// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * fschmd.c
 *
 * Copyright (C) 2007 - 2009 Hans de Goede <hdegoede@redhat.com>
 */

/*
 *  Merged Fujitsu Siemens hwmon driver, supporting the Poseidon, Hermes,
 *  Scylla, Heracles, Heimdall, Hades and Syleus chips
 *
 *  Based on the original 2.4 fscscy, 2.6 fscpos, 2.6 fscher and 2.6
 *  (candidate) fschmd drivers:
 *  Copyright (C) 2006 Thilo Cestonaro
 *                      <thilo.cestonaro.external@fujitsu-siemens.com>
 *  Copyright (C) 2004, 2005 Stefan Ott <stefan@desire.ch>
 *  Copyright (C) 2003, 2004 Reinhard Nissl <rnissl@gmx.de>
 *  Copyright (c) 2001 Martin Knoblauch <mkn@teraport.de, knobi@knobisoft.de>
 *  Copyright (C) 2000 Hermann Jung <hej@odn.de>
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/jiffies.h>
#include <linux/i2c.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/sysfs.h>
#include <linux/dmi.h>
#include <linux/fs.h>
#include <linux/watchdog.h>
#include <linux/miscdevice.h>
#include <linux/uaccess.h>
#include <linux/kref.h>

/* Addresses to scan */
static const unsigned short normal_i2c[] = { 0x73, I2C_CLIENT_END };

/* Insmod parameters */
static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
        __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");

enum chips { fscpos, fscher, fscscy, fschrc, fschmd, fschds, fscsyl };

/*
 * The FSCHMD registers and other defines
 */

/* chip identification */
#define FSCHMD_REG_IDENT_0              0x00
#define FSCHMD_REG_IDENT_1              0x01
#define FSCHMD_REG_IDENT_2              0x02
#define FSCHMD_REG_REVISION             0x03

/* global control and status */
#define FSCHMD_REG_EVENT_STATE          0x04
#define FSCHMD_REG_CONTROL              0x05

#define FSCHMD_CONTROL_ALERT_LED        0x01

/* watchdog */
static const u8 FSCHMD_REG_WDOG_CONTROL[7] = {
        0x21, 0x21, 0x21, 0x21, 0x21, 0x28, 0x28 };
static const u8 FSCHMD_REG_WDOG_STATE[7] = {
        0x23, 0x23, 0x23, 0x23, 0x23, 0x29, 0x29 };
static const u8 FSCHMD_REG_WDOG_PRESET[7] = {
        0x28, 0x28, 0x28, 0x28, 0x28, 0x2a, 0x2a };

#define FSCHMD_WDOG_CONTROL_TRIGGER     0x10
#define FSCHMD_WDOG_CONTROL_STARTED     0x10 /* the same as trigger */
#define FSCHMD_WDOG_CONTROL_STOP        0x20
#define FSCHMD_WDOG_CONTROL_RESOLUTION  0x40

#define FSCHMD_WDOG_STATE_CARDRESET     0x02

/* voltages, weird order is to keep the same order as the old drivers */
static const u8 FSCHMD_REG_VOLT[7][6] = {
        { 0x45, 0x42, 0x48 },                           /* pos */
        { 0x45, 0x42, 0x48 },                           /* her */
        { 0x45, 0x42, 0x48 },                           /* scy */
        { 0x45, 0x42, 0x48 },                           /* hrc */
        { 0x45, 0x42, 0x48 },                           /* hmd */
        { 0x21, 0x20, 0x22 },                           /* hds */
        { 0x21, 0x20, 0x22, 0x23, 0x24, 0x25 },         /* syl */
};

static const int FSCHMD_NO_VOLT_SENSORS[7] = { 3, 3, 3, 3, 3, 3, 6 };

/*
 * minimum pwm at which the fan is driven (pwm can be increased depending on
 * the temp. Notice that for the scy some fans share there minimum speed.
 * Also notice that with the scy the sensor order is different than with the
 * other chips, this order was in the 2.4 driver and kept for consistency.
 */
static const u8 FSCHMD_REG_FAN_MIN[7][7] = {
        { 0x55, 0x65 },                                 /* pos */
        { 0x55, 0x65, 0xb5 },                           /* her */
        { 0x65, 0x65, 0x55, 0xa5, 0x55, 0xa5 },         /* scy */
        { 0x55, 0x65, 0xa5, 0xb5 },                     /* hrc */
        { 0x55, 0x65, 0xa5, 0xb5, 0xc5 },               /* hmd */
        { 0x55, 0x65, 0xa5, 0xb5, 0xc5 },               /* hds */
        { 0x54, 0x64, 0x74, 0x84, 0x94, 0xa4, 0xb4 },   /* syl */
};

/* actual fan speed */
static const u8 FSCHMD_REG_FAN_ACT[7][7] = {
        { 0x0e, 0x6b, 0xab },                           /* pos */
        { 0x0e, 0x6b, 0xbb },                           /* her */
        { 0x6b, 0x6c, 0x0e, 0xab, 0x5c, 0xbb },         /* scy */
        { 0x0e, 0x6b, 0xab, 0xbb },                     /* hrc */
        { 0x5b, 0x6b, 0xab, 0xbb, 0xcb },               /* hmd */
        { 0x5b, 0x6b, 0xab, 0xbb, 0xcb },               /* hds */
        { 0x57, 0x67, 0x77, 0x87, 0x97, 0xa7, 0xb7 },   /* syl */
};

/* fan status registers */
static const u8 FSCHMD_REG_FAN_STATE[7][7] = {
        { 0x0d, 0x62, 0xa2 },                           /* pos */
        { 0x0d, 0x62, 0xb2 },                           /* her */
        { 0x62, 0x61, 0x0d, 0xa2, 0x52, 0xb2 },         /* scy */
        { 0x0d, 0x62, 0xa2, 0xb2 },                     /* hrc */
        { 0x52, 0x62, 0xa2, 0xb2, 0xc2 },               /* hmd */
        { 0x52, 0x62, 0xa2, 0xb2, 0xc2 },               /* hds */
        { 0x50, 0x60, 0x70, 0x80, 0x90, 0xa0, 0xb0 },   /* syl */
};

