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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Shared helper functions for devices from the ADAU family4 *5 * Copyright 2011-2016 Analog Devices Inc.6 * Author: Lars-Peter Clausen <lars@metafoo.de>7 */8 9#include <linux/gcd.h>10#include <linux/kernel.h>11#include <linux/module.h>12 13#include "adau-utils.h"14 15int 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}56EXPORT_SYMBOL_GPL(adau_calc_pll_cfg);57 58MODULE_DESCRIPTION("ASoC ADAU audio CODECs shared helper functions");59MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");60MODULE_LICENSE("GPL v2");61