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/*
* Shared helper functions for devices from the ADAU family
*
* Copyright 2011-2016 Analog Devices Inc.
* Author: Lars-Peter Clausen <lars@metafoo.de>
*
* Licensed under the GPL-2 or later.
*/
#include <linux/gcd.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include "adau-utils.h"
int adau_calc_pll_cfg(unsigned int freq_in, unsigned int freq_out,
uint8_t regs[5])
{
unsigned int r, n, m, i, j;
unsigned int div;
if (!freq_out) {
r = 0;
n = 0;
m = 0;
div = 0;
} else {
if (freq_out % freq_in != 0) {
div = DIV_ROUND_UP(freq_in, 13500000);
freq_in /= div;
r = freq_out / freq_in;
i = freq_out % freq_in;
j = gcd(i, freq_in);
n = i / j;
m = freq_in / j;
div--;
} else {
r = freq_out / freq_in;
n = 0;
m = 0;
div = 0;
}
if (n > 0xffff || m > 0xffff || div > 3 || r > 8 || r < 2)
return -EINVAL;
}
regs[0] = m >> 8;
regs[1] = m & 0xff;
regs[2] = n >> 8;
regs[3] = n & 0xff;
regs[4] = (r << 3) | (div << 1);
if (m != 0)
regs[4] |= 1; /* Fractional mode */
return 0;
}
EXPORT_SYMBOL_GPL(adau_calc_pll_cfg);
MODULE_DESCRIPTION("ASoC ADAU audio CODECs shared helper functions");
MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
MODULE_LICENSE("GPL v2");
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