linux-pinenote/include/linux/hwmon-vid.h

/*
    hwmon-vid.h - VID/VRM/VRD voltage conversions

    Originally part of lm_sensors
    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.
*/

#ifndef _LINUX_HWMON_VID_H
#define _LINUX_HWMON_VID_H

int vid_from_reg(int val, u8 vrm);
u8 vid_which_vrm(void);

/* vrm is the VRM/VRD document version multiplied by 10.
   val is in mV to avoid floating point in the kernel.
   Returned value is the 4-, 5- or 6-bit VID code.
   Note that only VRM 9.x is supported for now. */
static inline int vid_to_reg(int val, u8 vrm)
{
	switch (vrm) {
	case 91:		/* VRM 9.1 */
	case 90:		/* VRM 9.0 */
		return ((val >= 1100) && (val <= 1850) ?
			((18499 - val * 10) / 25 + 5) / 10 : -1);
	default:
		return -EINVAL;
	}
}

#endif /* _LINUX_HWMON_VID_H */