// SPDX-License-Identifier: GPL-2.0
//
// Copyright (c) 2018 Samsung Electronics Co., Ltd.
// Author: Marek Szyprowski <m.szyprowski@samsung.com>
// Common Clock Framework support for Exynos5 power-domain dependent clocks

#include <linux/io.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/pm_domain.h>
#include <linux/pm_runtime.h>

#include "clk.h"
#include "clk-exynos5-subcmu.h"

static struct samsung_clk_provider *ctx;
static const struct exynos5_subcmu_info **cmu;
static int nr_cmus;

static void exynos5_subcmu_clk_save(void __iomem *base,
                                    struct exynos5_subcmu_reg_dump *rd,
                                    unsigned int num_regs)
{
        for (; num_regs > 0; --num_regs, ++rd) {
                rd->save = readl(base + rd->offset);
                writel((rd->save & ~rd->mask) | rd->value, base + rd->offset);
                rd->save &= rd->mask;
        }
};

static void exynos5_subcmu_clk_restore(void __iomem *base,
                                       struct exynos5_subcmu_reg_dump *rd,
                                       unsigned int num_regs)
{
        for (; num_regs > 0; --num_regs, ++rd)
                writel((readl(base + rd->offset) & ~rd->mask) | rd->save,
                       base + rd->offset);
}

static void exynos5_subcmu_defer_gate(struct samsung_clk_provider *ctx,
                              const struct samsung_gate_clock *list, int nr_clk)
{
        while (nr_clk--)
                samsung_clk_add_lookup(ctx, ERR_PTR(-EPROBE_DEFER), list++->id);
}

/*
 * Pass the needed clock provider context and register sub-CMU clocks
 *
 * NOTE: This function has to be called from the main, OF_CLK_DECLARE-
 * initialized clock provider driver. This happens very early during boot
 * process. Then this driver, during core_initcall registers two platform
 * drivers: one which binds to the same device-tree node as OF_CLK_DECLARE
 * driver and second, for handling its per-domain child-devices. Those
 * platform drivers are bound to their devices a bit later in arch_initcall,
 * when OF-core populates all device-tree nodes.
 */
void exynos5_subcmus_init(struct samsung_clk_provider *_ctx, int _nr_cmus,
                          const struct exynos5_subcmu_info **_cmu)
{
        ctx = _ctx;
        cmu = _cmu;
        nr_cmus = _nr_cmus;

        for (; _nr_cmus--; _cmu++) {
                exynos5_subcmu_defer_gate(ctx, (*_cmu)->gate_clks,
                                          (*_cmu)->nr_gate_clks);
                exynos5_subcmu_clk_save(ctx->reg_base, (*_cmu)->suspend_regs,
                                        (*_cmu)->nr_suspend_regs);
        }
}

static int __maybe_unused exynos5_subcmu_suspend(struct device *dev)
{
        struct exynos5_subcmu_info *info = dev_get_drvdata(dev);
        unsigned long flags;

        spin_lock_irqsave(&ctx->lock, flags);
        exynos5_subcmu_clk_save(ctx->reg_base, info->suspend_regs,
                                info->nr_suspend_regs);
        spin_unlock_irqrestore(&ctx->lock, flags);

        return 0;
}

static int __maybe_unused exynos5_subcmu_resume(struct device *dev)
{
        struct exynos5_subcmu_info *info = dev_get_drvdata(dev);
        unsigned long flags;

        spin_lock_irqsave(&ctx->lock, flags);
        exynos5_subcmu_clk_restore(ctx->reg_base, info->suspend_regs,
                                   info->nr_suspend_regs);
        spin_unlock_irqrestore(&ctx->lock, flags);

        return 0;
}

static int __init exynos5_subcmu_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct exynos5_subcmu_info *info = dev_get_drvdata(dev);

        pm_runtime_set_suspended(dev);
        pm_runtime_enable(dev);
        pm_runtime_get(dev);

        ctx->dev = dev;
        samsung_clk_register_div(ctx, info->div_clks, info->nr_div_clks);
        samsung_clk_register_gate(ctx, info->gate_clks, info->nr_gate_clks);
        ctx->dev = NULL;

        pm_runtime_put_sync(dev);

        return 0;
}

static const struct dev_pm_ops exynos5_subcmu_pm_ops = {
        SET_RUNTIME_PM_OPS(exynos5_subcmu_suspend,
                           exynos5_subcmu_resume, NULL)
        SET_LATE_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
                                     pm_runtime_force_resume)
};

static struct platform_driver exynos5_subcmu_driver __refdata = {
        .driver = {
                .name = "exynos5-subcmu",
                .suppress_bind_attrs = true,
                .pm = &exynos5_subcmu_pm_ops,
        },
        .probe = exynos5_subcmu_probe,
};

static int __init exynos5_clk_register_subcmu(struct device *parent,
                                         const struct exynos5_subcmu_info *info,
                                              struct device_node *pd_node)
{
        struct of_phandle_args genpdspec = { .np = pd_node };
        struct platform_device *pdev;
        int ret;

        pdev = platform_device_alloc("exynos5-subcmu", PLATFORM_DEVID_AUTO);
        if (!pdev)
                return -ENOMEM;

        pdev->dev.parent = parent;
        platform_set_drvdata(pdev, (void *)info);
        of_genpd_add_device(&genpdspec, &pdev->dev);
        ret = platform_device_add(pdev);
        if (ret)
                platform_device_put(pdev);

        return ret;
}

static int __init exynos5_clk_probe(struct platform_device *pdev)
{
        struct device_node *np;
        const char *name;
        int i;

        for_each_compatible_node(np, NULL, "samsung,exynos4210-pd") {
                if (of_property_read_string(np, "label", &name) < 0)
                        continue;
                for (i = 0; i < nr_cmus; i++)
                        if (strcmp(cmu[i]->pd_name, name) == 0)
                                exynos5_clk_register_subcmu(&pdev->dev,
                                                            cmu[i], np);
        }
        return 0;
}

static const struct of_device_id exynos5_clk_of_match[] = {
        { .compatible = "samsung,exynos5250-clock", },
        { .compatible = "samsung,exynos5420-clock", },
        { .compatible = "samsung,exynos5800-clock", },
        { },
};

static struct platform_driver exynos5_clk_driver __refdata = {
        .driver = {
                .name = "exynos5-clock",
                .of_match_table = exynos5_clk_of_match,
                .suppress_bind_attrs = true,
        },
        .probe = exynos5_clk_probe,
};

static int __init exynos5_clk_drv_init(void)
{
        platform_driver_register(&exynos5_clk_driver);
        platform_driver_register(&exynos5_subcmu_driver);
        return 0;
}
core_initcall(exynos5_clk_drv_init);