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
21static int mac_asc_inited;
22/*
23 * dumb triangular wave table
24 */
25static __u8 mac_asc_wave_tab[ 0x800 ];
26
27/*
28 * where the ASC hides ...
29 */
30static volatile __u8* mac_asc_regs = ( void* )0x50F14000;
31
32/*
33 * sample rate; is this a good default value?
34 */
35static unsigned long mac_asc_samplespersec = 11050;
36static int mac_bell_duration;
37static unsigned long mac_bell_phase; /* 0..2*Pi -> 0..0x800 (wavetable size) */
38static unsigned long mac_bell_phasepersample;
39
40/*
41 * some function protos
42 */
43static void mac_init_asc( void );
44static void mac_nosound(struct timer_list *);
45static void mac_quadra_start_bell( unsigned int, unsigned int, unsigned int );
46static void mac_quadra_ring_bell(struct timer_list *);
47static void mac_av_start_bell( unsigned int, unsigned int, unsigned int );
48static void ( *mac_special_bell )( unsigned int, unsigned int, unsigned int );
49
50/*
51 * our timer to start/continue/stop the bell
52 */
53static 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 */
59static 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 */
157void 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 */
212static 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 */
220static 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 */
266static 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 */
301static void mac_av_start_bell( unsigned int freq, unsigned int length, unsigned int volume )
302{
303}
304