// SPDX-License-Identifier: GPL-2.0
//
// Copyright (c) 2011-2014 Samsung Electronics Co., Ltd.
//              http://www.samsung.com
//
// Exynos - Power Management support
//
// Based on arch/arm/mach-s3c2410/pm.c
// Copyright (c) 2006 Simtec Electronics
//      Ben Dooks <ben@simtec.co.uk>

#include <linux/init.h>
#include <linux/suspend.h>
#include <linux/cpu_pm.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/soc/samsung/exynos-regs-pmu.h>
#include <linux/soc/samsung/exynos-pmu.h>

#include <asm/firmware.h>
#include <asm/smp_scu.h>
#include <asm/suspend.h>
#include <asm/cacheflush.h>

#include "common.h"

static inline void __iomem *exynos_boot_vector_addr(void)
{
        if (exynos_rev() == EXYNOS4210_REV_1_1)
                return pmu_base_addr + S5P_INFORM7;
        else if (exynos_rev() == EXYNOS4210_REV_1_0)
                return sysram_base_addr + 0x24;
        return pmu_base_addr + S5P_INFORM0;
}

static inline void __iomem *exynos_boot_vector_flag(void)
{
        if (exynos_rev() == EXYNOS4210_REV_1_1)
                return pmu_base_addr + S5P_INFORM6;
        else if (exynos_rev() == EXYNOS4210_REV_1_0)
                return sysram_base_addr + 0x20;
        return pmu_base_addr + S5P_INFORM1;
}

#define S5P_CHECK_AFTR  0xFCBA0D10

/* For Cortex-A9 Diagnostic and Power control register */
static unsigned int save_arm_register[2];

void exynos_cpu_save_register(void)
{
        unsigned long tmp;

        /* Save Power control register */
        asm ("mrc p15, 0, %0, c15, c0, 0"
             : "=r" (tmp) : : "cc");

        save_arm_register[0] = tmp;

        /* Save Diagnostic register */
        asm ("mrc p15, 0, %0, c15, c0, 1"
             : "=r" (tmp) : : "cc");

        save_arm_register[1] = tmp;
}

void exynos_cpu_restore_register(void)
{
        unsigned long tmp;

        /* Restore Power control register */
        tmp = save_arm_register[0];

        asm volatile ("mcr p15, 0, %0, c15, c0, 0"
                      : : "r" (tmp)
                      : "cc");

        /* Restore Diagnostic register */
        tmp = save_arm_register[1];

        asm volatile ("mcr p15, 0, %0, c15, c0, 1"
                      : : "r" (tmp)
                      : "cc");
}

void exynos_pm_central_suspend(void)
{
        unsigned long tmp;

        /* Setting Central Sequence Register for power down mode */
        tmp = pmu_raw_readl(S5P_CENTRAL_SEQ_CONFIGURATION);
        tmp &= ~S5P_CENTRAL_LOWPWR_CFG;
        pmu_raw_writel(tmp, S5P_CENTRAL_SEQ_CONFIGURATION);
}

int exynos_pm_central_resume(void)
{
        unsigned long tmp;

        /*
         * If PMU failed while entering sleep mode, WFI will be
         * ignored by PMU and then exiting cpu_do_idle().
         * S5P_CENTRAL_LOWPWR_CFG bit will not be set automatically
         * in this situation.
         */
        tmp = pmu_raw_readl(S5P_CENTRAL_SEQ_CONFIGURATION);
        if (!(tmp & S5P_CENTRAL_LOWPWR_CFG)) {
                tmp |= S5P_CENTRAL_LOWPWR_CFG;
                pmu_raw_writel(tmp, S5P_CENTRAL_SEQ_CONFIGURATION);
                /* clear the wakeup state register */
                pmu_raw_writel(0x0, S5P_WAKEUP_STAT);
                /* No need to perform below restore code */
                return -1;
        }

        return 0;
}

/* Ext-GIC nIRQ/nFIQ is the only wakeup source in AFTR */
static void exynos_set_wakeupmask(long mask)
{
        pmu_raw_writel(mask, S5P_WAKEUP_MASK);
        if (soc_is_exynos3250())
                pmu_raw_writel(0x0, S5P_WAKEUP_MASK2);
}

static void exynos_cpu_set_boot_vector(long flags)
{
        writel_relaxed(__pa_symbol(exynos_cpu_resume),
                       exynos_boot_vector_addr());
        writel_relaxed(flags, exynos_boot_vector_flag());
}

static int exynos_aftr_finisher(unsigned long flags)
{
        int ret;

        exynos_set_wakeupmask(soc_is_exynos3250() ? 0x40003ffe : 0x0000ff3e);
        /* Set value of power down register for aftr mode */
        exynos_sys_powerdown_conf(SYS_AFTR);

        ret = call_firmware_op(do_idle, FW_DO_IDLE_AFTR);
        if (ret == -ENOSYS) {
                if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A9)
                        exynos_cpu_save_register();
                exynos_cpu_set_boot_vector(S5P_CHECK_AFTR);
                cpu_do_idle();
        }

