drivers/hwmon/hwmon-vid.c

   1 /*
   2  * hwmon-vid.c - VID/VRM/VRD voltage conversions
   3  *
   4  * Copyright (c) 2004 Rudolf Marek <r.marek@assembler.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 NPT 0Fh (Athlon64 & Opteron), AMD Publication 32559,
  41  * http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/32559.pdf
  42  * Table 71. VID Code Voltages
  43  * AMD Opteron processors don't follow the Intel specifications.
  44  * I'm going to "make up" 2.4 as the spec number for the Opterons.
  45  * No good reason just a mnemonic for the 24x Opteron processor
  46  * series.
  47  *
  48  * The 17 specification is in fact Intel Mobile Voltage Positioning -
  49  * (IMVP-II). You can find more information in the datasheet of Max1718
  50  * http://www.maxim-ic.com/quick_view2.cfm/qv_pk/2452
  51  *
  52  * The 13 specification corresponds to the Intel Pentium M series. There
  53  * doesn't seem to be any named specification for these. The conversion
  54  * tables are detailed directly in the various Pentium M datasheets:
  55  * http://www.intel.com/design/intarch/pentiumm/docs_pentiumm.htm
  56  *
  57  * The 14 specification corresponds to Intel Core series. There
  58  * doesn't seem to be any named specification for these. The conversion
  59  * tables are detailed directly in the various Pentium Core datasheets:
  60  * http://www.intel.com/design/mobile/datashts/309221.htm
  61  *
  62  * The 110 (VRM 11) specification corresponds to Intel Conroe based series.
  63  * http://www.intel.com/design/processor/applnots/313214.htm
  64  */
  65
  66 /*
  67  * vrm is the VRM/VRD document version multiplied by 10.
  68  * val is the 4-bit or more VID code.
  69  * Returned value is in mV to avoid floating point in the kernel.
  70  * Some VID have some bits in uV scale, this is rounded to mV.
  71  */
  72 int vid_from_reg(int val, u8 vrm)
  73 {
  74         int vid;
  75
  76         switch(vrm) {
  77
  78         case 100:               /* VRD 10.0 */
  79                 /* compute in uV, round to mV */
  80                 val &= 0x3f;
  81                 if((val & 0x1f) == 0x1f)
  82                         return 0;
  83                 if((val & 0x1f) <= 0x09 || val == 0x0a)
  84                         vid = 1087500 - (val & 0x1f) * 25000;
  85                 else
  86                         vid = 1862500 - (val & 0x1f) * 25000;
  87                 if(val & 0x20)
  88                         vid -= 12500;
  89                 return((vid + 500) / 1000);
  90
  91         case 110:               /* Intel Conroe */
  92                                 /* compute in uV, round to mV */
  93                 val &= 0xff;
  94                 if (val < 0x02 || val > 0xb2)
  95                         return 0;
  96                 return((1600000 - (val - 2) * 6250 + 500) / 1000);
  97
  98         case 24:                /* AMD NPT 0Fh (Athlon64 & Opteron) */
  99                 val &= 0x3f;
 100                 return (val < 32) ? 1550 - 25 * val
 101                         : 775 - (25 * (val - 31)) / 2;
 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                 if (vrm)
 136                         printk(KERN_WARNING "hwmon-vid: Requested unsupported "
 137                                "VRM version (%u)\n", (unsigned int)vrm);
 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, 0xF, 0x0, ANY, 90},          /* P4 */
 172         {X86_VENDOR_INTEL, 0xF, 0x1, ANY, 90},          /* P4 Willamette */
 173         {X86_VENDOR_INTEL, 0xF, 0x2, ANY, 90},          /* P4 Northwood */
 174         {X86_VENDOR_INTEL, 0xF, ANY, ANY, 100},         /* Prescott and above assume VRD 10 */
 175         {X86_VENDOR_CENTAUR, 0x6, 0x7, ANY, 85},        /* Eden ESP/Ezra */
 176         {X86_VENDOR_CENTAUR, 0x6, 0x8, 0x7, 85},        /* Ezra T */
 177         {X86_VENDOR_CENTAUR, 0x6, 0x9, 0x7, 85},        /* Nemiah */
 178         {X86_VENDOR_CENTAUR, 0x6, 0x9, ANY, 17},        /* C3-M, Eden-N */
 179         {X86_VENDOR_CENTAUR, 0x6, 0xA, 0x7, 0},         /* No information */
 180         {X86_VENDOR_CENTAUR, 0x6, 0xA, ANY, 13},        /* C7, Esther */
 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(0);
 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@assembler.cz>");
 238
 239 MODULE_DESCRIPTION("hwmon-vid driver");
 240 MODULE_LICENSE("GPL");