drivers/hwmon/hwmon-vid.c

   1 /*
   2     hwmon-vid.c - VID/VRM/VRD voltage conversions
   3
   4     Copyright (c) 2004 Rudolf Marek <r.marek@sh.cvut.cz>
   5
   6     Partly imported from i2c-vid.h of the lm_sensors project
   7     Copyright (c) 2002 Mark D. Studebaker <mdsxyz123@yahoo.com>
   8     With assistance from Trent Piepho <xyzzy@speakeasy.org>
   9
  10     This program is free software; you can redistribute it and/or modify
  11     it under the terms of the GNU General Public License as published by
  12     the Free Software Foundation; either version 2 of the License, or
  13     (at your option) any later version.
  14
  15     This program is distributed in the hope that it will be useful,
  16     but WITHOUT ANY WARRANTY; without even the implied warranty of
  17     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18     GNU General Public License for more details.
  19
  20     You should have received a copy of the GNU General Public License
  21     along with this program; if not, write to the Free Software
  22     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  23 */
  24
  25 #include <linux/module.h>
  26 #include <linux/kernel.h>
  27 #include <linux/hwmon-vid.h>
  28
  29 /*
  30     Common code for decoding VID pins.
  31
  32     References:
  33
  34     For VRM 8.4 to 9.1, "VRM x.y DC-DC Converter Design Guidelines",
  35     available at http://developer.intel.com/.
  36
  37     For VRD 10.0 and up, "VRD x.y Design Guide",
  38     available at http://developer.intel.com/.
  39
  40     AMD Opteron processors don't follow the Intel specifications.
  41     I'm going to "make up" 2.4 as the spec number for the Opterons.
  42     No good reason just a mnemonic for the 24x Opteron processor
  43     series.
  44
  45     Opteron VID encoding is:
  46        00000  =  1.550 V
  47        00001  =  1.525 V
  48         . . . .
  49        11110  =  0.800 V
  50        11111  =  0.000 V (off)
  51
  52     The 17 specification is in fact Intel Mobile Voltage Positioning -
  53     (IMVP-II). You can find more information in the datasheet of Max1718
  54     http://www.maxim-ic.com/quick_view2.cfm/qv_pk/2452
  55
  56     The 13 specification corresponds to the Intel Pentium M series. There
  57     doesn't seem to be any named specification for these. The conversion
  58     tables are detailed directly in the various Pentium M datasheets:
  59     http://www.intel.com/design/intarch/pentiumm/docs_pentiumm.htm
  60
  61     The 14 specification corresponds to Intel Core series. There
  62     doesn't seem to be any named specification for these. The conversion
  63     tables are detailed directly in the various Pentium Core datasheets:
  64     http://www.intel.com/design/mobile/datashts/309221.htm
  65
  66     The 110 (VRM 11) specification corresponds to Intel Conroe based series.
  67     http://www.intel.com/design/processor/applnots/313214.htm
  68 */
  69
  70 /* vrm is the VRM/VRD document version multiplied by 10.
  71    val is the 4-bit or more VID code.
  72    Returned value is in mV to avoid floating point in the kernel.
  73    Some VID have some bits in uV scale, this is rounded to mV */
  74 int vid_from_reg(int val, u8 vrm)
  75 {
  76         int vid;
  77
  78         switch(vrm) {
  79
  80         case 100:               /* VRD 10.0 */
  81                 /* compute in uV, round to mV */
  82                 val &= 0x3f;
  83                 if((val & 0x1f) == 0x1f)
  84                         return 0;
  85                 if((val & 0x1f) <= 0x09 || val == 0x0a)
  86                         vid = 1087500 - (val & 0x1f) * 25000;
  87                 else
  88                         vid = 1862500 - (val & 0x1f) * 25000;
  89                 if(val & 0x20)
  90                         vid -= 12500;
  91                 return((vid + 500) / 1000);
  92
  93         case 110:               /* Intel Conroe */
  94                                 /* compute in uV, round to mV */
  95                 val &= 0xff;
  96                 if(((val & 0x7e) == 0xfe) || (!(val & 0x7e)))
  97                         return 0;
  98                 return((1600000 - (val - 2) * 6250 + 500) / 1000);
  99         case 24:                /* Opteron processor */
 100                 val &= 0x1f;
 101                 return(val == 0x1f ? 0 : 1550 - val * 25);
 102
 103         case 91:                /* VRM 9.1 */
 104         case 90:                /* VRM 9.0 */
 105                 val &= 0x1f;
 106                 return(val == 0x1f ? 0 :
 107                                        1850 - val * 25);
 108
 109         case 85:                /* VRM 8.5 */
 110                 val &= 0x1f;
 111                 return((val & 0x10  ? 25 : 0) +
 112                        ((val & 0x0f) > 0x04 ? 2050 : 1250) -
 113                        ((val & 0x0f) * 50));
 114
 115         case 84:                /* VRM 8.4 */
 116                 val &= 0x0f;
 117                                 /* fall through */
 118         case 82:                /* VRM 8.2 */
 119                 val &= 0x1f;
 120                 return(val == 0x1f ? 0 :
 121                        val & 0x10  ? 5100 - (val) * 100 :
 122                                      2050 - (val) * 50);
 123         case 17:                /* Intel IMVP-II */
 124                 val &= 0x1f;
 125                 return(val & 0x10 ? 975 - (val & 0xF) * 25 :
 126                                     1750 - val * 50);
 127         case 13:
 128                 val &= 0x3f;
 129                 return(1708 - val * 16);
 130         case 14:                /* Intel Core */
 131                                 /* compute in uV, round to mV */
 132                 val &= 0x7f;
 133                 return(val > 0x77 ? 0 : (1500000 - (val * 12500) + 500) / 1000);
 134         default:                /* report 0 for unknown */
 135 #ifndef CONFIG_ARM
 136                 printk(KERN_INFO "hwmon-vid: requested unknown VRM version\n");
 137 #endif
 138                 return 0;