/* fan ripple / divider registers */
static const u8 FSCHMD_REG_FAN_RIPPLE[7][7] = {
        { 0x0f, 0x6f, 0xaf },                           /* pos */
        { 0x0f, 0x6f, 0xbf },                           /* her */
        { 0x6f, 0x6f, 0x0f, 0xaf, 0x0f, 0xbf },         /* scy */
        { 0x0f, 0x6f, 0xaf, 0xbf },                     /* hrc */
        { 0x5f, 0x6f, 0xaf, 0xbf, 0xcf },               /* hmd */
        { 0x5f, 0x6f, 0xaf, 0xbf, 0xcf },               /* hds */
        { 0x56, 0x66, 0x76, 0x86, 0x96, 0xa6, 0xb6 },   /* syl */
};

static const int FSCHMD_NO_FAN_SENSORS[7] = { 3, 3, 6, 4, 5, 5, 7 };

/* Fan status register bitmasks */
#define FSCHMD_FAN_ALARM        0x04 /* called fault by FSC! */
#define FSCHMD_FAN_NOT_PRESENT  0x08
#define FSCHMD_FAN_DISABLED     0x80


/* actual temperature registers */
static const u8 FSCHMD_REG_TEMP_ACT[7][11] = {
        { 0x64, 0x32, 0x35 },                           /* pos */
        { 0x64, 0x32, 0x35 },                           /* her */
        { 0x64, 0xD0, 0x32, 0x35 },                     /* scy */
        { 0x64, 0x32, 0x35 },                           /* hrc */
        { 0x70, 0x80, 0x90, 0xd0, 0xe0 },               /* hmd */
        { 0x70, 0x80, 0x90, 0xd0, 0xe0 },               /* hds */
        { 0x58, 0x68, 0x78, 0x88, 0x98, 0xa8,           /* syl */
          0xb8, 0xc8, 0xd8, 0xe8, 0xf8 },
};

/* temperature state registers */
static const u8 FSCHMD_REG_TEMP_STATE[7][11] = {
        { 0x71, 0x81, 0x91 },                           /* pos */
        { 0x71, 0x81, 0x91 },                           /* her */
        { 0x71, 0xd1, 0x81, 0x91 },                     /* scy */
        { 0x71, 0x81, 0x91 },                           /* hrc */
        { 0x71, 0x81, 0x91, 0xd1, 0xe1 },               /* hmd */
        { 0x71, 0x81, 0x91, 0xd1, 0xe1 },               /* hds */
        { 0x59, 0x69, 0x79, 0x89, 0x99, 0xa9,           /* syl */
          0xb9, 0xc9, 0xd9, 0xe9, 0xf9 },
};

/*
 * temperature high limit registers, FSC does not document these. Proven to be
 * there with field testing on the fscher and fschrc, already supported / used
 * in the fscscy 2.4 driver. FSC has confirmed that the fschmd has registers
 * at these addresses, but doesn't want to confirm they are the same as with
 * the fscher??
 */
static const u8 FSCHMD_REG_TEMP_LIMIT[7][11] = {
        { 0, 0, 0 },                                    /* pos */
        { 0x76, 0x86, 0x96 },                           /* her */
        { 0x76, 0xd6, 0x86, 0x96 },                     /* scy */
        { 0x76, 0x86, 0x96 },                           /* hrc */
        { 0x76, 0x86, 0x96, 0xd6, 0xe6 },               /* hmd */
        { 0x76, 0x86, 0x96, 0xd6, 0xe6 },               /* hds */
        { 0x5a, 0x6a, 0x7a, 0x8a, 0x9a, 0xaa,           /* syl */
          0xba, 0xca, 0xda, 0xea, 0xfa },
};

/*
 * These were found through experimenting with an fscher, currently they are
 * not used, but we keep them around for future reference.
 * On the fscsyl AUTOP1 lives at 0x#c (so 0x5c for fan1, 0x6c for fan2, etc),
 * AUTOP2 lives at 0x#e, and 0x#1 is a bitmask defining which temps influence
 * the fan speed.
 * static const u8 FSCHER_REG_TEMP_AUTOP1[] =   { 0x73, 0x83, 0x93 };
 * static const u8 FSCHER_REG_TEMP_AUTOP2[] =   { 0x75, 0x85, 0x95 };
 */

static const int FSCHMD_NO_TEMP_SENSORS[7] = { 3, 3, 4, 3, 5, 5, 11 };

/* temp status register bitmasks */
#define FSCHMD_TEMP_WORKING     0x01
#define FSCHMD_TEMP_ALERT       0x02
#define FSCHMD_TEMP_DISABLED    0x80
/* there only really is an alarm if the sensor is working and alert == 1 */
#define FSCHMD_TEMP_ALARM_MASK \
        (FSCHMD_TEMP_WORKING | FSCHMD_TEMP_ALERT)

/*
 * Functions declarations
 */

static int fschmd_probe(struct i2c_client *client);
static int fschmd_detect(struct i2c_client *client,
                         struct i2c_board_info *info);
static void fschmd_remove(struct i2c_client *client);
static struct fschmd_data *fschmd_update_device(struct device *dev);

