// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * sis5595.c - Part of lm_sensors, Linux kernel modules
 *             for hardware monitoring
 *
 * Copyright (C) 1998 - 2001 Frodo Looijaard <frodol@dds.nl>,
 *                           Kyösti Mälkki <kmalkki@cc.hut.fi>, and
 *                           Mark D. Studebaker <mdsxyz123@yahoo.com>
 * Ported to Linux 2.6 by Aurelien Jarno <aurelien@aurel32.net> with
 * the help of Jean Delvare <jdelvare@suse.de>
 */

/*
 * SiS southbridge has a LM78-like chip integrated on the same IC.
 * This driver is a customized copy of lm78.c
 *
 * Supports following revisions:
 *      Version         PCI ID          PCI Revision
 *      1               1039/0008       AF or less
 *      2               1039/0008       B0 or greater
 *
 *  Note: these chips contain a 0008 device which is incompatible with the
 *       5595. We recognize these by the presence of the listed
 *       "blacklist" PCI ID and refuse to load.
 *
 * NOT SUPPORTED        PCI ID          BLACKLIST PCI ID
 *       540            0008            0540
 *       550            0008            0550
 *      5513            0008            5511
 *      5581            0008            5597
 *      5582            0008            5597
 *      5597            0008            5597
 *      5598            0008            5597/5598
 *       630            0008            0630
 *       645            0008            0645
 *       730            0008            0730
 *       735            0008            0735
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

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

/*
 * If force_addr is set to anything different from 0, we forcibly enable
 * the device at the given address.
 */
static u16 force_addr;
module_param(force_addr, ushort, 0);
MODULE_PARM_DESC(force_addr,
                 "Initialize the base address of the sensors");

static struct platform_device *pdev;

/* Many SIS5595 constants specified below */

/* Length of ISA address segment */
#define SIS5595_EXTENT 8
/* PCI Config Registers */
#define SIS5595_BASE_REG 0x68
#define SIS5595_PIN_REG 0x7A
#define SIS5595_ENABLE_REG 0x7B

/* Where are the ISA address/data registers relative to the base address */
#define SIS5595_ADDR_REG_OFFSET 5
#define SIS5595_DATA_REG_OFFSET 6

/* The SIS5595 registers */
#define SIS5595_REG_IN_MAX(nr) (0x2b + (nr) * 2)
#define SIS5595_REG_IN_MIN(nr) (0x2c + (nr) * 2)
#define SIS5595_REG_IN(nr) (0x20 + (nr))

#define SIS5595_REG_FAN_MIN(nr) (0x3b + (nr))
#define SIS5595_REG_FAN(nr) (0x28 + (nr))

/*
 * On the first version of the chip, the temp registers are separate.
 * On the second version,
 * TEMP pin is shared with IN4, configured in PCI register 0x7A.
 * The registers are the same as well.
 * OVER and HYST are really MAX and MIN.
 */

#define REV2MIN 0xb0
#define SIS5595_REG_TEMP        (((data->revision) >= REV2MIN) ? \
                                        SIS5595_REG_IN(4) : 0x27)
#define SIS5595_REG_TEMP_OVER   (((data->revision) >= REV2MIN) ? \
                                        SIS5595_REG_IN_MAX(4) : 0x39)
#define SIS5595_REG_TEMP_HYST   (((data->revision) >= REV2MIN) ? \
                                        SIS5595_REG_IN_MIN(4) : 0x3a)

#define SIS5595_REG_CONFIG 0x40
#define SIS5595_REG_ALARM1 0x41
#define SIS5595_REG_ALARM2 0x42
#define SIS5595_REG_FANDIV 0x47

/*
 * Conversions. Limit checking is only done on the TO_REG
 * variants.
 */

/*
 * IN: mV, (0V to 4.08V)
 * REG: 16mV/bit
 */
static inline u8 IN_TO_REG(unsigned long val)
{
        unsigned long nval = clamp_val(val, 0, 4080);
        return (nval + 8) / 16;
}
#define IN_FROM_REG(val) ((val) *  16)

static inline u8 FAN_TO_REG(long rpm, int div)
{
        if (rpm <= 0)
                return 255;
        if (rpm > 1350000)
                return 1;
        return clamp_val((1350000 + rpm * div / 2) / (rpm * div), 1, 254);
}

static inline int FAN_FROM_REG(u8 val, int div)
{
        return val == 0 ? -1 : val == 255 ? 0 : 1350000 / (val * div);
}

