// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2016 NVIDIA CORPORATION, All Rights Reserved.
 */
#include <linux/module.h>
#include <linux/clk.h>
#include <linux/of.h>
#include <linux/of_irq.h>
#include <linux/irqchip/arm-gic.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/slab.h>

struct gic_clk_data {
        unsigned int num_clocks;
        const char *const *clocks;
};

struct gic_chip_pm {
        struct gic_chip_data *chip_data;
        const struct gic_clk_data *clk_data;
        struct clk_bulk_data *clks;
};

static int gic_runtime_resume(struct device *dev)
{
        struct gic_chip_pm *chip_pm = dev_get_drvdata(dev);
        struct gic_chip_data *gic = chip_pm->chip_data;
        const struct gic_clk_data *data = chip_pm->clk_data;
        int ret;

        ret = clk_bulk_prepare_enable(data->num_clocks, chip_pm->clks);
        if (ret)
                return ret;

        /*
         * On the very first resume, the pointer to chip_pm->chip_data
         * will be NULL and this is intentional, because we do not
         * want to restore the GIC on the very first resume. So if
         * the pointer is not valid just return.
         */
        if (!gic)
                return 0;

        gic_dist_restore(gic);
        gic_cpu_restore(gic);

        return 0;
}

static int gic_runtime_suspend(struct device *dev)
{
        struct gic_chip_pm *chip_pm = dev_get_drvdata(dev);
        struct gic_chip_data *gic = chip_pm->chip_data;
        const struct gic_clk_data *data = chip_pm->clk_data;

        gic_dist_save(gic);
        gic_cpu_save(gic);

        clk_bulk_disable_unprepare(data->num_clocks, chip_pm->clks);

        return 0;
}

static int gic_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        const struct gic_clk_data *data;
        struct gic_chip_pm *chip_pm;
        int ret, irq, i;

        data = of_device_get_match_data(&pdev->dev);
        if (!data) {
                dev_err(&pdev->dev, "no device match found\n");
                return -ENODEV;
        }

        chip_pm = devm_kzalloc(dev, sizeof(*chip_pm), GFP_KERNEL);
        if (!chip_pm)
                return -ENOMEM;

        irq = irq_of_parse_and_map(dev->of_node, 0);
        if (!irq) {
                dev_err(dev, "no parent interrupt found!\n");
                return -EINVAL;
        }

        chip_pm->clks = devm_kcalloc(dev, data->num_clocks,
                                     sizeof(*chip_pm->clks), GFP_KERNEL);
        if (!chip_pm->clks)
                return -ENOMEM;

        for (i = 0; i < data->num_clocks; i++)
                chip_pm->clks[i].id = data->clocks[i];

        ret = devm_clk_bulk_get(dev, data->num_clocks, chip_pm->clks);
        if (ret)
                goto irq_dispose;

        chip_pm->clk_data = data;
        dev_set_drvdata(dev, chip_pm);

        pm_runtime_enable(dev);

        ret = pm_runtime_resume_and_get(dev);
        if (ret < 0)
                goto rpm_disable;

        ret = gic_of_init_child(dev, &chip_pm->chip_data, irq);
        if (ret)
                goto rpm_put;

        pm_runtime_put(dev);

        dev_info(dev, "GIC IRQ controller registered\n");

        return 0;

rpm_put:
        pm_runtime_put_sync(dev);
rpm_disable:
        pm_runtime_disable(dev);
irq_dispose:
        irq_dispose_mapping(irq);

        return ret;
}

static const struct dev_pm_ops gic_pm_ops = {
        SET_RUNTIME_PM_OPS(gic_runtime_suspend,
                           gic_runtime_resume, NULL)
        SET_LATE_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
                                     pm_runtime_force_resume)
};

static const char * const gic400_clocks[] = {
        "clk",
};

static const struct gic_clk_data gic400_data = {
        .num_clocks = ARRAY_SIZE(gic400_clocks),
        .clocks = gic400_clocks,
};

static const struct of_device_id gic_match[] = {
        { .compatible = "nvidia,tegra210-agic", .data = &gic400_data },
        {},
};
MODULE_DEVICE_TABLE(of, gic_match);

static struct platform_driver gic_driver = {
        .probe          = gic_probe,
        .driver         = {
                .name   = "gic",
                .of_match_table = gic_match,
                .pm     = &gic_pm_ops,
        }
};

builtin_platform_driver(gic_driver);