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root/cebix/Frodo4/Src/SID_linux.h
Revision: 1.3
Committed: 2004-01-10T18:11:07Z (19 years, 1 month ago) by cebix
Content type: text/plain
Branch: MAIN
Changes since 1.2: +85 -0 lines
Log Message:
added Catweasel SID support under Linux

File Contents

# Content
1 /*
2 * SID_linux.h - 6581 emulation, Linux specific stuff
3 *
4 * Frodo (C) 1994-1997,2002-2003 Christian Bauer
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 #include <unistd.h>
22 #include <fcntl.h>
23 #include <sys/ioctl.h>
24 #include <linux/soundcard.h>
25
26 // Catweasel ioctls (included here for convenience)
27 #include <linux/ioctl.h>
28 #define CWSID_IOCTL_TYPE ('S')
29 #define CWSID_IOCTL_RESET _IO(CWSID_IOCTL_TYPE, 0)
30 #define CWSID_IOCTL_CARDTYPE _IOR(CWSID_IOCTL_TYPE, 4, int)
31 #define CWSID_IOCTL_PAL _IO(CWSID_IOCTL_TYPE, 0x11)
32 #define CWSID_IOCTL_NTSC _IO(CWSID_IOCTL_TYPE, 0x12)
33 #define CWSID_IOCTL_DOUBLEBUFFER _IOW(CWSID_IOCTL_TYPE, 0x21, int)
34 #define CWSID_IOCTL_DELAY _IOW(CWSID_IOCTL_TYPE, 0x22, int)
35 #define CWSID_MAGIC 0x100
36 #define HAVE_CWSID 1
37
38 #include "VIC.h"
39
40
41 /*
42 * Initialization
43 */
44
45 void DigitalRenderer::init_sound(void)
46 {
47 int tmp;
48 unsigned long format;
49
50 ready = false;
51 devfd = open("/dev/dsp", O_WRONLY);
52 if (devfd < 0)
53 return;
54
55 ioctl(devfd, SNDCTL_DSP_GETFMTS, &format);
56 if (!(format & AFMT_S16_LE))
57 return;
58 format = AFMT_S16_LE;
59 ioctl(devfd, SNDCTL_DSP_SETFMT, &format);
60
61 /*
62 * Buffer size: 2^9 == 512 bytes. Note that too large buffers will not work
63 * very well: The speed of the C64 is slowed down to an average speed of
64 * 100% by the blocking write() call in EmulateLine(). If you use a buffer
65 * of, say 4096 bytes, that will happen only about every 4 frames, which
66 * means that the emulation runs much faster in some frames, and much
67 * slower in others.
68 * On really fast machines, it might make sense to use an even smaller
69 * buffer size.
70 */
71 tmp = 0x00100009;
72 ioctl(devfd, SNDCTL_DSP_SETFRAGMENT, &tmp);
73 tmp = 0;
74 ioctl(devfd, SNDCTL_DSP_STEREO, &tmp);
75 tmp = 44100;
76 ioctl(devfd, SNDCTL_DSP_SPEED, &tmp);
77 ioctl(devfd, SOUND_PCM_READ_RATE, &tmp);
78 if (tmp < 43000 || tmp > 45000)
79 return;
80
81 ioctl(devfd, SNDCTL_DSP_GETBLKSIZE, &sndbufsize);
82 sound_buffer = new int16[sndbufsize];
83 ready = true;
84 }
85
86
87 /*
88 * Destructor
89 */
90
91 DigitalRenderer::~DigitalRenderer()
92 {
93 if (devfd >= 0)
94 close(devfd);
95 }
96
97
98 /*
99 * Pause sound output
100 */
101
102 void DigitalRenderer::Pause(void)
103 {
104 }
105
106
107 /*
108 * Resume sound output
109 */
110
111 void DigitalRenderer::Resume(void)
112 {
113 }
114
115
116 /*
117 * Fill buffer, sample volume (for sampled voice)
118 */
119
120 void DigitalRenderer::EmulateLine(void)
121 {
122 static int divisor = 0;
123 static int to_output = 0;
124 static int buffer_pos = 0;
125
126 if (!ready)
127 return;
128
129 sample_buf[sample_in_ptr] = volume;
130 sample_in_ptr = (sample_in_ptr + 1) % SAMPLE_BUF_SIZE;
131
132 /*
133 * Now see how many samples have to be added for this line
134 */
135 divisor += SAMPLE_FREQ;
136 while (divisor >= 0)
137 divisor -= TOTAL_RASTERS*SCREEN_FREQ, to_output++;
138
139 /*
140 * Calculate the sound data only when we have enough to fill
141 * the buffer entirely.
142 */
143 if ((buffer_pos + to_output) >= sndbufsize) {
144 int datalen = sndbufsize - buffer_pos;
145 to_output -= datalen;
146 calc_buffer(sound_buffer + buffer_pos, datalen*2);
147 write(devfd, sound_buffer, sndbufsize*2);
148 buffer_pos = 0;
149 }
150 }
151
152
153 /*
154 * Renderer for Catweasel card
155 */
156
157 // Rendere class
158 class CatweaselRenderer : public SIDRenderer {
159 public:
160 CatweaselRenderer();
161 virtual ~CatweaselRenderer();
162
163 virtual void Reset(void);
164 virtual void EmulateLine(void) {}
165 virtual void WriteRegister(uint16 adr, uint8 byte);
166 virtual void NewPrefs(Prefs *prefs) {}
167 virtual void Pause(void) {}
168 virtual void Resume(void) {}
169
170 private:
171 int cwsid_fh; // Catweasel device file handle
172 };
173
174 // Constructor: Open Catweasel device and reset SID
175 CatweaselRenderer::CatweaselRenderer()
176 {
177 cwsid_fh = open("/dev/sid", O_WRONLY);
178 if (cwsid_fh >= 0) {
179 int i;
180 if (ioctl(cwsid_fh, CWSID_IOCTL_CARDTYPE, &i) < 0 || i != CWSID_MAGIC) {
181 close(cwsid_fh);
182 cwsid_fh = -1;
183 } else {
184 ioctl(cwsid_fh, CWSID_IOCTL_RESET);
185 ioctl(cwsid_fh, CWSID_IOCTL_DOUBLEBUFFER, 0);
186 }
187 }
188
189 Reset();
190 }
191
192 // Destructor: Reset SID and close Catweasel device
193 CatweaselRenderer::~CatweaselRenderer()
194 {
195 Reset();
196
197 if (cwsid_fh >= 0) {
198 close(cwsid_fh);
199 cwsid_fh = -1;
200 }
201 }
202
203 // Reset SID
204 void CatweaselRenderer::Reset(void)
205 {
206 if (cwsid_fh >= 0) {
207 uint8 zero = 0;
208 ioctl(cwsid_fh, CWSID_IOCTL_RESET);
209 lseek(cwsid_fh, 24, SEEK_SET);
210 write(cwsid_fh, &zero, 1);
211 }
212 }
213
214 // Write to register
215 void CatweaselRenderer::WriteRegister(uint16 adr, uint8 byte)
216 {
217 if (cwsid_fh >= 0 && adr < 0x1a) {
218 lseek(cwsid_fh, adr, SEEK_SET);
219 write(cwsid_fh, &byte, 1);
220 lseek(cwsid_fh, adr, SEEK_SET);
221 write(cwsid_fh, &byte, 1);
222 }
223 }