arch/mips/vr41xx/common/bcu.c

   1 /*
   2  *  bcu.c, Bus Control Unit routines for the NEC VR4100 series.
   3  *
   4  *  Copyright (C) 2002  MontaVista Software Inc.
   5  *    Author: Yoichi Yuasa <yyuasa@mvista.com, or source@mvista.com>
   6  *  Copyright (C) 2003-2004  Yoichi Yuasa <yuasa@hh.iij4u.or.jp>
   7  *
   8  *  This program is free software; you can redistribute it and/or modify
   9  *  it under the terms of the GNU General Public License as published by
  10  *  the Free Software Foundation; either version 2 of the License, or
  11  *  (at your option) any later version.
  12  *
  13  *  This program is distributed in the hope that it will be useful,
  14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  *  GNU General Public License for more details.
  17  *
  18  *  You should have received a copy of the GNU General Public License
  19  *  along with this program; if not, write to the Free Software
  20  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  21  */
  22 /*
  23  * Changes:
  24  *  MontaVista Software Inc. <yyuasa@mvista.com> or <source@mvista.com>
  25  *  - New creation, NEC VR4122 and VR4131 are supported.
  26  *  - Added support for NEC VR4111 and VR4121.
  27  *
  28  *  Yoichi Yuasa <yuasa@hh.iij4u.or.jp>
  29  *  - Added support for NEC VR4133.
  30  */
  31 #include <linux/init.h>
  32 #include <linux/ioport.h>
  33 #include <linux/smp.h>
  34 #include <linux/types.h>
  35
  36 #include <asm/cpu.h>
  37 #include <asm/io.h>
  38
  39 #define IO_MEM_RESOURCE_START   0UL
  40 #define IO_MEM_RESOURCE_END     0x1fffffffUL
  41
  42 #define CLKSPEEDREG_TYPE1       KSEG1ADDR(0x0b000014)
  43 #define CLKSPEEDREG_TYPE2       KSEG1ADDR(0x0f000014)
  44  #define CLKSP(x)               ((x) & 0x001f)
  45  #define CLKSP_VR4133(x)        ((x) & 0x0007)
  46
  47  #define DIV2B                  0x8000
  48  #define DIV3B                  0x4000
  49  #define DIV4B                  0x2000
  50
  51  #define DIVT(x)                (((x) & 0xf000) >> 12)
  52  #define DIVVT(x)               (((x) & 0x0f00) >> 8)
  53
  54  #define TDIVMODE(x)            (2 << (((x) & 0x1000) >> 12))
  55  #define VTDIVMODE(x)           (((x) & 0x0700) >> 8)
  56
  57 static unsigned long vr41xx_vtclock;
  58 static unsigned long vr41xx_tclock;
  59
  60 unsigned long vr41xx_get_vtclock_frequency(void)
  61 {
  62         return vr41xx_vtclock;
  63 }
  64
  65 unsigned long vr41xx_get_tclock_frequency(void)
  66 {
  67         return vr41xx_tclock;
  68 }
  69
  70 static inline uint16_t read_clkspeed(void)
  71 {
  72         switch (current_cpu_data.cputype) {
  73         case CPU_VR4111:
  74         case CPU_VR4121: return readw(CLKSPEEDREG_TYPE1);
  75         case CPU_VR4122:
  76         case CPU_VR4131:
  77         case CPU_VR4133: return readw(CLKSPEEDREG_TYPE2);
  78         default:
  79                 printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
  80                 break;
  81         }
  82
  83         return 0;
  84 }
  85
  86 static inline unsigned long calculate_pclock(uint16_t clkspeed)
  87 {
  88         unsigned long pclock = 0;
  89
  90         switch (current_cpu_data.cputype) {
  91         case CPU_VR4111:
  92         case CPU_VR4121:
  93                 pclock = 18432000 * 64;
  94                 pclock /= CLKSP(clkspeed);
  95                 break;
  96         case CPU_VR4122:
  97                 pclock = 18432000 * 98;
  98                 pclock /= CLKSP(clkspeed);
  99                 break;
 100         case CPU_VR4131:
 101                 pclock = 18432000 * 108;
 102                 pclock /= CLKSP(clkspeed);
 103                 break;
 104         case CPU_VR4133:
 105                 switch (CLKSP_VR4133(clkspeed)) {
 106                 case 0:
 107                         pclock = 133000000;
 108                         break;
 109                 case 1:
 110                         pclock = 149000000;
 111                         break;
 112                 case 2:
 113                         pclock = 165900000;
 114                         break;
 115                 case 3:
