xref: /openbmc/linux/sound/isa/gus/gus_volume.c (revision 293d5b43)
1 /*
2  *  Copyright (c) by Jaroslav Kysela <perex@perex.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 <linux/time.h>
22 #include <linux/export.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 #if 0
59 
60 unsigned int snd_gf1_gvol_to_lvol_raw(unsigned short gf1_vol)
61 {
62 	unsigned int rvol;
63 	unsigned short e, m;
64 
65 	if (!gf1_vol)
66 		return 0;
67 	e = gf1_vol >> 8;
68 	m = (unsigned char) gf1_vol;
69 	rvol = 1 << e;
70 	if (e > 8)
71 		return rvol | (m << (e - 8));
72 	return rvol | (m >> (8 - e));
73 }
74 
75 unsigned int snd_gf1_calc_ramp_rate(struct snd_gus_card * gus,
76 				    unsigned short start,
77 				    unsigned short end,
78 				    unsigned int us)
79 {
80 	static unsigned char vol_rates[19] =
81 	{
82 		23, 24, 26, 28, 29, 31, 32, 34,
83 		36, 37, 39, 40, 42, 44, 45, 47,
84 		49, 50, 52
85 	};
86 	unsigned short range, increment, value, i;
87 
88 	start >>= 4;
89 	end >>= 4;
90 	if (start < end)
91 		us /= end - start;
92 	else
93 		us /= start - end;
94 	range = 4;
95 	value = gus->gf1.enh_mode ?
96 	    vol_rates[0] :
97 	    vol_rates[gus->gf1.active_voices - 14];
98 	for (i = 0; i < 3; i++) {
99 		if (us < value) {
100 			range = i;
101 			break;
102 		} else
103 			value <<= 3;
104 	}
105 	if (range == 4) {
106 		range = 3;
107 		increment = 1;
108 	} else
109 		increment = (value + (value >> 1)) / us;
110 	return (range << 6) | (increment & 0x3f);
111 }
112 
113 #endif  /*  0  */
114 
115 unsigned short snd_gf1_translate_freq(struct snd_gus_card * gus, unsigned int freq16)
116 {
117 	freq16 >>= 3;
118 	if (freq16 < 50)
119 		freq16 = 50;
120 	if (freq16 & 0xf8000000) {
121 		freq16 = ~0xf8000000;
122 		snd_printk(KERN_ERR "snd_gf1_translate_freq: overflow - freq = 0x%x\n", freq16);
123 	}
124 	return ((freq16 << 9) + (gus->gf1.playback_freq >> 1)) / gus->gf1.playback_freq;
125 }
126 
127 #if 0
128 
129 short snd_gf1_compute_vibrato(short cents, unsigned short fc_register)
130 {
131 	static short vibrato_table[] =
132 	{
133 		0, 0, 32, 592, 61, 1175, 93, 1808,
134 		124, 2433, 152, 3007, 182, 3632, 213, 4290,
135 		241, 4834, 255, 5200
136 	};
137 
138 	long depth;
139 	short *vi1, *vi2, pcents, v1;
140 
141 	pcents = cents < 0 ? -cents : cents;
142 	for (vi1 = vibrato_table, vi2 = vi1 + 2; pcents > *vi2; vi1 = vi2, vi2 += 2);
143 	v1 = *(vi1 + 1);
144 	/* The FC table above is a list of pairs. The first number in the pair     */
145 	/* is the cents index from 0-255 cents, and the second number in the       */
146 	/* pair is the FC adjustment needed to change the pitch by the indexed     */
147 	/* number of cents. The table was created for an FC of 32768.              */
148 	/* The following expression does a linear interpolation against the        */
149 	/* approximated log curve in the table above, and then scales the number   */
150 	/* by the FC before the LFO. This calculation also adjusts the output      */
151 	/* value to produce the appropriate depth for the hardware. The depth      */
152 	/* is 2 * desired FC + 1.                                                  */
153 	depth = (((int) (*(vi2 + 1) - *vi1) * (pcents - *vi1) / (*vi2 - *vi1)) + v1) * fc_register >> 14;
154 	if (depth)
155 		depth++;
156 	if (depth > 255)
157 		depth = 255;
158 	return cents < 0 ? -(short) depth : (short) depth;
159 }
160 
161 unsigned short snd_gf1_compute_pitchbend(unsigned short pitchbend, unsigned short sens)
162 {
163 	static long log_table[] = {1024, 1085, 1149, 1218, 1290, 1367, 1448, 1534, 1625, 1722, 1825, 1933};
164 	int wheel, sensitivity;
165 	unsigned int mantissa, f1, f2;
166 	unsigned short semitones, f1_index, f2_index, f1_power, f2_power;
167 	char bend_down = 0;
168 	int bend;
169 
170 	if (!sens)
171 		return 1024;
172 	wheel = (int) pitchbend - 8192;
173 	sensitivity = ((int) sens * wheel) / 128;
174 	if (sensitivity < 0) {
175 		bend_down = 1;
176 		sensitivity = -sensitivity;
177 	}
178 	semitones = (unsigned int) (sensitivity >> 13);
179 	mantissa = sensitivity % 8192;
180 	f1_index = semitones % 12;
181 	f2_index = (semitones + 1) % 12;
182 	f1_power = semitones / 12;
183 	f2_power = (semitones + 1) / 12;
184 	f1 = log_table[f1_index] << f1_power;
185 	f2 = log_table[f2_index] << f2_power;
186 	bend = (int) ((((f2 - f1) * mantissa) >> 13) + f1);
187 	if (bend_down)
188 		bend = 1048576L / bend;
189 	return bend;
190 }
191 
192 unsigned short snd_gf1_compute_freq(unsigned int freq,
193 				    unsigned int rate,
194 				    unsigned short mix_rate)
195 {
196 	unsigned int fc;
197 	int scale = 0;
198 
199 	while (freq >= 4194304L) {
200 		scale++;
201 		freq >>= 1;
202 	}
203 	fc = (freq << 10) / rate;
204 	if (fc > 97391L) {
205 		fc = 97391;
206 		snd_printk(KERN_ERR "patch: (1) fc frequency overflow - %u\n", fc);
207 	}
208 	fc = (fc * 44100UL) / mix_rate;
209 	while (scale--)
210 		fc <<= 1;
211 	if (fc > 65535L) {
212 		fc = 65535;
213 		snd_printk(KERN_ERR "patch: (2) fc frequency overflow - %u\n", fc);
214 	}
215 	return (unsigned short) fc;
216 }
217 
218 #endif  /*  0  */
219