/*
 * TEMP: mC (-54.12C to +157.53C)
 * REG: 0.83C/bit + 52.12, two's complement
 */
static inline int TEMP_FROM_REG(s8 val)
{
        return val * 830 + 52120;
}
static inline s8 TEMP_TO_REG(long val)
{
        int nval = clamp_val(val, -54120, 157530) ;
        return nval < 0 ? (nval - 5212 - 415) / 830 : (nval - 5212 + 415) / 830;
}

/*
 * FAN DIV: 1, 2, 4, or 8 (defaults to 2)
 * REG: 0, 1, 2, or 3 (respectively) (defaults to 1)
 */
static inline u8 DIV_TO_REG(int val)
{
        return val == 8 ? 3 : val == 4 ? 2 : val == 1 ? 0 : 1;
}
#define DIV_FROM_REG(val) (1 << (val))

/*
 * For each registered chip, we need to keep some data in memory.
 * The structure is dynamically allocated.
 */
struct sis5595_data {
        unsigned short addr;
        const char *name;
        struct device *hwmon_dev;
        struct mutex lock;

        struct mutex update_lock;
        char valid;             /* !=0 if following fields are valid */
        unsigned long last_updated;     /* In jiffies */
        char maxins;            /* == 3 if temp enabled, otherwise == 4 */
        u8 revision;            /* Reg. value */

        u8 in[5];               /* Register value */
        u8 in_max[5];           /* Register value */
        u8 in_min[5];           /* Register value */
        u8 fan[2];              /* Register value */
        u8 fan_min[2];          /* Register value */
        s8 temp;                /* Register value */
        s8 temp_over;           /* Register value */
        s8 temp_hyst;           /* Register value */
        u8 fan_div[2];          /* Register encoding, shifted right */
        u16 alarms;             /* Register encoding, combined */
};

static struct pci_dev *s_bridge;        /* pointer to the (only) sis5595 */

static int sis5595_probe(struct platform_device *pdev);
static int sis5595_remove(struct platform_device *pdev);

static int sis5595_read_value(struct sis5595_data *data, u8 reg);
static void sis5595_write_value(struct sis5595_data *data, u8 reg, u8 value);
static struct sis5595_data *sis5595_update_device(struct device *dev);
static void sis5595_init_device(struct sis5595_data *data);

static struct platform_driver sis5595_driver = {
        .driver = {
                .name   = "sis5595",
        },
        .probe          = sis5595_probe,
        .remove         = sis5595_remove,
};

/* 4 Voltages */
static ssize_t in_show(struct device *dev, struct device_attribute *da,
                       char *buf)
{
        struct sis5595_data *data = sis5595_update_device(dev);
        struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
        int nr = attr->index;
        return sprintf(buf, "%d\n", IN_FROM_REG(data->in[nr]));
}

static ssize_t in_min_show(struct device *dev, struct device_attribute *da,
                           char *buf)
{
        struct sis5595_data *data = sis5595_update_device(dev);
        struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
        int nr = attr->index;
        return sprintf(buf, "%d\n", IN_FROM_REG(data->in_min[nr]));
}

static ssize_t in_max_show(struct device *dev, struct device_attribute *da,
                           char *buf)
{
        struct sis5595_data *data = sis5595_update_device(dev);
        struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
        int nr = attr->index;
        return sprintf(buf, "%d\n", IN_FROM_REG(data->in_max[nr]));
}

static ssize_t in_min_store(struct device *dev, struct device_attribute *da,
                            const char *buf, size_t count)
{
        struct sis5595_data *data = dev_get_drvdata(dev);
        struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
        int nr = attr->index;
        unsigned long val;
        int err;

