2 hwmon-vid.c - VID/VRM/VRD voltage conversions
4 Copyright (c) 2004 Rudolf Marek <r.marek@sh.cvut.cz>
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>
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.
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.
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.
25 #include <linux/module.h>
26 #include <linux/kernel.h>
27 #include <linux/hwmon-vid.h>
30 Common code for decoding VID pins.
34 For VRM 8.4 to 9.1, "VRM x.y DC-DC Converter Design Guidelines",
35 available at http://developer.intel.com/.
37 For VRD 10.0 and up, "VRD x.y Design Guide",
38 available at http://developer.intel.com/.
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
45 Opteron VID encoding is:
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
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
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
66 The 110 (VRM 11) specification corresponds to Intel Conroe based series.
67 http://www.intel.com/design/processor/applnots/313214.htm
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
)
80 case 100: /* VRD 10.0 */
81 /* compute in uV, round to mV */
83 if((val
& 0x1f) == 0x1f)
85 if((val
& 0x1f) <= 0x09 || val
== 0x0a)
86 vid
= 1087500 - (val
& 0x1f) * 25000;
88 vid
= 1862500 - (val
& 0x1f) * 25000;
91 return((vid
+ 500) / 1000);
93 case 110: /* Intel Conroe */
94 /* compute in uV, round to mV */
96 if(((val
& 0x7e) == 0xfe) || (!(val
& 0x7e)))
98 return((1600000 - (val
- 2) * 6250 + 500) / 1000);
99 case 24: /* Opteron processor */
101 return(val
== 0x1f ? 0 : 1550 - val
* 25);
103 case 91: /* VRM 9.1 */
104 case 90: /* VRM 9.0 */
106 return(val
== 0x1f ? 0 :
109 case 85: /* VRM 8.5 */
111 return((val
& 0x10 ? 25 : 0) +
112 ((val
& 0x0f) > 0x04 ? 2050 : 1250) -
113 ((val
& 0x0f) * 50));
115 case 84: /* VRM 8.4 */
118 case 82: /* VRM 8.2 */
120 return(val
== 0x1f ? 0 :
121 val
& 0x10 ? 5100 - (val
) * 100 :
123 case 17: /* Intel IMVP-II */
125 return(val
& 0x10 ? 975 - (val
& 0xF) * 25 :
129 return(1708 - val
* 16);
130 case 14: /* Intel Core */
131 /* compute in uV, round to mV */
133 return(val
> 0x77 ? 0 : (1500000 - (val
* 12500) + 500) / 1000);
134 default: /* report 0 for unknown */
135 printk(KERN_INFO
"hwmon-vid: requested unknown VRM version\n");
142 After this point is the code to automatically determine which
143 VRM/VRD specification should be used depending on the CPU.
158 /* the stepping parameter is highest acceptable stepping for current line */
160 static struct vrm_model vrm_models
[] = {
161 {X86_VENDOR_AMD
, 0x6, ANY
, ANY
, 90}, /* Athlon Duron etc */
162 {X86_VENDOR_AMD
, 0xF, ANY
, ANY
, 24}, /* Athlon 64, Opteron and above VRM 24 */
163 {X86_VENDOR_INTEL
, 0x6, 0x9, ANY
, 13}, /* Pentium M (130 nm) */
164 {X86_VENDOR_INTEL
, 0x6, 0xB, ANY
, 85}, /* Tualatin */
165 {X86_VENDOR_INTEL
, 0x6, 0xD, ANY
, 13}, /* Pentium M (90 nm) */
166 {X86_VENDOR_INTEL
, 0x6, 0xE, ANY
, 14}, /* Intel Core (65 nm) */
167 {X86_VENDOR_INTEL
, 0x6, 0xF, ANY
, 110}, /* Intel Conroe */
168 {X86_VENDOR_INTEL
, 0x6, ANY
, ANY
, 82}, /* any P6 */
169 {X86_VENDOR_INTEL
, 0x7, ANY
, ANY
, 0}, /* Itanium */
170 {X86_VENDOR_INTEL
, 0xF, 0x0, ANY
, 90}, /* P4 */
171 {X86_VENDOR_INTEL
, 0xF, 0x1, ANY
, 90}, /* P4 Willamette */
172 {X86_VENDOR_INTEL
, 0xF, 0x2, ANY
, 90}, /* P4 Northwood */
173 {X86_VENDOR_INTEL
, 0xF, ANY
, ANY
, 100}, /* Prescott and above assume VRD 10 */
174 {X86_VENDOR_INTEL
, 0x10, ANY
, ANY
, 0}, /* Itanium 2 */
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 */
179 {X86_VENDOR_UNKNOWN
, ANY
, ANY
, ANY
, 0} /* stop here */
182 static u8
find_vrm(u8 eff_family
, u8 eff_model
, u8 eff_stepping
, u8 vendor
)
186 while (vrm_models
[i
].vendor
!=X86_VENDOR_UNKNOWN
) {
187 if (vrm_models
[i
].vendor
==vendor
)
188 if ((vrm_models
[i
].eff_family
==eff_family
)
189 && ((vrm_models
[i
].eff_model
==eff_model
) ||
190 (vrm_models
[i
].eff_model
==ANY
)) &&
191 (eff_stepping
<= vrm_models
[i
].eff_stepping
))
192 return vrm_models
[i
].vrm_type
;
199 u8
vid_which_vrm(void)
201 struct cpuinfo_x86
*c
= cpu_data
;
203 u8 eff_family
, eff_model
, eff_stepping
, vrm_ret
;
205 if (c
->x86
< 6) /* Any CPU with family lower than 6 */
206 return 0; /* doesn't have VID and/or CPUID */
209 eff_family
= ((eax
& 0x00000F00)>>8);
210 eff_model
= ((eax
& 0x000000F0)>>4);
211 eff_stepping
= eax
& 0xF;
212 if (eff_family
== 0xF) { /* use extended model & family */
213 eff_family
+= ((eax
& 0x00F00000)>>20);
214 eff_model
+= ((eax
& 0x000F0000)>>16)<<4;
216 vrm_ret
= find_vrm(eff_family
, eff_model
, eff_stepping
, c
->x86_vendor
);
218 printk(KERN_INFO
"hwmon-vid: Unknown VRM version of your "
223 /* and now for something completely different for the non-x86 world */
225 u8
vid_which_vrm(void)
227 printk(KERN_INFO
"hwmon-vid: Unknown VRM version of your CPU\n");
232 EXPORT_SYMBOL(vid_from_reg
);
233 EXPORT_SYMBOL(vid_which_vrm
);
235 MODULE_AUTHOR("Rudolf Marek <r.marek@sh.cvut.cz>");
237 MODULE_DESCRIPTION("hwmon-vid driver");
238 MODULE_LICENSE("GPL");