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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

# User Rev Content
1 cebix 1.1 /*
2     * SID_linux.h - 6581 emulation, Linux specific stuff
3     *
4 cebix 1.2 * Frodo (C) 1994-1997,2002-2003 Christian Bauer
5 cebix 1.1 *
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 cebix 1.3 // 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 cebix 1.1 #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 cebix 1.3 }
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 cebix 1.1 }