 139         }
 140 }
 141
 142
 143 /*
 144     After this point is the code to automatically determine which
 145     VRM/VRD specification should be used depending on the CPU.
 146 */
 147
 148 struct vrm_model {
 149         u8 vendor;
 150         u8 eff_family;
 151         u8 eff_model;
 152         u8 eff_stepping;
 153         u8 vrm_type;
 154 };
 155
 156 #define ANY 0xFF
 157
 158 #ifdef CONFIG_X86
 159
 160 /* the stepping parameter is highest acceptable stepping for current line */
 161
 162 static struct vrm_model vrm_models[] = {
 163         {X86_VENDOR_AMD, 0x6, ANY, ANY, 90},            /* Athlon Duron etc */
 164         {X86_VENDOR_AMD, 0xF, ANY, ANY, 24},            /* Athlon 64, Opteron and above VRM 24 */
 165         {X86_VENDOR_INTEL, 0x6, 0x9, ANY, 13},          /* Pentium M (130 nm) */
 166         {X86_VENDOR_INTEL, 0x6, 0xB, ANY, 85},          /* Tualatin */
 167         {X86_VENDOR_INTEL, 0x6, 0xD, ANY, 13},          /* Pentium M (90 nm) */
 168         {X86_VENDOR_INTEL, 0x6, 0xE, ANY, 14},          /* Intel Core (65 nm) */
 169         {X86_VENDOR_INTEL, 0x6, 0xF, ANY, 110},         /* Intel Conroe */
 170         {X86_VENDOR_INTEL, 0x6, ANY, ANY, 82},          /* any P6 */
 171         {X86_VENDOR_INTEL, 0x7, ANY, ANY, 0},           /* Itanium */
 172         {X86_VENDOR_INTEL, 0xF, 0x0, ANY, 90},          /* P4 */
 173         {X86_VENDOR_INTEL, 0xF, 0x1, ANY, 90},          /* P4 Willamette */
 174         {X86_VENDOR_INTEL, 0xF, 0x2, ANY, 90},          /* P4 Northwood */
 175         {X86_VENDOR_INTEL, 0xF, ANY, ANY, 100},         /* Prescott and above assume VRD 10 */
 176         {X86_VENDOR_INTEL, 0x10, ANY, ANY, 0},          /* Itanium 2 */
 177         {X86_VENDOR_CENTAUR, 0x6, 0x7, ANY, 85},        /* Eden ESP/Ezra */
 178         {X86_VENDOR_CENTAUR, 0x6, 0x8, 0x7, 85},        /* Ezra T */
 179         {X86_VENDOR_CENTAUR, 0x6, 0x9, 0x7, 85},        /* Nemiah */
 180         {X86_VENDOR_CENTAUR, 0x6, 0x9, ANY, 17},        /* C3-M */
 181         {X86_VENDOR_UNKNOWN, ANY, ANY, ANY, 0}          /* stop here */
 182 };
 183
 184 static u8 find_vrm(u8 eff_family, u8 eff_model, u8 eff_stepping, u8 vendor)
 185 {
 186         int i = 0;
 187
 188         while (vrm_models[i].vendor!=X86_VENDOR_UNKNOWN) {
 189                 if (vrm_models[i].vendor==vendor)
 190                         if ((vrm_models[i].eff_family==eff_family)
 191                          && ((vrm_models[i].eff_model==eff_model) ||
 192                              (vrm_models[i].eff_model==ANY)) &&
 193                              (eff_stepping <= vrm_models[i].eff_stepping))
 194                                 return vrm_models[i].vrm_type;
 195                 i++;
 196         }
 197
 198         return 0;
 199 }
 200
 201 u8 vid_which_vrm(void)
 202 {
 203         struct cpuinfo_x86 *c = cpu_data;
 204         u32 eax;
 205         u8 eff_family, eff_model, eff_stepping, vrm_ret;
 206
 207         if (c->x86 < 6)         /* Any CPU with family lower than 6 */
 208                 return 0;       /* doesn't have VID and/or CPUID */
 209
 210         eax = cpuid_eax(1);
 211         eff_family = ((eax & 0x00000F00)>>8);
 212         eff_model  = ((eax & 0x000000F0)>>4);
 213         eff_stepping = eax & 0xF;
 214         if (eff_family == 0xF) {        /* use extended model & family */
 215                 eff_family += ((eax & 0x00F00000)>>20);
 216                 eff_model += ((eax & 0x000F0000)>>16)<<4;
 217         }
 218         vrm_ret = find_vrm(eff_family, eff_model, eff_stepping, c->x86_vendor);
 219         if (vrm_ret == 0)
 220                 printk(KERN_INFO "hwmon-vid: Unknown VRM version of your "
 221                        "x86 CPU\n");
 222         return vrm_ret;
 223 }
 224
 225 /* and now for something completely different for the non-x86 world */
 226 #else
 227 u8 vid_which_vrm(void)
 228 {
 229         printk(KERN_INFO "hwmon-vid: Unknown VRM version of your CPU\n");
 230         return 0;
 231 }
 232 #endif
 233
 234 EXPORT_SYMBOL(vid_from_reg);
 235 EXPORT_SYMBOL(vid_which_vrm);
 236
 237 MODULE_AUTHOR("Rudolf Marek <r.marek@sh.cvut.cz>");
 238
 239 MODULE_DESCRIPTION("hwmon-vid driver");
 240 MODULE_LICENSE("GPL");