xref: /kernel/linux/linux-6.6/arch/m68k/mac/macboing.c (revision 62306a36)
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
19static int mac_asc_inited;
20/*
21 * dumb triangular wave table
22 */
23static __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 */
29static 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 */
37static volatile __u8* mac_asc_regs = ( void* )0x50F14000;
38
39/*
40 * sample rate; is this a good default value?
41 */
42static unsigned long mac_asc_samplespersec = 11050;
43static int mac_bell_duration;
44static unsigned long mac_bell_phase; /* 0..2*Pi -> 0..0x800 (wavetable size) */
45static unsigned long mac_bell_phasepersample;
46
47/*
48 * some function protos
49 */
50static void mac_init_asc( void );
51static void mac_nosound(struct timer_list *);
52static void mac_quadra_start_bell( unsigned int, unsigned int, unsigned int );
53static void mac_quadra_ring_bell(struct timer_list *);
54static void mac_av_start_bell( unsigned int, unsigned int, unsigned int );
55static void ( *mac_special_bell )( unsigned int, unsigned int, unsigned int );
56
57/*
58 * our timer to start/continue/stop the bell
59 */
60static 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 */
66static 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			 *   https://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 */
164void 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 */
219static 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 */
227static 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 */
273static 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 */
308static void mac_av_start_bell( unsigned int freq, unsigned int length, unsigned int volume )
309{
310}
311