cpuidle.c

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/* linux/arch/arm/mach-s3c64xx/cpuidle.c
 *
 * Copyright (c) 2011 Wolfson Microelectronics, plc
 * Copyright (c) 2011 Samsung Electronics Co., Ltd.
 *      http://www.samsung.com
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
*/

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

#include <asm/proc-fns.h>

#include <mach/map.h>

#include <mach/regs-sys.h>
#include <mach/regs-syscon-power.h>

static int s3c64xx_enter_idle(struct cpuidle_device *dev,
                  struct cpuidle_driver *drv,
                  int index)
{
    unsigned long tmp;

    /* Setup PWRCFG to enter idle mode */
    tmp = __raw_readl(S3C64XX_PWR_CFG);
    tmp &= ~S3C64XX_PWRCFG_CFG_WFI_MASK;
    tmp |= S3C64XX_PWRCFG_CFG_WFI_IDLE;
    __raw_writel(tmp, S3C64XX_PWR_CFG);

    cpu_do_idle();

    return index;
}

static DEFINE_PER_CPU(struct cpuidle_device, s3c64xx_cpuidle_device);

static struct cpuidle_driver s3c64xx_cpuidle_driver = {
    .name   = "s3c64xx_cpuidle",
    .owner  = THIS_MODULE,
    .en_core_tk_irqen = 1,
    .states = {
        {
            .enter            = s3c64xx_enter_idle,
            .exit_latency     = 1,
            .target_residency = 1,
            .flags            = CPUIDLE_FLAG_TIME_VALID,
            .name             = "IDLE",
            .desc             = "System active, ARM gated",
        },
    },
    .state_count = 1,
};

static int __init s3c64xx_init_cpuidle(void)
{
    int ret;

    cpuidle_register_driver(&s3c64xx_cpuidle_driver);

    ret = cpuidle_register_device(&s3c64xx_cpuidle_device);
    if (ret) {
        pr_err("Failed to register cpuidle device: %d\n", ret);
        return ret;
    }

    return 0;
}
device_initcall(s3c64xx_init_cpuidle);