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/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
  44 static 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
  49 static 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
  61 static 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
  83 static void vr41xx_restart(char *command)
  84 {
  85         local_irq_disable();
  86         software_reset();
  87         while (1) ;
  88 }
  89
  90 static 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
  97 static 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
 135 core_initcall(vr41xx_pmu_init);