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