linux/drivers/hwmon/hwmon-vid.c
Rudolf Marek 734a12a366 [PATCH] hwmon: add VRM/VID support for some VIA CPUs
This patch adds the VIA CENTAUR CPUs to detection table.
Table was updated to treat future Intel x86 CPUs as VRD10.
Stepping field was added, because some VIA CPUs have
different VRM specs across stepping. I changed the vrm type
to u8 because all drivers use u8 anyway.

Signed-off-by: Rudolf Marek <r.marek@sh.cvut.cz>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-05 22:16:26 -08:00

205 lines
6.0 KiB
C

/*
hwmon-vid.c - VID/VRM/VRD voltage conversions
Copyright (c) 2004 Rudolf Marek <r.marek@sh.cvut.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.
*/
#include <linux/config.h>
#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 Opteron processors don't follow the Intel specifications.
I'm going to "make up" 2.4 as the spec number for the Opterons.
No good reason just a mnemonic for the 24x Opteron processor
series.
Opteron VID encoding is:
00000 = 1.550 V
00001 = 1.525 V
. . . .
11110 = 0.800 V
11111 = 0.000 V (off)
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
*/
/* vrm is the VRM/VRD document version multiplied by 10.
val is the 4-, 5- or 6-bit VID code.
Returned value is in mV to avoid floating point in the kernel. */
int vid_from_reg(int val, u8 vrm)
{
int vid;
switch(vrm) {
case 100: /* VRD 10.0 */
if((val & 0x1f) == 0x1f)
return 0;
if((val & 0x1f) <= 0x09 || val == 0x0a)
vid = 10875 - (val & 0x1f) * 250;
else
vid = 18625 - (val & 0x1f) * 250;
if(val & 0x20)
vid -= 125;
vid /= 10; /* only return 3 dec. places for now */
return vid;
case 24: /* Opteron processor */
return(val == 0x1f ? 0 : 1550 - val * 25);
case 91: /* VRM 9.1 */
case 90: /* VRM 9.0 */
return(val == 0x1f ? 0 :
1850 - val * 25);
case 85: /* VRM 8.5 */
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 */
return(val == 0x1f ? 0 :
val & 0x10 ? 5100 - (val) * 100 :
2050 - (val) * 50);
case 17: /* Intel IMVP-II */
return(val & 0x10 ? 975 - (val & 0xF) * 25 :
1750 - val * 50);
default: /* report 0 for unknown */
printk(KERN_INFO "hwmon-vid: requested unknown VRM version\n");
return 0;
}
}
/*
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 eff_family;
u8 eff_model;
u8 eff_stepping;
u8 vrm_type;
};
#define ANY 0xFF
#ifdef CONFIG_X86
/* the stepping parameter is highest acceptable stepping for current line */
static struct vrm_model vrm_models[] = {
{X86_VENDOR_AMD, 0x6, ANY, ANY, 90}, /* Athlon Duron etc */
{X86_VENDOR_AMD, 0xF, ANY, ANY, 24}, /* Athlon 64, Opteron and above VRM 24 */
{X86_VENDOR_INTEL, 0x6, 0x9, ANY, 85}, /* 0.13um too */
{X86_VENDOR_INTEL, 0x6, 0xB, ANY, 85}, /* Tualatin */
{X86_VENDOR_INTEL, 0x6, ANY, ANY, 82}, /* any P6 */
{X86_VENDOR_INTEL, 0x7, ANY, ANY, 0}, /* Itanium */
{X86_VENDOR_INTEL, 0xF, 0x0, ANY, 90}, /* P4 */
{X86_VENDOR_INTEL, 0xF, 0x1, ANY, 90}, /* P4 Willamette */
{X86_VENDOR_INTEL, 0xF, 0x2, ANY, 90}, /* P4 Northwood */
{X86_VENDOR_INTEL, 0xF, ANY, ANY, 100}, /* Prescott and above assume VRD 10 */
{X86_VENDOR_INTEL, 0x10, ANY, ANY, 0}, /* Itanium 2 */
{X86_VENDOR_CENTAUR, 0x6, 0x7, ANY, 85}, /* Eden ESP/Ezra */
{X86_VENDOR_CENTAUR, 0x6, 0x8, 0x7, 85}, /* Ezra T */
{X86_VENDOR_CENTAUR, 0x6, 0x9, 0x7, 85}, /* Nemiah */
{X86_VENDOR_CENTAUR, 0x6, 0x9, ANY, 17}, /* C3-M */
{X86_VENDOR_UNKNOWN, ANY, ANY, ANY, 0} /* stop here */
};
static u8 find_vrm(u8 eff_family, u8 eff_model, u8 eff_stepping, u8 vendor)
{
int i = 0;
while (vrm_models[i].vendor!=X86_VENDOR_UNKNOWN) {
if (vrm_models[i].vendor==vendor)
if ((vrm_models[i].eff_family==eff_family)
&& ((vrm_models[i].eff_model==eff_model) ||
(vrm_models[i].eff_model==ANY)) &&
(eff_stepping <= vrm_models[i].eff_stepping))
return vrm_models[i].vrm_type;
i++;
}
return 0;
}
u8 vid_which_vrm(void)
{
struct cpuinfo_x86 *c = cpu_data;
u32 eax;
u8 eff_family, eff_model, eff_stepping, vrm_ret;
if (c->x86 < 6) /* Any CPU with family lower than 6 */
return 0; /* doesn't have VID and/or CPUID */
eax = cpuid_eax(1);
eff_family = ((eax & 0x00000F00)>>8);
eff_model = ((eax & 0x000000F0)>>4);
eff_stepping = eax & 0xF;
if (eff_family == 0xF) { /* use extended model & family */
eff_family += ((eax & 0x00F00000)>>20);
eff_model += ((eax & 0x000F0000)>>16)<<4;
}
vrm_ret = find_vrm(eff_family, eff_model, eff_stepping, c->x86_vendor);
if (vrm_ret == 0)
printk(KERN_INFO "hwmon-vid: 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)
{
printk(KERN_INFO "hwmon-vid: Unknown VRM version of your CPU\n");
return 0;
}
#endif
EXPORT_SYMBOL(vid_from_reg);
EXPORT_SYMBOL(vid_which_vrm);
MODULE_AUTHOR("Rudolf Marek <r.marek@sh.cvut.cz>");
MODULE_DESCRIPTION("hwmon-vid driver");
MODULE_LICENSE("GPL");