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   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) 2003-2005  Yoichi Yuasa <yoichi_yuasa@tripeaks.co.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 <yoichi_yuasa@tripeaks.co.jp>
  29  *  - Added support for NEC VR4133.
  30  */
  31 #include <linux/kernel.h>
  32 #include <linux/module.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 CLKSPEEDREG_TYPE1       (void __iomem *)KSEG1ADDR(0x0b000014)
  40 #define CLKSPEEDREG_TYPE2       (void __iomem *)KSEG1ADDR(0x0f000014)
  41  #define CLKSP(x)               ((x) & 0x001f)
  42  #define CLKSP_VR4133(x)        ((x) & 0x0007)
  43
  44  #define DIV2B                  0x8000
  45  #define DIV3B                  0x4000
  46  #define DIV4B                  0x2000
  47
  48  #define DIVT(x)                (((x) & 0xf000) >> 12)
  49  #define DIVVT(x)               (((x) & 0x0f00) >> 8)
  50
  51  #define TDIVMODE(x)            (2 << (((x) & 0x1000) >> 12))
  52  #define VTDIVMODE(x)           (((x) & 0x0700) >> 8)
  53
  54 static unsigned long vr41xx_vtclock;
  55 static unsigned long vr41xx_tclock;
  56
  57 unsigned long vr41xx_get_vtclock_frequency(void)
  58 {
  59         return vr41xx_vtclock;
  60 }
  61
  62 EXPORT_SYMBOL_GPL(vr41xx_get_vtclock_frequency);
  63
  64 unsigned long vr41xx_get_tclock_frequency(void)
  65 {
  66         return vr41xx_tclock;
  67 }
  68
  69 EXPORT_SYMBOL_GPL(vr41xx_get_tclock_frequency);
  70
  71 static inline uint16_t read_clkspeed(void)
  72 {
  73         switch (current_cpu_type()) {
  74         case CPU_VR4111:
  75         case CPU_VR4121: return readw(CLKSPEEDREG_TYPE1);
  76         case CPU_VR4122:
  77         case CPU_VR4131:
  78         case CPU_VR4133: return readw(CLKSPEEDREG_TYPE2);
  79         default:
  80                 printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
  81                 break;
  82         }
  83
  84         return 0;
  85 }
  86
  87 static inline unsigned long calculate_pclock(uint16_t clkspeed)
  88 {
  89         unsigned long pclock = 0;
  90
  91         switch (current_cpu_type()) {
  92         case CPU_VR4111:
  93         case CPU_VR4121:
  94                 pclock = 18432000 * 64;
  95                 pclock /= CLKSP(clkspeed);
  96                 break;
  97         case CPU_VR4122:
  98                 pclock = 18432000 * 98;
  99                 pclock /= CLKSP(clkspeed);
 100                 break;
 101         case CPU_VR4131:
 102                 pclock = 18432000 * 108;
 103                 pclock /= CLKSP(clkspeed);
 104                 break;
 105         case CPU_VR4133:
 106                 switch (CLKSP_VR4133(clkspeed)) {
 107                 case 0:
 108                         pclock = 133000000;
 109                         break;
 110                 case 1:
 111                         pclock = 149000000;
 112                         break;
 113                 case 2:
 114                         pclock = 165900000;
 115                         break;
 116                 case 3:
 117                         pclock = 199100000;
 118                         break;
 119                 case 4:
 120                         pclock = 265900000;
 121                         break;
 122                 default:
 123                         printk(KERN_INFO "Unknown PClock speed for NEC VR4133\n");
 124                         break;
 125                 }
 126                 break;
 127         default:
 128                 printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
 129                 break;
 130         }
 131
 132         printk(KERN_INFO "PClock: %ldHz\n", pclock);
 133
 134         return pclock;
 135 }
 136
 137 static inline unsigned long calculate_vtclock(uint16_t clkspeed, unsigned long pclock)
 138 {
 139         unsigned long vtclock = 0;
 140
 141         switch (current_cpu_type()) {
 142         case CPU_VR4111:
 143                 /* The NEC VR4111 doesn't have the VTClock. */
 144                 break;
 145         case CPU_VR4121:
 146                 vtclock = pclock;
 147                 /* DIVVT == 9 Divide by 1.5 . VTClock = (PClock * 6) / 9 */
 148                 if (DIVVT(clkspeed) == 9)
 149                         vtclock = pclock * 6;
 150                 /* DIVVT == 10 Divide by 2.5 . VTClock = (PClock * 4) / 10 */
 151                 else if (DIVVT(clkspeed) == 10)
 152                         vtclock = pclock * 4;
 153                 vtclock /= DIVVT(clkspeed);
 154                 printk(KERN_INFO "VTClock: %ldHz\n", vtclock);
 155                 break;
 156         case CPU_VR4122:
 157                 if(VTDIVMODE(clkspeed) == 7)
 158                         vtclock = pclock / 1;
 159                 else if(VTDIVMODE(clkspeed) == 1)
 160                         vtclock = pclock / 2;
 161                 else
 162                         vtclock = pclock / VTDIVMODE(clkspeed);
 163                 printk(KERN_INFO "VTClock: %ldHz\n", vtclock);
 164                 break;
 165         case CPU_VR4131:
 166         case CPU_VR4133:
 167                 vtclock = pclock / VTDIVMODE(clkspeed);
 168                 printk(KERN_INFO "VTClock: %ldHz\n", vtclock);
 169                 break;
 170         default:
 171                 printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
 172                 break;
 173         }
 174
 175         return vtclock;
 176 }
 177
 178 static inline unsigned long calculate_tclock(uint16_t clkspeed, unsigned long pclock,
 179                                              unsigned long vtclock)
 180 {
 181         unsigned long tclock = 0;
 182
 183         switch (current_cpu_type()) {
 184         case CPU_VR4111:
 185                 if (!(clkspeed & DIV2B))
 186                         tclock = pclock / 2;
 187                 else if (!(clkspeed & DIV3B))
 188                         tclock = pclock / 3;
 189                 else if (!(clkspeed & DIV4B))
 190                         tclock = pclock / 4;
 191                 break;
 192         case CPU_VR4121:
 193                 tclock = pclock / DIVT(clkspeed);
 194                 break;
 195         case CPU_VR4122:
 196         case CPU_VR4131:
 197         case CPU_VR4133:
 198                 tclock = vtclock / TDIVMODE(clkspeed);
 199                 break;
 200         default:
 201                 printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
 202                 break;
 203         }
 204
 205         printk(KERN_INFO "TClock: %ldHz\n", tclock);
 206
 207         return tclock;
 208 }
 209
 210 void vr41xx_calculate_clock_frequency(void)
 211 {
 212         unsigned long pclock;
 213         uint16_t clkspeed;
 214
 215         clkspeed = read_clkspeed();
 216
 217         pclock = calculate_pclock(clkspeed);
 218         vr41xx_vtclock = calculate_vtclock(clkspeed, pclock);
 219         vr41xx_tclock = calculate_tclock(clkspeed, pclock, vr41xx_vtclock);
 220 }
 221
 222 EXPORT_SYMBOL_GPL(vr41xx_calculate_clock_frequency);