 116                         pclock = 199100000;
 117                         break;
 118                 case 4:
 119                         pclock = 265900000;
 120                         break;
 121                 default:
 122                         printk(KERN_INFO "Unknown PClock speed for NEC VR4133\n");
 123                         break;
 124                 }
 125                 break;
 126         default:
 127                 printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
 128                 break;
 129         }
 130
 131         printk(KERN_INFO "PClock: %ldHz\n", pclock);
 132
 133         return pclock;
 134 }
 135
 136 static inline unsigned long calculate_vtclock(uint16_t clkspeed, unsigned long pclock)
 137 {
 138         unsigned long vtclock = 0;
 139
 140         switch (current_cpu_data.cputype) {
 141         case CPU_VR4111:
 142                 /* The NEC VR4111 doesn't have the VTClock. */
 143                 break;
 144         case CPU_VR4121:
 145                 vtclock = pclock;
 146                 /* DIVVT == 9 Divide by 1.5 . VTClock = (PClock * 6) / 9 */
 147                 if (DIVVT(clkspeed) == 9)
 148                         vtclock = pclock * 6;
 149                 /* DIVVT == 10 Divide by 2.5 . VTClock = (PClock * 4) / 10 */
 150                 else if (DIVVT(clkspeed) == 10)
 151                         vtclock = pclock * 4;
 152                 vtclock /= DIVVT(clkspeed);
 153                 printk(KERN_INFO "VTClock: %ldHz\n", vtclock);
 154                 break;
 155         case CPU_VR4122:
 156                 if(VTDIVMODE(clkspeed) == 7)
 157                         vtclock = pclock / 1;
 158                 else if(VTDIVMODE(clkspeed) == 1)
 159                         vtclock = pclock / 2;
 160                 else
 161                         vtclock = pclock / VTDIVMODE(clkspeed);
 162                 printk(KERN_INFO "VTClock: %ldHz\n", vtclock);
 163                 break;
 164         case CPU_VR4131:
 165         case CPU_VR4133:
 166                 vtclock = pclock / VTDIVMODE(clkspeed);
 167                 printk(KERN_INFO "VTClock: %ldHz\n", vtclock);
 168                 break;
 169         default:
 170                 printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
 171                 break;
 172         }
 173
 174         return vtclock;
 175 }
 176
 177 static inline unsigned long calculate_tclock(uint16_t clkspeed, unsigned long pclock,
 178                                              unsigned long vtclock)
 179 {
 180         unsigned long tclock = 0;
 181
 182         switch (current_cpu_data.cputype) {
 183         case CPU_VR4111:
 184                 if (!(clkspeed & DIV2B))
 185                         tclock = pclock / 2;
 186                 else if (!(clkspeed & DIV3B))
 187                         tclock = pclock / 3;
 188                 else if (!(clkspeed & DIV4B))
 189                         tclock = pclock / 4;
 190                 break;
 191         case CPU_VR4121:
 192                 tclock = pclock / DIVT(clkspeed);
 193                 break;
 194         case CPU_VR4122:
 195         case CPU_VR4131:
 196         case CPU_VR4133:
 197                 tclock = vtclock / TDIVMODE(clkspeed);
 198                 break;
 199         default:
 200                 printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
 201                 break;
 202         }
 203
 204         printk(KERN_INFO "TClock: %ldHz\n", tclock);
 205
 206         return tclock;
 207 }
 208
 209 static int __init vr41xx_bcu_init(void)
 210 {
 211         unsigned long pclock;
 212         uint16_t clkspeed;
 213
 214         clkspeed = read_clkspeed();
 215
 216         pclock = calculate_pclock(clkspeed);
 217         vr41xx_vtclock = calculate_vtclock(clkspeed, pclock);
 218         vr41xx_tclock = calculate_tclock(clkspeed, pclock, vr41xx_vtclock);
 219
 220         iomem_resource.start = IO_MEM_RESOURCE_START;
 221         iomem_resource.end = IO_MEM_RESOURCE_END;
 222
 223         return 0;
 224 }
 225
 226 early_initcall(vr41xx_bcu_init);