// SPDX-License-Identifier: GPL-2.0-or-later
//
// Actions Semi Owl SoCs Reset Management Unit driver
//
// Copyright (c) 2018 Linaro Ltd.
// Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

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

#include "owl-reset.h"

static int owl_reset_assert(struct reset_controller_dev *rcdev,
                            unsigned long id)
{
        struct owl_reset *reset = to_owl_reset(rcdev);
        const struct owl_reset_map *map = &reset->reset_map[id];

        return regmap_update_bits(reset->regmap, map->reg, map->bit, 0);
}

static int owl_reset_deassert(struct reset_controller_dev *rcdev,
                              unsigned long id)
{
        struct owl_reset *reset = to_owl_reset(rcdev);
        const struct owl_reset_map *map = &reset->reset_map[id];

        return regmap_update_bits(reset->regmap, map->reg, map->bit, map->bit);
}

static int owl_reset_reset(struct reset_controller_dev *rcdev,
                           unsigned long id)
{
        owl_reset_assert(rcdev, id);
        udelay(1);
        owl_reset_deassert(rcdev, id);

        return 0;
}

static int owl_reset_status(struct reset_controller_dev *rcdev,
                            unsigned long id)
{
        struct owl_reset *reset = to_owl_reset(rcdev);
        const struct owl_reset_map *map = &reset->reset_map[id];
        u32 reg;
        int ret;

        ret = regmap_read(reset->regmap, map->reg, &reg);
        if (ret)
                return ret;

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

const struct reset_control_ops owl_reset_ops = {
        .assert         = owl_reset_assert,
        .deassert       = owl_reset_deassert,
        .reset          = owl_reset_reset,
        .status         = owl_reset_status,
};