arch/mips/vr41xx/common/pmu.c

   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/cpu.h>
  21 #include <linux/errno.h>
  22 #include <linux/init.h>
  23 #include <linux/ioport.h>
  24 #include <linux/kernel.h>
  25 #include <linux/pm.h>
  26 #include <linux/sched.h>
  27 #include <linux/types.h>
  28
  29 #include <asm/cacheflush.h>
  30 #include <asm/cpu.h>
  31 #include <asm/idle.h>
  32 #include <asm/io.h>
  33 #include <asm/processor.h>
  34 #include <asm/reboot.h>
  35
  36 #define PMU_TYPE1_BASE  0x0b0000a0UL
  37 #define PMU_TYPE1_SIZE  0x0eUL
  38
  39 #define PMU_TYPE2_BASE  0x0f0000c0UL
  40 #define PMU_TYPE2_SIZE  0x10UL
  41
  42 #define PMUCNT2REG      0x06
  43  #define SOFTRST        0x0010
  44
  45 static void __iomem *pmu_base;
  46
  47 #define pmu_read(offset)                readw(pmu_base + (offset))
  48 #define pmu_write(offset, value)        writew((value), pmu_base + (offset))
  49
  50 static void __cpuidle vr41xx_cpu_wait(void)
  51 {
  52         local_irq_disable();
  53         if (!need_resched())
  54                 /*
  55                  * "standby" sets IE bit of the CP0_STATUS to 1.
  56                  */
  57                 __asm__("standby;\n");
  58         else
  59                 local_irq_enable();
  60 }
  61
  62 static inline void software_reset(void)
  63 {
  64         uint16_t pmucnt2;
  65
  66         switch (current_cpu_type()) {
  67         case CPU_VR4122:
  68         case CPU_VR4131:
  69         case CPU_VR4133:
  70                 pmucnt2 = pmu_read(PMUCNT2REG);
  71                 pmucnt2 |= SOFTRST;
  72                 pmu_write(PMUCNT2REG, pmucnt2);
  73                 break;
  74         default:
  75                 set_c0_status(ST0_BEV | ST0_ERL);
  76                 change_c0_config(CONF_CM_CMASK, CONF_CM_UNCACHED);
  77                 __flush_cache_all();
  78                 write_c0_wired(0);
  79                 __asm__("jr     %0"::"r"(0xbfc00000));
  80                 break;
  81         }
  82 }
  83
  84 static void vr41xx_restart(char *command)
  85 {
  86         local_irq_disable();
  87         software_reset();
  88         while (1) ;
  89 }
  90
  91 static void vr41xx_halt(void)
  92 {
  93         local_irq_disable();
  94         printk(KERN_NOTICE "\nYou can turn off the power supply\n");
  95         __asm__("hibernate;\n");
  96 }
  97
  98 static int __init vr41xx_pmu_init(void)
  99 {
 100         unsigned long start, size;
 101
 102         switch (current_cpu_type()) {
 103         case CPU_VR4111:
 104         case CPU_VR4121:
 105                 start = PMU_TYPE1_BASE;
 106                 size = PMU_TYPE1_SIZE;
 107                 break;
 108         case CPU_VR4122:
 109         case CPU_VR4131:
 110         case CPU_VR4133:
 111                 start = PMU_TYPE2_BASE;
 112                 size = PMU_TYPE2_SIZE;
 113                 break;
 114         default:
 115                 printk("Unexpected CPU of NEC VR4100 series\n");
 116                 return -ENODEV;
 117         }
 118
 119         if (request_mem_region(start, size, "PMU") == NULL)
 120                 return -EBUSY;
 121
 122         pmu_base = ioremap(start, size);
 123         if (pmu_base == NULL) {
 124                 release_mem_region(start, size);
 125                 return -EBUSY;
 126         }
 127
 128         cpu_wait = vr41xx_cpu_wait;
 129         _machine_restart = vr41xx_restart;
 130         _machine_halt = vr41xx_halt;
 131         pm_power_off = vr41xx_halt;
 132
 133         return 0;
 134 }
 135
 136 core_initcall(vr41xx_pmu_init);