// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2016 Maxime Ripard
 * Maxime Ripard <maxime.ripard@free-electrons.com>
 */

#include <linux/delay.h>
#include <linux/io.h>
#include <linux/reset-controller.h>

#include "ccu_reset.h"

static int ccu_reset_assert(struct reset_controller_dev *rcdev,
                            unsigned long id)
{
        struct ccu_reset *ccu = rcdev_to_ccu_reset(rcdev);
        const struct ccu_reset_map *map = &ccu->reset_map[id];
        unsigned long flags;
        u32 reg;

        spin_lock_irqsave(ccu->lock, flags);

        reg = readl(ccu->base + map->reg);
        writel(reg & ~map->bit, ccu->base + map->reg);

        spin_unlock_irqrestore(ccu->lock, flags);

        return 0;
}

static int ccu_reset_deassert(struct reset_controller_dev *rcdev,
                              unsigned long id)
{
        struct ccu_reset *ccu = rcdev_to_ccu_reset(rcdev);
        const struct ccu_reset_map *map = &ccu->reset_map[id];
        unsigned long flags;
        u32 reg;

        spin_lock_irqsave(ccu->lock, flags);

        reg = readl(ccu->base + map->reg);
        writel(reg | map->bit, ccu->base + map->reg);

        spin_unlock_irqrestore(ccu->lock, flags);

        return 0;
}

static int ccu_reset_reset(struct reset_controller_dev *rcdev,
                           unsigned long id)
{
        ccu_reset_assert(rcdev, id);
        udelay(10);
        ccu_reset_deassert(rcdev, id);

        return 0;
}

static int ccu_reset_status(struct reset_controller_dev *rcdev,
                            unsigned long id)
{
        struct ccu_reset *ccu = rcdev_to_ccu_reset(rcdev);
        const struct ccu_reset_map *map = &ccu->reset_map[id];

        /*
         * The reset control API expects 0 if reset is not asserted,
         * which is the opposite of what our hardware uses.
         */
        return !(map->bit & readl(ccu->base + map->reg));
}

const struct reset_control_ops ccu_reset_ops = {
        .assert         = ccu_reset_assert,
        .deassert       = ccu_reset_deassert,
        .reset          = ccu_reset_reset,
        .status         = ccu_reset_status,
};
EXPORT_SYMBOL_NS_GPL(ccu_reset_ops, "SUNXI_CCU");