AMD NPT 0Fh cpus use 6 bit VID codes. Successive codes with msb 0 describe 25mV decrements, while those with msb 1 describe 12.5mV decrements. Existing hwmon-vid.c is correct only for codes with msb 0; this patch adds support for the codes with msb 1. Ref: p 309, Table 71 AMD Publication 32559, BIOS and Kernel Developer's Guide for AMD NPT Family 0Fh Processors http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/32559.pdf Signed-off-by: Frank Myhr <fmyhr at fhmtech.com> --- --- linux-2.6.26-rc5_before/drivers/hwmon/hwmon-vid.c 2008-06-11 18:09:26.000000000 -0400 +++ linux-2.6.26-rc5_after/drivers/hwmon/hwmon-vid.c 2008-06-11 18:35:55.000000000 -0400 @@ -37,17 +37,26 @@ * For VRD 10.0 and up, "VRD x.y Design Guide", * available at http://developer.intel.com/. * + * AMD NPT 0Fh (Athlon64 & Opteron), AMD Publication 32559, + * http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/32559.pdf * 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) + * AMD NPT 0Fh VID encoding is: + * VID[5:0] Voltage [V] Delta [mV] + * -------- ----------- --------- + * 00 0000 1.550 + * 00 0001 1.525 -25 + * . . . . + * 01 1110 0.800 + * 01 1111 0.775 -25 + * 10 0000 0.7625 -12.5 + * 10 0001 0.7500 -12.5 + * . . . . + * 11 1110 0.3875 + * 11 1111 0.3750 -12.5 * * The 17 specification is in fact Intel Mobile Voltage Positioning - * (IMVP-II). You can find more information in the datasheet of Max1718 @@ -98,9 +107,11 @@ int vid_from_reg(int val, u8 vrm) if (val < 0x02 || val > 0xb2) return 0; return((1600000 - (val - 2) * 6250 + 500) / 1000); - case 24: /* Opteron processor */ - val &= 0x1f; - return(val == 0x1f ? 0 : 1550 - val * 25); + + case 24: /* AMD NPT 0Fh (Athlon64 & Opteron) */ + val &= 0x3f; + return((val < 32) ? 1550 - 25 * val + : 775 - (25 * (val - 31)) / 2); case 91: /* VRM 9.1 */ case 90: /* VRM 9.0 */