/*
 * Driver data (common to all clients)
 */

static const struct i2c_device_id fschmd_id[] = {
        { "fscpos", fscpos },
        { "fscher", fscher },
        { "fscscy", fscscy },
        { "fschrc", fschrc },
        { "fschmd", fschmd },
        { "fschds", fschds },
        { "fscsyl", fscsyl },
        { }
};
MODULE_DEVICE_TABLE(i2c, fschmd_id);

static struct i2c_driver fschmd_driver = {
        .class          = I2C_CLASS_HWMON,
        .driver = {
                .name   = "fschmd",
        },
        .probe          = fschmd_probe,
        .remove         = fschmd_remove,
        .id_table       = fschmd_id,
        .detect         = fschmd_detect,
        .address_list   = normal_i2c,
};

/*
 * Client data (each client gets its own)
 */

struct fschmd_data {
        struct i2c_client *client;
        struct device *hwmon_dev;
        struct mutex update_lock;
        struct mutex watchdog_lock;
        struct list_head list; /* member of the watchdog_data_list */
        struct kref kref;
        struct miscdevice watchdog_miscdev;
        enum chips kind;
        unsigned long watchdog_is_open;
        char watchdog_expect_close;
        char watchdog_name[10]; /* must be unique to avoid sysfs conflict */
        bool valid; /* false until following fields are valid */
        unsigned long last_updated; /* in jiffies */

        /* register values */
        u8 revision;            /* chip revision */
        u8 global_control;      /* global control register */
        u8 watchdog_control;    /* watchdog control register */
        u8 watchdog_state;      /* watchdog status register */
        u8 watchdog_preset;     /* watchdog counter preset on trigger val */
        u8 volt[6];             /* voltage */
        u8 temp_act[11];        /* temperature */
        u8 temp_status[11];     /* status of sensor */
        u8 temp_max[11];        /* high temp limit, notice: undocumented! */
        u8 fan_act[7];          /* fans revolutions per second */
        u8 fan_status[7];       /* fan status */
        u8 fan_min[7];          /* fan min value for rps */
        u8 fan_ripple[7];       /* divider for rps */
};

/*
 * Global variables to hold information read from special DMI tables, which are
 * available on FSC machines with an fscher or later chip. There is no need to
 * protect these with a lock as they are only modified from our attach function
 * which always gets called with the i2c-core lock held and never accessed
 * before the attach function is done with them.
 */
static int dmi_mult[6] = { 490, 200, 100, 100, 200, 100 };
static int dmi_offset[6] = { 0, 0, 0, 0, 0, 0 };
static int dmi_vref = -1;

/*
 * Somewhat ugly :( global data pointer list with all fschmd devices, so that
 * we can find our device data as when using misc_register there is no other
 * method to get to ones device data from the open fop.
 */
static LIST_HEAD(watchdog_data_list);
/* Note this lock not only protect list access, but also data.kref access */
static DEFINE_MUTEX(watchdog_data_mutex);

/*
 * Release our data struct when we're detached from the i2c client *and* all
 * references to our watchdog device are released
 */
static void fschmd_release_resources(struct kref *ref)
{
        struct fschmd_data *data = container_of(ref, struct fschmd_data, kref);
        kfree(data);
}

/*
 * Sysfs attr show / store functions
 */

static ssize_t in_value_show(struct device *dev,
                             struct device_attribute *devattr, char *buf)
{
        const int max_reading[3] = { 14200, 6600, 3300 };
        int index = to_sensor_dev_attr(devattr)->index;
        struct fschmd_data *data = fschmd_update_device(dev);

        if (data->kind == fscher || data->kind >= fschrc)
                return sprintf(buf, "%d\n", (data->volt[index] * dmi_vref *
                        dmi_mult[index]) / 255 + dmi_offset[index]);
        else
                return sprintf(buf, "%d\n", (data->volt[index] *
                        max_reading[index] + 128) / 255);
}


#define TEMP_FROM_REG(val)      (((val) - 128) * 1000)

static ssize_t temp_value_show(struct device *dev,
                               struct device_attribute *devattr, char *buf)
{
        int index = to_sensor_dev_attr(devattr)->index;
        struct fschmd_data *data = fschmd_update_device(dev);

        return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp_act[index]));
}

static ssize_t temp_max_show(struct device *dev,
                             struct device_attribute *devattr, char *buf)
{
        int index = to_sensor_dev_attr(devattr)->index;
        struct fschmd_data *data = fschmd_update_device(dev);

        return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp_max[index]));
}

static ssize_t temp_max_store(struct device *dev,
                              struct device_attribute *devattr,
                              const char *buf, size_t count)
{
        int index = to_sensor_dev_attr(devattr)->index;
        struct fschmd_data *data = dev_get_drvdata(dev);
        long v;
        int err;

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

        v = clamp_val(v / 1000, -128, 127) + 128;

        mutex_lock(&data->update_lock);
        i2c_smbus_write_byte_data(to_i2c_client(dev),
                FSCHMD_REG_TEMP_LIMIT[data->kind][index], v);
        data->temp_max[index] = v;
        mutex_unlock(&data->update_lock);

        return count;
}

static ssize_t temp_fault_show(struct device *dev,
                               struct device_attribute *devattr, char *buf)
{
        int index = to_sensor_dev_attr(devattr)->index;
        struct fschmd_data *data = fschmd_update_device(dev);

        /* bit 0 set means sensor working ok, so no fault! */
        if (data->temp_status[index] & FSCHMD_TEMP_WORKING)
                return sprintf(buf, "0\n");
        else
                return sprintf(buf, "1\n");
}

static ssize_t temp_alarm_show(struct device *dev,
                               struct device_attribute *devattr, char *buf)
{
        int index = to_sensor_dev_attr(devattr)->index;
        struct fschmd_data *data = fschmd_update_device(dev);

        if ((data->temp_status[index] & FSCHMD_TEMP_ALARM_MASK) ==
                        FSCHMD_TEMP_ALARM_MASK)
                return sprintf(buf, "1\n");
        else
                return sprintf(buf, "0\n");
}


