path: root/drivers/hwmon/vt8231.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * vt8231.c - Part of lm_sensors, Linux kernel modules
 *	      for hardware monitoring
 *
 * Copyright (c) 2005 Roger Lucas <vt8231@hiddenengine.co.uk>
 * Copyright (c) 2002 Mark D. Studebaker <mdsxyz123@yahoo.com>
 *		      Aaron M. Marsh <amarsh@sdf.lonestar.org>
 */

/*
 * Supports VIA VT8231 South Bridge embedded sensors
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/pci.h>
#include <linux/jiffies.h>
#include <linux/platform_device.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/hwmon-vid.h>
#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/acpi.h>
#include <linux/io.h>

static int force_addr;
module_param(force_addr, int, 0);
MODULE_PARM_DESC(force_addr, "Initialize the base address of the sensors");

static struct platform_device *pdev;

#define VT8231_EXTENT 0x80
#define VT8231_BASE_REG 0x70
#define VT8231_ENABLE_REG 0x74

/*
 * The VT8231 registers
 *
 * The reset value for the input channel configuration is used (Reg 0x4A=0x07)
 * which sets the selected inputs marked with '*' below if multiple options are
 * possible:
 *
 *		    Voltage Mode	  Temperature Mode
 *	Sensor	      Linux Id	      Linux Id	      VIA Id
 *	--------      --------	      --------	      ------
 *	CPU Diode	N/A		temp1		0
 *	UIC1		in0		temp2 *		1
 *	UIC2		in1 *		temp3		2
 *	UIC3		in2 *		temp4		3
 *	UIC4		in3 *		temp5		4
 *	UIC5		in4 *		temp6		5
 *	3.3V		in5		N/A
 *
 * Note that the BIOS may set the configuration register to a different value
 * to match the motherboard configuration.
 */

/* fans numbered 0-1 */
#define VT8231_REG_FAN_MIN(nr)	(0x3b + (nr))
#define VT8231_REG_FAN(nr)	(0x29 + (nr))

/* Voltage inputs numbered 0-5 */

static const u8 regvolt[]    = { 0x21, 0x22, 0x23, 0x24, 0x25, 0x26 };
static const u8 regvoltmax[] = { 0x3d, 0x2b, 0x2d, 0x2f, 0x31, 0x33 };
static const u8 regvoltmin[] = { 0x3e, 0x2c, 0x2e, 0x30, 0x32, 0x34 };

/*
 * Temperatures are numbered 1-6 according to the Linux kernel specification.
 *
 * In the VIA datasheet, however, the temperatures are numbered from zero.
 * Since it is important that this driver can easily be compared to the VIA
 * datasheet, we will use the VIA numbering within this driver and map the
 * kernel sysfs device name to the VIA number in the sysfs callback.
 */

#define VT8231_REG_TEMP_LOW01	0x49
#define VT8231_REG_TEMP_LOW25	0x4d

static const u8 regtemp[]    = { 0x1f, 0x21, 0x22, 0x23, 0x24, 0x25 };
static const u8 regtempmax[] = { 0x39, 0x3d, 0x2b, 0x2d, 0x2f, 0x31 };
static const u8 regtempmin[] = { 0x3a, 0x3e, 0x2c, 0x2e, 0x30, 0x32 };

#define TEMP_FROM_REG(reg)		(((253 * 4 - (reg)) * 550 + 105) / 210)
#define TEMP_MAXMIN_FROM_REG(reg)	(((253 - (reg)) * 2200 + 105) / 210)
#define TEMP_MAXMIN_TO_REG(val)		(253 - ((val) * 210 + 1100) / 2200)

#define VT8231_REG_CONFIG 0x40
#define VT8231_REG_ALARM1 0x41
#define VT8231_REG_ALARM2 0x42
#define VT8231_REG_FANDIV 0x47
#define VT8231_REG_UCH_CONFIG 0x4a
#define VT8231_REG_TEMP1_CONFIG 0x4b
#define VT8231_REG_TEMP2_CONFIG 0x4c

/*
 * temps 0-5 as numbered in VIA datasheet - see later for mapping to Linux
 * numbering
 */
#define ISTEMP(i, ch_config) ((i) == 0 ? 1 : \
			      ((ch_config) >> ((i)+1)) & 0x01)
/* voltages 0-5 */
#define ISVOLT(i, ch_config) ((i) == 5 ? 1 : \
			      !(((ch_config) >> ((i)+2)) & 0x01))

#define DIV_FROM_REG(val) (1 << (val))

/*
 * NB  The values returned here are NOT temperatures.  The calibration curves
 *     for the thermistor curves are board-specific and must go in the
 *     sensors.conf file.  Temperature sensors are actually ten bits, but the
 *     VIA datasheet only considers the 8 MSBs obtained from the regtemp[]
 *     register.  The temperature value returned should have a magnitude of 3,
 *     so we use the VIA scaling as the "true" scaling and use the remaining 2
 *     LSBs as fractional precision.
 *
 *     All the on-chip hardware temperature comparisons for the alarms are only
 *     8-bits wide, and compare against the 8 MSBs of the temperature.  The bits
 *     in the registers VT8231_REG_TEMP_LOW01 and VT8231_REG_TEMP_LOW25 are
 *     ignored.
 */

/*
 ****** FAN RPM CONVERSIONS ********
 * This chip saturates back at 0, not at 255 like many the other chips.
 * So, 0 means 0 RPM
 */
static inline u8 FAN_TO_REG(long rpm, int div)
{
	if (rpm <= 0 || rpm > 1310720)
		return 0;
	return clamp_val(1310720 / (rpm * div), 1, 255);
}

#define FAN_FROM_REG(val, div) ((val) == 0 ? 0 : 1310720 / ((val) * (div)))

struct vt8231_data {
	unsigned short addr;
	const char *name;

	struct mutex update_lock;
	struct device *hwmon_dev;
	char valid;		/* !=0 if following fields are valid */
	unsigned long last_updated;	/* In jiffies */

	u8 in[6];		/* Register value */
	u8 in_max[6];		/* Register value */
	u8 in_min[6];		/* Register value */
	u16 temp[6];		/* Register value 10 bit, right aligned */
	u8 temp_max[6];		/* Register value */
	u8 temp_min[6];		/* Register value */
	u8 fan[2];		/* Register value */
	u8 fan_min[2];		/* Register value */
	u8 fan_div[2];		/* Register encoding, shifted right */
	u16 alarms;		/* Register encoding */
	u8 uch_config;
};

static struct pci_dev *s_bridge;
static int vt8231_probe(struct platform_device *pdev);
static int vt8231_remove(struct platform_device *pdev);
static struct vt8231_data *vt8231_update_device(struct device *dev);
static void