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/config.h> 26 #include <linux/module.h> 27 #include <linux/kernel.h> 28 #include <linux/hwmon-vid.h> 29 30 /* 31 Common code for decoding VID pins. 32 33 References: 34 35 For VRM 8.4 to 9.1, "VRM x.y DC-DC Converter Design Guidelines", 36 available at http://developer.intel.com/. 37 38 For VRD 10.0 and up, "VRD x.y Design Guide", 39 available at http://developer.intel.com/. 40 41 AMD Opteron processors don't follow the Intel specifications. 42 I'm going to "make up" 2.4 as the spec number for the Opterons. 43 No good reason just a mnemonic for the 24x Opteron processor 44 series. 45 46 Opteron VID encoding is: 47 00000 = 1.550 V 48 00001 = 1.525 V 49 . . . . 50 11110 = 0.800 V 51 11111 = 0.000 V (off) 52 53 The 17 specification is in fact Intel Mobile Voltage Positioning - 54 (IMVP-II). You can find more information in the datasheet of Max1718 55 http://www.maxim-ic.com/quick_view2.cfm/qv_pk/2452 56 57 The 13 specification corresponds to the Intel Pentium M series. There 58 doesn't seem to be any named specification for these. The conversion 59 tables are detailed directly in the various Pentium M datasheets: 60 http://www.intel.com/design/intarch/pentiumm/docs_pentiumm.htm 61 */ 62 63 /* vrm is the VRM/VRD document version multiplied by 10. 64 val is the 4-, 5- or 6-bit VID code. 65 Returned value is in mV to avoid floating point in the kernel. */ 66 int vid_from_reg(int val, u8 vrm) 67 { 68 int vid; 69 70 switch(vrm) { 71 72 case 100: /* VRD 10.0 */ 73 if((val & 0x1f) == 0x1f) 74 return 0; 75 if((val & 0x1f) <= 0x09 || val == 0x0a) 76 vid = 10875 - (val & 0x1f) * 250; 77 else 78 vid = 18625 - (val & 0x1f) * 250; 79 if(val & 0x20) 80 vid -= 125; 81 vid /= 10; /* only return 3 dec. places for now */ 82 return vid; 83 84 case 24: /* Opteron processor */ 85 return(val == 0x1f ? 0 : 1550 - val * 25); 86 87 case 91: /* VRM 9.1 */ 88 case 90: /* VRM 9.0 */ 89 return(val == 0x1f ? 0 : 90 1850 - val * 25); 91 92 case 85: /* VRM 8.5 */ 93 return((val & 0x10 ? 25 : 0) + 94 ((val & 0x0f) > 0x04 ? 2050 : 1250) - 95 ((val & 0x0f) * 50)); 96 97 case 84: /* VRM 8.4 */ 98 val &= 0x0f; 99 /* fall through */ 100 case 82: /* VRM 8.2 */ 101 return(val == 0x1f ? 0 : 102 val & 0x10 ? 5100 - (val) * 100 : 103 2050 - (val) * 50); 104 case 17: /* Intel IMVP-II */ 105 return(val & 0x10 ? 975 - (val & 0xF) * 25 : 106 1750 - val * 50); 107 case 13: 108 return(1708 - (val & 0x3f) * 16); 109 default: /* report 0 for unknown */ 110 printk(KERN_INFO "hwmon-vid: requested unknown VRM version\n"); 111 return 0; 112 } 113 } 114 115 116 /* 117 After this point is the code to automatically determine which 118 VRM/VRD specification should be used depending on the CPU. 119 */ 120 121 struct vrm_model { 122 u8 vendor; 123 u8 eff_family; 124 u8 eff_model; 125 u8 eff_stepping; 126 u8 vrm_type; 127 }; 128 129 #define ANY 