#define RPM_FROM_REG(val)       ((val) * 60)

static ssize_t fan_value_show(struct device *dev,
                              struct device_attribute *devattr, char *buf)
{
        int index = to_sensor_dev_attr(devattr)->index;
        struct fschmd_data *data = fschmd_update_device(dev);

        return sprintf(buf, "%u\n", RPM_FROM_REG(data->fan_act[index]));
}

static ssize_t fan_div_show(struct device *dev,
                            struct device_attribute *devattr, char *buf)
{
        int index = to_sensor_dev_attr(devattr)->index;
        struct fschmd_data *data = fschmd_update_device(dev);

        /* bits 2..7 reserved => mask with 3 */
        return sprintf(buf, "%d\n", 1 << (data->fan_ripple[index] & 3));
}

static ssize_t fan_div_store(struct device *dev,
                             struct device_attribute *devattr,
                             const char *buf, size_t count)
{
        u8 reg;
        int index = to_sensor_dev_attr(devattr)->index;
        struct fschmd_data *data = dev_get_drvdata(dev);
        /* supported values: 2, 4, 8 */
        unsigned long v;
        int err;

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

        switch (v) {
        case 2:
                v = 1;
                break;
        case 4:
                v = 2;
                break;
        case 8:
                v = 3;
                break;
        default:
                dev_err(dev,
                        "fan_div value %lu not supported. Choose one of 2, 4 or 8!\n",
                        v);
                return -EINVAL;
        }

        mutex_lock(&data->update_lock);

        reg = i2c_smbus_read_byte_data(to_i2c_client(dev),
                FSCHMD_REG_FAN_RIPPLE[data->kind][index]);

        /* bits 2..7 reserved => mask with 0x03 */
        reg &= ~0x03;
        reg |= v;

        i2c_smbus_write_byte_data(to_i2c_client(dev),
                FSCHMD_REG_FAN_RIPPLE[data->kind][index], reg);

        data->fan_ripple[index] = reg;

        mutex_unlock(&data->update_lock);

        return count;
}

static ssize_t fan_alarm_show(struct device *dev,
                              struct device_attribute *devattr, char *buf)
{
        int index = to_sensor_dev_attr(devattr)->index;
        struct fschmd_data *data = fschmd_update_device(dev);

        if (data->fan_status[index] & FSCHMD_FAN_ALARM)
                return sprintf(buf, "1\n");
        else
                return sprintf(buf, "0\n");
}

static ssize_t fan_fault_show(struct device *dev,
                              struct device_attribute *devattr, char *buf)
{
        int index = to_sensor_dev_attr(devattr)->index;
        struct fschmd_data *data = fschmd_update_device(dev);

        if (data->fan_status[index] & FSCHMD_FAN_NOT_PRESENT)
                return sprintf(buf, "1\n");
        else
                return sprintf(buf, "0\n");
}


static ssize_t pwm_auto_point1_pwm_show(struct device *dev,
                                        struct device_attribute *devattr,
                                        char *buf)
{
        int index = to_sensor_dev_attr(devattr)->index;
        struct fschmd_data *data = fschmd_update_device(dev);
        int val = data->fan_min[index];

        /* 0 = allow turning off (except on the syl), 1-255 = 50-100% */
        if (val || data->kind == fscsyl)
                val = val / 2 + 128;

        return sprintf(buf, "%d\n", val);
}

static ssize_t pwm_auto_point1_pwm_store(struct device *dev,
                                         struct device_attribute *devattr,
                                         const char *buf, size_t count)
{
        int index = to_sensor_dev_attr(devattr)->index;
        struct fschmd_data *data = dev_get_drvdata(dev);
        unsigned long v;
        int err;

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

        /* reg: 0 = allow turning off (except on the syl), 1-255 = 50-100% */
        if (v || data->kind == fscsyl) {
                v = clamp_val(v, 128, 255);
                v = (v - 128) * 2 + 1;
        }

        mutex_lock(&data->update_lock);

        i2c_smbus_write_byte_data(to_i2c_client(dev),
                FSCHMD_REG_FAN_MIN[data->kind][index], v);
        data->fan_min[index] = v;

        mutex_unlock(&data->update_lock);

        return count;
}


/*
 * The FSC hwmon family has the ability to force an attached alert led to flash
 * from software, we export this as an alert_led sysfs attr
 */
static ssize_t alert_led_show(struct device *dev,
        struct device_attribute *devattr, char *buf)
{
        struct fschmd_data *data = fschmd_update_device(dev);

        if (data->global_control & FSCHMD_CONTROL_ALERT_LED)
                return sprintf(buf, "1\n");
        else
                return sprintf(buf, "0\n");
}

static ssize_t alert_led_store(struct device *dev,
        struct device_attribute *devattr, const char *buf, size_t count)
{
        u8 reg;
        struct fschmd_data *data = dev_get_drvdata(dev);
        unsigned long v;
        int err;

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

        mutex_lock(&data->update_lock);

        reg = i2c_smbus_read_byte_data(to_i2c_client(dev), FSCHMD_REG_CONTROL);

        if (v)
                reg |= FSCHMD_CONTROL_ALERT_LED;
        else
                reg &= ~FSCHMD_CONTROL_ALERT_LED;

        i2c_smbus_write_byte_data(to_i2c_client(dev), FSCHMD_REG_CONTROL, reg);

        data->global_control = reg;

        mutex_unlock(&data->update_lock);

        return count;
}

static DEVICE_ATTR_RW(alert_led);

static struct sensor_device_attribute fschmd_attr[] = {
        SENSOR_ATTR_RO(in0_input, in_value, 0),
        SENSOR_ATTR_RO(in1_input, in_value, 1),
        SENSOR_ATTR_RO(in2_input, in_value, 2),
        SENSOR_ATTR_RO(in3_input, in_value, 3),
        SENSOR_ATTR_RO(in4_input, in_value, 4),
        SENSOR_ATTR_RO(in5_input, in_value, 5),
};

