path: root/drivers/hwmon/nct7802.c

/*
 * nct7802 - Driver for Nuvoton NCT7802Y
 *
 * Copyright (C) 2014  Guenter Roeck <linux@roeck-us.net>
 *
 * 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.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/jiffies.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/regmap.h>
#include <linux/slab.h>

#define DRVNAME "nct7802"

static const u8 REG_VOLTAGE[5] = { 0x09, 0x0a, 0x0c, 0x0d, 0x0e };

static const u8 REG_VOLTAGE_LIMIT_LSB[2][5] = {
	{ 0x40, 0x00, 0x42, 0x44, 0x46 },
	{ 0x3f, 0x00, 0x41, 0x43, 0x45 },
};

static const u8 REG_VOLTAGE_LIMIT_MSB[5] = { 0x48, 0x00, 0x47, 0x47, 0x48 };

static const u8 REG_VOLTAGE_LIMIT_MSB_SHIFT[2][5] = {
	{ 0, 0, 4, 0, 4 },
	{ 2, 0, 6, 2, 6 },
};

#define REG_BANK		0x00
#define REG_TEMP_LSB		0x05
#define REG_TEMP_PECI_LSB	0x08
#define REG_VOLTAGE_LOW		0x0f
#define REG_FANCOUNT_LOW	0x13
#define REG_START		0x21
#define REG_MODE		0x22 /* 7.2.32 Mode Selection Register */
#define REG_PECI_ENABLE		0x23
#define REG_FAN_ENABLE		0x24
#define REG_VMON_ENABLE		0x25
#define REG_PWM(x)		(0x60 + (x))
#define REG_SMARTFAN_EN(x)      (0x64 + (x) / 2)
#define SMARTFAN_EN_SHIFT(x)    ((x) % 2 * 4)
#define REG_VENDOR_ID		0xfd
#define REG_CHIP_ID		0xfe
#define REG_VERSION_ID		0xff

/*
 * Data structures and manipulation thereof
 */

struct nct7802_data {
	struct regmap *regmap;
	struct mutex access_lock; /* for multi-byte read and write operations */
};

static ssize_t show_temp_type(struct device *dev, struct device_attribute *attr,
			      char *buf)
{
	struct nct7802_data *data = dev_get_drvdata(dev);
	struct sensor_device_attribute *sattr = to_sensor_dev_attr(attr);
	unsigned int mode;
	int ret;

	ret = regmap_read(data->regmap, REG_MODE, &mode);
	if (ret < 0)
		return ret;

	return sprintf(buf, "%u\n", (mode >> (2 * sattr->index) & 3) + 2);
}

static ssize_t store_temp_type(struct device *dev,
			       struct device_attribute *attr,
			       const char *buf, size_t count)
{
	struct nct7802_data *data = dev_get_drvdata(dev);
	struct sensor_device_attribute *sattr = to_sensor_dev_attr(attr);
	unsigned int type;
	int err;

	err = kstrtouint(buf, 0, &type);
	if (err < 0)
		return err;
	if (sattr->index == 2 && type != 4) /* RD3 */
		return -EINVAL;
	if (type < 3 || type > 4)
		return -EINVAL;
	err = regmap_update_bits(data->regmap, REG_MODE,
			3 << 2 * sattr->index, (type - 2) << 2 * sattr->index);
	return err ? : count;
}

static ssize_t show_pwm_mode(struct device *dev, struct device_attribute *attr,
			     char *buf)
{
	struct sensor_device_attribute *sattr = to_sensor_dev_attr(attr);
	struct nct7802_data *data = dev_get_drvdata(dev);
	unsigned int regval;
	int ret;

	if (sattr->index > 1)
		return sprintf(buf, "1\n");

	ret = regmap_read(data->regmap, 0x5E, &regval);
	if (ret < 0)
		return ret;

	return sprintf(buf, "%u\n", !(regval & (1 << sattr->index)));
}

static ssize_t show_pwm(struct device *dev, struct device_attribute *devattr,
			char *buf)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct nct7802_data *data = dev_get_drvdata(dev);
	unsigned int val;
	int ret;

	if (!attr->index)
		return sprintf(buf, "255\n");

	ret = regmap_read(data