xref: /openbmc/linux/sound/isa/gus/gus_volume.c (revision 7fe2f639)
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 <sound/core.h>
23 #include <sound/gus.h>
24 #define __GUS_TABLES_ALLOC__
25 #include "gus_tables.h"
26 
27 EXPORT_SYMBOL(snd_gf1_atten_table); /* for snd-gus-synth module */
28 
29 unsigned short snd_gf1_lvol_to_gvol_raw(unsigned int vol)
30 {
31 	unsigned short e, m, tmp;
32 
33 	if (vol > 65535)
34 		vol = 65535;
35 	tmp = vol;
36 	e = 7;
37 	if (tmp < 128) {
38 		while (e > 0 && tmp < (1 << e))
39 			e--;
40 	} else {
41 		while (tmp > 255) {
42 			tmp >>= 1;
43 			e++;
44 		}
45 	}
46 	m = vol - (1 << e);
47 	if (m > 0) {
48 		if (e > 8)
49 			m >>= e - 8;
50 		else if (e < 8)
51 			m <<= 8 - e;
52 		m &= 255;
53 	}
54 	return (e << 8) | m;
55 }
56 
57 #if 0
58 
59 unsigned int snd_gf1_gvol_to_lvol_raw(unsigned short gf1_vol)
60 {
61 	unsigned int rvol;
62 	unsigned short e, m;
63 
64 	if (!gf1_vol)
65 		return 0;
66 	e = gf1_vol >> 8;
67 	m = (unsigned char) gf1_vol;
68 	rvol = 1 << e;
69 	if (e > 8)
70 		return rvol | (m << (e - 8));
71 	return rvol | (m >> (8 - e));
72 }
73 
74 unsigned int snd_gf1_calc_ramp_rate(struct snd_gus_card * gus,
75 				    unsigned short start,
76 				    unsigned short end,
77 				    unsigned int us)
78 {
79 	static unsigned char vol_rates[19] =
80 	{
81 		23, 24, 26, 28, 29, 31, 32, 34,
82 		36, 37, 39, 40, 42, 44, 45, 47,
83 		49, 50, 52
84 	};
85 	unsigned short range, increment, value, i;
86 
87 	start >>= 4;
88 	end >>= 4;
89 	if (start < end)
90 		us /= end - start;
91 	else
92 		us /= start - end;
93 	range = 4;
94 	value = gus->gf1.enh_mode ?
95 	    vol_rates[0] :
96 	    vol_rates[gus->gf1.active_voices - 14];
97 	for (i = 0; i < 3; i++) {
98 		if (us < value) {
99 			range = i;
100 			break;
101 		} else
102 			value <<= 3;
103 	}
104 	if (range == 4) {
105 		range = 3;
106 		increment = 1;
107 	} else
108 		increment = (value + (value >> 1)) / us;
109 	return (range << 6) | (increment & 0x3f);
110 }
111 
112 #endif  /*  0  */
113 
114 unsigned short snd_gf1_translate_freq(struct snd_gus_card * gus, unsigned int freq16)
115 {
116 	freq16 >>= 3;
117 	if (freq16 < 50)
118 		freq16 = 50;
119 	if (freq16 & 0xf8000000) {
120 		freq16 = ~0xf8000000;
121 		snd_printk(KERN_ERR "snd_gf1_translate_freq: overflow - freq = 0x%x\n", freq16);
122 	}
123 	return ((freq16 << 9) + (gus->gf1.playback_freq >> 1)) / gus->gf1.playback_freq;
124 }
125 
126 #if 0
127 
128 short snd_gf1_compute_vibrato(short cents, unsigned short fc_register)
129 {
130 	static short vibrato_table[] =
131 	{
132 		0, 0, 32, 592, 61, 1175, 93, 1808,
133 		124, 2433, 152, 3007, 182, 3632, 213, 4290,
134 		241, 4834, 255, 5200
135 	};
136 
137 	long depth;
138 	short *vi1, *vi2, pcents, v1;
139 
140 	pcents = cents < 0 ? -cents : cents;
141 	for (vi1 = vibrato_table, vi2 = vi1 + 2; pcents > *vi2; vi1 = vi2, vi2 += 2);
142 	v1 = *(vi1 + 1);
143 	/* The FC table above is a list of pairs. The first number in the pair     */
144 	/* is the cents index from 0-255 cents, and the second number in the       */
145 	/* pair is the FC adjustment needed to change the pitch by the indexed     */
146 	/* number of cents. The table was created for an FC of 32768.              */
147 	/* The following expression does a linear interpolation against the        */
148 	/* approximated log curve in the table above, and then scales the number   */
149 	/* by the FC before the LFO. This calculation also adjusts the output      */
150 	/* value to produce the appropriate depth for the hardware. The depth      */
151 	/* is 2 * desired FC + 1.                                                  */
152 	depth = (((int) (*(vi2 + 1) - *vi1) * (pcents - *vi1) / (*vi2 - *vi1)) + v1) * fc_register >> 14;
153 	if (depth)
154 		depth++;
155 	if (depth > 255)
156 		depth = 255;
157 	return cents < 0 ? -(short) depth : (short) depth;
158 }
159 
160 unsigned short snd_gf1_compute_pitchbend(unsigned short pitchbend, unsigned short sens)
161 {
162 	static long log_table[] = {1024, 1085, 1149, 1218, 1290, 1367, 1448, 1534, 1625, 1722, 1825, 1933};
163 	int wheel, sensitivity;
164 	unsigned int mantissa, f1, f2;
165 	unsigned short semitones, f1_index, f2_index, f1_power, f2_power;
166 	char bend_down = 0;
167 	int bend;
168 
169 	if (!sens)
170 		return 1024;
171 	wheel = (int) pitchbend - 8192;
172 	sensitivity = ((int) sens * wheel) / 128;
173 	if (sensitivity < 0) {
174 		bend_down = 1;
175 		sensitivity = -sensitivity;
176 	}
177 	semitones = (unsigned int) (sensitivity >> 13);
178 	mantissa = sensitivity % 8192;
179 	f1_index = semitones % 12;
180 	f2_index = (semitones + 1) % 12;
181 	f1_power = semitones / 12;
182 	f2_power = (semitones + 1) / 12;
183 	f1 = log_table[f1_index] << f1_power;
184 	f2 = log_table[f2_index] << f2_power;
185 	bend = (int) ((((f2 - f1) * mantissa) >> 13) + f1);
186 	if (bend_down)
187 		bend = 1048576L / bend;
188 	return bend;
189 }
190 
191 unsigned short snd_gf1_compute_freq(unsigned int freq,
192 				    unsigned int rate,
193 				    unsigned short mix_rate)
194 {
195 	unsigned int fc;
196 	int scale = 0;
197 
198 	while (freq >= 4194304L) {
199 		scale++;
200 		freq >>= 1;
201 	}
202 	fc = (freq << 10) / rate;
203 	if (fc > 97391L) {
204 		fc = 97391;
205 		snd_printk(KERN_ERR "patch: (1) fc frequency overflow - %u\n", fc);
206 	}
207 	fc = (fc * 44100UL) / mix_rate;
208 	while (scale--)
209 		fc <<= 1;
210 	if (fc > 65535L) {
211 		fc = 65535;
212 		snd_printk(KERN_ERR "patch: (2) fc frequency overflow - %u\n", fc);
213 	}
214 	return (unsigned short) fc;
215 }
216 
217 #endif  /*  0  */
218