pmu.c

Go to the documentation of this file.

/*
 *  pmu.c, Power Management Unit routines for NEC VR4100 series.
 *
 *  Copyright (C) 2003-2007  Yoichi Yuasa <[email protected]>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/kernel.h>
#include <linux/pm.h>
#include <linux/sched.h>
#include <linux/types.h>

#include <asm/cacheflush.h>
#include <asm/cpu.h>
#include <asm/io.h>
#include <asm/processor.h>
#include <asm/reboot.h>

#define PMU_TYPE1_BASE  0x0b0000a0UL
#define PMU_TYPE1_SIZE  0x0eUL

#define PMU_TYPE2_BASE  0x0f0000c0UL
#define PMU_TYPE2_SIZE  0x10UL

#define PMUCNT2REG  0x06
 #define SOFTRST    0x0010

static void __iomem *pmu_base;

#define pmu_read(offset)        readw(pmu_base + (offset))
#define pmu_write(offset, value)    writew((value), pmu_base + (offset))

static void vr41xx_cpu_wait(void)
{
    local_irq_disable();
    if (!need_resched())
        /*
         * "standby" sets IE bit of the CP0_STATUS to 1.
         */
        __asm__("standby;\n");
    else
        local_irq_enable();
}

static inline void software_reset(void)
{
    uint16_t pmucnt2;

    switch (current_cpu_type()) {
    case CPU_VR4122:
    case CPU_VR4131:
    case CPU_VR4133:
        pmucnt2 = pmu_read(PMUCNT2REG);
        pmucnt2 |= SOFTRST;
        pmu_write(PMUCNT2REG, pmucnt2);
        break;
    default:
        set_c0_status(ST0_BEV | ST0_ERL);
        change_c0_config(CONF_CM_CMASK, CONF_CM_UNCACHED);
        flush_cache_all();
        write_c0_wired(0);
        __asm__("jr     %0"::"r"(0xbfc00000));
        break;
    }
}

static void vr41xx_restart(char *command)
{
    local_irq_disable();
    software_reset();
    while (1) ;
}

static void vr41xx_halt(void)
{
    local_irq_disable();
    printk(KERN_NOTICE "\nYou can turn off the power supply\n");
    __asm__("hibernate;\n");
}

static int __init vr41xx_pmu_init(void)
{
    unsigned long start, size;

    switch (current_cpu_type()) {
    case CPU_VR4111:
    case CPU_VR4121:
        start = PMU_TYPE1_BASE;
        size = PMU_TYPE1_SIZE;
        break;
    case CPU_VR4122:
    case CPU_VR4131:
    case CPU_VR4133:
        start = PMU_TYPE2_BASE;
        size = PMU_TYPE2_SIZE;
        break;
    default:
        printk("Unexpected CPU of NEC VR4100 series\n");
        return -ENODEV;
    }

    if (request_mem_region(start, size, "PMU") == NULL)
        return -EBUSY;

    pmu_base = ioremap(start, size);
    if (pmu_base == NULL) {
        release_mem_region(start, size);
        return -EBUSY;
    }

    cpu_wait = vr41xx_cpu_wait;
    _machine_restart = vr41xx_restart;
    _machine_halt = vr41xx_halt;
    pm_power_off = vr41xx_halt;

    return 0;
}

core_initcall(vr41xx_pmu_init);