        err = kstrtoul(buf, 10, &val);
        if (err)
                return err;

        mutex_lock(&data->update_lock);
        data->in_min[nr] = IN_TO_REG(val);
        sis5595_write_value(data, SIS5595_REG_IN_MIN(nr), data->in_min[nr]);
        mutex_unlock(&data->update_lock);
        return count;
}

static ssize_t in_max_store(struct device *dev, struct device_attribute *da,
                            const char *buf, size_t count)
{
        struct sis5595_data *data = dev_get_drvdata(dev);
        struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
        int nr = attr->index;
        unsigned long val;
        int err;

        err = kstrtoul(buf, 10, &val);
        if (err)
                return err;

        mutex_lock(&data->update_lock);
        data->in_max[nr] = IN_TO_REG(val);
        sis5595_write_value(data, SIS5595_REG_IN_MAX(nr), data->in_max[nr]);
        mutex_unlock(&data->update_lock);
        return count;
}

static SENSOR_DEVICE_ATTR_RO(in0_input, in, 0);
static SENSOR_DEVICE_ATTR_RW(in0_min, in_min, 0);
static SENSOR_DEVICE_ATTR_RW(in0_max, in_max, 0);
static SENSOR_DEVICE_ATTR_RO(in1_input, in, 1);
static SENSOR_DEVICE_ATTR_RW(in1_min, in_min, 1);
static SENSOR_DEVICE_ATTR_RW(in1_max, in_max, 1);
static SENSOR_DEVICE_ATTR_RO(in2_input, in, 2);
static SENSOR_DEVICE_ATTR_RW(in2_min, in_min, 2);
static SENSOR_DEVICE_ATTR_RW(in2_max, in_max, 2);
static SENSOR_DEVICE_ATTR_RO(in3_input, in, 3);
static SENSOR_DEVICE_ATTR_RW(in3_min, in_min, 3);
static SENSOR_DEVICE_ATTR_RW(in3_max, in_max, 3);
static SENSOR_DEVICE_ATTR_RO(in4_input, in, 4);
static SENSOR_DEVICE_ATTR_RW(in4_min, in_min, 4);
static SENSOR_DEVICE_ATTR_RW(in4_max, in_max, 4);

/* Temperature */
static ssize_t temp1_input_show(struct device *dev,
                                struct device_attribute *attr, char *buf)
{
        struct sis5595_data *data = sis5595_update_device(dev);
        return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp));
}

static ssize_t temp1_max_show(struct device *dev, struct device_attribute *attr,
                              char *buf)
{
        struct sis5595_data *data = sis5595_update_device(dev);
        return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp_over));
}

static ssize_t temp1_max_store(struct device *dev,
                               struct device_attribute *attr, const char *buf,
                               size_t count)
{
        struct sis5595_data *data = dev_get_drvdata(dev);
        long val;
        int err;

        err = kstrtol(buf, 10, &val);
        if (err)
                return err;

        mutex_lock(&data->update_lock);
        data->temp_over = TEMP_TO_REG(val);
        sis5595_write_value(data, SIS5595_REG_TEMP_OVER, data->temp_over);
        mutex_unlock(&data->update_lock);
        return count;
}

static ssize_t temp1_max_hyst_show(struct device *dev,
                                   struct device_attribute *attr, char *buf)
{
        struct sis5595_data *data = sis5595_update_device(dev);
        return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp_hyst));
}

static ssize_t temp1_max_hyst_store(struct device *dev,
                                    struct device_attribute *attr,
                                    const char *buf, size_t count)
{
        struct sis5595_data *data = dev_get_drvdata(dev);
        long val;
        int err;

        err = kstrtol(buf, 10, &val);
        if (err)
                return err;

        mutex_lock(&data->update_lock);
        data->temp_hyst = TEMP_TO_REG(val);
        sis5595_write_value(data, SIS5595_REG_TEMP_HYST, data->temp_hyst);
        mutex_unlock(&data->update_lock);
        return count;
}

static DEVICE_ATTR_RO(temp1_input);
static DEVICE_ATTR_RW(temp1_max);
static DEVICE_ATTR_RW(temp1_max_hyst);

