, stat = 0x%x\n",
134 		   gus->uart_enable, gus->gf1.uart_cmd, snd_gf1_uart_stat(gus));
135 	snd_printk(KERN_DEBUG
136 		   "[0x%x] reg (ctrl/status) = 0x%x, reg (data) = 0x%x "
137 		   "(page = 0x%x)\n",
138 		   gus->gf1.port + 0x100, inb(gus->gf1.port + 0x100),
139 		   inb(gus->gf1.port + 0x101), inb(gus->gf1.port + 0x102));
140 #endif
141 	return 0;
142 }
143 
144 static int snd_gf1_uart_output_close(struct snd_rawmidi_substream *substream)
145 {
146 	unsigned long flags;
147 	struct snd_gus_card *gus;
148 
149 	gus = substream->rmidi->private_data;
150 	spin_lock_irqsave(&gus->uart_cmd_lock, flags);
151 	if (gus->gf1.interrupt_handler_midi_in != snd_gf1_interrupt_midi_in)
152 		snd_gf1_uart_reset(gus, 1);
153 	snd_gf1_set_default_handlers(gus, SNDRV_GF1_HANDLER_MIDI_OUT);
154 	gus->midi_substream_output = NULL;
155 	spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
156 	return 0;
157 }
158 
159 static int snd_gf1_uart_input_close(struct snd_rawmidi_substream *substream)
160 {
161 	unsigned long flags;
162 	struct snd_gus_card *gus;
163 
164 	gus = substream->rmidi->private_data;
165 	spin_lock_irqsave(&gus->uart_cmd_lock, flags);
166 	if (gus->gf1.interrupt_handler_midi_out != snd_gf1_interrupt_midi_out)
167 		snd_gf1_uart_reset(gus, 1);
168 	snd_gf1_set_default_handlers(gus, SNDRV_GF1_HANDLER_MIDI_IN);
169 	gus->midi_substream_input = NULL;
170 	spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
171 	return 0;
172 }
173 
174 static void snd_gf1_uart_input_trigger(struct snd_rawmidi_substream *substream, int up)
175 {
176 	struct snd_gus_card *gus;
177 	unsigned long flags;
178 
179 	gus = substream->rmidi->private_data;
180 
181 	spin_lock_irqsave(&gus->uart_cmd_lock, flags);
182 	if (up) {
183 		if ((gus->gf1.uart_cmd & 0x80) == 0)
184 			snd_gf1_uart_cmd(gus, gus->gf1.uart_cmd | 0x80); /* enable Rx interrupts */
185 	} else {
186 		if (gus->gf1.uart_cmd & 0x80)
187 			snd_gf1_uart_cmd(gus, gus->gf1.uart_cmd & ~0x80); /* disable Rx interrupts */
188 	}
189 	spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
190 }
191 
192 static void snd_gf1_uart_output_trigger(struct snd_rawmidi_substream *substream, int up)
193 {
194 	unsigned long flags;
195 	struct snd_gus_card *gus;
196 	char byte;
197 	int timeout;
198 
199 	gus = substream->rmidi->private_data;
200 
201 	spin_lock_irqsave(&gus->uart_cmd_lock, flags);
202 	if (up) {
203 		if ((gus->gf1.uart_cmd & 0x20) == 0) {
204 			spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
205 			/* wait for empty Rx - Tx is probably unlocked */
206 			timeout = 10000;
207 			while (timeout-- > 0 && snd_gf1_uart_stat(gus) & 0x01);
208 			/* Tx FIFO free? */
209 			spin_lock_irqsave(&gus->uart_cmd_lock, flags);
210 			if (gus->gf1.uart_cmd & 0x20) {
211 				spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
212 				return;
213 			}
214 			if (snd_gf1_uart_stat(gus) & 0x02) {
215 				if (snd_rawmidi_transmit(substream, &byte, 1) != 1) {
216 					spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
217 					return;
218 				}
219 				snd_gf1_uart_put(gus, byte);
220 			}
221 			snd_gf1_uart_cmd(gus, gus->gf1.uart_cmd | 0x20);	/* enable Tx interrupt */
222 		}
223 	} else {
224 		if (gus->gf1.uart_cmd & 0x20)
225 			snd_gf1_uart_cmd(gus, gus->gf1.uart_cmd & ~0x20);
226 	}
227 	spin_unlock_irqrestore(&gus->uart_cmd_lock, flags);
228 }
229 
230 static const struct snd_rawmidi_ops snd_gf1_uart_output =
231 {
232 	.open =		snd_gf1_uart_output_open,
233 	.close =	snd_gf1_uart_output_close,
234 	.trigger =	snd_gf1_uart_output_trigger,
235 };
236 
237 static const struct snd_rawmidi_ops snd_gf1_uart_input =
238 {
239 	.open =		snd_gf1_uart_input_open,
240 	.close =	snd_gf1_uart_input_close,
241 	.trigger =	snd_gf1_uart_input_trigger,
242 };
243 
244 int snd_gf1_rawmidi_new(struct snd_gus_card *gus, int device)
245 {
246 	struct snd_rawmidi *rmidi;
247 	int err;
248 
249 	if ((err = snd_rawmidi_new(gus->card, "GF1", device, 1, 1, &rmidi)) < 0)
250 		return err;
251 	strcpy(rmidi->name, gus->interwave ? "AMD InterWave" : "GF1");
252 	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT, &snd_gf1_uart_output);
253 	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT, &snd_gf1_uart_input);
254 	rmidi->info_flags |= SNDRV_RAWMIDI_INFO_OUTPUT | SNDRV_RAWMIDI_INFO_INPUT | SNDRV_RAWMIDI_INFO_DUPLEX;
255 	rmidi->private_data = gus;
256 	gus->midi_uart = rmidi;
257 	return err;
258 }
259