static struct sensor_device_attribute fschmd_temp_attr[] = {
        SENSOR_ATTR_RO(temp1_input, temp_value, 0),
        SENSOR_ATTR_RW(temp1_max, temp_max, 0),
        SENSOR_ATTR_RO(temp1_fault, temp_fault, 0),
        SENSOR_ATTR_RO(temp1_alarm, temp_alarm, 0),
        SENSOR_ATTR_RO(temp2_input, temp_value, 1),
        SENSOR_ATTR_RW(temp2_max, temp_max, 1),
        SENSOR_ATTR_RO(temp2_fault, temp_fault, 1),
        SENSOR_ATTR_RO(temp2_alarm, temp_alarm, 1),
        SENSOR_ATTR_RO(temp3_input, temp_value, 2),
        SENSOR_ATTR_RW(temp3_max, temp_max, 2),
        SENSOR_ATTR_RO(temp3_fault, temp_fault, 2),
        SENSOR_ATTR_RO(temp3_alarm, temp_alarm, 2),
        SENSOR_ATTR_RO(temp4_input, temp_value, 3),
        SENSOR_ATTR_RW(temp4_max, temp_max, 3),
        SENSOR_ATTR_RO(temp4_fault, temp_fault, 3),
        SENSOR_ATTR_RO(temp4_alarm, temp_alarm, 3),
        SENSOR_ATTR_RO(temp5_input, temp_value, 4),
        SENSOR_ATTR_RW(temp5_max, temp_max, 4),
        SENSOR_ATTR_RO(temp5_fault, temp_fault, 4),
        SENSOR_ATTR_RO(temp5_alarm, temp_alarm, 4),
        SENSOR_ATTR_RO(temp6_input, temp_value, 5),
        SENSOR_ATTR_RW(temp6_max, temp_max, 5),
        SENSOR_ATTR_RO(temp6_fault, temp_fault, 5),
        SENSOR_ATTR_RO(temp6_alarm, temp_alarm, 5),
        SENSOR_ATTR_RO(temp7_input, temp_value, 6),
        SENSOR_ATTR_RW(temp7_max, temp_max, 6),
        SENSOR_ATTR_RO(temp7_fault, temp_fault, 6),
        SENSOR_ATTR_RO(temp7_alarm, temp_alarm, 6),
        SENSOR_ATTR_RO(temp8_input, temp_value, 7),
        SENSOR_ATTR_RW(temp8_max, temp_max, 7),
        SENSOR_ATTR_RO(temp8_fault, temp_fault, 7),
        SENSOR_ATTR_RO(temp8_alarm, temp_alarm, 7),
        SENSOR_ATTR_RO(temp9_input, temp_value, 8),
        SENSOR_ATTR_RW(temp9_max, temp_max, 8),
        SENSOR_ATTR_RO(temp9_fault, temp_fault, 8),
        SENSOR_ATTR_RO(temp9_alarm, temp_alarm, 8),
        SENSOR_ATTR_RO(temp10_input, temp_value, 9),
        SENSOR_ATTR_RW(temp10_max, temp_max, 9),
        SENSOR_ATTR_RO(temp10_fault, temp_fault, 9),
        SENSOR_ATTR_RO(temp10_alarm, temp_alarm, 9),
        SENSOR_ATTR_RO(temp11_input, temp_value, 10),
        SENSOR_ATTR_RW(temp11_max, temp_max, 10),
        SENSOR_ATTR_RO(temp11_fault, temp_fault, 10),
        SENSOR_ATTR_RO(temp11_alarm, temp_alarm, 10),
};

static struct sensor_device_attribute fschmd_fan_attr[] = {
        SENSOR_ATTR_RO(fan1_input, fan_value, 0),
        SENSOR_ATTR_RW(fan1_div, fan_div, 0),
        SENSOR_ATTR_RO(fan1_alarm, fan_alarm, 0),
        SENSOR_ATTR_RO(fan1_fault, fan_fault, 0),
        SENSOR_ATTR_RW(pwm1_auto_point1_pwm, pwm_auto_point1_pwm, 0),
        SENSOR_ATTR_RO(fan2_input, fan_value, 1),
        SENSOR_ATTR_RW(fan2_div, fan_div, 1),
        SENSOR_ATTR_RO(fan2_alarm, fan_alarm, 1),
        SENSOR_ATTR_RO(fan2_fault, fan_fault, 1),
        SENSOR_ATTR_RW(pwm2_auto_point1_pwm, pwm_auto_point1_pwm, 1),
        SENSOR_ATTR_RO(fan3_input, fan_value, 2),
        SENSOR_ATTR_RW(fan3_div, fan_div, 2),
        SENSOR_ATTR_RO(fan3_alarm, fan_alarm, 2),
        SENSOR_ATTR_RO(fan3_fault, fan_fault, 2),
        SENSOR_ATTR_RW(pwm3_auto_point1_pwm, pwm_auto_point1_pwm, 2),
        SENSOR_ATTR_RO(fan4_input, fan_value, 3),
        SENSOR_ATTR_RW(fan4_div, fan_div, 3),
        SENSOR_ATTR_RO(fan4_alarm, fan_alarm, 3),
        SENSOR_ATTR_RO(fan4_fault, fan_fault, 3),
        SENSOR_ATTR_RW(pwm4_auto_point1_pwm, pwm_auto_point1_pwm, 3),
        SENSOR_ATTR_RO(fan5_input, fan_value, 4),
        SENSOR_ATTR_RW(fan5_div, fan_div, 4),
        SENSOR_ATTR_RO(fan5_alarm, fan_alarm, 4),
        SENSOR_ATTR_RO(fan5_fault, fan_fault, 4),
        SENSOR_ATTR_RW(pwm5_auto_point1_pwm, pwm_auto_point1_pwm, 4),
        SENSOR_ATTR_RO(fan6_input, fan_value, 5),
        SENSOR_ATTR_RW(fan6_div, fan_div, 5),
        SENSOR_ATTR_RO(fan6_alarm, fan_alarm, 5),
        SENSOR_ATTR_RO(fan6_fault, fan_fault, 5),
        SENSOR_ATTR_RW(pwm6_auto_point1_pwm, pwm_auto_point1_pwm, 5),
        SENSOR_ATTR_RO(fan7_input, fan_value, 6),
        SENSOR_ATTR_RW(fan7_div, fan_div, 6),
        SENSOR_ATTR_RO(fan7_alarm, fan_alarm, 6),
        SENSOR_ATTR_RO(fan7_fault, fan_fault, 6),
        SENSOR_ATTR_RW(pwm7_auto_point1_pwm, pwm_auto_point1_pwm, 6),
};


