diff options
Diffstat (limited to 'drivers/hwmon/hwmon-vid.c')
| -rw-r--r-- | drivers/hwmon/hwmon-vid.c | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/drivers/hwmon/hwmon-vid.c b/drivers/hwmon/hwmon-vid.c new file mode 100644 index 00000000000..312769ad4da --- /dev/null +++ b/drivers/hwmon/hwmon-vid.c @@ -0,0 +1,189 @@ +/* + 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"); |