1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-or-later
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * Shared helper functions for devices from the ADAU family
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * Copyright 2011-2016 Analog Devices Inc.
6*4882a593Smuzhiyun * Author: Lars-Peter Clausen <lars@metafoo.de>
7*4882a593Smuzhiyun */
8*4882a593Smuzhiyun
9*4882a593Smuzhiyun #include <linux/gcd.h>
10*4882a593Smuzhiyun #include <linux/kernel.h>
11*4882a593Smuzhiyun #include <linux/module.h>
12*4882a593Smuzhiyun
13*4882a593Smuzhiyun #include "adau-utils.h"
14*4882a593Smuzhiyun
adau_calc_pll_cfg(unsigned int freq_in,unsigned int freq_out,uint8_t regs[5])15*4882a593Smuzhiyun int adau_calc_pll_cfg(unsigned int freq_in, unsigned int freq_out,
16*4882a593Smuzhiyun uint8_t regs[5])
17*4882a593Smuzhiyun {
18*4882a593Smuzhiyun unsigned int r, n, m, i, j;
19*4882a593Smuzhiyun unsigned int div;
20*4882a593Smuzhiyun
21*4882a593Smuzhiyun if (!freq_out) {
22*4882a593Smuzhiyun r = 0;
23*4882a593Smuzhiyun n = 0;
24*4882a593Smuzhiyun m = 0;
25*4882a593Smuzhiyun div = 0;
26*4882a593Smuzhiyun } else {
27*4882a593Smuzhiyun if (freq_out % freq_in != 0) {
28*4882a593Smuzhiyun div = DIV_ROUND_UP(freq_in, 13500000);
29*4882a593Smuzhiyun freq_in /= div;
30*4882a593Smuzhiyun r = freq_out / freq_in;
31*4882a593Smuzhiyun i = freq_out % freq_in;
32*4882a593Smuzhiyun j = gcd(i, freq_in);
33*4882a593Smuzhiyun n = i / j;
34*4882a593Smuzhiyun m = freq_in / j;
35*4882a593Smuzhiyun div--;
36*4882a593Smuzhiyun } else {
37*4882a593Smuzhiyun r = freq_out / freq_in;
38*4882a593Smuzhiyun n = 0;
39*4882a593Smuzhiyun m = 0;
40*4882a593Smuzhiyun div = 0;
41*4882a593Smuzhiyun }
42*4882a593Smuzhiyun if (n > 0xffff || m > 0xffff || div > 3 || r > 8 || r < 2)
43*4882a593Smuzhiyun return -EINVAL;
44*4882a593Smuzhiyun }
45*4882a593Smuzhiyun
46*4882a593Smuzhiyun regs[0] = m >> 8;
47*4882a593Smuzhiyun regs[1] = m & 0xff;
48*4882a593Smuzhiyun regs[2] = n >> 8;
49*4882a593Smuzhiyun regs[3] = n & 0xff;
50*4882a593Smuzhiyun regs[4] = (r << 3) | (div << 1);
51*4882a593Smuzhiyun if (m != 0)
52*4882a593Smuzhiyun regs[4] |= 1; /* Fractional mode */
53*4882a593Smuzhiyun
54*4882a593Smuzhiyun return 0;
55*4882a593Smuzhiyun }
56*4882a593Smuzhiyun EXPORT_SYMBOL_GPL(adau_calc_pll_cfg);
57*4882a593Smuzhiyun
58*4882a593Smuzhiyun MODULE_DESCRIPTION("ASoC ADAU audio CODECs shared helper functions");
59*4882a593Smuzhiyun MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
60*4882a593Smuzhiyun MODULE_LICENSE("GPL v2");
61