// SPDX-License-Identifier: GPL-2.0
/*
 */

#define pr_fmt(fmt) "imx:clk-gpr-mux: " fmt

#include <linux/module.h>

#include <linux/clk-provider.h>
#include <linux/errno.h>
#include <linux/export.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/regmap.h>
#include <linux/mfd/syscon.h>

#include "clk.h"

struct imx_clk_gpr {
        struct clk_hw hw;
        struct regmap *regmap;
        u32 mask;
        u32 reg;
        const u32 *mux_table;
};

static struct imx_clk_gpr *to_imx_clk_gpr(struct clk_hw *hw)
{
        return container_of(hw, struct imx_clk_gpr, hw);
}

static u8 imx_clk_gpr_mux_get_parent(struct clk_hw *hw)
{
        struct imx_clk_gpr *priv = to_imx_clk_gpr(hw);
        unsigned int val;
        int ret;

        ret = regmap_read(priv->regmap, priv->reg, &val);
        if (ret)
                goto get_parent_err;

        val &= priv->mask;

        ret = clk_mux_val_to_index(hw, priv->mux_table, 0, val);
        if (ret < 0)
                goto get_parent_err;

        return ret;

get_parent_err:
        pr_err("%s: failed to get parent (%pe)\n",
               clk_hw_get_name(hw), ERR_PTR(ret));

        /* return some realistic non negative value. Potentially we could
         * give index to some dummy error parent.
         */
        return 0;
}

static int imx_clk_gpr_mux_set_parent(struct clk_hw *hw, u8 index)
{
        struct imx_clk_gpr *priv = to_imx_clk_gpr(hw);
        unsigned int val = clk_mux_index_to_val(priv->mux_table, 0, index);

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

static const struct clk_ops imx_clk_gpr_mux_ops = {
        .get_parent = imx_clk_gpr_mux_get_parent,
        .set_parent = imx_clk_gpr_mux_set_parent,
        .determine_rate = __clk_mux_determine_rate,
};

struct clk_hw *imx_clk_gpr_mux(const char *name, const char *compatible,
                               u32 reg, const char **parent_names,
                               u8 num_parents, const u32 *mux_table, u32 mask)
{
        struct clk_init_data init  = { };
        struct imx_clk_gpr *priv;
        struct regmap *regmap;
        struct clk_hw *hw;
        int ret;

        regmap = syscon_regmap_lookup_by_compatible(compatible);
        if (IS_ERR(regmap)) {
                pr_err("failed to find %s regmap\n", compatible);
                return ERR_CAST(regmap);
        }

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

        init.name = name;
        init.ops = &imx_clk_gpr_mux_ops;
        init.parent_names = parent_names;
        init.num_parents = num_parents;
        init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE;

        priv->hw.init = &init;
        priv->regmap = regmap;
        priv->mux_table = mux_table;
        priv->reg = reg;
        priv->mask = mask;

        hw = &priv->hw;
        ret = clk_hw_register(NULL, &priv->hw);
        if (ret) {
                kfree(priv);
                hw = ERR_PTR(ret);
        }

        return hw;
}