// SPDX-License-Identifier: GPL-2.0-or-later
/*
* hwmon-vid.c - VID/VRM/VRD voltage conversions
*
* Copyright (c) 2004 Rudolf Marek <r.marek@assembler.cz>
*
* Partly imported from i2c-vid.h of the lm_sensors project
* Copyright (c) 2002 Mark D. Studebaker <mdsxyz123@yahoo.com>
* With assistance from Trent Piepho <xyzzy@speakeasy.org>
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/hwmon-vid.h>
/*
* Common code for decoding VID pins.
*
* References:
*
* For VRM 8.4 to 9.1, "VRM x.y DC-DC Converter Design Guidelines",
* available at http://developer.intel.com/.
*
* For VRD 10.0 and up, "VRD x.y Design Guide",
* available at http://developer.intel.com/.
*
* AMD Athlon 64 and AMD Opteron Processors, AMD Publication 26094,
* http://support.amd.com/us/Processor_TechDocs/26094.PDF
* Table 74. VID Code Voltages
* This corresponds to an arbitrary VRM code of 24 in the functions below.
* These CPU models (K8 revision <= E) have 5 VID pins. See also:
* Revision Guide for AMD Athlon 64 and AMD Opteron Processors, AMD Publication 25759,
* http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/25759.pdf
*
* AMD NPT Family 0Fh Processors, AMD Publication 32559,
* http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/32559.pdf
* Table 71. VID Code Voltages
* This corresponds to an arbitrary VRM code of 25 in the functions below.
* These CPU models (K8 revision >= F) have 6 VID pins. See also:
* Revision Guide for AMD NPT Family 0Fh Processors, AMD Publication 33610,
* http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/33610.pdf
*
* The 17 specification is in fact Intel Mobile Voltage Positioning -
* (IMVP-II). You can find more information in the datasheet of Max1718
* http://www.maxim-ic.com/quick_view2.cfm/qv_pk/2452
*
* The 13 specification corresponds to the Intel Pentium M series. There
* doesn't seem to be any named specification for these. The conversion
* tables are detailed directly in the various Pentium M datasheets:
* http://www.intel.com/design/intarch/pentiumm/docs_pentiumm.htm
*
* The 14 specification corresponds to Intel Core series. There
* doesn't seem to be any named specification for these. The conversion
* tables are detailed directly in the various Pentium Core datasheets:
* http://www.intel.com/design/mobile/datashts/309221.htm
*
* The 110 (VRM 11) specification corresponds to Intel Conroe based series.
* http://www.intel.com/design/processor/applnots/313214.htm
*/
/*
* vrm is the VRM/VRD document version multiplied by 10.
* val is the 4-bit or more VID code.
* Returned value is in mV to avoid floating point in the kernel.
* Some VID have some bits in uV scale, this is rounded to mV.
*/
int vid_from_reg(int val, u8 vrm)
{
int vid;
switch (vrm) {
case 100: /* VRD 10.0 */
/* compute in uV, round to mV */
val &= 0x3f;
if ((val & 0x1f) == 0x1f)
return 0;
if ((val & 0x1f) <= 0x09 || val == 0x0a)
vid = 1087500 - (val & 0x1f) * 25000;
else
vid = 1862500 - (val & 0x1f) * 25000;
if (val & 0x20)
vid -= 12500;
return (vid + 500) / 1000;
case 110: /* Intel Conroe */
