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Diffstat (limited to 'drivers/hwmon/hwmon-vid.c')
-rw-r--r--drivers/hwmon/hwmon-vid.c189
1 files changed, 189 insertions, 0 deletions
diff --git a/drivers/hwmon/hwmon-vid.c b/drivers/hwmon/hwmon-vid.c
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+++ b/drivers/hwmon/hwmon-vid.c
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+/*
+ 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)
+*/
+
+/* 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, int vrm)
+{
+ int vid;
+
+ switch(vrm) {
+
+ case 0:
+ return 0;
+
+ 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 */
+ default: /* VRM 8.2 */
+ return(val == 0x1f ? 0 :
+ val & 0x10 ? 5100 - (val) * 100 :
+ 2050 - (val) * 50);
+ }
+}
+
+
+/*
+ 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;
+ int vrm_type;
+};
+
+#define ANY 0xFF
+
+#ifdef CONFIG_X86
+
+static struct vrm_model vrm_models[] = {
+ {X86_VENDOR_AMD, 0x6, ANY, 90}, /* Athlon Duron etc */
+ {X86_VENDOR_AMD, 0xF, ANY, 24}, /* Athlon 64, Opteron */
+ {X86_VENDOR_INTEL, 0x6, 0x9, 85}, /* 0.13um too */
+ {X86_VENDOR_INTEL, 0x6, 0xB, 85}, /* Tualatin */
+ {X86_VENDOR_INTEL, 0x6, ANY, 82}, /* any P6 */
+ {X86_VENDOR_INTEL, 0x7, ANY, 0}, /* Itanium */
+ {X86_VENDOR_INTEL, 0xF, 0x0, 90}, /* P4 */
+ {X86_VENDOR_INTEL, 0xF, 0x1, 90}, /* P4 Willamette */
+ {X86_VENDOR_INTEL, 0xF, 0x2, 90}, /* P4 Northwood */
+ {X86_VENDOR_INTEL, 0xF, 0x3, 100}, /* P4 Prescott */
+ {X86_VENDOR_INTEL, 0xF, 0x4, 100}, /* P4 Prescott */
+ {X86_VENDOR_INTEL, 0x10,ANY, 0}, /* Itanium 2 */
+ {X86_VENDOR_UNKNOWN, ANY, ANY, 0} /* stop here */
+};
+
+static int find_vrm(u8 eff_family, u8 eff_model, 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)))
+ return vrm_models[i].vrm_type;
+ i++;
+ }
+
+ return 0;
+}
+
+int vid_which_vrm(void)
+{
+ struct cpuinfo_x86 *c = cpu_data;
+ u32 eax;
+ u8 eff_family, eff_model;
+ int 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);
+ 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,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 something completely different for the non-x86 world */
+#else
+int 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");