162306a36Sopenharmony_ci// SPDX-License-Identifier: GPL-2.0-or-later
262306a36Sopenharmony_ci/*
362306a36Sopenharmony_ci * Shared helper functions for devices from the ADAU family
462306a36Sopenharmony_ci *
562306a36Sopenharmony_ci * Copyright 2011-2016 Analog Devices Inc.
662306a36Sopenharmony_ci * Author: Lars-Peter Clausen <lars@metafoo.de>
762306a36Sopenharmony_ci */
862306a36Sopenharmony_ci
962306a36Sopenharmony_ci#include <linux/gcd.h>
1062306a36Sopenharmony_ci#include <linux/kernel.h>
1162306a36Sopenharmony_ci#include <linux/module.h>
1262306a36Sopenharmony_ci
1362306a36Sopenharmony_ci#include "adau-utils.h"
1462306a36Sopenharmony_ci
1562306a36Sopenharmony_ciint adau_calc_pll_cfg(unsigned int freq_in, unsigned int freq_out,
1662306a36Sopenharmony_ci	uint8_t regs[5])
1762306a36Sopenharmony_ci{
1862306a36Sopenharmony_ci	unsigned int r, n, m, i, j;
1962306a36Sopenharmony_ci	unsigned int div;
2062306a36Sopenharmony_ci
2162306a36Sopenharmony_ci	if (!freq_out) {
2262306a36Sopenharmony_ci		r = 0;
2362306a36Sopenharmony_ci		n = 0;
2462306a36Sopenharmony_ci		m = 0;
2562306a36Sopenharmony_ci		div = 0;
2662306a36Sopenharmony_ci	} else {
2762306a36Sopenharmony_ci		if (freq_out % freq_in != 0) {
2862306a36Sopenharmony_ci			div = DIV_ROUND_UP(freq_in, 13500000);
2962306a36Sopenharmony_ci			freq_in /= div;
3062306a36Sopenharmony_ci			r = freq_out / freq_in;
3162306a36Sopenharmony_ci			i = freq_out % freq_in;
3262306a36Sopenharmony_ci			j = gcd(i, freq_in);
3362306a36Sopenharmony_ci			n = i / j;
3462306a36Sopenharmony_ci			m = freq_in / j;
3562306a36Sopenharmony_ci			div--;
3662306a36Sopenharmony_ci		} else {
3762306a36Sopenharmony_ci			r = freq_out / freq_in;
3862306a36Sopenharmony_ci			n = 0;
3962306a36Sopenharmony_ci			m = 0;
4062306a36Sopenharmony_ci			div = 0;
4162306a36Sopenharmony_ci		}
4262306a36Sopenharmony_ci		if (n > 0xffff || m > 0xffff || div > 3 || r > 8 || r < 2)
4362306a36Sopenharmony_ci			return -EINVAL;
4462306a36Sopenharmony_ci	}
4562306a36Sopenharmony_ci
4662306a36Sopenharmony_ci	regs[0] = m >> 8;
4762306a36Sopenharmony_ci	regs[1] = m & 0xff;
4862306a36Sopenharmony_ci	regs[2] = n >> 8;
4962306a36Sopenharmony_ci	regs[3] = n & 0xff;
5062306a36Sopenharmony_ci	regs[4] = (r << 3) | (div << 1);
5162306a36Sopenharmony_ci	if (m != 0)
5262306a36Sopenharmony_ci		regs[4] |= 1; /* Fractional mode */
5362306a36Sopenharmony_ci
5462306a36Sopenharmony_ci	return 0;
5562306a36Sopenharmony_ci}
5662306a36Sopenharmony_ciEXPORT_SYMBOL_GPL(adau_calc_pll_cfg);
5762306a36Sopenharmony_ci
5862306a36Sopenharmony_ciMODULE_DESCRIPTION("ASoC ADAU audio CODECs shared helper functions");
5962306a36Sopenharmony_ciMODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
6062306a36Sopenharmony_ciMODULE_LICENSE("GPL v2");
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