xref: /openbmc/linux/sound/isa/gus/gus_volume.c (revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2)
1 /*
2  *  Copyright (c) by Jaroslav Kysela <perex@suse.cz>
3  *
4  *
5  *   This program is free software; you can redistribute it and/or modify
6  *   it under the terms of the GNU General Public License as published by
7  *   the Free Software Foundation; either version 2 of the License, or
8  *   (at your option) any later version.
9  *
10  *   This program is distributed in the hope that it will be useful,
11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  *   GNU General Public License for more details.
14  *
15  *   You should have received a copy of the GNU General Public License
16  *   along with this program; if not, write to the Free Software
17  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
18  *
19  */
20 
21 #include <sound/driver.h>
22 #include <linux/time.h>
23 #include <sound/core.h>
24 #include <sound/gus.h>
25 #define __GUS_TABLES_ALLOC__
26 #include "gus_tables.h"
27 
28 EXPORT_SYMBOL(snd_gf1_atten_table); /* for snd-gus-synth module */
29 
30 unsigned short snd_gf1_lvol_to_gvol_raw(unsigned int vol)
31 {
32 	unsigned short e, m, tmp;
33 
34 	if (vol > 65535)
35 		vol = 65535;
36 	tmp = vol;
37 	e = 7;
38 	if (tmp < 128) {
39 		while (e > 0 && tmp < (1 << e))
40 			e--;
41 	} else {
42 		while (tmp > 255) {
43 			tmp >>= 1;
44 			e++;
45 		}
46 	}
47 	m = vol - (1 << e);
48 	if (m > 0) {
49 		if (e > 8)
50 			m >>= e - 8;
51 		else if (e < 8)
52 			m <<= 8 - e;
53 		m &= 255;
54 	}
55 	return (e << 8) | m;
56 }
57 
58 unsigned int snd_gf1_gvol_to_lvol_raw(unsigned short gf1_vol)
59 {
60 	unsigned int rvol;
61 	unsigned short e, m;
62 
63 	if (!gf1_vol)
64 		return 0;
65 	e = gf1_vol >> 8;
66 	m = (unsigned char) gf1_vol;
67 	rvol = 1 << e;
68 	if (e > 8)
69 		return rvol | (m << (e - 8));
70 	return rvol | (m >> (8 - e));
71 }
72 
73 unsigned int snd_gf1_calc_ramp_rate(snd_gus_card_t * gus,
74 				    unsigned short start,
75 				    unsigned short end,
76 				    unsigned int us)
77 {
78 	static unsigned char vol_rates[19] =
79 	{
80 		23, 24, 26, 28, 29, 31, 32, 34,
81 		36, 37, 39, 40, 42, 44, 45, 47,
82 		49, 50, 52
83 	};
84 	unsigned short range, increment, value, i;
85 
86 	start >>= 4;
87 	end >>= 4;
88 	if (start < end)
89 		us /= end - start;
90 	else
91 		us /= start - end;
92 	range = 4;
93 	value = gus->gf1.enh_mode ?