/*
 * Watchdog routines
 */

static int watchdog_set_timeout(struct fschmd_data *data, int timeout)
{
        int ret, resolution;
        int kind = data->kind + 1; /* 0-x array index -> 1-x module param */

        /* 2 second or 60 second resolution? */
        if (timeout <= 510 || kind == fscpos || kind == fscscy)
                resolution = 2;
        else
                resolution = 60;

        if (timeout < resolution || timeout > (resolution * 255))
                return -EINVAL;

        mutex_lock(&data->watchdog_lock);
        if (!data->client) {
                ret = -ENODEV;
                goto leave;
        }

        if (resolution == 2)
                data->watchdog_control &= ~FSCHMD_WDOG_CONTROL_RESOLUTION;
        else
                data->watchdog_control |= FSCHMD_WDOG_CONTROL_RESOLUTION;

        data->watchdog_preset = DIV_ROUND_UP(timeout, resolution);

        /* Write new timeout value */
        i2c_smbus_write_byte_data(data->client,
                FSCHMD_REG_WDOG_PRESET[data->kind], data->watchdog_preset);
        /* Write new control register, do not trigger! */
        i2c_smbus_write_byte_data(data->client,
                FSCHMD_REG_WDOG_CONTROL[data->kind],
                data->watchdog_control & ~FSCHMD_WDOG_CONTROL_TRIGGER);

        ret = data->watchdog_preset * resolution;

leave:
        mutex_unlock(&data->watchdog_lock);
        return ret;
}

static int watchdog_get_timeout(struct fschmd_data *data)
{
        int timeout;

        mutex_lock(&data->watchdog_lock);
        if (data->watchdog_control & FSCHMD_WDOG_CONTROL_RESOLUTION)
                timeout = data->watchdog_preset * 60;
        else
                timeout = data->watchdog_preset * 2;
        mutex_unlock(&data->watchdog_lock);

        return timeout;
}

static int watchdog_trigger(struct fschmd_data *data)
{
        int ret = 0;

        mutex_lock(&data->watchdog_lock);
        if (!data->client) {
                ret = -ENODEV;
                goto leave;
        }

        data->watchdog_control |= FSCHMD_WDOG_CONTROL_TRIGGER;
        i2c_smbus_write_byte_data(data->client,
                                  FSCHMD_REG_WDOG_CONTROL[data->kind],
                                  data->watchdog_control);
leave:
        mutex_unlock(&data->watchdog_lock);
        return ret;
}

static int watchdog_stop(struct fschmd_data *data)
{
        int ret = 0;

        mutex_lock(&data->watchdog_lock);
        if (!data->client) {
                ret = -ENODEV;
                goto leave;
        }

        data->watchdog_control &= ~FSCHMD_WDOG_CONTROL_STARTED;
        /*
         * Don't store the stop flag in our watchdog control register copy, as
         * its a write only bit (read always returns 0)
         */
        i2c_smbus_write_byte_data(data->client,
                FSCHMD_REG_WDOG_CONTROL[data->kind],
                data->watchdog_control | FSCHMD_WDOG_CONTROL_STOP);
leave:
        mutex_unlock(&data->watchdog_lock);
        return ret;
}

static int watchdog_open(struct inode *inode, struct file *filp)
{
        struct fschmd_data *pos, *data = NULL;
        int watchdog_is_open;

        /*
         * We get called from drivers/char/misc.c with misc_mtx hold, and we
         * call misc_register() from fschmd_probe() with watchdog_data_mutex
         * hold, as misc_register() takes the misc_mtx lock, this is a possible
         * deadlock, so we use mutex_trylock here.
         */
        if (!mutex_trylock(&watchdog_data_mutex))
                return -ERESTARTSYS;
        list_for_each_entry(pos, &watchdog_data_list, list) {
                if (pos->watchdog_miscdev.minor == iminor(inode)) {
                        data = pos;
                        break;
                }
        }
        /* Note we can never not have found data, so we don't check for this */
        watchdog_is_open = test_and_set_bit(0, &data->watchdog_is_open);
        if (!watchdog_is_open)
                kref_get(&data->kref);
        mutex_unlock(&watchdog_data_mutex);

        if (watchdog_is_open)
                return -EBUSY;

        /* Start the watchdog */
        watchdog_trigger(data);
        filp->private_data = data;

        return stream_open(inode, filp);
}

static int watchdog_release(struct inode *inode, struct file *filp)
{
        struct fschmd_data *data = filp->private_data;

        if (data->watchdog_expect_close) {
                watchdog_stop(data);
                data->watchdog_expect_close = 0;
        } else {
                watchdog_trigger(data);
                dev_crit(&data->client->dev,
                        "unexpected close, not stopping watchdog!\n");
        }

        clear_bit(0, &data->watchdog_is_open);

        mutex_lock(&watchdog_data_mutex);
        kref_put(&data->kref, fschmd_release_resources);
        mutex_unlock(&watchdog_data_mutex);

        return 0;
}

static ssize_t watchdog_write(struct file *filp, const char __user *buf,
        size_t count, loff_t *offset)
{
        int ret;
        struct fschmd_data *data = filp->private_data;

        if (count) {
                if (!nowayout) {
                        size_t i;