/* compute in uV, round to mV */
val &= 0xff;
if (val < 0x02 || val > 0xb2)
return 0;
return (1600000 - (val - 2) * 6250 + 500) / 1000;
case 24: /* Athlon64 & Opteron */
val &= 0x1f;
if (val == 0x1f)
return 0;
/* fall through */
case 25: /* AMD NPT 0Fh */
val &= 0x3f;
return (val < 32) ? 1550 - 25 * val
: 775 - (25 * (val - 31)) / 2;
case 26: /* AMD family 10h to 15h, serial VID */
val &= 0x7f;
if (val >= 0x7c)
return 0;
return DIV_ROUND_CLOSEST(15500 - 125 * val, 10);
case 91: /* VRM 9.1 */
case 90: /* VRM 9.0 */
val &= 0x1f;
return val == 0x1f ? 0 :
1850 - val * 25;
case 85: /* VRM 8.5 */
val &= 0x1f;
return (val & 0x10 ? 25 : 0) +
((val & 0x0f) > 0x04 ? 2050 : 1250) -
((val & 0x0f) * 50);
case 84: /* VRM 8.4 */
val &= 0x0f;
/* fall through */
case 82: /* VRM 8.2 */
val &= 0x1f;
return val == 0x1f ? 0 :
val & 0x10 ? 5100 - (val) * 100 :
2050 - (val) * 50;
case 17: /* Intel IMVP-II */
val &= 0x1f;
return val & 0x10 ? 975 - (val & 0xF) * 25 :
1750 - val * 50;
case 13:
case 131:
val &= 0x3f;
/* Exception for Eden ULV 500 MHz */
if (vrm == 131 && val == 0x3f)
val++;
return 1708 - val * 16;
case 14: /* Intel Core */
/* compute in uV, round to mV */
val &= 0x7f;
return val > 0x77 ? 0 : (1500000 - (val * 12500) + 500) / 1000;
default: /* report 0 for unknown */
if (vrm)
pr_warn("Requested unsupported VRM version (%u)\n",
(unsigned int)vrm);
return 0;
}
}
EXPORT_SYMBOL(vid_from_reg);
/*
* After this point is the code to automatically determine which
* VRM/VRD specification should be used depending on the CPU.
*/
struct vrm_model {
u8 vendor;
u8 family;
u8 model_from;
u8 model_to;
u8 stepping_to;
u8 vrm_type;
};
#define ANY 0xFF
#ifdef CONFIG_X86
/*
* The stepping_to parameter is highest acceptable stepping for current line.
* The model match must be exact for 4-bit values. For model values 0x10
* and above (extended model), all models below the parameter will match.
*/
static struct vrm_model vrm_models[] = {
{X86_VENDOR_AMD, 0x6, 0x0, ANY, ANY, 90}, /* Athlon Duron etc */
{X86_VENDOR_AMD, 0xF, 0x0, 0x3F, ANY, 24}, /* Athlon 64, Opteron */
/*
* In theory, all NPT family 0Fh processors have 6 VID pins and should
* thus use vrm 25, however in practice not all mainboards route the
* 6th VID pin because it is never needed. So we use the 5 VID pin
* variant (vrm 24) for the models which exist today.
*/
{X86_VENDOR_AMD, 0xF, 0x40, 0x7F, ANY, 24}, /* NPT family 0Fh */
{X86_VENDOR_AMD, 0xF, 0x80, ANY, ANY, 25}, /* future fam. 0Fh */
{X86_VENDOR_AMD, 0x10, 0x0, ANY, ANY, 25}, /* NPT family 10h */
{X86_VENDOR_AMD, 0x11, 0x0, ANY, ANY, 26}, /* family 11h */
{X86_VENDOR_AMD, 0x12, 0x0, ANY, ANY, 26}, /* family 12h */
{X86_VENDOR_AMD, 0x14, 0x0, ANY, ANY, 26}, /* family 14h */
{X86_VENDOR_AMD, 0x15, 0x0, ANY, ANY, 26}, /* family 15h */
{X86_VENDOR_INTEL, 0x6, 0x0, 0x6, ANY, 82}, /* Pentium Pro,
* Pentium II, Xeon,
* Mobile Pentium,
* Celeron */
{X86_VENDOR_INTEL, 0x6, 0x7, 0x7, ANY, 84}, /* Pentium III, Xeon */
{X86_VENDOR_INTEL, 0x6, 0x8, 0x8, ANY, 82}, /* Pentium III, Xeon */
