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 */ 58 59 /* vrm is the VRM/VRD document version multiplied by 10. 60 val is the 4-, 5- or 6-bit VID code. 61 Returned value is in mV to avoid floating point in the kernel. */ 62 int vid_from_reg(int val, u8 vrm) 63 { 64 int vid; 65 66 switch(vrm) { 67 68 case 100: /* VRD 10.0 */ 69 if((val & 0x1f) == 0x1f) 70 return 0; 71 if((val & 0x1f) <= 0x09 || val == 0x0a) 72 vid = 10875 - (val & 0x1f) * 250; 73 else 74 vid = 18625 - (val & 0x1f) * 250; 75 if(val & 0x20) 76 vid -= 125; 77 vid /= 10; /* only return 3 dec. places for now */ 78 return vid; 79 80 case 24: /* Opteron processor */ 81 return(val == 0x1f ? 0 : 1550 - val * 25); 82 83 case 91: /* VRM 9.1 */ 84 case 90: /* VRM 9.0 */ 85 return(val == 0x1f ? 0 : 86 1850 - val * 25); 87 88 case 85: /* VRM 8.5 */ 89 return((val & 0x10 ? 25 : 0) + 90 ((val & 0x0f) > 0x04 ? 2050 : 1250) - 91 ((val & 0x0f) * 50)); 92 93 case 84: /* VRM 8.4 */ 94 val &= 0x0f; 95 /* fall through */ 96 case 82: /* VRM 8.2 */ 97 return(val == 0x1f ? 0 : 98 val & 0x10 ? 5100 - (val) * 100 : 99 2050 - (val) * 50); 100 case 17: /* Intel IMVP-II */ 101 return(val & 0x10 ? 975 - (val & 0xF) * 25 : 102 1750 - val * 50); 103 default: /* report 0 for unknown */ 104 printk(KERN_INFO "hwmon-vid: requested unknown VRM version\n"); 105 return 0; 106 } 107 } 108 109 110 /* 111 After this point is the code to automatically determine which 112 VRM/VRD specification should be used depending on the CPU. 113 */ 114 115 struct vrm_model { 116 u8 vendor; 117 u8 eff_family; 118 u8 eff_model; 119 u8 eff_stepping; 120 u8 vrm_type; 121 }; 122 123 #define ANY 0xFF 124 125 #ifdef CONFIG_X86 126 127 /* the stepping parameter is highest acceptable stepping for current line */ 128 129 static struct vrm_model vrm_models[] = { 130 {X86_VENDOR_AMD, 0x6, ANY, ANY, 90}, /* Athlon Duron etc */ 131 {X86_VENDOR_AMD, 0xF, ANY, ANY, 24}, /* Athlon 64, Opteron and above VRM 24 */ 132 {X86_VENDOR_INTEL, 0x6, 0x9, ANY, 85}, /* 0.13um too */ 133 {X86_VENDOR_INTEL, 0x6, 0xB, ANY, 85}, /* Tualatin */ 134 {X86_VENDOR_INTEL, 0x6, ANY, ANY, 82}, /* any P6 */ 135 {X86_VENDOR_INTEL, 0x7, ANY, ANY, 0}, /* Itanium */ 136 {X86_VENDOR_INTEL, 0xF, 0x0, ANY, 90}, /* P4 */ 137 {X86_VENDOR_INTEL, 0xF, 0x1, ANY, 90}, /* P4 Willamette */ 138 {X86_VENDOR_INTEL, 0xF, 0x2, ANY, 90}, /* P4 Northwood */ 139 {X86_VENDOR_INTEL, 0xF, ANY, ANY, 100}, /* Prescott and above assume VRD 10 */ 140 {X86_VENDOR_INTEL, 0x10, ANY, ANY, 0}, /* Itanium 2 */ 141 {X86_VENDOR_CENTAUR, 0x6, 0x7, ANY, 85}, /* Eden ESP/Ezra */ 142 {X86_VENDOR_CENTAUR, 0x6, 0x8, 0x7, 85}, /* Ezra T */ 143 {X86_VENDOR_CENTAUR, 0x6, 0x9, 0x7, 85}, /* Nemiah */ 144 {X86_VENDOR_CENTAUR, 0x6, 0x9, ANY, 17}, /* C3-M */ 145 {X86_VENDOR_UNKNOWN, ANY, ANY, ANY, 0} /* stop here */ 146 }; 147 148 static u8 find_vrm(u8 eff_family, u8 eff_model, u8 eff_stepping, u8 vendor) 149 { 150 int i = 0; 151 152 while (vrm_models[i].vendor!=X86_VENDOR_UNKNOWN) { 153 if (vrm_models[i].vendor==vendor) 154 if ((vrm_models[i].eff_family==eff_family) 155 && ((vrm_models[i].eff_model==eff_model) || 156 (vrm_models[i].eff_model==ANY)) && 157 (eff_stepping <= vrm_models[i].eff_stepping)) 158 return vrm_models[i].vrm_type; 159 i++; 160 } 161 162 return 0; 163 } 164 165 u8 vid_which_vrm(void) 166 { 167 struct cpuinfo_x86 *c = cpu_data; 168 u32 eax; 169 u8 eff_family, eff_model, eff_stepping, vrm_ret; 170 171 if (c->x86 < 6) /* Any CPU with family lower than 6 */ 172 return 0; /* doesn't have VID and/or CPUID */ 173 174 eax = cpuid_eax(1); 175 eff_family = ((eax & 0x00000F00)>>8); 176 eff_model = ((eax & 0x000000F0)>>4); 177 eff_stepping = eax & 0xF; 178 if (eff_family == 0xF) { /* use extended model & family */ 179 eff_family += ((eax & 0x00F00000)>>20); 180 eff_model += ((eax & 0x000F0000)>>16)<<4; 181 } 182 vrm_ret = find_vrm(eff_family, eff_model, eff_stepping, c->x86_vendor); 183 if (vrm_ret == 0) 184 printk(KERN_INFO "hwmon-vid: Unknown VRM version of your " 185 "x86 CPU\n"); 186 return vrm_ret; 187 } 188 189 /* and now for something completely different for the non-x86 world */ 190 #else 191 u8 vid_which_vrm(void) 192 { 193 printk(KERN_INFO "hwmon-vid: Unknown VRM version of your CPU\n"); 194 return 0; 195 } 196 #endif 197 198 EXPORT_SYMBOL(vid_from_reg); 199 EXPORT_SYMBOL(vid_which_vrm); 200 201 MODULE_AUTHOR("Rudolf Marek <r.marek@sh.cvut.cz>"); 202 203 MODULE_DESCRIPTION("hwmon-vid driver"); 204 MODULE_LICENSE("GPL"); 205