pm.c

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/*
 * arch/sh/kernel/cpu/shmobile/pm.c
 *
 * Power management support code for SuperH Mobile
 *
 *  Copyright (C) 2009 Magnus Damm
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 */
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/io.h>
#include <linux/suspend.h>
#include <asm/suspend.h>
#include <asm/uaccess.h>
#include <asm/cacheflush.h>
#include <asm/bl_bit.h>

/*
 * Notifier lists for pre/post sleep notification
 */
ATOMIC_NOTIFIER_HEAD(sh_mobile_pre_sleep_notifier_list);
ATOMIC_NOTIFIER_HEAD(sh_mobile_post_sleep_notifier_list);

/*
 * Sleep modes available on SuperH Mobile:
 *
 * Sleep mode is just plain "sleep" instruction
 * Sleep Self-Refresh mode is above plus RAM put in Self-Refresh
 * Standby Self-Refresh mode is above plus stopped clocks
 */
#define SUSP_MODE_SLEEP     (SUSP_SH_SLEEP)
#define SUSP_MODE_SLEEP_SF  (SUSP_SH_SLEEP | SUSP_SH_SF)
#define SUSP_MODE_STANDBY_SF    (SUSP_SH_STANDBY | SUSP_SH_SF)
#define SUSP_MODE_RSTANDBY_SF \
    (SUSP_SH_RSTANDBY | SUSP_SH_MMU | SUSP_SH_REGS | SUSP_SH_SF)
 /*
  * U-standby mode is unsupported since it needs bootloader hacks
  */

#ifdef CONFIG_CPU_SUBTYPE_SH7724
#define RAM_BASE 0xfd800000 /* RSMEM */
#else
#define RAM_BASE 0xe5200000 /* ILRAM */
#endif

void sh_mobile_call_standby(unsigned long mode)
{
    void *onchip_mem = (void *)RAM_BASE;
    struct sh_sleep_data *sdp = onchip_mem;
    void (*standby_onchip_mem)(unsigned long, unsigned long);

    /* code located directly after data structure */
    standby_onchip_mem = (void *)(sdp + 1);

    atomic_notifier_call_chain(&sh_mobile_pre_sleep_notifier_list,
                   mode, NULL);

    /* flush the caches if MMU flag is set */
    if (mode & SUSP_SH_MMU)
        flush_cache_all();

    /* Let assembly snippet in on-chip memory handle the rest */
    standby_onchip_mem(mode, RAM_BASE);

    atomic_notifier_call_chain(&sh_mobile_post_sleep_notifier_list,
                   mode, NULL);
}

extern char sh_mobile_sleep_enter_start;
extern char sh_mobile_sleep_enter_end;

extern char sh_mobile_sleep_resume_start;
extern char sh_mobile_sleep_resume_end;

unsigned long sh_mobile_sleep_supported = SUSP_SH_SLEEP;

void sh_mobile_register_self_refresh(unsigned long flags,
                     void *pre_start, void *pre_end,
                     void *post_start, void *post_end)
{
    void *onchip_mem = (void *)RAM_BASE;
    void *vp;
    struct sh_sleep_data *sdp;
    int n;

    /* part 0: data area */
    sdp = onchip_mem;
    sdp->addr.stbcr = 0xa4150020; /* STBCR */
    sdp->addr.bar = 0xa4150040; /* BAR */
    sdp->addr.pteh = 0xff000000; /* PTEH */
    sdp->addr.ptel = 0xff000004; /* PTEL */
    sdp->addr.ttb = 0xff000008; /* TTB */
    sdp->addr.tea = 0xff00000c; /* TEA */
    sdp->addr.mmucr = 0xff000010; /* MMUCR */
    sdp->addr.ptea = 0xff000034; /* PTEA */
    sdp->addr.pascr = 0xff000070; /* PASCR */
    sdp->addr.irmcr = 0xff000078; /* IRMCR */
    sdp->addr.ccr = 0xff00001c; /* CCR */
    sdp->addr.ramcr = 0xff000074; /* RAMCR */
    vp = sdp + 1;

    /* part 1: common code to enter sleep mode */
    n = &sh_mobile_sleep_enter_end - &sh_mobile_sleep_enter_start;
    memcpy(vp, &sh_mobile_sleep_enter_start, n);
    vp += roundup(n, 4);

    /* part 2: board specific code to enter self-refresh mode */
    n = pre_end - pre_start;
    memcpy(vp, pre_start, n);
    sdp->sf_pre = (unsigned long)vp;
    vp += roundup(n, 4);

    /* part 3: board specific code to resume from self-refresh mode */
    n = post_end - post_start;
    memcpy(vp, post_start, n);
    sdp->sf_post = (unsigned long)vp;
    vp += roundup(n, 4);

    /* part 4: common code to resume from sleep mode */
    WARN_ON(vp > (onchip_mem + 0x600));
    vp = onchip_mem + 0x600; /* located at interrupt vector */
    n = &sh_mobile_sleep_resume_end - &sh_mobile_sleep_resume_start;
    memcpy(vp, &sh_mobile_sleep_resume_start, n);
    sdp->resume = (unsigned long)vp;

    sh_mobile_sleep_supported |= flags;
}

static int sh_pm_enter(suspend_state_t state)
{
    if (!(sh_mobile_sleep_supported & SUSP_MODE_STANDBY_SF))
        return -ENXIO;

    local_irq_disable();
    set_bl_bit();
    sh_mobile_call_standby(SUSP_MODE_STANDBY_SF);
    local_irq_disable();
    clear_bl_bit();
    return 0;
}

static const struct platform_suspend_ops sh_pm_ops = {
    .enter          = sh_pm_enter,
    .valid          = suspend_valid_only_mem,
};

static int __init sh_pm_init(void)
{
    suspend_set_ops(&sh_pm_ops);
    sh_mobile_setup_cpuidle();
    return 0;
}

late_initcall(sh_pm_init);