drivers/hwmon/hwmon-vid.c - third_party/linux - Git at Google

 /*
  * 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>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */

 #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_mask, 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");
	/*
	* 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>
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	*/

	#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_mask, 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");