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80503b23 | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
0eadaa9c LPC |
2 | /* |
3 | * Shared helper functions for devices from the ADAU family | |
4 | * | |
5 | * Copyright 2011-2016 Analog Devices Inc. | |
6 | * Author: Lars-Peter Clausen <lars@metafoo.de> | |
0eadaa9c LPC |
7 | */ |
8 | ||
9 | #include <linux/gcd.h> | |
10 | #include <linux/kernel.h> | |
11 | #include <linux/module.h> | |
12 | ||
13 | #include "adau-utils.h" | |
14 | ||
15 | int adau_calc_pll_cfg(unsigned int freq_in, unsigned int freq_out, | |
16 | uint8_t regs[5]) | |
17 | { | |
18 | unsigned int r, n, m, i, j; | |
19 | unsigned int div; | |
20 | ||
21 | if (!freq_out) { | |
22 | r = 0; | |
23 | n = 0; | |
24 | m = 0; | |
25 | div = 0; | |
26 | } else { | |
27 | if (freq_out % freq_in != 0) { | |
28 | div = DIV_ROUND_UP(freq_in, 13500000); | |
29 | freq_in /= div; | |
30 | r = freq_out / freq_in; | |
31 | i = freq_out % freq_in; | |
32 | j = gcd(i, freq_in); | |
33 | n = i / j; | |
34 | m = freq_in / j; | |
35 | div--; | |
36 | } else { | |
37 | r = freq_out / freq_in; | |
38 | n = 0; | |
39 | m = 0; | |
40 | div = 0; | |
41 | } | |
42 | if (n > 0xffff || m > 0xffff || div > 3 || r > 8 || r < 2) | |
43 | return -EINVAL; | |
44 | } | |
45 | ||
46 | regs[0] = m >> 8; | |
47 | regs[1] = m & 0xff; | |
48 | regs[2] = n >> 8; | |
49 | regs[3] = n & 0xff; | |
50 | regs[4] = (r << 3) | (div << 1); | |
51 | if (m != 0) | |
52 | regs[4] |= 1; /* Fractional mode */ | |
53 | ||
54 | return 0; | |
55 | } | |
56 | EXPORT_SYMBOL_GPL(adau_calc_pll_cfg); | |
57 | ||
58 | MODULE_DESCRIPTION("ASoC ADAU audio CODECs shared helper functions"); | |
59 | MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); | |
60 | MODULE_LICENSE("GPL v2"); |