drivers/clk/uniphier/clk-uniphier-mux.c

root/drivers/clk/uniphier/clk-uniphier-mux.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2016 Socionext Inc.
 *   Author: Masahiro Yamada <yamada.masahiro@socionext.com>
 */

#include <linux/clk-provider.h>
#include <linux/device.h>
#include <linux/regmap.h>

#include "clk-uniphier.h"

struct uniphier_clk_mux {
        struct clk_hw hw;
        struct regmap *regmap;
        unsigned int reg;
        const unsigned int *masks;
        const unsigned int *vals;
};

#define to_uniphier_clk_mux(_hw) container_of(_hw, struct uniphier_clk_mux, hw)

static int uniphier_clk_mux_set_parent(struct clk_hw *hw, u8 index)
{
        struct uniphier_clk_mux *mux = to_uniphier_clk_mux(hw);

        return regmap_write_bits(mux->regmap, mux->reg, mux->masks[index],
                                 mux->vals[index]);
}

static u8 uniphier_clk_mux_get_parent(struct clk_hw *hw)
{
        struct uniphier_clk_mux *mux = to_uniphier_clk_mux(hw);
        unsigned int num_parents = clk_hw_get_num_parents(hw);
        int ret;
        unsigned int val;
        unsigned int i;

        ret = regmap_read(mux->regmap, mux->reg, &val);
        if (ret)
                return ret;

        for (i = 0; i < num_parents; i++)
                if ((mux->masks[i] & val) == mux->vals[i])
                        return i;

        return -EINVAL;
}

static const struct clk_ops uniphier_clk_mux_ops = {
        .determine_rate = __clk_mux_determine_rate,
        .set_parent = uniphier_clk_mux_set_parent,
        .get_parent = uniphier_clk_mux_get_parent,
};

struct clk_hw *uniphier_clk_register_mux(struct device *dev,
                                         struct regmap *regmap,
                                         const char *name,
                                const struct uniphier_clk_mux_data *data)
{
        struct uniphier_clk_mux *mux;
        struct clk_init_data init;
        int ret;

        mux = devm_kzalloc(dev, sizeof(*mux), GFP_KERNEL);
        if (!mux)
                return ERR_PTR(-ENOMEM);

        init.name = name;
        init.ops = &uniphier_clk_mux_ops;
        init.flags = CLK_SET_RATE_PARENT;
        init.parent_names = data->parent_names;
        init.num_parents = data->num_parents;

        mux->regmap = regmap;
        mux->reg = data->reg;
        mux->masks = data->masks;
        mux->vals = data->vals;
        mux->hw.init = &init;

        ret = devm_clk_hw_register(dev, &mux->hw);
        if (ret)
                return ERR_PTR(ret);

        return &mux->hw;
}
Linux
