linux-imx

/*

 * Copyright (C) 2016 Maxime Ripard

 * Maxime Ripard <maxime.ripard@free-electrons.com>

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License as

 * published by the Free Software Foundation; either version 2 of

 * the License, or (at your option) any later version.

 */

​

#include <linux/clk-provider.h>

​

#include "ccu_gate.h"

#include "ccu_nkmp.h"

​

struct _ccu_nkmp {

    unsigned long   n, min_n, max_n;

    unsigned long   k, min_k, max_k;

    unsigned long   m, min_m, max_m;

    unsigned long   p, min_p, max_p;

};

​

static unsigned long ccu_nkmp_calc_rate(unsigned long parent,

                    unsigned long n, unsigned long k,

                    unsigned long m, unsigned long p)

{

    u64 rate = parent;

​

    rate *= n * k;

    do_div(rate, m * p);

​

    return rate;

}

​

static void ccu_nkmp_find_best(unsigned long parent, unsigned long rate,

                   struct _ccu_nkmp *nkmp)

{

    unsigned long best_rate = 0;

    unsigned long best_n = 0, best_k = 0, best_m = 0, best_p = 0;

    unsigned long _n, _k, _m, _p;

​

    for (_k = nkmp->min_k; _k <= nkmp->max_k; _k++) {

        for (_n = nkmp->min_n; _n <= nkmp->max_n; _n++) {

            for (_m = nkmp->min_m; _m <= nkmp->max_m; _m++) {

                for (_p = nkmp->min_p; _p <= nkmp->max_p; _p <<= 1) {

                    unsigned long tmp_rate;

​

                    tmp_rate = ccu_nkmp_calc_rate(parent,

                                      _n, _k,

                                      _m, _p);

​

                    if (tmp_rate > rate)

                        continue;

​

                    if ((rate - tmp_rate) < (rate - best_rate)) {

                        best_rate = tmp_rate;

                        best_n = _n;

                        best_k = _k;

                        best_m = _m;

                        best_p = _p;

                    }

                }

            }