xref: /openbmc/linux/include/linux/hwmon-vid.h (revision 74ba9207)
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3     hwmon-vid.h - VID/VRM/VRD voltage conversions
4 
5     Originally part of lm_sensors
6     Copyright (c) 2002 Mark D. Studebaker <mdsxyz123@yahoo.com>
7     With assistance from Trent Piepho <xyzzy@speakeasy.org>
8 
9 */
10 
11 #ifndef _LINUX_HWMON_VID_H
12 #define _LINUX_HWMON_VID_H
13 
14 int vid_from_reg(int val, u8 vrm);
15 u8 vid_which_vrm(void);
16 
17 /* vrm is the VRM/VRD document version multiplied by 10.
18    val is in mV to avoid floating point in the kernel.
19    Returned value is the 4-, 5- or 6-bit VID code.
20    Note that only VRM 9.x is supported for now. */
vid_to_reg(int val,u8 vrm)21 static inline int vid_to_reg(int val, u8 vrm)
22 {
23 	switch (vrm) {
24 	case 91:		/* VRM 9.1 */
25 	case 90:		/* VRM 9.0 */
26 		return ((val >= 1100) && (val <= 1850) ?
27 			((18499 - val * 10) / 25 + 5) / 10 : -1);
28 	default:
29 		return -EINVAL;
30 	}
31 }
32 
33 #endif /* _LINUX_HWMON_VID_H */
34