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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Jean Delvare303760b2005-07-31 21:52:01 +02002 hwmon-vid.c - VID/VRM/VRD voltage conversions
Linus Torvalds1da177e2005-04-16 15:20:36 -07003
4 Copyright (c) 2004 Rudolf Marek <r.marek@sh.cvut.cz>
5
Jean Delvared0f28272005-08-01 22:50:08 +02006 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
Linus Torvalds1da177e2005-04-16 15:20:36 -070010 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>
Jean Delvare303760b2005-07-31 21:52:01 +020028#include <linux/hwmon-vid.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070029
Jean Delvared0f28272005-08-01 22:50:08 +020030/*
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)
Rudolf Marek734a12a2005-12-18 16:36:52 +010052
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
Jean Delvared0f28272005-08-01 22:50:08 +020057*/
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. */
Rudolf Marek734a12a2005-12-18 16:36:52 +010062int vid_from_reg(int val, u8 vrm)
Jean Delvared0f28272005-08-01 22:50:08 +020063{
64 int vid;
65
66 switch(vrm) {
67
Jean Delvared0f28272005-08-01 22:50:08 +020068 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 */
Rudolf Marek734a12a2005-12-18 16:36:52 +010096 case 82: /* VRM 8.2 */
Jean Delvared0f28272005-08-01 22:50:08 +020097 return(val == 0x1f ? 0 :
98 val & 0x10 ? 5100 - (val) * 100 :
99 2050 - (val) * 50);
Rudolf Marek734a12a2005-12-18 16:36:52 +0100100 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;
Jean Delvared0f28272005-08-01 22:50:08 +0200106 }
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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115struct vrm_model {
116 u8 vendor;
117 u8 eff_family;
118 u8 eff_model;
Rudolf Marek734a12a2005-12-18 16:36:52 +0100119 u8 eff_stepping;
120 u8 vrm_type;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121};
122
123#define ANY 0xFF
124
125#ifdef CONFIG_X86
126
Rudolf Marek734a12a2005-12-18 16:36:52 +0100127/* the stepping parameter is highest acceptable stepping for current line */
128
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129static struct vrm_model vrm_models[] = {
Rudolf Marek734a12a2005-12-18 16:36:52 +0100130 {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 */
Jean Delvareda97a5a2005-07-31 21:54:28 +0200146};
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147
Rudolf Marek734a12a2005-12-18 16:36:52 +0100148static u8 find_vrm(u8 eff_family, u8 eff_model, u8 eff_stepping, u8 vendor)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149{
150 int i = 0;
151
152 while (vrm_models[i].vendor!=X86_VENDOR_UNKNOWN) {
153 if (vrm_models[i].vendor==vendor)
Jean Delvareda97a5a2005-07-31 21:54:28 +0200154 if ((vrm_models[i].eff_family==eff_family)
155 && ((vrm_models[i].eff_model==eff_model) ||
Rudolf Marek734a12a2005-12-18 16:36:52 +0100156 (vrm_models[i].eff_model==ANY)) &&
157 (eff_stepping <= vrm_models[i].eff_stepping))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158 return vrm_models[i].vrm_type;
159 i++;
160 }
161
162 return 0;
163}
164
Rudolf Marek734a12a2005-12-18 16:36:52 +0100165u8 vid_which_vrm(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166{
167 struct cpuinfo_x86 *c = cpu_data;
168 u32 eax;
Rudolf Marek734a12a2005-12-18 16:36:52 +0100169 u8 eff_family, eff_model, eff_stepping, vrm_ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170
Jean Delvareda97a5a2005-07-31 21:54:28 +0200171 if (c->x86 < 6) /* Any CPU with family lower than 6 */
172 return 0; /* doesn't have VID and/or CPUID */
173
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174 eax = cpuid_eax(1);
175 eff_family = ((eax & 0x00000F00)>>8);
176 eff_model = ((eax & 0x000000F0)>>4);
Rudolf Marek734a12a2005-12-18 16:36:52 +0100177 eff_stepping = eax & 0xF;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178 if (eff_family == 0xF) { /* use extended model & family */
179 eff_family += ((eax & 0x00F00000)>>20);
180 eff_model += ((eax & 0x000F0000)>>16)<<4;
181 }
Rudolf Marek734a12a2005-12-18 16:36:52 +0100182 vrm_ret = find_vrm(eff_family, eff_model, eff_stepping, c->x86_vendor);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183 if (vrm_ret == 0)
Jean Delvareda97a5a2005-07-31 21:54:28 +0200184 printk(KERN_INFO "hwmon-vid: Unknown VRM version of your "
185 "x86 CPU\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186 return vrm_ret;
187}
188
Rudolf Marek734a12a2005-12-18 16:36:52 +0100189/* and now for something completely different for the non-x86 world */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190#else
Rudolf Marek734a12a2005-12-18 16:36:52 +0100191u8 vid_which_vrm(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192{
Jean Delvare303760b2005-07-31 21:52:01 +0200193 printk(KERN_INFO "hwmon-vid: Unknown VRM version of your CPU\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194 return 0;
195}
196#endif
197
Jean Delvared0f28272005-08-01 22:50:08 +0200198EXPORT_SYMBOL(vid_from_reg);
Jean Delvare303760b2005-07-31 21:52:01 +0200199EXPORT_SYMBOL(vid_which_vrm);
Jean Delvare96478ef2005-07-31 21:45:27 +0200200
201MODULE_AUTHOR("Rudolf Marek <r.marek@sh.cvut.cz>");
202
Jean Delvare303760b2005-07-31 21:52:01 +0200203MODULE_DESCRIPTION("hwmon-vid driver");
Jean Delvare96478ef2005-07-31 21:45:27 +0200204MODULE_LICENSE("GPL");