18c2ecf20Sopenharmony_ci// SPDX-License-Identifier: GPL-2.0-or-later
28c2ecf20Sopenharmony_ci/*
38c2ecf20Sopenharmony_ci * Shared helper functions for devices from the ADAU family
48c2ecf20Sopenharmony_ci *
58c2ecf20Sopenharmony_ci * Copyright 2011-2016 Analog Devices Inc.
68c2ecf20Sopenharmony_ci * Author: Lars-Peter Clausen <lars@metafoo.de>
78c2ecf20Sopenharmony_ci */
88c2ecf20Sopenharmony_ci
98c2ecf20Sopenharmony_ci#include <linux/gcd.h>
108c2ecf20Sopenharmony_ci#include <linux/kernel.h>
118c2ecf20Sopenharmony_ci#include <linux/module.h>
128c2ecf20Sopenharmony_ci
138c2ecf20Sopenharmony_ci#include "adau-utils.h"
148c2ecf20Sopenharmony_ci
158c2ecf20Sopenharmony_ciint adau_calc_pll_cfg(unsigned int freq_in, unsigned int freq_out,
168c2ecf20Sopenharmony_ci	uint8_t regs[5])
178c2ecf20Sopenharmony_ci{
188c2ecf20Sopenharmony_ci	unsigned int r, n, m, i, j;
198c2ecf20Sopenharmony_ci	unsigned int div;
208c2ecf20Sopenharmony_ci
218c2ecf20Sopenharmony_ci	if (!freq_out) {
228c2ecf20Sopenharmony_ci		r = 0;
238c2ecf20Sopenharmony_ci		n = 0;
248c2ecf20Sopenharmony_ci		m = 0;
258c2ecf20Sopenharmony_ci		div = 0;
268c2ecf20Sopenharmony_ci	} else {
278c2ecf20Sopenharmony_ci		if (freq_out % freq_in != 0) {
288c2ecf20Sopenharmony_ci			div = DIV_ROUND_UP(freq_in, 13500000);
298c2ecf20Sopenharmony_ci			freq_in /= div;
308c2ecf20Sopenharmony_ci			r = freq_out / freq_in;
318c2ecf20Sopenharmony_ci			i = freq_out % freq_in;
328c2ecf20Sopenharmony_ci			j = gcd(i, freq_in);
338c2ecf20Sopenharmony_ci			n = i / j;
348c2ecf20Sopenharmony_ci			m = freq_in / j;
358c2ecf20Sopenharmony_ci			div--;
368c2ecf20Sopenharmony_ci		} else {
378c2ecf20Sopenharmony_ci			r = freq_out / freq_in;
388c2ecf20Sopenharmony_ci			n = 0;
398c2ecf20Sopenharmony_ci			m = 0;
408c2ecf20Sopenharmony_ci			div = 0;
418c2ecf20Sopenharmony_ci		}
428c2ecf20Sopenharmony_ci		if (n > 0xffff || m > 0xffff || div > 3 || r > 8 || r < 2)
438c2ecf20Sopenharmony_ci			return -EINVAL;
448c2ecf20Sopenharmony_ci	}
458c2ecf20Sopenharmony_ci
468c2ecf20Sopenharmony_ci	regs[0] = m >> 8;
478c2ecf20Sopenharmony_ci	regs[1] = m & 0xff;
488c2ecf20Sopenharmony_ci	regs[2] = n >> 8;
498c2ecf20Sopenharmony_ci	regs[3] = n & 0xff;
508c2ecf20Sopenharmony_ci	regs[4] = (r << 3) | (div << 1);
518c2ecf20Sopenharmony_ci	if (m != 0)
528c2ecf20Sopenharmony_ci		regs[4] |= 1; /* Fractional mode */
538c2ecf20Sopenharmony_ci
548c2ecf20Sopenharmony_ci	return 0;
558c2ecf20Sopenharmony_ci}
568c2ecf20Sopenharmony_ciEXPORT_SYMBOL_GPL(adau_calc_pll_cfg);
578c2ecf20Sopenharmony_ci
588c2ecf20Sopenharmony_ciMODULE_DESCRIPTION("ASoC ADAU audio CODECs shared helper functions");
598c2ecf20Sopenharmony_ciMODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
608c2ecf20Sopenharmony_ciMODULE_LICENSE("GPL v2");
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