/* 2 Fans */
static ssize_t fan_show(struct device *dev, struct device_attribute *da,
                        char *buf)
{
        struct sis5595_data *data = sis5595_update_device(dev);
        struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
        int nr = attr->index;
        return sprintf(buf, "%d\n", FAN_FROM_REG(data->fan[nr],
                DIV_FROM_REG(data->fan_div[nr])));
}

static ssize_t fan_min_show(struct device *dev, struct device_attribute *da,
                            char *buf)
{
        struct sis5595_data *data = sis5595_update_device(dev);
        struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
        int nr = attr->index;
        return sprintf(buf, "%d\n", FAN_FROM_REG(data->fan_min[nr],
                DIV_FROM_REG(data->fan_div[nr])));
}

static ssize_t fan_min_store(struct device *dev, struct device_attribute *da,
                             const char *buf, size_t count)
{
        struct sis5595_data *data = dev_get_drvdata(dev);
        struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
        int nr = attr->index;
        unsigned long val;
        int err;

        err = kstrtoul(buf, 10, &val);
        if (err)
                return err;

        mutex_lock(&data->update_lock);
        data->fan_min[nr] = FAN_TO_REG(val, DIV_FROM_REG(data->fan_div[nr]));
        sis5595_write_value(data, SIS5595_REG_FAN_MIN(nr), data->fan_min[nr]);
        mutex_unlock(&data->update_lock);
        return count;
}

static ssize_t fan_div_show(struct device *dev, struct device_attribute *da,
                            char *buf)
{
        struct sis5595_data *data = sis5595_update_device(dev);
        struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
        int nr = attr->index;
        return sprintf(buf, "%d\n", DIV_FROM_REG(data->fan_div[nr]));
}

/*
 * Note: we save and restore the fan minimum here, because its value is
 * determined in part by the fan divisor.  This follows the principle of
 * least surprise; the user doesn't expect the fan minimum to change just
 * because the divisor changed.
 */
static ssize_t fan_div_store(struct device *dev, struct device_attribute *da,
                             const char *buf, size_t count)
{
        struct sis5595_data *data = dev_get_drvdata(dev);
        struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
        int nr = attr->index;
        unsigned long min;
        int reg;
        unsigned long val;
        int err;

        err = kstrtoul(buf, 10, &val);
        if (err)
                return err;

        mutex_lock(&data->update_lock);
        min = FAN_FROM_REG(data->fan_min[nr],
                        DIV_FROM_REG(data->fan_div[nr]));
        reg = sis5595_read_value(data, SIS5595_REG_FANDIV);

        switch (val) {
        case 1:
                data->fan_div[nr] = 0;
                break;
        case 2:
                data->fan_div[nr] = 1;
                break;
        case 4:
                data->fan_div[nr] = 2;
                break;
        case 8:
                data->fan_div[nr] = 3;
                break;
        default:
                dev_err(dev,
                        "fan_div value %ld not supported. Choose one of 1, 2, 4 or 8!\n",
                        val);
                mutex_unlock(&data->update_lock);
                return -EINVAL;
        }

        switch (nr) {
        case 0:
                reg = (reg & 0xcf) | (data->fan_div[nr] << 4);
                break;
        case 1:
                reg = (reg & 0x3f) | (data->fan_div[nr] << 6);
                break;
        }
        sis5595_write_value(data, SIS5595_REG_FANDIV, reg);
        data->fan_min[nr] =
                FAN_TO_REG(min, DIV_FROM_REG(data->fan_div[nr]));
        sis5595_write_value(data, SIS5595_REG_FAN_MIN(nr), data->fan_min[nr]);
        mutex_unlock(&data->update_lock);
        return count;
}

static SENSOR_DEVICE_ATTR_RO(fan1_input, fan, 0);
static SENSOR_DEVICE_ATTR_RW(fan1_min, fan_min, 0);
static SENSOR_DEVICE_ATTR_RW(fan1_div, fan_div, 0);
static SENSOR_DEVICE_ATTR_RO(fan2_input, fan, 1);
static SENSOR_DEVICE_ATTR_RW(fan2_min, fan_min, 1);
static SENSOR_DEVICE_ATTR_RW(fan2_div, fan_div, 1);

