// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * MMP PMU power island support
 *
 * Copyright (C) 2020 Lubomir Rintel <lkundrak@v3.sk>
 */

#include <linux/pm_domain.h>
#include <linux/slab.h>
#include <linux/io.h>

#include "clk.h"

#define to_mmp_pm_domain(genpd) container_of(genpd, struct mmp_pm_domain, genpd)

struct mmp_pm_domain {
        struct generic_pm_domain genpd;
        void __iomem *reg;
        spinlock_t *lock;
        u32 power_on;
        u32 reset;
        u32 clock_enable;
        unsigned int flags;
};

static int mmp_pm_domain_power_on(struct generic_pm_domain *genpd)
{
        struct mmp_pm_domain *pm_domain = to_mmp_pm_domain(genpd);
        unsigned long flags = 0;
        u32 val;

        if (pm_domain->lock)
                spin_lock_irqsave(pm_domain->lock, flags);

        val = readl(pm_domain->reg);

        /* Turn on the power island */
        val |= pm_domain->power_on;
        writel(val, pm_domain->reg);

        /* Disable isolation */
        val |= 0x100;
        writel(val, pm_domain->reg);

        /* Some blocks need to be reset after a power up */
        if (pm_domain->reset || pm_domain->clock_enable) {
                u32 after_power_on = val;

                val &= ~pm_domain->reset;
                writel(val, pm_domain->reg);

                val |= pm_domain->clock_enable;
                writel(val, pm_domain->reg);

                val |= pm_domain->reset;
                writel(val, pm_domain->reg);

                writel(after_power_on, pm_domain->reg);
        }

        if (pm_domain->lock)
                spin_unlock_irqrestore(pm_domain->lock, flags);

        return 0;
}

static int mmp_pm_domain_power_off(struct generic_pm_domain *genpd)
{
        struct mmp_pm_domain *pm_domain = to_mmp_pm_domain(genpd);
        unsigned long flags = 0;
        u32 val;

        if (pm_domain->flags & MMP_PM_DOMAIN_NO_DISABLE)
                return 0;

        if (pm_domain->lock)
                spin_lock_irqsave(pm_domain->lock, flags);

        /* Turn off and isolate the power island. */
        val = readl(pm_domain->reg);
        val &= ~pm_domain->power_on;
        val &= ~0x100;
        writel(val, pm_domain->reg);

        if (pm_domain->lock)
                spin_unlock_irqrestore(pm_domain->lock, flags);

        return 0;
}

struct generic_pm_domain *mmp_pm_domain_register(const char *name,
                void __iomem *reg,
                u32 power_on, u32 reset, u32 clock_enable,
                unsigned int flags, spinlock_t *lock)
{
        struct mmp_pm_domain *pm_domain;

        pm_domain = kzalloc_obj(*pm_domain);
        if (!pm_domain)
                return ERR_PTR(-ENOMEM);

        pm_domain->reg = reg;
        pm_domain->power_on = power_on;
        pm_domain->reset = reset;
        pm_domain->clock_enable = clock_enable;
        pm_domain->flags = flags;
        pm_domain->lock = lock;

        pm_domain->genpd.name = name;
        pm_domain->genpd.power_on = mmp_pm_domain_power_on;
        pm_domain->genpd.power_off = mmp_pm_domain_power_off;
        pm_genpd_init(&pm_domain->genpd, NULL, true);

        return &pm_domain->genpd;
}