0xFF 130 131 #ifdef CONFIG_X86 132 133 /* the stepping parameter is highest acceptable stepping for current line */ 134 135 static struct vrm_model vrm_models[] = { 136 {X86_VENDOR_AMD, 0x6, ANY, ANY, 90}, /* Athlon Duron etc */ 137 {X86_VENDOR_AMD, 0xF, ANY, ANY, 24}, /* Athlon 64, Opteron and above VRM 24 */ 138 {X86_VENDOR_INTEL, 0x6, 0x9, ANY, 13}, /* Pentium M (130 nm) */ 139 {X86_VENDOR_INTEL, 0x6, 0xB, ANY, 85}, /* Tualatin */ 140 {X86_VENDOR_INTEL, 0x6, 0xD, ANY, 13}, /* Pentium M (90 nm) */ 141 {X86_VENDOR_INTEL, 0x6, ANY, ANY, 82}, /* any P6 */ 142 {X86_VENDOR_INTEL, 0x7, ANY, ANY, 0}, /* Itanium */ 143 {X86_VENDOR_INTEL, 0xF, 0x0, ANY, 90}, /* P4 */ 144 {X86_VENDOR_INTEL, 0xF, 0x1, ANY, 90}, /* P4 Willamette */ 145 {X86_VENDOR_INTEL, 0xF, 0x2, ANY, 90}, /* P4 Northwood */ 146 {X86_VENDOR_INTEL, 0xF, ANY, ANY, 100}, /* Prescott and above assume VRD 10 */ 147 {X86_VENDOR_INTEL, 0x10, ANY, ANY, 0}, /* Itanium 2 */ 148 {X86_VENDOR_CENTAUR, 0x6, 0x7, ANY, 85}, /* Eden ESP/Ezra */ 149 {X86_VENDOR_CENTAUR, 0x6, 0x8, 0x7, 85}, /* Ezra T */ 150 {X86_VENDOR_CENTAUR, 0x6, 0x9, 0x7, 85}, /* Nemiah */ 151 {X86_VENDOR_CENTAUR, 0x6, 0x9, ANY, 17}, /* C3-M */ 152 {X86_VENDOR_UNKNOWN, ANY, ANY, ANY, 0} /* stop here */ 153 }; 154 155 static u8 find_vrm(u8 eff_family, u8 eff_model, u8 eff_stepping, u8 vendor) 156 { 157 int i = 0; 158 159 while (vrm_models[i].vendor!=X86_VENDOR_UNKNOWN) { 160 if (vrm_models[i].vendor==vendor) 161 if ((vrm_models[i].eff_family==eff_family) 162 && ((vrm_models[i].eff_model==eff_model) || 163 (vrm_models[i].eff_model==ANY)) && 164 (eff_stepping <= vrm_models[i].eff_stepping)) 165 return vrm_models[i].vrm_type; 166 i++; 167 } 168 169 return 0; 170 } 171 172 u8 vid_which_vrm(void) 173 { 174 struct cpuinfo_x86 *c = cpu_data; 175 u32 eax; 176 u8 eff_family, eff_model, eff_stepping, vrm_ret; 177 178 if (c->x86 < 6) /* Any CPU with family lower than 6 */ 179 return 0; /* doesn't have VID and/or CPUID */ 180 181 eax = cpuid_eax(1); 182 eff_family = ((eax & 0x00000F00)>>8); 183 eff_model = ((eax & 0x000000F0)>>4); 184 eff_stepping = eax & 0xF; 185 if (eff_family == 0xF) { /* use extended model & family */ 186 eff_family += ((eax & 0x00F00000)>>20); 187 eff_model += ((eax & 0x000F0000)>>16)<<4; 188 } 189 vrm_ret = find_vrm(eff_family, eff_model, eff_stepping, c->x86_vendor); 190 if (vrm_ret == 0) 191 printk(KERN_INFO "hwmon-vid: Unknown VRM version of your " 192 "x86 CPU\n"); 193 return vrm_ret; 194 } 195 196 /* and now for something completely different for the non-x86 world */ 197 #else 198 u8 vid_which_vrm(void) 199 { 200 printk(KERN_INFO "hwmon-vid: Unknown VRM version of your CPU\n"); 201 return 0; 202 } 203 #endif 204 205 EXPORT_SYMBOL(vid_from_reg); 206 EXPORT_SYMBOL(vid_which_vrm); 207 208 MODULE_AUTHOR("Rudolf Marek <r.marek@sh.cvut.cz>"); 209 210 MODULE_DESCRIPTION("hwmon-vid driver"); 211 MODULE_LICENSE("GPL"); 212