// SPDX-License-Identifier: GPL-2.0-only
/*
 * based on arch/arm/mach-kirkwood/cpuidle.c
 *
 * CPU idle support for AT91 SoC
 *
 * The cpu idle uses wait-for-interrupt and RAM self refresh in order
 * to implement two idle states -
 * #1 wait-for-interrupt
 * #2 wait-for-interrupt and RAM self refresh
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/cpuidle.h>
#include <linux/io.h>
#include <linux/export.h>
#include <asm/cpuidle.h>

#define AT91_MAX_STATES 2

static void (*at91_standby)(void);

/* Actual code that puts the SoC in different idle states */
static int at91_enter_idle(struct cpuidle_device *dev,
                        struct cpuidle_driver *drv,
                               int index)
{
        at91_standby();
        return index;
}

static struct cpuidle_driver at91_idle_driver = {
        .name                   = "at91_idle",
        .owner                  = THIS_MODULE,
        .states[0]              = ARM_CPUIDLE_WFI_STATE,
        .states[1]              = {
                .enter                  = at91_enter_idle,
                .exit_latency           = 10,
                .target_residency       = 10000,
                .name                   = "RAM_SR",
                .desc                   = "WFI and DDR Self Refresh",
        },
        .state_count = AT91_MAX_STATES,
};

/* Initialize CPU idle by registering the idle states */
static int at91_cpuidle_probe(struct platform_device *dev)
{
        at91_standby = (void *)(dev->dev.platform_data);
        
        return cpuidle_register(&at91_idle_driver, NULL);
}

static struct platform_driver at91_cpuidle_driver = {
        .driver = {
                .name = "cpuidle-at91",
        },
        .probe = at91_cpuidle_probe,
};
builtin_platform_driver(at91_cpuidle_driver);