        return 1;
}

void exynos_enter_aftr(void)
{
        unsigned int cpuid = smp_processor_id();

        cpu_pm_enter();

        if (soc_is_exynos3250())
                exynos_set_boot_flag(cpuid, C2_STATE);

        exynos_pm_central_suspend();

        if (soc_is_exynos4212() || soc_is_exynos4412()) {
                /* Setting SEQ_OPTION register */
                pmu_raw_writel(S5P_USE_STANDBY_WFI0 | S5P_USE_STANDBY_WFE0,
                               S5P_CENTRAL_SEQ_OPTION);
        }

        cpu_suspend(0, exynos_aftr_finisher);

        if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A9) {
                exynos_scu_enable();
                if (call_firmware_op(resume) == -ENOSYS)
                        exynos_cpu_restore_register();
        }

        exynos_pm_central_resume();

        if (soc_is_exynos3250())
                exynos_clear_boot_flag(cpuid, C2_STATE);

        cpu_pm_exit();
}

#if defined(CONFIG_SMP) && defined(CONFIG_ARM_EXYNOS_CPUIDLE)
static atomic_t cpu1_wakeup = ATOMIC_INIT(0);

static int exynos_cpu0_enter_aftr(void)
{
        int ret = -1;

        /*
         * If the other cpu is powered on, we have to power it off, because
         * the AFTR state won't work otherwise
         */
        if (cpu_online(1)) {
                /*
                 * We reach a sync point with the coupled idle state, we know
                 * the other cpu will power down itself or will abort the
                 * sequence, let's wait for one of these to happen
                 */
                while (exynos_cpu_power_state(1)) {
                        unsigned long boot_addr;

                        /*
                         * The other cpu may skip idle and boot back
                         * up again
                         */
                        if (atomic_read(&cpu1_wakeup))
                                goto abort;

                        /*
                         * The other cpu may bounce through idle and
                         * boot back up again, getting stuck in the
                         * boot rom code
                         */
                        ret = exynos_get_boot_addr(1, &boot_addr);
                        if (ret)
                                goto fail;
                        ret = -1;
                        if (boot_addr == 0)
                                goto abort;

                        cpu_relax();
                }
        }

        exynos_enter_aftr();
        ret = 0;

abort:
        if (cpu_online(1)) {
                unsigned long boot_addr = __pa_symbol(exynos_cpu_resume);

                /*
                 * Set the boot vector to something non-zero
                 */
                ret = exynos_set_boot_addr(1, boot_addr);
                if (ret)
                        goto fail;
                dsb();

                /*
                 * Turn on cpu1 and wait for it to be on
                 */
                exynos_cpu_power_up(1);
                while (exynos_cpu_power_state(1) != S5P_CORE_LOCAL_PWR_EN)
                        cpu_relax();

                if (soc_is_exynos3250()) {
                        while (!pmu_raw_readl(S5P_PMU_SPARE2) &&
                               !atomic_read(&cpu1_wakeup))
                                cpu_relax();

                        if (!atomic_read(&cpu1_wakeup))
                                exynos_core_restart(1);
                }

                while (!atomic_read(&cpu1_wakeup)) {
                        smp_rmb();

                        /*
                         * Poke cpu1 out of the boot rom
                         */

                        ret = exynos_set_boot_addr(1, boot_addr);
                        if (ret)
                                goto fail;

                        call_firmware_op(cpu_boot, 1);
                        dsb_sev();
                }
        }
fail:
        return ret;
}

static int exynos_wfi_finisher(unsigned long flags)
{
        if (soc_is_exynos3250())
                flush_cache_all();
        cpu_do_idle();

        return -1;
}

static int exynos_cpu1_powerdown(void)
{
        int ret = -1;

        /*
         * Idle sequence for cpu1
         */
        if (cpu_pm_enter())
                goto cpu1_aborted;

        /*
         * Turn off cpu 1
         */
        exynos_cpu_power_down(1);

        if (soc_is_exynos3250())
                pmu_raw_writel(0, S5P_PMU_SPARE2);

        ret = cpu_suspend(0, exynos_wfi_finisher);

        cpu_pm_exit();

cpu1_aborted:
        dsb();
        /*
         * Notify cpu 0 that cpu 1 is awake
         */
        atomic_set(&cpu1_wakeup, 1);

        return ret;
}

static void exynos_pre_enter_aftr(void)
{
        unsigned long boot_addr = __pa_symbol(exynos_cpu_resume);

        (void)exynos_set_boot_addr(1, boot_addr);
}

static void exynos_post_enter_aftr(void)
{
        atomic_set(&cpu1_wakeup, 0);
}

struct cpuidle_exynos_data cpuidle_coupled_exynos_data = {
        .cpu0_enter_aftr                = exynos_cpu0_enter_aftr,
        .cpu1_powerdown         = exynos_cpu1_powerdown,
        .pre_enter_aftr         = exynos_pre_enter_aftr,
        .post_enter_aftr                = exynos_post_enter_aftr,
};
#endif /* CONFIG_SMP && CONFIG_ARM_EXYNOS_CPUIDLE */