drivers/clk/mxs/clk-div.c

root/drivers/clk/mxs/clk-div.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright 2012 Freescale Semiconductor, Inc.
 */

#include <linux/clk-provider.h>
#include <linux/err.h>
#include <linux/slab.h>
#include "clk.h"

/**
 * struct clk_div - mxs integer divider clock
 * @divider: the parent class
 * @ops: pointer to clk_ops of parent class
 * @reg: register address
 * @busy: busy bit shift
 *
 * The mxs divider clock is a subclass of basic clk_divider with an
 * additional busy bit.
 */
struct clk_div {
        struct clk_divider divider;
        const struct clk_ops *ops;
        void __iomem *reg;
        u8 busy;
};

static inline struct clk_div *to_clk_div(struct clk_hw *hw)
{
        struct clk_divider *divider = to_clk_divider(hw);

        return container_of(divider, struct clk_div, divider);
}

static unsigned long clk_div_recalc_rate(struct clk_hw *hw,
                                         unsigned long parent_rate)
{
        struct clk_div *div = to_clk_div(hw);

        return div->ops->recalc_rate(&div->divider.hw, parent_rate);
}

static int clk_div_determine_rate(struct clk_hw *hw,
                                  struct clk_rate_request *req)
{
        struct clk_div *div = to_clk_div(hw);

        return div->ops->determine_rate(&div->divider.hw, req);
}

static int clk_div_set_rate(struct clk_hw *hw, unsigned long rate,
                            unsigned long parent_rate)
{
        struct clk_div *div = to_clk_div(hw);
        int ret;

        ret = div->ops->set_rate(&div->divider.hw, rate, parent_rate);
        if (!ret)
                ret = mxs_clk_wait(div->reg, div->busy);

        return ret;
}

static const struct clk_ops clk_div_ops = {
        .recalc_rate = clk_div_recalc_rate,
        .determine_rate = clk_div_determine_rate,
        .set_rate = clk_div_set_rate,
};

struct clk *mxs_clk_div(const char *name, const char *parent_name,
                        void __iomem *reg, u8 shift, u8 width, u8 busy)
{
        struct clk_div *div;
        struct clk *clk;
        struct clk_init_data init;

        div = kzalloc_obj(*div);
        if (!div)
                return ERR_PTR(-ENOMEM);

        init.name = name;
        init.ops = &clk_div_ops;
        init.flags = CLK_SET_RATE_PARENT;
        init.parent_names = (parent_name ? &parent_name: NULL);
        init.num_parents = (parent_name ? 1 : 0);

        div->reg = reg;
        div->busy = busy;

        div->divider.reg = reg;
        div->divider.shift = shift;
        div->divider.width = width;
        div->divider.flags = CLK_DIVIDER_ONE_BASED;
        div->divider.lock = &mxs_lock;
        div->divider.hw.init = &init;
        div->ops = &clk_divider_ops;

        clk = clk_register(NULL, &div->divider.hw);
        if (IS_ERR(clk))
                kfree(div);

        return clk;
}
Linux
