// SPDX-License-Identifier: GPL-2.0-or-later /* * Shared helper functions for devices from the ADAU family * * Copyright 2011-2016 Analog Devices Inc. * Author: Lars-Peter Clausen <lars@metafoo.de> */ #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");