LXR linux/arch/mips/vr41xx/common/pmu.c

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 *  pmu.c, Power Management Unit routines for NEC VR4100 series.
   4 *
   5 *  Copyright (C) 2003-2007  Yoichi Yuasa <yuasa@linux-mips.org>
   6 */
   7#include <linux/cpu.h>
   8#include <linux/errno.h>
   9#include <linux/init.h>
  10#include <linux/ioport.h>
  11#include <linux/kernel.h>
  12#include <linux/pm.h>
  13#include <linux/sched.h>
  14#include <linux/types.h>
  15
  16#include <asm/cacheflush.h>
  17#include <asm/cpu.h>
  18#include <asm/idle.h>
  19#include <asm/io.h>
  20#include <asm/processor.h>
  21#include <asm/reboot.h>
  22
  23#define PMU_TYPE1_BASE  0x0b0000a0UL
  24#define PMU_TYPE1_SIZE  0x0eUL
  25
  26#define PMU_TYPE2_BASE  0x0f0000c0UL
  27#define PMU_TYPE2_SIZE  0x10UL
  28
  29#define PMUCNT2REG      0x06
  30 #define SOFTRST        0x0010
  31
  32static void __iomem *pmu_base;
  33
  34#define pmu_read(offset)                readw(pmu_base + (offset))
  35#define pmu_write(offset, value)        writew((value), pmu_base + (offset))
  36
  37static void __cpuidle vr41xx_cpu_wait(void)
  38{
  39        local_irq_disable();
  40        if (!need_resched())
  41                /*
  42                 * "standby" sets IE bit of the CP0_STATUS to 1.
  43                 */
  44                __asm__("standby;\n");
  45        else
  46                local_irq_enable();
  47}
  48
  49static inline void software_reset(void)
  50{
  51        uint16_t pmucnt2;
  52
  53        switch (current_cpu_type()) {
  54        case CPU_VR4122:
  55        case CPU_VR4131:
  56        case CPU_VR4133:
  57                pmucnt2 = pmu_read(PMUCNT2REG);
  58                pmucnt2 |= SOFTRST;
  59                pmu_write(PMUCNT2REG, pmucnt2);
  60                break;
  61        default:
  62                set_c0_status(ST0_BEV | ST0_ERL);
  63                change_c0_config(CONF_CM_CMASK, CONF_CM_UNCACHED);
  64                __flush_cache_all();
  65                write_c0_wired(0);
  66                __asm__("jr     %0"::"r"(0xbfc00000));
  67                break;
  68        }
  69}
  70
  71static void vr41xx_restart(char *command)
  72{
  73        local_irq_disable();
  74        software_reset();
  75        while (1) ;
  76}
  77
  78static void vr41xx_halt(void)
  79{
  80        local_irq_disable();
  81        printk(KERN_NOTICE "\nYou can turn off the power supply\n");
  82        __asm__("hibernate;\n");
  83}
  84
  85static int __init vr41xx_pmu_init(void)
  86{
  87        unsigned long start, size;
  88
  89        switch (current_cpu_type()) {
  90        case CPU_VR4111:
  91        case CPU_VR4121:
  92                start = PMU_TYPE1_BASE;
  93                size = PMU_TYPE1_SIZE;
  94                break;
  95        case CPU_VR4122:
  96        case CPU_VR4131:
  97        case CPU_VR4133:
  98                start = PMU_TYPE2_BASE;
  99                size = PMU_TYPE2_SIZE;
 100                break;
 101        default:
 102                printk("Unexpected CPU of NEC VR4100 series\n");
 103                return -ENODEV;
 104        }
 105
 106        if (request_mem_region(start, size, "PMU") == NULL)
 107                return -EBUSY;
 108
 109        pmu_base = ioremap(start, size);
 110        if (pmu_base == NULL) {
 111                release_mem_region(start, size);
 112                return -EBUSY;
 113        }
 114
 115        cpu_wait = vr41xx_cpu_wait;
 116        _machine_restart = vr41xx_restart;
 117        _machine_halt = vr41xx_halt;
 118        pm_power_off = vr41xx_halt;
 119
 120        return 0;
 121}
 122
 123core_initcall(vr41xx_pmu_init);
 124