// SPDX-License-Identifier: GPL-2.0
/*
 * arch/sh/kernel/cpu/shmobile/cpuidle.c
 *
 * Cpuidle support code for SuperH Mobile
 *
 *  Copyright (C) 2009 Magnus Damm
 */
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/io.h>
#include <linux/suspend.h>
#include <linux/cpuidle.h>
#include <linux/export.h>
#include <asm/suspend.h>
#include <linux/uaccess.h>

static unsigned long cpuidle_mode[] = {
        SUSP_SH_SLEEP, /* regular sleep mode */
        SUSP_SH_SLEEP | SUSP_SH_SF, /* sleep mode + self refresh */
        SUSP_SH_STANDBY | SUSP_SH_SF, /* software standby mode + self refresh */
};

static int cpuidle_sleep_enter(struct cpuidle_device *dev,
                                struct cpuidle_driver *drv,
                                int index)
{
        unsigned long allowed_mode = SUSP_SH_SLEEP;
        int requested_state = index;
        int allowed_state;
        int k;

        /* convert allowed mode to allowed state */
        for (k = ARRAY_SIZE(cpuidle_mode) - 1; k > 0; k--)
                if (cpuidle_mode[k] == allowed_mode)
                        break;

        allowed_state = k;

        /* take the following into account for sleep mode selection:
         * - allowed_state: best mode allowed by hardware (clock deps)
         * - requested_state: best mode allowed by software (latencies)
         */
        k = min_t(int, allowed_state, requested_state);

        sh_mobile_call_standby(cpuidle_mode[k]);

        return k;
}

static struct cpuidle_driver cpuidle_driver = {
        .name   = "sh_idle",
        .owner  = THIS_MODULE,
        .states = {
                {
                        .exit_latency = 1,
                        .target_residency = 1 * 2,
                        .power_usage = 3,
                        .enter = cpuidle_sleep_enter,
                        .name = "C1",
                        .desc = "SuperH Sleep Mode",
                },
                {
                        .exit_latency = 100,
                        .target_residency = 1 * 2,
                        .power_usage = 1,
                        .enter = cpuidle_sleep_enter,
                        .name = "C2",
                        .desc = "SuperH Sleep Mode [SF]",
                        .flags = CPUIDLE_FLAG_UNUSABLE,
                },
                {
                        .exit_latency = 2300,
                        .target_residency = 1 * 2,
                        .power_usage = 1,
                        .enter = cpuidle_sleep_enter,
                        .name = "C3",
                        .desc = "SuperH Mobile Standby Mode [SF]",
                        .flags = CPUIDLE_FLAG_UNUSABLE,
                },
        },
        .safe_state_index = 0,
        .state_count = 3,
};

int __init sh_mobile_setup_cpuidle(void)
{
        if (sh_mobile_sleep_supported & SUSP_SH_SF)
                cpuidle_driver.states[1].flags = CPUIDLE_FLAG_NONE;

        if (sh_mobile_sleep_supported & SUSP_SH_STANDBY)
                cpuidle_driver.states[2].flags = CPUIDLE_FLAG_NONE;

        return cpuidle_register(&cpuidle_driver, NULL);
}