/* Alarms */
static ssize_t alarms_show(struct device *dev, struct device_attribute *attr,
                           char *buf)
{
        struct sis5595_data *data = sis5595_update_device(dev);
        return sprintf(buf, "%d\n", data->alarms);
}
static DEVICE_ATTR_RO(alarms);

static ssize_t alarm_show(struct device *dev, struct device_attribute *da,
                          char *buf)
{
        struct sis5595_data *data = sis5595_update_device(dev);
        int nr = to_sensor_dev_attr(da)->index;
        return sprintf(buf, "%u\n", (data->alarms >> nr) & 1);
}
static SENSOR_DEVICE_ATTR_RO(in0_alarm, alarm, 0);
static SENSOR_DEVICE_ATTR_RO(in1_alarm, alarm, 1);
static SENSOR_DEVICE_ATTR_RO(in2_alarm, alarm, 2);
static SENSOR_DEVICE_ATTR_RO(in3_alarm, alarm, 3);
static SENSOR_DEVICE_ATTR_RO(in4_alarm, alarm, 15);
static SENSOR_DEVICE_ATTR_RO(fan1_alarm, alarm, 6);
static SENSOR_DEVICE_ATTR_RO(fan2_alarm, alarm, 7);
static SENSOR_DEVICE_ATTR_RO(temp1_alarm, alarm, 15);

static ssize_t name_show(struct device *dev, struct device_attribute *attr,
                         char *buf)
{
        struct sis5595_data *data = dev_get_drvdata(dev);
        return sprintf(buf, "%s\n", data->name);
}
static DEVICE_ATTR_RO(name);

static struct attribute *sis5595_attributes[] = {
        &sensor_dev_attr_in0_input.dev_attr.attr,
        &sensor_dev_attr_in0_min.dev_attr.attr,
        &sensor_dev_attr_in0_max.dev_attr.attr,
        &sensor_dev_attr_in0_alarm.dev_attr.attr,
        &sensor_dev_attr_in1_input.dev_attr.attr,
        &sensor_dev_attr_in1_min.dev_attr.attr,
        &sensor_dev_attr_in1_max.dev_attr.attr,
        &sensor_dev_attr_in1_alarm.dev_attr.attr,
        &sensor_dev_attr_in2_input.dev_attr.attr,
        &sensor_dev_attr_in2_min.dev_attr.attr,
        &sensor_dev_attr_in2_max.dev_attr.attr,
        &sensor_dev_attr_in2_alarm.dev_attr.attr,
        &sensor_dev_attr_in3_input.dev_attr.attr,
        &sensor_dev_attr_in3_min.dev_attr.attr,
        &sensor_dev_attr_in3_max.dev_attr.attr,
        &sensor_dev_attr_in3_alarm.dev_attr.attr,

        &sensor_dev_attr_fan1_input.dev_attr.attr,
        &sensor_dev_attr_fan1_min.dev_attr.attr,
        &sensor_dev_attr_fan1_div.dev_attr.attr,
        &sensor_dev_attr_fan1_alarm.dev_attr.attr,
        &sensor_dev_attr_fan2_input.dev_attr.attr,
        &sensor_dev_attr_fan2_min.dev_attr.attr,
        &sensor_dev_attr_fan2_div.dev_attr.attr,
        &sensor_dev_attr_fan2_alarm.dev_attr.attr,

