linux/arch/mips/vr41xx/common/pmu.c
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   1/*
   2 *  pmu.c, Power Management Unit routines for NEC VR4100 series.
   3 *
   4 *  Copyright (C) 2003-2007  Yoichi Yuasa <yuasa@linux-mips.org>
   5 *
   6 *  This program is free software; you can redistribute it and/or modify
   7 *  it under the terms of the GNU General Public License as published by
   8 *  the Free Software Foundation; either version 2 of the License, or
   9 *  (at your option) any later version.
  10 *
  11 *  This program is distributed in the hope that it will be useful,
  12 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 *  GNU General Public License for more details.
  15 *
  16 *  You should have received a copy of the GNU General Public License
  17 *  along with this program; if not, write to the Free Software
  18 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19 */
  20#include <linux/errno.h>
  21#include <linux/init.h>
  22#include <linux/ioport.h>
  23#include <linux/kernel.h>
  24#include <linux/pm.h>
  25#include <linux/sched.h>
  26#include <linux/types.h>
  27
  28#include <asm/cacheflush.h>
  29#include <asm/cpu.h>
  30#include <asm/io.h>
  31#include <asm/processor.h>
  32#include <asm/reboot.h>
  33#include <asm/system.h>
  34
  35#define PMU_TYPE1_BASE  0x0b0000a0UL
  36#define PMU_TYPE1_SIZE  0x0eUL
  37
  38#define PMU_TYPE2_BASE  0x0f0000c0UL
  39#define PMU_TYPE2_SIZE  0x10UL
  40
  41#define PMUCNT2REG      0x06
  42 #define SOFTRST        0x0010
  43
  44static void __iomem *pmu_base;
  45
  46#define pmu_read(offset)                readw(pmu_base + (offset))
  47#define pmu_write(offset, value)        writew((value), pmu_base + (offset))
  48
  49static void vr41xx_cpu_wait(void)
  50{
  51        local_irq_disable();
  52        if (!need_resched())
  53                /*
  54                 * "standby" sets IE bit of the CP0_STATUS to 1.
  55                 */
  56                __asm__("standby;\n");
  57        else
  58                local_irq_enable();
  59}
  60
  61static inline void software_reset(void)
  62{
  63        uint16_t pmucnt2;
  64
  65        switch (current_cpu_type()) {
  66        case CPU_VR4122:
  67        case CPU_VR4131:
  68        case CPU_VR4133:
  69                pmucnt2 = pmu_read(PMUCNT2REG);
  70                pmucnt2 |= SOFTRST;
  71                pmu_write(PMUCNT2REG, pmucnt2);
  72                break;
  73        default:
  74                set_c0_status(ST0_BEV | ST0_ERL);
  75                change_c0_config(CONF_CM_CMASK, CONF_CM_UNCACHED);
  76                flush_cache_all();
  77                write_c0_wired(0);
  78                __asm__("jr     %0"::"r"(0xbfc00000));
  79                break;
  80        }
  81}
  82
  83static void vr41xx_restart(char *command)
  84{
  85        local_irq_disable();
  86        software_reset();
  87        while (1) ;
  88}
  89
  90static void vr41xx_halt(void)
  91{
  92        local_irq_disable();
  93        printk(KERN_NOTICE "\nYou can turn off the power supply\n");
  94        __asm__("hibernate;\n");
  95}
  96
  97static int __init vr41xx_pmu_init(void)
  98{
  99        unsigned long start, size;
 100
 101        switch (current_cpu_type()) {
 102        case CPU_VR4111:
 103        case CPU_VR4121:
 104                start = PMU_TYPE1_BASE;
 105                size = PMU_TYPE1_SIZE;
 106                break;
 107        case CPU_VR4122:
 108        case CPU_VR4131:
 109        case CPU_VR4133:
 110                start = PMU_TYPE2_BASE;
 111                size = PMU_TYPE2_SIZE;
 112                break;
 113        default:
 114                printk("Unexpected CPU of NEC VR4100 series\n");
 115                return -ENODEV;
 116        }
 117
 118        if (request_mem_region(start, size, "PMU") == NULL)
 119                return -EBUSY;
 120
 121        pmu_base = ioremap(start, size);
 122        if (pmu_base == NULL) {
 123                release_mem_region(start, size);
 124                return -EBUSY;
 125        }
 126
 127        cpu_wait = vr41xx_cpu_wait;
 128        _machine_restart = vr41xx_restart;
 129        _machine_halt = vr41xx_halt;
 130        pm_power_off = vr41xx_halt;
 131
 132        return 0;
 133}
 134
 135core_initcall(vr41xx_pmu_init);
 136