// SPDX-License-Identifier: GPL-2.0-only
/*
 * PRCC clock implementation for ux500 platform.
 *
 * Copyright (C) 2012 ST-Ericsson SA
 * Author: Ulf Hansson <ulf.hansson@linaro.org>
 */

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

#include "clk.h"

#define PRCC_PCKEN                      0x000
#define PRCC_PCKDIS                     0x004
#define PRCC_KCKEN                      0x008
#define PRCC_KCKDIS                     0x00C
#define PRCC_PCKSR                      0x010
#define PRCC_KCKSR                      0x014

#define to_clk_prcc(_hw) container_of(_hw, struct clk_prcc, hw)

struct clk_prcc {
        struct clk_hw hw;
        void __iomem *base;
        u32 cg_sel;
        int is_enabled;
};

/* PRCC clock operations. */

static int clk_prcc_pclk_enable(struct clk_hw *hw)
{
        struct clk_prcc *clk = to_clk_prcc(hw);

        writel(clk->cg_sel, (clk->base + PRCC_PCKEN));
        while (!(readl(clk->base + PRCC_PCKSR) & clk->cg_sel))
                cpu_relax();

        clk->is_enabled = 1;
        return 0;
}

static void clk_prcc_pclk_disable(struct clk_hw *hw)
{
        struct clk_prcc *clk = to_clk_prcc(hw);

        writel(clk->cg_sel, (clk->base + PRCC_PCKDIS));
        clk->is_enabled = 0;
}

static int clk_prcc_kclk_enable(struct clk_hw *hw)
{
        struct clk_prcc *clk = to_clk_prcc(hw);

        writel(clk->cg_sel, (clk->base + PRCC_KCKEN));
        while (!(readl(clk->base + PRCC_KCKSR) & clk->cg_sel))
                cpu_relax();

        clk->is_enabled = 1;
        return 0;
}

static void clk_prcc_kclk_disable(struct clk_hw *hw)
{
        struct clk_prcc *clk = to_clk_prcc(hw);

        writel(clk->cg_sel, (clk->base + PRCC_KCKDIS));
        clk->is_enabled = 0;
}

static int clk_prcc_is_enabled(struct clk_hw *hw)
{
        struct clk_prcc *clk = to_clk_prcc(hw);
        return clk->is_enabled;
}

static const struct clk_ops clk_prcc_pclk_ops = {
        .enable = clk_prcc_pclk_enable,
        .disable = clk_prcc_pclk_disable,
        .is_enabled = clk_prcc_is_enabled,
};

static const struct clk_ops clk_prcc_kclk_ops = {
        .enable = clk_prcc_kclk_enable,
        .disable = clk_prcc_kclk_disable,
        .is_enabled = clk_prcc_is_enabled,
};

static struct clk *clk_reg_prcc(const char *name,
                                const char *parent_name,
                                resource_size_t phy_base,
                                u32 cg_sel,
                                unsigned long flags,
                                const struct clk_ops *clk_prcc_ops)
{
        struct clk_prcc *clk;
        struct clk_init_data clk_prcc_init;
        struct clk *clk_reg;

        if (!name) {
                pr_err("clk_prcc: %s invalid arguments passed\n", __func__);
                return ERR_PTR(-EINVAL);
        }

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

        clk->base = ioremap(phy_base, SZ_4K);
        if (!clk->base)
                goto free_clk;

        clk->cg_sel = cg_sel;
        clk->is_enabled = 1;

        clk_prcc_init.name = name;
        clk_prcc_init.ops = clk_prcc_ops;
        clk_prcc_init.flags = flags;
        clk_prcc_init.parent_names = (parent_name ? &parent_name : NULL);
        clk_prcc_init.num_parents = (parent_name ? 1 : 0);
        clk->hw.init = &clk_prcc_init;

        clk_reg = clk_register(NULL, &clk->hw);
        if (IS_ERR_OR_NULL(clk_reg))
                goto unmap_clk;

        return clk_reg;

unmap_clk:
        iounmap(clk->base);
free_clk:
        kfree(clk);
        pr_err("clk_prcc: %s failed to register clk\n", __func__);
        return ERR_PTR(-ENOMEM);
}

struct clk *clk_reg_prcc_pclk(const char *name,
                              const char *parent_name,
                              resource_size_t phy_base,
                              u32 cg_sel,
                              unsigned long flags)
{
        return clk_reg_prcc(name, parent_name, phy_base, cg_sel, flags,
                        &clk_prcc_pclk_ops);
}

struct clk *clk_reg_prcc_kclk(const char *name,
                              const char *parent_name,
                              resource_size_t phy_base,
                              u32 cg_sel,
                              unsigned long flags)
{
        return clk_reg_prcc(name, parent_name, phy_base, cg_sel, flags,
                        &clk_prcc_kclk_ops);
}