        &dev_attr_alarms.attr,
        &dev_attr_name.attr,
        NULL
};

static const struct attribute_group sis5595_group = {
        .attrs = sis5595_attributes,
};

static struct attribute *sis5595_attributes_in4[] = {
        &sensor_dev_attr_in4_input.dev_attr.attr,
        &sensor_dev_attr_in4_min.dev_attr.attr,
        &sensor_dev_attr_in4_max.dev_attr.attr,
        &sensor_dev_attr_in4_alarm.dev_attr.attr,
        NULL
};

static const struct attribute_group sis5595_group_in4 = {
        .attrs = sis5595_attributes_in4,
};

static struct attribute *sis5595_attributes_temp1[] = {
        &dev_attr_temp1_input.attr,
        &dev_attr_temp1_max.attr,
        &dev_attr_temp1_max_hyst.attr,
        &sensor_dev_attr_temp1_alarm.dev_attr.attr,
        NULL
};

static const struct attribute_group sis5595_group_temp1 = {
        .attrs = sis5595_attributes_temp1,
};

/* This is called when the module is loaded */
static int sis5595_probe(struct platform_device *pdev)
{
        int err = 0;
        int i;
        struct sis5595_data *data;
        struct resource *res;
        char val;

        /* Reserve the ISA region */
        res = platform_get_resource(pdev, IORESOURCE_IO, 0);
        if (!devm_request_region(&pdev->dev, res->start, SIS5595_EXTENT,
                                 sis5595_driver.driver.name))
                return -EBUSY;

        data = devm_kzalloc(&pdev->dev, sizeof(struct sis5595_data),
                            GFP_KERNEL);
        if (!data)
                return -ENOMEM;

        mutex_init(&data->lock);
        mutex_init(&data->update_lock);
        data->addr = res->start;
        data->name = "sis5595";
        platform_set_drvdata(pdev, data);

        /*
         * Check revision and pin registers to determine whether 4 or 5 voltages
         */
        data->revision = s_bridge->revision;
        /* 4 voltages, 1 temp */
        data->maxins = 3;
        if (data->revision >= REV2MIN) {
                pci_read_config_byte(s_bridge, SIS5595_PIN_REG, &val);
                if (!(val & 0x80))
                        /* 5 voltages, no temps */
                        data->maxins = 4;
        }

        /* Initialize the SIS5595 chip */
        sis5595_init_device(data);

        /* A few vars need to be filled upon startup */
        for (i = 0; i < 2; i++) {
                data->fan_min[i] = sis5595_read_value(data,
                                        SIS5595_REG_FAN_MIN(i));
        }

        /* Register sysfs hooks */
        err = sysfs_create_group(&pdev->dev.kobj, &sis5595_group);
        if (err)
                return err;
        if (data->maxins == 4) {
                err = sysfs_create_group(&pdev->dev.kobj, &sis5595_group_in4);
                if (err)
                        goto exit_remove_files;
        } else {
                err = sysfs_create_group(&pdev->dev.kobj, &sis5595_group_temp1);
                if (err)
                        goto exit_remove_files;
        }

        data->hwmon_dev = hwmon_device_register(&pdev->dev);
        if (IS_ERR(data->hwmon_dev)) {
                err = PTR_ERR(data->hwmon_dev);
                goto exit_remove_files;
        }

        return 0;

exit_remove_files:
        sysfs_remove_group(&pdev->dev.kobj, &sis5595_group);
        sysfs_remove_group(&pdev->dev.kobj, &sis5595_group_in4);
        sysfs_remove_group(&pdev->dev.kobj, &sis5595_group_temp1);
        return err;
}

static int sis5595_remove(struct platform_device *pdev)
{
        struct sis5595_data *data = platform_get_drvdata(pdev);

        hwmon_device_unregister(data->hwmon_dev);
        sysfs_remove_group(&pdev->dev.kobj, &sis5595_group);
        sysfs_remove_group(&pdev->dev.kobj, &sis5595_group_in4);
        sysfs_remove_group(&pdev->dev.kobj, &sis5595_group_temp1);

        return 0;
}

/* ISA access must be locked explicitly. */
static int sis5595_read_value(struct sis5595_data *data, u8 reg)
{
        int res;

        mutex_lock(&data->lock);
        outb_p(reg, data->addr + SIS5595_ADDR_REG_OFFSET);
        res = inb_p(data->addr + SIS5595_DATA_REG_OFFSET);
        mutex_unlock(&data->lock);
        return res;
}

static void sis5595_write_value(struct sis5595_data *data, u8 reg, u8 value)
{
        mutex_lock(&data->lock);
        outb_p(reg, data->addr + SIS5595_ADDR_REG_OFFSET);
        outb_p(value, data->addr + SIS5595_DATA_REG_OFFSET);
        mutex_unlock(&data->lock);
}

