// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2015 Linaro Ltd.
 * Author: Pi-Cheng Chen <pi-cheng.chen@linaro.org>
 */

#include <linux/clk-provider.h>
#include <linux/container_of.h>
#include <linux/err.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/regmap.h>
#include <linux/slab.h>

#include "clk-mtk.h"
#include "clk-cpumux.h"

struct mtk_clk_cpumux {
        struct clk_hw   hw;
        struct regmap   *regmap;
        u32             reg;
        u32             mask;
        u8              shift;
};

static inline struct mtk_clk_cpumux *to_mtk_clk_cpumux(struct clk_hw *_hw)
{
        return container_of(_hw, struct mtk_clk_cpumux, hw);
}

static u8 clk_cpumux_get_parent(struct clk_hw *hw)
{
        struct mtk_clk_cpumux *mux = to_mtk_clk_cpumux(hw);
        unsigned int val;

        regmap_read(mux->regmap, mux->reg, &val);

        val >>= mux->shift;
        val &= mux->mask;

        return val;
}

static int clk_cpumux_set_parent(struct clk_hw *hw, u8 index)
{
        struct mtk_clk_cpumux *mux = to_mtk_clk_cpumux(hw);
        u32 mask, val;

        val = index << mux->shift;
        mask = mux->mask << mux->shift;

        return regmap_update_bits(mux->regmap, mux->reg, mask, val);
}

static const struct clk_ops clk_cpumux_ops = {
        .determine_rate = clk_hw_determine_rate_no_reparent,
        .get_parent = clk_cpumux_get_parent,
        .set_parent = clk_cpumux_set_parent,
};

static struct clk_hw *
mtk_clk_register_cpumux(struct device *dev, const struct mtk_composite *mux,
                        struct regmap *regmap)
{
        struct mtk_clk_cpumux *cpumux;
        int ret;
        struct clk_init_data init;

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

        init.name = mux->name;
        init.ops = &clk_cpumux_ops;
        init.parent_names = mux->parent_names;
        init.num_parents = mux->num_parents;
        init.flags = mux->flags;

        cpumux->reg = mux->mux_reg;
        cpumux->shift = mux->mux_shift;
        cpumux->mask = BIT(mux->mux_width) - 1;
        cpumux->regmap = regmap;
        cpumux->hw.init = &init;

        ret = clk_hw_register(dev, &cpumux->hw);
        if (ret) {
                kfree(cpumux);
                return ERR_PTR(ret);
        }

        return &cpumux->hw;
}

static void mtk_clk_unregister_cpumux(struct clk_hw *hw)
{
        struct mtk_clk_cpumux *cpumux;
        if (!hw)
                return;

        cpumux = to_mtk_clk_cpumux(hw);

        clk_hw_unregister(hw);
        kfree(cpumux);
}

int mtk_clk_register_cpumuxes(struct device *dev, struct device_node *node,
                              const struct mtk_composite *clks, int num,
                              struct clk_hw_onecell_data *clk_data)
{
        int i;
        struct clk_hw *hw;
        struct regmap *regmap;

        regmap = device_node_to_regmap(node);
        if (IS_ERR(regmap)) {
                pr_err("Cannot find regmap for %pOF: %pe\n", node, regmap);
                return PTR_ERR(regmap);
        }

        for (i = 0; i < num; i++) {
                const struct mtk_composite *mux = &clks[i];

                if (!IS_ERR_OR_NULL(clk_data->hws[mux->id])) {
                        pr_warn("%pOF: Trying to register duplicate clock ID: %d\n",
                                node, mux->id);
                        continue;
                }

                hw = mtk_clk_register_cpumux(dev, mux, regmap);
                if (IS_ERR(hw)) {
                        pr_err("Failed to register clk %s: %pe\n", mux->name,
                               hw);
                        goto err;
                }

                clk_data->hws[mux->id] = hw;
        }

        return 0;

err:
        while (--i >= 0) {
                const struct mtk_composite *mux = &clks[i];

                if (IS_ERR_OR_NULL(clk_data->hws[mux->id]))
                        continue;

                mtk_clk_unregister_cpumux(clk_data->hws[mux->id]);
                clk_data->hws[mux->id] = ERR_PTR(-ENOENT);
        }

        return PTR_ERR(hw);
}
EXPORT_SYMBOL_GPL(mtk_clk_register_cpumuxes);

void mtk_clk_unregister_cpumuxes(const struct mtk_composite *clks, int num,
                                 struct clk_hw_onecell_data *clk_data)
{
        int i;

        for (i = num; i > 0; i--) {
                const struct mtk_composite *mux = &clks[i - 1];

                if (IS_ERR_OR_NULL(clk_data->hws[mux->id]))
                        continue;

                mtk_clk_unregister_cpumux(clk_data->hws[mux->id]);
                clk_data->hws[mux->id] = ERR_PTR(-ENOENT);
        }
}
EXPORT_SYMBOL_GPL(mtk_clk_unregister_cpumuxes);

MODULE_LICENSE("GPL");