// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright 2014 Chen-Yu Tsai
 *
 * Chen-Yu Tsai <wens@csie.org>
 */

#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/of_address.h>

#define SUN8I_MBUS_ENABLE       31
#define SUN8I_MBUS_MUX_SHIFT    24
#define SUN8I_MBUS_MUX_MASK     0x3
#define SUN8I_MBUS_DIV_SHIFT    0
#define SUN8I_MBUS_DIV_WIDTH    3
#define SUN8I_MBUS_MAX_PARENTS  4

static DEFINE_SPINLOCK(sun8i_a23_mbus_lock);

static void __init sun8i_a23_mbus_setup(struct device_node *node)
{
        int num_parents = of_clk_get_parent_count(node);
        const char **parents;
        const char *clk_name = node->name;
        struct resource res;
        struct clk_divider *div;
        struct clk_gate *gate;
        struct clk_mux *mux;
        struct clk *clk;
        void __iomem *reg;
        int err;

        parents = kcalloc(num_parents, sizeof(*parents), GFP_KERNEL);
        if (!parents)
                return;

        reg = of_io_request_and_map(node, 0, of_node_full_name(node));
        if (IS_ERR(reg)) {
                pr_err("Could not get registers for sun8i-mbus-clk\n");
                goto err_free_parents;
        }

        div = kzalloc_obj(*div);
        if (!div)
                goto err_unmap;

        mux = kzalloc_obj(*mux);
        if (!mux)
                goto err_free_div;

        gate = kzalloc_obj(*gate);
        if (!gate)
                goto err_free_mux;

        of_property_read_string(node, "clock-output-names", &clk_name);
        of_clk_parent_fill(node, parents, num_parents);

        gate->reg = reg;
        gate->bit_idx = SUN8I_MBUS_ENABLE;
        gate->lock = &sun8i_a23_mbus_lock;

        div->reg = reg;
        div->shift = SUN8I_MBUS_DIV_SHIFT;
        div->width = SUN8I_MBUS_DIV_WIDTH;
        div->lock = &sun8i_a23_mbus_lock;

        mux->reg = reg;
        mux->shift = SUN8I_MBUS_MUX_SHIFT;
        mux->mask = SUN8I_MBUS_MUX_MASK;
        mux->lock = &sun8i_a23_mbus_lock;

        /* The MBUS clocks needs to be always enabled */
        clk = clk_register_composite(NULL, clk_name, parents, num_parents,
                                     &mux->hw, &clk_mux_ops,
                                     &div->hw, &clk_divider_ops,
                                     &gate->hw, &clk_gate_ops,
                                     CLK_IS_CRITICAL);
        if (IS_ERR(clk))
                goto err_free_gate;

        err = of_clk_add_provider(node, of_clk_src_simple_get, clk);
        if (err)
                goto err_unregister_clk;

        kfree(parents); /* parents is deep copied */

        return;

err_unregister_clk:
        /* TODO: The composite clock stuff will leak a bit here. */
        clk_unregister(clk);
err_free_gate:
        kfree(gate);
err_free_mux:
        kfree(mux);
err_free_div:
        kfree(div);
err_unmap:
        iounmap(reg);
        of_address_to_resource(node, 0, &res);
        release_mem_region(res.start, resource_size(&res));
err_free_parents:
        kfree(parents);
}
CLK_OF_DECLARE(sun8i_a23_mbus, "allwinner,sun8i-a23-mbus-clk", sun8i_a23_mbus_setup);