// SPDX-License-Identifier: GPL-2.0-only
/*
 * CPU idle Marvell Kirkwood SoCs
 *
 * The cpu idle uses wait-for-interrupt and DDR self refresh in order
 * to implement two idle states -
 * #1 wait-for-interrupt
 * #2 wait-for-interrupt and DDR self refresh
 *
 * Maintainer: Jason Cooper <jason@lakedaemon.net>
 * Maintainer: Andrew Lunn <andrew@lunn.ch>
 */

#include <linux/kernel.h>
#include <linux/module.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 KIRKWOOD_MAX_STATES     2

static void __iomem *ddr_operation_base;

/* Actual code that puts the SoC in different idle states */
static int kirkwood_enter_idle(struct cpuidle_device *dev,
                               struct cpuidle_driver *drv,
                               int index)
{
        writel(0x7, ddr_operation_base);
        cpu_do_idle();

        return index;
}

static struct cpuidle_driver kirkwood_idle_driver = {
        .name                   = "kirkwood_idle",
        .owner                  = THIS_MODULE,
        .states[0]              = ARM_CPUIDLE_WFI_STATE,
        .states[1]              = {
                .enter                  = kirkwood_enter_idle,
                .exit_latency           = 10,
                .target_residency       = 100000,
                .name                   = "DDR SR",
                .desc                   = "WFI and DDR Self Refresh",
        },
        .state_count = KIRKWOOD_MAX_STATES,
};

/* Initialize CPU idle by registering the idle states */
static int kirkwood_cpuidle_probe(struct platform_device *pdev)
{
        ddr_operation_base = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(ddr_operation_base))
                return PTR_ERR(ddr_operation_base);

        return cpuidle_register(&kirkwood_idle_driver, NULL);
}

static void kirkwood_cpuidle_remove(struct platform_device *pdev)
{
        cpuidle_unregister(&kirkwood_idle_driver);
}

static struct platform_driver kirkwood_cpuidle_driver = {
        .probe = kirkwood_cpuidle_probe,
        .remove = kirkwood_cpuidle_remove,
        .driver = {
                   .name = "kirkwood_cpuidle",
                   },
};

module_platform_driver(kirkwood_cpuidle_driver);

MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch>");
MODULE_DESCRIPTION("Kirkwood cpu idle driver");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:kirkwood-cpuidle");