1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Mac bong noise generator. Note - we ought to put a boingy noise
4 * here 8)
5 *
6 * ----------------------------------------------------------------------
7 * 16.11.98:
8 * rewrote some functions, added support for Enhanced ASC (Quadras)
9 * after the NetBSD asc.c console bell patch by Colin Wood/Frederick Bruck
10 * Juergen Mellinger (juergen.mellinger@t-online.de)
11 */
12
13 #include <linux/sched.h>
14 #include <linux/timer.h>
15
16 #include <asm/macintosh.h>
17 #include <asm/mac_asc.h>
18
19 static int mac_asc_inited;
20 /*
21 * dumb triangular wave table
22 */
23 static __u8 mac_asc_wave_tab[ 0x800 ];
24
25 /*
26 * Alan's original sine table; needs interpolating to 0x800
27 * (hint: interpolate or hardwire [0 -> Pi/2[, it's symmetric)
28 */
29 static const signed char sine_data[] = {
30 0, 39, 75, 103, 121, 127, 121, 103, 75, 39,
31 0, -39, -75, -103, -121, -127, -121, -103, -75, -39
32 };
33
34 /*
35 * where the ASC hides ...
36 */
37 static volatile __u8* mac_asc_regs = ( void* )0x50F14000;
38
39 /*
40 * sample rate; is this a good default value?
41 */
42 static unsigned long mac_asc_samplespersec = 11050;
43 static int mac_bell_duration;
44 static unsigned long mac_bell_phase; /* 0..2*Pi -> 0..0x800 (wavetable size) */
45 static unsigned long mac_bell_phasepersample;
46
47 /*
48 * some function protos
49 */
50 static void mac_init_asc( void );
51 static void mac_nosound(struct timer_list *);
52 static void mac_quadra_start_bell( unsigned int, unsigned int, unsigned int );
53 static void mac_quadra_ring_bell(struct timer_list *);
54 static void mac_av_start_bell( unsigned int, unsigned int, unsigned int );
55 static void ( *mac_special_bell )( unsigned int, unsigned int, unsigned int );
56
57 /*
58 * our timer to start/continue/stop the bell
59 */
60 static DEFINE_TIMER(mac_sound_timer, mac_nosound);
61
62 /*
63 * Sort of initialize the sound chip (called from mac_mksound on the first
64 * beep).
65 */
66 static void mac_init_asc( void )
67 {
68 int i;
69
70 /*
71 * do some machine specific initialization
72 * BTW:
73 * the NetBSD Quadra patch identifies the Enhanced Apple Sound Chip via
74 * mac_asc_regs[ 0x800 ] & 0xF0 != 0
75 * this makes no sense here, because we have to set the default sample
76 * rate anyway if we want correct frequencies
77 */
78 switch ( macintosh_config->ident )
79 {
80 case MAC_MODEL_IIFX:
81 /*
82 * The IIfx is always special ...
83 */
84 mac_asc_regs = ( void* )0x50010000;
85 break;
86 /*
87 * not sure about how correct this list is
88 * machines with the EASC enhanced apple sound chip
89 */
90 case MAC_MODEL_Q630:
91 case MAC_MODEL_P475:
92 mac_special_bell = mac_quadra_start_bell;
93 mac_asc_samplespersec = 22150;
94 break;
95 case MAC_MODEL_C660:
96 case MAC_MODEL_Q840:
97 /*
98 * The Quadra 660AV and 840AV use the "Singer" custom ASIC for sound I/O.
99 * It appears to be similar to the "AWACS" custom ASIC in the Power Mac
100 * [678]100. Because Singer and AWACS may have a similar hardware
101 * interface, this would imply that the code in drivers/sound/dmasound.c
102 * for AWACS could be used as a basis for Singer support. All we have to
103 * do is figure out how to do DMA on the 660AV/840AV through the PSC and
104 * figure out where the Singer hardware sits in memory. (I'd look in the
105 * vicinity of the AWACS location in a Power Mac [678]100 first, or the
106 * current location of the Apple Sound Chip--ASC--in other Macs.) The
107 * Power Mac [678]100 info can be found in MkLinux Mach kernel sources.
108 *
109 * Quoted from Apple's Tech Info Library, article number 16405:
110 * "Among desktop Macintosh computers, only the 660AV, 840AV, and Power
111 * Macintosh models have 16-bit audio input and output capability
112 * because of the AT&T DSP3210 hardware circuitry and the 16-bit Singer
113 * codec circuitry in the AVs. The Audio Waveform Amplifier and
114 * Converter (AWAC) chip in the Power Macintosh performs the same
115 * 16-bit I/O functionality. The PowerBook 500 series computers
116 * support 16-bit stereo output, but only mono input."
117 *
118 * Technical Information Library (TIL) article number 16405.
119 * http://support.apple.com/kb/TA32601
120 *
121 * --David Kilzer
122 */
123 mac_special_bell = mac_av_start_bell;
124 break;
125 case MAC_MODEL_Q650:
126 case MAC_MODEL_Q700:
127 case MAC_MODEL_Q800:
128 case MAC_MODEL_Q900:
129 case MAC_MODEL_Q950:
130 /*
131 * Currently not implemented!
132 */
133 mac_special_bell = NULL;
134 break;
135 default:
136 /*
137 * Every switch needs a default
138 */
139 mac_special_bell = NULL;
140 break;
141 }
142
143 /*
144 * init the wave table with a simple triangular wave
145 * A sine wave would sure be nicer here ...