                        /* Clear it in case it was set with a previous write */
                        data->watchdog_expect_close = 0;

                        for (i = 0; i != count; i++) {
                                char c;
                                if (get_user(c, buf + i))
                                        return -EFAULT;
                                if (c == 'V')
                                        data->watchdog_expect_close = 1;
                        }
                }
                ret = watchdog_trigger(data);
                if (ret < 0)
                        return ret;
        }
        return count;
}

static long watchdog_ioctl(struct file *filp, unsigned int cmd,
                           unsigned long arg)
{
        struct watchdog_info ident = {
                .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT |
                                WDIOF_CARDRESET,
                .identity = "FSC watchdog"
        };
        int i, ret = 0;
        struct fschmd_data *data = filp->private_data;

        switch (cmd) {
        case WDIOC_GETSUPPORT:
                ident.firmware_version = data->revision;
                if (!nowayout)
                        ident.options |= WDIOF_MAGICCLOSE;
                if (copy_to_user((void __user *)arg, &ident, sizeof(ident)))
                        ret = -EFAULT;
                break;

        case WDIOC_GETSTATUS:
                ret = put_user(0, (int __user *)arg);
                break;

        case WDIOC_GETBOOTSTATUS:
                if (data->watchdog_state & FSCHMD_WDOG_STATE_CARDRESET)
                        ret = put_user(WDIOF_CARDRESET, (int __user *)arg);
                else
                        ret = put_user(0, (int __user *)arg);
                break;

        case WDIOC_KEEPALIVE:
                ret = watchdog_trigger(data);
                break;

        case WDIOC_GETTIMEOUT:
                i = watchdog_get_timeout(data);
                ret = put_user(i, (int __user *)arg);
                break;

        case WDIOC_SETTIMEOUT:
                if (get_user(i, (int __user *)arg)) {
                        ret = -EFAULT;
                        break;
                }
                ret = watchdog_set_timeout(data, i);
                if (ret > 0)
                        ret = put_user(ret, (int __user *)arg);
                break;

        case WDIOC_SETOPTIONS:
                if (get_user(i, (int __user *)arg)) {
                        ret = -EFAULT;
                        break;
                }

                if (i & WDIOS_DISABLECARD)
                        ret = watchdog_stop(data);
                else if (i & WDIOS_ENABLECARD)
                        ret = watchdog_trigger(data);
                else
                        ret = -EINVAL;

                break;
        default:
                ret = -ENOTTY;
        }
        return ret;
}

static const struct file_operations watchdog_fops = {
        .owner = THIS_MODULE,
        .open = watchdog_open,
        .release = watchdog_release,
        .write = watchdog_write,
        .unlocked_ioctl = watchdog_ioctl,
        .compat_ioctl = compat_ptr_ioctl,
};


/*
 * Detect, register, unregister and update device functions
 */

/*
 * DMI decode routine to read voltage scaling factors from special DMI tables,
 * which are available on FSC machines with an fscher or later chip.
 */
static void fschmd_dmi_decode(const struct dmi_header *header, void *dummy)
{
        int i, mult[3] = { 0 }, offset[3] = { 0 }, vref = 0, found = 0;

        /*
         * dmi code ugliness, we get passed the address of the contents of
         * a complete DMI record, but in the form of a dmi_header pointer, in
         * reality this address holds header->length bytes of which the header
         * are the first 4 bytes
         */
        u8 *dmi_data = (u8 *)header;

        /* We are looking for OEM-specific type 185 */
        if (header->type != 185)
                return;

        /*
         * we are looking for what Siemens calls "subtype" 19, the subtype
         * is stored in byte 5 of the dmi block
         */
        if (header->length < 5 || dmi_data[4] != 19)
                return;

        /*
         * After the subtype comes 1 unknown byte and then blocks of 5 bytes,
         * consisting of what Siemens calls an "Entity" number, followed by
         * 2 16-bit words in LSB first order
         */
        for (i = 6; (i + 4) < header->length; i += 5) {
                /* entity 1 - 3: voltage multiplier and offset */
                if (dmi_data[i] >= 1 && dmi_data[i] <= 3) {
                        /* Our in sensors order and the DMI order differ */
                        const int shuffle[3] = { 1, 0, 2 };
                        int in = shuffle[dmi_data[i] - 1];

                        /* Check for twice the same entity */
                        if (found & (1 << in))
                                return;

                        mult[in] = dmi_data[i + 1] | (dmi_data[i + 2] << 8);
                        offset[in] = dmi_data[i + 3] | (dmi_data[i + 4] << 8);

                        found |= 1 << in;
                }

                /* entity 7: reference voltage */
                if (dmi_data[i] == 7) {
                        /* Check for twice the same entity */
                        if (found & 0x08)
                                return;

                        vref = dmi_data[i + 1] | (dmi_data[i + 2] << 8);

                        found |= 0x08;
                }
        }

        if (found == 0x0F) {
                for (i = 0; i < 3; i++) {
                        dmi_mult[i] = mult[i] * 10;
                        dmi_offset[i] = offset[i] * 10;
                }
                /*
                 * According to the docs there should be separate dmi entries
                 * for the mult's and offsets of in3-5 of the syl, but on
                 * my test machine these are not present
                 */
                dmi_mult[3] = dmi_mult[2];
                dmi_mult[4] = dmi_mult[1];
                dmi_mult[5] = dmi_mult[2];
                dmi_offset[3] = dmi_offset[2];
                dmi_offset[4] = dmi_offset[1];
                dmi_offset[5] = dmi_offset[2];
                dmi_vref = vref;
        }
}

static int fschmd_detect(struct i2c_client *client,
                         struct i2c_board_info *info)
{
        enum chips kind;
        struct i2c_adapter *adapter = client->adapter;
        char id[4];

        if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
                return -ENODEV;

