| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
| 26 | #include <asm/atarihw.h> |
| 27 | #include <asm/system.h> |
| 28 | #include <asm/irq.h> |
| 29 | #include <asm/pgtable.h> |
| 30 | #include <asm/atariints.h> |
| 31 | |
| 32 | |
| 33 | /* |
| 34 | * stuff from the old atasound.c |
| 35 | */ |
| 36 | |
| 37 | void atari_microwire_cmd (int cmd) |
| 38 | { |
| 39 | tt_microwire.mask = 0x7ff; |
| 40 | tt_microwire.data = MW_LM1992_ADDR | cmd; |
| 41 | |
| 42 | /* Busy wait for data being completely sent :-( */ |
| 43 | while( tt_microwire.mask != 0x7ff) |
| 44 | ; |
| 45 | } |
| 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 | |
| 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 | } |