/*
 * Copyright (C) 2017 Synopsys.
 *
 * Synopsys AXS10x reset driver.
 *
 * This file is licensed under the terms of the GNU General Public
 * License version 2. This program is licensed "as is" without any
 * warranty of any kind, whether express or implied.
 */

#include <linux/io.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/platform_device.h>
#include <linux/reset-controller.h>

#define to_axs10x_rst(p)        container_of((p), struct axs10x_rst, rcdev)

#define AXS10X_MAX_RESETS       32

struct axs10x_rst {
        void __iomem                    *regs_rst;
        spinlock_t                      lock;
        struct reset_controller_dev     rcdev;
};

static int axs10x_reset_reset(struct reset_controller_dev *rcdev,
                              unsigned long id)
{
        struct axs10x_rst *rst = to_axs10x_rst(rcdev);
        unsigned long flags;

        spin_lock_irqsave(&rst->lock, flags);
        writel(BIT(id), rst->regs_rst);
        spin_unlock_irqrestore(&rst->lock, flags);

        return 0;
}

static const struct reset_control_ops axs10x_reset_ops = {
        .reset  = axs10x_reset_reset,
};

static int axs10x_reset_probe(struct platform_device *pdev)
{
        struct axs10x_rst *rst;

        rst = devm_kzalloc(&pdev->dev, sizeof(*rst), GFP_KERNEL);
        if (!rst)
                return -ENOMEM;

        rst->regs_rst = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(rst->regs_rst))
                return PTR_ERR(rst->regs_rst);

        spin_lock_init(&rst->lock);

        rst->rcdev.owner = THIS_MODULE;
        rst->rcdev.ops = &axs10x_reset_ops;
        rst->rcdev.of_node = pdev->dev.of_node;
        rst->rcdev.nr_resets = AXS10X_MAX_RESETS;

        return devm_reset_controller_register(&pdev->dev, &rst->rcdev);
}

static const struct of_device_id axs10x_reset_dt_match[] = {
        { .compatible = "snps,axs10x-reset" },
        { },
};

static struct platform_driver axs10x_reset_driver = {
        .probe  = axs10x_reset_probe,
        .driver = {
                .name = "axs10x-reset",
                .of_match_table = axs10x_reset_dt_match,
        },
};
builtin_platform_driver(axs10x_reset_driver);

MODULE_AUTHOR("Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>");
MODULE_DESCRIPTION("Synopsys AXS10x reset driver");
MODULE_LICENSE("GPL v2");