/* Called when we have found a new SIS5595. */
static void sis5595_init_device(struct sis5595_data *data)
{
        u8 config = sis5595_read_value(data, SIS5595_REG_CONFIG);
        if (!(config & 0x01))
                sis5595_write_value(data, SIS5595_REG_CONFIG,
                                (config & 0xf7) | 0x01);
}

static struct sis5595_data *sis5595_update_device(struct device *dev)
{
        struct sis5595_data *data = dev_get_drvdata(dev);
        int i;

        mutex_lock(&data->update_lock);

        if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
            || !data->valid) {

                for (i = 0; i <= data->maxins; i++) {
                        data->in[i] =
                            sis5595_read_value(data, SIS5595_REG_IN(i));
                        data->in_min[i] =
                            sis5595_read_value(data,
                                               SIS5595_REG_IN_MIN(i));
                        data->in_max[i] =
                            sis5595_read_value(data,
                                               SIS5595_REG_IN_MAX(i));
                }
                for (i = 0; i < 2; i++) {
                        data->fan[i] =
                            sis5595_read_value(data, SIS5595_REG_FAN(i));
                        data->fan_min[i] =
                            sis5595_read_value(data,
                                               SIS5595_REG_FAN_MIN(i));
                }
                if (data->maxins == 3) {
                        data->temp =
                            sis5595_read_value(data, SIS5595_REG_TEMP);
                        data->temp_over =
                            sis5595_read_value(data, SIS5595_REG_TEMP_OVER);
                        data->temp_hyst =
                            sis5595_read_value(data, SIS5595_REG_TEMP_HYST);
                }
                i = sis5595_read_value(data, SIS5595_REG_FANDIV);
                data->fan_div[0] = (i >> 4) & 0x03;
                data->fan_div[1] = i >> 6;
                data->alarms =
                    sis5595_read_value(data, SIS5595_REG_ALARM1) |
                    (sis5595_read_value(data, SIS5595_REG_ALARM2) << 8);
                data->last_updated = jiffies;
                data->valid = 1;
        }

        mutex_unlock(&data->update_lock);

        return data;
}

static const struct pci_device_id sis5595_pci_ids[] = {
        { PCI_DEVICE(PCI_VENDOR_ID_SI, PCI_DEVICE_ID_SI_503) },
        { 0, }
};

MODULE_DEVICE_TABLE(pci, sis5595_pci_ids);

static int blacklist[] = {
        PCI_DEVICE_ID_SI_540,
        PCI_DEVICE_ID_SI_550,
        PCI_DEVICE_ID_SI_630,
        PCI_DEVICE_ID_SI_645,
        PCI_DEVICE_ID_SI_730,
        PCI_DEVICE_ID_SI_735,
        PCI_DEVICE_ID_SI_5511, /*
                                * 5513 chip has the 0008 device but
                                * that ID shows up in other chips so we
                                * use the 5511 ID for recognition
                                */
        PCI_DEVICE_ID_SI_5597,
        PCI_DEVICE_ID_SI_5598,
        0 };

static int sis5595_device_add(unsigned short address)
{
        struct resource res = {
                .start  = address,
                .end    = address + SIS5595_EXTENT - 1,
                .name   = "sis5595",
                .flags  = IORESOURCE_IO,
        };
        int err;

        err = acpi_check_resource_conflict(&res);
        if (err)
                goto exit;

        pdev = platform_device_alloc("sis5595", address);
        if (!pdev) {
                err = -ENOMEM;
                pr_err("Device allocation failed\n");
                goto exit;
        }

        err = platform_device_add_resources(pdev, &res, 1);
        if (err) {
                pr_err("Device resource addition failed (%d)\n", err);
                goto exit_device_put;
        }