{X86_VENDOR_INTEL, 0x6, 0x9, 0x9, ANY, 13}, /* Pentium M (130 nm) */
{X86_VENDOR_INTEL, 0x6, 0xA, 0xA, ANY, 82}, /* Pentium III Xeon */
{X86_VENDOR_INTEL, 0x6, 0xB, 0xB, ANY, 85}, /* Tualatin */
{X86_VENDOR_INTEL, 0x6, 0xD, 0xD, ANY, 13}, /* Pentium M (90 nm) */
{X86_VENDOR_INTEL, 0x6, 0xE, 0xE, ANY, 14}, /* Intel Core (65 nm) */
{X86_VENDOR_INTEL, 0x6, 0xF, ANY, ANY, 110}, /* Intel Conroe and
* later */
{X86_VENDOR_INTEL, 0xF, 0x0, 0x0, ANY, 90}, /* P4 */
{X86_VENDOR_INTEL, 0xF, 0x1, 0x1, ANY, 90}, /* P4 Willamette */
{X86_VENDOR_INTEL, 0xF, 0x2, 0x2, ANY, 90}, /* P4 Northwood */
{X86_VENDOR_INTEL, 0xF, 0x3, ANY, ANY, 100}, /* Prescott and above
* assume VRD 10 */
{X86_VENDOR_CENTAUR, 0x6, 0x7, 0x7, ANY, 85}, /* Eden ESP/Ezra */
{X86_VENDOR_CENTAUR, 0x6, 0x8, 0x8, 0x7, 85}, /* Ezra T */
{X86_VENDOR_CENTAUR, 0x6, 0x9, 0x9, 0x7, 85}, /* Nehemiah */
{X86_VENDOR_CENTAUR, 0x6, 0x9, 0x9, ANY, 17}, /* C3-M, Eden-N */
{X86_VENDOR_CENTAUR, 0x6, 0xA, 0xA, 0x7, 0}, /* No information */
{X86_VENDOR_CENTAUR, 0x6, 0xA, 0xA, ANY, 13}, /* C7-M, C7,
* Eden (Esther) */
{X86_VENDOR_CENTAUR, 0x6, 0xD, 0xD, ANY, 134}, /* C7-D, C7-M, C7,
* Eden (Esther) */
};
/*
* Special case for VIA model D: there are two different possible
* VID tables, so we have to figure out first, which one must be
* used. This resolves temporary drm value 134 to 14 (Intel Core
* 7-bit VID), 13 (Pentium M 6-bit VID) or 131 (Pentium M 6-bit VID
* + quirk for Eden ULV 500 MHz).
* Note: something similar might be needed for model A, I'm not sure.
*/
static u8 get_via_model_d_vrm(void)
{
unsigned int vid, brand, __maybe_unused dummy;
static const char *brands[4] = {
"C7-M", "C7", "Eden", "C7-D"
};
rdmsr(0x198, dummy, vid);
vid &= 0xff;
rdmsr(0x1154, brand, dummy);
brand = ((brand >> 4) ^ (brand >> 2)) & 0x03;
if (vid > 0x3f) {
pr_info("Using %d-bit VID table for VIA %s CPU\n",
7, brands[brand]);
return 14;
} else {
pr_info("Using %d-bit VID table for VIA %s CPU\n",
6, brands[brand]);
/* Enable quirk for Eden */
return brand == 2 ? 131 : 13;
}
}
static u8 find_vrm(u8 family, u8 model, u8 stepping, u8 vendor)
{
int i;
for (i = 0; i < ARRAY_SIZE(vrm_models); i++) {
if (vendor == vrm_models[i].vendor &&
family == vrm_models[i].family &&
model >= vrm_models[i].model_from &&
model <= vrm_models[i].model_to &&
stepping <= vrm_models[i].stepping_to)
return vrm_models[i].vrm_type;
}
return 0;
}
u8 vid_which_vrm(void)
{
struct cpuinfo_x86 *c = &cpu_data(0);
u8 vrm_ret;
if (c->x86 < 6) /* Any CPU with family lower than 6 */
return 0; /* doesn't have VID */
vrm_ret = find_vrm(c->x86, c->x86_model, c->x86_stepping, c->x86_vendor);
if (vrm_ret == 134)
vrm_ret = get_via_model_d_vrm();
if (vrm_ret == 0)
pr_info("Unknown VRM version of your x86 CPU\n");
return vrm_ret;
}
/* and now for something completely different for the non-x86 world */
#else
u8 vid_which_vrm(void)
{
pr_info("Unknown VRM version of your CPU\n");
return 0;
}
#endif
EXPORT_SYMBOL(vid_which_vrm);
MODULE_AUTHOR("Rudolf Marek <r.marek@assembler.cz>");
MODULE_DESCRIPTION("hwmon-vid driver");
MODULE_LICENSE("GPL");