94 	    vol_rates[0] :
95 	    vol_rates[gus->gf1.active_voices - 14];
96 	for (i = 0; i < 3; i++) {
97 		if (us < value) {
98 			range = i;
99 			break;
100 		} else
101 			value <<= 3;
102 	}
103 	if (range == 4) {
104 		range = 3;
105 		increment = 1;
106 	} else
107 		increment = (value + (value >> 1)) / us;
108 	return (range << 6) | (increment & 0x3f);
109 }
110 
111 unsigned short snd_gf1_translate_freq(snd_gus_card_t * gus, unsigned int freq16)
112 {
113 	freq16 >>= 3;
114 	if (freq16 < 50)
115 		freq16 = 50;
116 	if (freq16 & 0xf8000000) {
117 		freq16 = ~0xf8000000;
118 		snd_printk("snd_gf1_translate_freq: overflow - freq = 0x%x\n", freq16);
119 	}
120 	return ((freq16 << 9) + (gus->gf1.playback_freq >> 1)) / gus->gf1.playback_freq;
121 }
122 
123 short snd_gf1_compute_vibrato(short cents, unsigned short fc_register)
124 {
125 	static short vibrato_table[] =
126 	{
127 		0, 0, 32, 592, 61, 1175, 93, 1808,
128 		124, 2433, 152, 3007, 182, 3632, 213, 4290,
129 		241, 4834, 255, 5200
130 	};
131 
132 	long depth;
133 	short *vi1, *vi2, pcents, v1;
134 
135 	pcents = cents < 0 ? -cents : cents;
136 	for (vi1 = vibrato_table, vi2 = vi1 + 2; pcents > *vi2; vi1 = vi2, vi2 += 2);
137 	v1 = *(vi1 + 1);
138 	/* The FC table above is a list of pairs. The first number in the pair     */
139 	/* is the cents index from 0-255 cents, and the second number in the       */
140 	/* pair is the FC adjustment needed to change the pitch by the indexed     */
141 	/* number of cents. The table was created for an FC of 32768.              */
142 	/* The following expression does a linear interpolation against the        */
143 	/* approximated log curve in the table above, and then scales the number   */
144 	/* by the FC before the LFO. This calculation also adjusts the output      */
145 	/* value to produce the appropriate depth for the hardware. The depth      */
146 	/* is 2 * desired FC + 1.                                                  */
147 	depth = (((int) (*(vi2 + 1) - *vi1) * (pcents - *vi1) / (*vi2 - *vi1)) + v1) * fc_register >> 14;
148 	if (depth)
149 		depth++;
150 	if (depth > 255)
151 		depth = 255;
152 	return cents < 0 ? -(short) depth : (short) depth;
153 }
154 
155 unsigned short snd_gf1_compute_pitchbend(unsigned short pitchbend, unsigned short sens)
156 {
157 	static long log_table[] = {1024, 1085, 1149, 1218, 1290, 1367, 1448, 1534, 1625, 1722, 1825, 1933};
158 	int wheel, sensitivity;
159 	unsigned int mantissa, f1, f2;
160 	unsigned short semitones, f1_index, f2_index, f1_power, f2_power;
161 	char bend_down = 0;
162 	int bend;
163 
164 	if (!sens)
165 		return 1024;
166 	wheel = (int) pitchbend - 8192;
167 	sensitivity = ((int) sens * wheel) / 128;
168 	if (sensitivity < 0) {
169 		bend_down = 1;
170 		sensitivity = -sensitivity;
171 	}
172 	semitones = (unsigned int) (sensitivity >> 13);
173 	mantissa = sensitivity % 8192;
174 	f1_index = semitones % 12;
175 	f2_index = (semitones + 1) % 12;
176 	f1_power = semitones / 12;
177 	f2_power = (semitones + 1) / 12;
178 	f1 = log_table[f1_index] << f1_power;
179 	f2 = log_table[f2_index] << f2_power;
180 	bend = (int) ((((f2 - f1) * mantissa) >> 13) + f1);
181 	if (bend_down)
182 		bend = 1048576L / bend;
183 	return bend;
184 }
185 
186 unsigned short snd_gf1_compute_freq(unsigned int freq,
187 				    unsigned int rate,
188 				    unsigned short mix_rate)
189 {
190 	unsigned int fc;
191 	int scale = 0;
192 
193 	while (freq >= 4194304L) {
194 		scale++;
195 		freq >>= 1;
196 	}
197 	fc = (freq << 10) / rate;
198 	if (fc > 97391L) {
199 		fc = 97391;
200 		snd_printk("patch: (1) fc frequency overflow - %u\n", fc);
201 	}
202 	fc = (fc * 44100UL) / mix_rate;
203 	while (scale--)
204 		fc <<= 1;
205 	if (fc > 65535L) {
206 		fc = 65535;
207 		snd_printk("patch: (2) fc frequency overflow - %u\n", fc);
208 	}
209 	return (unsigned short) fc;
210 }
211