        err = platform_device_add(pdev);
        if (err) {
                pr_err("Device addition failed (%d)\n", err);
                goto exit_device_put;
        }

        return 0;

exit_device_put:
        platform_device_put(pdev);
exit:
        return err;
}

static int sis5595_pci_probe(struct pci_dev *dev,
                                       const struct pci_device_id *id)
{
        u16 address;
        u8 enable;
        int *i;

        for (i = blacklist; *i != 0; i++) {
                struct pci_dev *d;
                d = pci_get_device(PCI_VENDOR_ID_SI, *i, NULL);
                if (d) {
                        dev_err(&d->dev,
                                "Looked for SIS5595 but found unsupported device %.4x\n",
                                *i);
                        pci_dev_put(d);
                        return -ENODEV;
                }
        }

        force_addr &= ~(SIS5595_EXTENT - 1);
        if (force_addr) {
                dev_warn(&dev->dev, "Forcing ISA address 0x%x\n", force_addr);
                pci_write_config_word(dev, SIS5595_BASE_REG, force_addr);
        }

        if (PCIBIOS_SUCCESSFUL !=
            pci_read_config_word(dev, SIS5595_BASE_REG, &address)) {
                dev_err(&dev->dev, "Failed to read ISA address\n");
                return -ENODEV;
        }

        address &= ~(SIS5595_EXTENT - 1);
        if (!address) {
                dev_err(&dev->dev,
                        "Base address not set - upgrade BIOS or use force_addr=0xaddr\n");
                return -ENODEV;
        }
        if (force_addr && address != force_addr) {
                /* doesn't work for some chips? */
                dev_err(&dev->dev, "Failed to force ISA address\n");
                return -ENODEV;
        }

        if (PCIBIOS_SUCCESSFUL !=
            pci_read_config_byte(dev, SIS5595_ENABLE_REG, &enable)) {
                dev_err(&dev->dev, "Failed to read enable register\n");
                return -ENODEV;
        }
        if (!(enable & 0x80)) {
                if ((PCIBIOS_SUCCESSFUL !=
                     pci_write_config_byte(dev, SIS5595_ENABLE_REG,
                                           enable | 0x80))
                 || (PCIBIOS_SUCCESSFUL !=
                     pci_read_config_byte(dev, SIS5595_ENABLE_REG, &enable))
                 || (!(enable & 0x80))) {
                        /* doesn't work for some chips! */
                        dev_err(&dev->dev, "Failed to enable HWM device\n");
                        return -ENODEV;
                }
        }

        if (platform_driver_register(&sis5595_driver)) {
                dev_dbg(&dev->dev, "Failed to register sis5595 driver\n");
                goto exit;
        }

        s_bridge = pci_dev_get(dev);
        /* Sets global pdev as a side effect */
        if (sis5595_device_add(address))
                goto exit_unregister;

        /*
         * Always return failure here.  This is to allow other drivers to bind
         * to this pci device.  We don't really want to have control over the
         * pci device, we only wanted to read as few register values from it.
         */
        return -ENODEV;

exit_unregister:
        pci_dev_put(dev);
        platform_driver_unregister(&sis5595_driver);
exit:
        return -ENODEV;
}

static struct pci_driver sis5595_pci_driver = {
        .name            = "sis5595",
        .id_table        = sis5595_pci_ids,
        .probe           = sis5595_pci_probe,
};

static int __init sm_sis5595_init(void)
{
        return pci_register_driver(&sis5595_pci_driver);
}

static void __exit sm_sis5595_exit(void)
{
        pci_unregister_driver(&sis5595_pci_driver);
        if (s_bridge != NULL) {
                platform_device_unregister(pdev);
                platform_driver_unregister(&sis5595_driver);
                pci_dev_put(s_bridge);
                s_bridge = NULL;
        }
}

MODULE_AUTHOR("Aurelien Jarno <aurelien@aurel32.net>");
MODULE_DESCRIPTION("SiS 5595 Sensor device");
MODULE_LICENSE("GPL");

module_init(sm_sis5595_init);
module_exit(sm_sis5595_exit);