// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
 */

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

#include "clk.h"

static unsigned long clk_sync_source_recalc_rate(struct clk_hw *hw,
                                                 unsigned long parent_rate)
{
        struct tegra_clk_sync_source *sync = to_clk_sync_source(hw);

        return sync->rate;
}

static int clk_sync_source_determine_rate(struct clk_hw *hw,
                                          struct clk_rate_request *req)
{
        struct tegra_clk_sync_source *sync = to_clk_sync_source(hw);

        if (req->rate > sync->max_rate)
                return -EINVAL;
        else
                return 0;
}

static int clk_sync_source_set_rate(struct clk_hw *hw, unsigned long rate,
                                    unsigned long parent_rate)
{
        struct tegra_clk_sync_source *sync = to_clk_sync_source(hw);

        sync->rate = rate;
        return 0;
}

const struct clk_ops tegra_clk_sync_source_ops = {
        .determine_rate = clk_sync_source_determine_rate,
        .set_rate = clk_sync_source_set_rate,
        .recalc_rate = clk_sync_source_recalc_rate,
};

struct clk *tegra_clk_register_sync_source(const char *name,
                                           unsigned long max_rate)
{
        struct tegra_clk_sync_source *sync;
        struct clk_init_data init;
        struct clk *clk;

        sync = kzalloc_obj(*sync);
        if (!sync) {
                pr_err("%s: could not allocate sync source clk\n", __func__);
                return ERR_PTR(-ENOMEM);
        }

        sync->max_rate = max_rate;

        init.ops = &tegra_clk_sync_source_ops;
        init.name = name;
        init.flags = 0;
        init.parent_names = NULL;
        init.num_parents = 0;

        /* Data in .init is copied by clk_register(), so stack variable OK */
        sync->hw.init = &init;

        clk = clk_register(NULL, &sync->hw);
        if (IS_ERR(clk))
                kfree(sync);

        return clk;
}