1 /*
2  * linux/arch/m68k/atari/atasound.c
3  *
4  * ++Geert: Moved almost all stuff to linux/drivers/sound/
5  *
6  * The author of atari_nosound, atari_mksound and atari_microwire_cmd is
7  * unknown. (++roman: That's me... :-)
8  *
9  * This file is subject to the terms and conditions of the GNU General Public
10  * License.  See the file COPYING in the main directory of this archive
11  * for more details.
12  *
13  * 1998-05-31 ++andreas: atari_mksound rewritten to always use the envelope,
14  *			 no timer, atari_nosound removed.
15  *
16  */
17 
18 
19 #include <linux/sched.h>
20 #include <linux/timer.h>
21 #include <linux/major.h>
22 #include <linux/fcntl.h>
23 #include <linux/errno.h>
24 #include <linux/mm.h>
25 #include <linux/module.h>
26 
27 #include <asm/atarihw.h>
28 #include <asm/irq.h>
29 #include <asm/atariints.h>
30 
31 
32 /*
33  * stuff from the old atasound.c
34  */
35 
atari_microwire_cmd(int cmd)36 void atari_microwire_cmd (int cmd)
37 {
38 	tt_microwire.mask = 0x7ff;
39 	tt_microwire.data = MW_LM1992_ADDR | cmd;
40 
41 	/* Busy wait for data being completely sent :-( */
42 	while( tt_microwire.mask != 0x7ff)
43 		;
44 }
45 EXPORT_SYMBOL(atari_microwire_cmd);
46 
47 
48 /* PSG base frequency */
49 #define	PSG_FREQ	125000
50 /* PSG envelope base frequency times 10 */
51 #define PSG_ENV_FREQ_10	78125
52 
atari_mksound(unsigned int hz,unsigned int ticks)53 void atari_mksound (unsigned int hz, unsigned int ticks)
54 {
55 	/* Generates sound of some frequency for some number of clock
56 	   ticks.  */
57 	unsigned long flags;
58 	unsigned char tmp;
59 	int period;
60 
61 	local_irq_save(flags);
62 
63 
64 	/* Disable generator A in mixer control.  */
65 	sound_ym.rd_data_reg_sel = 7;
66 	tmp = sound_ym.rd_data_reg_sel;
67 	tmp |= 011;
68 	sound_ym.wd_data = tmp;
69 
70 	if (hz) {
71 	    /* Convert from frequency value to PSG period value (base
72 	       frequency 125 kHz).  */
73 
74 	    period = PSG_FREQ / hz;
75 
76 	    if (period > 0xfff) period = 0xfff;
77 
78 	/* Set generator A frequency to hz.  */
79 	sound_ym.rd_data_reg_sel = 0;
80 	sound_ym.wd_data = period & 0xff;
81 	sound_ym.rd_data_reg_sel = 1;
82 	sound_ym.wd_data = (period >> 8) & 0xf;
83 	if (ticks) {
84 		/* Set length of envelope (max 8 sec).  */
85 		int length = (ticks * PSG_ENV_FREQ_10) / HZ / 10;
86 
87 		if (length > 0xffff) length = 0xffff;
88 		sound_ym.rd_data_reg_sel = 11;
89 		sound_ym.wd_data = length & 0xff;
90 		sound_ym.rd_data_reg_sel = 12;
91 		sound_ym.wd_data = length >> 8;
92 		/* Envelope form: max -> min single.  */
93 		sound_ym.rd_data_reg_sel = 13;
94 		sound_ym.wd_data = 0;
95 		/* Use envelope for generator A.  */
96 		sound_ym.rd_data_reg_sel = 8;
97 		sound_ym.wd_data = 0x10;
98 	} else {
99 		/* Set generator A level to maximum, no envelope.  */
100 		sound_ym.rd_data_reg_sel = 8;
101 		sound_ym.wd_data = 15;
102 	}
103 	/* Turn on generator A in mixer control.  */
104 	sound_ym.rd_data_reg_sel = 7;
105 	tmp &= ~1;
106 	sound_ym.wd_data = tmp;
107 	}
108 	local_irq_restore(flags);
109 }
110