diff options
Diffstat (limited to 'drivers/hwmon')
| -rw-r--r-- | drivers/hwmon/hwmon-vid.c | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/drivers/hwmon/hwmon-vid.c b/drivers/hwmon/hwmon-vid.c index 7c8ed0353302..a54d08699973 100644 --- a/drivers/hwmon/hwmon-vid.c +++ b/drivers/hwmon/hwmon-vid.c @@ -3,6 +3,10 @@ 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 @@ -23,6 +27,83 @@ #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; @@ -96,6 +177,7 @@ int vid_which_vrm(void) } #endif +EXPORT_SYMBOL(vid_from_reg); EXPORT_SYMBOL(vid_which_vrm); MODULE_AUTHOR("Rudolf Marek <r.marek@sh.cvut.cz>"); |