pm-imx27.c

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/*
 * i.MX27 Power Management Routines
 *
 * Based on Freescale's BSP
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License.
 */

#include <linux/kernel.h>
#include <linux/suspend.h>
#include <linux/io.h>
#include <mach/hardware.h>

static int mx27_suspend_enter(suspend_state_t state)
{
    u32 cscr;
    switch (state) {
    case PM_SUSPEND_MEM:
        /* Clear MPEN and SPEN to disable MPLL/SPLL */
        cscr = __raw_readl(MX27_IO_ADDRESS(MX27_CCM_BASE_ADDR));
        cscr &= 0xFFFFFFFC;
        __raw_writel(cscr, MX27_IO_ADDRESS(MX27_CCM_BASE_ADDR));
        /* Executes WFI */
        cpu_do_idle();
        break;

    default:
        return -EINVAL;
    }
    return 0;
}

static const struct platform_suspend_ops mx27_suspend_ops = {
    .enter = mx27_suspend_enter,
    .valid = suspend_valid_only_mem,
};

static int __init mx27_pm_init(void)
{
    if (!cpu_is_mx27())
        return 0;

    suspend_set_ops(&mx27_suspend_ops);
    return 0;
}

device_initcall(mx27_pm_init);