146 */
147 for ( i = 0; i < 0x400; i++ )
148 {
149 mac_asc_wave_tab[ i ] = i / 4;
150 mac_asc_wave_tab[ i + 0x400 ] = 0xFF - i / 4;
151 }
152 mac_asc_inited = 1;
153 }
154
155 /*
156 * Called to make noise; current single entry to the boing driver.
157 * Does the job for simple ASC, calls other routines else.
158 * XXX Fixme:
159 * Should be split into asc_mksound, easc_mksound, av_mksound and
160 * function pointer set in mac_init_asc which would be called at
161 * init time.
162 * _This_ is rather ugly ...
163 */
164 void mac_mksound( unsigned int freq, unsigned int length )
165 {
166 __u32 cfreq = ( freq << 5 ) / 468;
167 unsigned long flags;
168 int i;
169
170 if ( mac_special_bell == NULL )
171 {
172 /* Do nothing */
173 return;
174 }
175
176 if ( !mac_asc_inited )
177 mac_init_asc();
178
179 if ( mac_special_bell )
180 {
181 mac_special_bell( freq, length, 128 );
182 return;
183 }
184
185 if ( freq < 20 || freq > 20000 || length == 0 )
186 {
187 mac_nosound( 0 );
188 return;
189 }
190
191 local_irq_save(flags);
192
193 del_timer( &mac_sound_timer );
194
195 for ( i = 0; i < 0x800; i++ )
196 mac_asc_regs[ i ] = 0;
197 for ( i = 0; i < 0x800; i++ )
198 mac_asc_regs[ i ] = mac_asc_wave_tab[ i ];
199
200 for ( i = 0; i < 8; i++ )
201 *( __u32* )( ( __u32 )mac_asc_regs + ASC_CONTROL + 0x814 + 8 * i ) = cfreq;
202
203 mac_asc_regs[ 0x807 ] = 0;
204 mac_asc_regs[ ASC_VOLUME ] = 128;
205 mac_asc_regs[ 0x805 ] = 0;
206 mac_asc_regs[ 0x80F ] = 0;
207 mac_asc_regs[ ASC_MODE ] = ASC_MODE_SAMPLE;
208 mac_asc_regs[ ASC_ENABLE ] = ASC_ENABLE_SAMPLE;
209
210 mac_sound_timer.expires = jiffies + length;
211 add_timer( &mac_sound_timer );
212
213 local_irq_restore(flags);
214 }
215
216 /*
217 * regular ASC: stop whining ..
218 */
219 static void mac_nosound(struct timer_list *unused)
220 {
221 mac_asc_regs[ ASC_ENABLE ] = 0;
222 }
223
224 /*
225 * EASC entry; init EASC, don't load wavetable, schedule 'start whining'.
226 */
227 static void mac_quadra_start_bell( unsigned int freq, unsigned int length, unsigned int volume )
228 {
229 unsigned long flags;
230
231 /* if the bell is already ringing, ring longer */
232 if ( mac_bell_duration > 0 )
233 {
234 mac_bell_duration += length;
235 return;
236 }
237
238 mac_bell_duration = length;
239 mac_bell_phase = 0;
240 mac_bell_phasepersample = ( freq * sizeof( mac_asc_wave_tab ) ) / mac_asc_samplespersec;
241 /* this is reasonably big for small frequencies */
242
243 local_irq_save(flags);
244
245 /* set the volume */
246 mac_asc_regs[ 0x806 ] = volume;
247
248 /* set up the ASC registers */
249 if ( mac_asc_regs[ 0x801 ] != 1 )
250 {
251 /* select mono mode */
252 mac_asc_regs[ 0x807 ] = 0;
253 /* select sampled sound mode */
254 mac_asc_regs[ 0x802 ] = 0;
255 /* ??? */
256 mac_asc_regs[ 0x801 ] = 1;
257 mac_asc_regs[ 0x803 ] |= 0x80;
258 mac_asc_regs[ 0x803 ] &= 0x7F;
259 }
260
261 mac_sound_timer.function = mac_quadra_ring_bell;
262 mac_sound_timer.expires = jiffies + 1;
263 add_timer( &mac_sound_timer );
264
265 local_irq_restore(flags);
266 }
267
268 /*
269 * EASC 'start/continue whining'; I'm not sure why the above function didn't
270 * already load the wave table, or at least call this one...
271 * This piece keeps reloading the wave table until done.
272 */
273 static void mac_quadra_ring_bell(struct timer_list *unused)
274 {
275 int i, count = mac_asc_samplespersec / HZ;
276 unsigned long flags;
277
278 /*
279 * we neither want a sound buffer overflow nor underflow, so we need to match
280 * the number of samples per timer interrupt as exactly as possible.
281 * using the asc interrupt will give better results in the future
282 * ...and the possibility to use a real sample (a boingy noise, maybe...)
283 */
284
285 local_irq_save(flags);
286
287 del_timer( &mac_sound_timer );
288
289 if ( mac_bell_duration-- > 0 )
290 {
291 for ( i = 0; i < count; i++ )
292 {
293 mac_bell_phase += mac_bell_phasepersample;
294 mac_asc_regs[ 0 ] = mac_asc_wave_tab[ mac_bell_phase & ( sizeof( mac_asc_wave_tab ) - 1 ) ];
295 }
296 mac_sound_timer.expires = jiffies + 1;
297 add_timer( &mac_sound_timer );
298 }
299 else
300 mac_asc_regs[ 0x801 ] = 0;
301
302 local_irq_restore(flags);
303 }
304
305 /*
306 * AV code - please fill in.
307 */
308 static void mac_av_start_bell( unsigned int freq, unsigned int length, unsigned int volume )
309 {
310 }