linux-imx

// SPDX-License-Identifier: GPL-2.0

/*

 * Copyright 2018 NXP

 */

​

#include <linux/errno.h>

#include <linux/slab.h>

#include <linux/clk-provider.h>

​

#include "clk.h"

​

#define PCG_PREDIV_SHIFT    16

#define PCG_PREDIV_WIDTH    3

#define PCG_PREDIV_MAX      8

​

#define PCG_DIV_SHIFT       0

#define PCG_DIV_WIDTH       6

#define PCG_DIV_MAX     64

​

#define PCG_PCS_SHIFT       24

#define PCG_PCS_MASK        0x7

​

#define PCG_CGC_SHIFT       28

​

static unsigned long imx8m_clk_composite_divider_recalc_rate(struct clk_hw *hw,

                        unsigned long parent_rate)

{

    struct clk_divider *divider = to_clk_divider(hw);

    unsigned long prediv_rate;

    unsigned int prediv_value;

    unsigned int div_value;

​

    prediv_value = readl(divider->reg) >> divider->shift;

    prediv_value &= clk_div_mask(divider->width);

​

    prediv_rate = divider_recalc_rate(hw, parent_rate, prediv_value,

                        NULL, divider->flags,

                        divider->width);

​

    div_value = readl(divider->reg) >> PCG_DIV_SHIFT;

    div_value &= clk_div_mask(PCG_DIV_WIDTH);

​

    return divider_recalc_rate(hw, prediv_rate, div_value, NULL,

                   divider->flags, PCG_DIV_WIDTH);

}

​

static int imx8m_clk_composite_compute_dividers(unsigned long rate,

                        unsigned long parent_rate,

                        int *prediv, int *postdiv)

{

    int div1, div2;

    int error = INT_MAX;

    int ret = -EINVAL;

​

    *prediv = 1;

    *postdiv = 1;

​

    for (div1 = 1; div1 <= PCG_PREDIV_MAX; div1++) {

        for (div2 = 1; div2 <= PCG_DIV_MAX; div2++) {

            int new_error = ((parent_rate / div1) / div2) - rate;

​

            if (abs(new_error) < abs(error)) {

                *prediv = div1;