/* 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");