        /* Detect & Identify the chip */
        id[0] = i2c_smbus_read_byte_data(client, FSCHMD_REG_IDENT_0);
        id[1] = i2c_smbus_read_byte_data(client, FSCHMD_REG_IDENT_1);
        id[2] = i2c_smbus_read_byte_data(client, FSCHMD_REG_IDENT_2);
        id[3] = '\0';

        if (!strcmp(id, "PEG"))
                kind = fscpos;
        else if (!strcmp(id, "HER"))
                kind = fscher;
        else if (!strcmp(id, "SCY"))
                kind = fscscy;
        else if (!strcmp(id, "HRC"))
                kind = fschrc;
        else if (!strcmp(id, "HMD"))
                kind = fschmd;
        else if (!strcmp(id, "HDS"))
                kind = fschds;
        else if (!strcmp(id, "SYL"))
                kind = fscsyl;
        else
                return -ENODEV;

        strscpy(info->type, fschmd_id[kind].name, I2C_NAME_SIZE);

        return 0;
}

static int fschmd_probe(struct i2c_client *client)
{
        struct fschmd_data *data;
        static const char * const names[7] = { "Poseidon", "Hermes", "Scylla",
                                "Heracles", "Heimdall", "Hades", "Syleus" };
        static const int watchdog_minors[] = { WATCHDOG_MINOR, 212, 213, 214, 215 };
        int i, err;
        enum chips kind = (uintptr_t)i2c_get_match_data(client);

        data = kzalloc_obj(struct fschmd_data);
        if (!data)
                return -ENOMEM;

        i2c_set_clientdata(client, data);
        mutex_init(&data->update_lock);
        mutex_init(&data->watchdog_lock);
        INIT_LIST_HEAD(&data->list);
        kref_init(&data->kref);
        /*
         * Store client pointer in our data struct for watchdog usage
         * (where the client is found through a data ptr instead of the
         * otherway around)
         */
        data->client = client;
        data->kind = kind;

        if (kind == fscpos) {
                /*
                 * The Poseidon has hardwired temp limits, fill these
                 * in for the alarm resetting code
                 */
                data->temp_max[0] = 70 + 128;
                data->temp_max[1] = 50 + 128;
                data->temp_max[2] = 50 + 128;
        }

        /* Read the special DMI table for fscher and newer chips */
        if ((kind == fscher || kind >= fschrc) && dmi_vref == -1) {
                dmi_walk(fschmd_dmi_decode, NULL);
                if (dmi_vref == -1) {
                        dev_warn(&client->dev,
                                "Couldn't get voltage scaling factors from "
                                "BIOS DMI table, using builtin defaults\n");
                        dmi_vref = 33;
                }
        }

        /* Read in some never changing registers */
        data->revision = i2c_smbus_read_byte_data(client, FSCHMD_REG_REVISION);
        data->global_control = i2c_smbus_read_byte_data(client,
                                        FSCHMD_REG_CONTROL);
        data->watchdog_control = i2c_smbus_read_byte_data(client,
                                        FSCHMD_REG_WDOG_CONTROL[data->kind]);
        data->watchdog_state = i2c_smbus_read_byte_data(client,
                                        FSCHMD_REG_WDOG_STATE[data->kind]);
        data->watchdog_preset = i2c_smbus_read_byte_data(client,
                                        FSCHMD_REG_WDOG_PRESET[data->kind]);

        err = device_create_file(&client->dev, &dev_attr_alert_led);
        if (err)
                goto exit_detach;

        for (i = 0; i < FSCHMD_NO_VOLT_SENSORS[data->kind]; i++) {
                err = device_create_file(&client->dev,
                                        &fschmd_attr[i].dev_attr);
                if (err)
                        goto exit_detach;
        }

        for (i = 0; i < (FSCHMD_NO_TEMP_SENSORS[data->kind] * 4); i++) {
                /* Poseidon doesn't have TEMP_LIMIT registers */
                if (kind == fscpos && fschmd_temp_attr[i].dev_attr.show ==
                                temp_max_show)
                        continue;

                if (kind == fscsyl) {
                        if (i % 4 == 0)
                                data->temp_status[i / 4] =
                                        i2c_smbus_read_byte_data(client,
                                                FSCHMD_REG_TEMP_STATE
                                                [data->kind][i / 4]);
                        if (data->temp_status[i / 4] & FSCHMD_TEMP_DISABLED)
                                continue;
                }

                err = device_create_file(&client->dev,
                                        &fschmd_temp_attr[i].dev_attr);
                if (err)
                        goto exit_detach;
        }

        for (i = 0; i < (FSCHMD_NO_FAN_SENSORS[data->kind] * 5); i++) {
                /* Poseidon doesn't have a FAN_MIN register for its 3rd fan */
                if (kind == fscpos &&
                                !strcmp(fschmd_fan_attr[i].dev_attr.attr.name,
                                        "pwm3_auto_point1_pwm"))
                        continue;

                if (kind == fscsyl) {
                        if (i % 5 == 0)
                                data->fan_status[i / 5] =
                                        i2c_smbus_read_byte_data(client,
                                                FSCHMD_REG_FAN_STATE
                                                [data->kind][i / 5]);
                        if (data->fan_status[i / 5] & FSCHMD_FAN_DISABLED)
                                continue;
                }

                err = device_create_file(&client->dev,
                                        &fschmd_fan_attr[i].dev_attr);
                if (err)
                        goto exit_detach;
        }

        data->hwmon_dev = hwmon_device_register(&client->dev);
        if (IS_ERR(data->hwmon_dev)) {
                err = PTR_ERR(data->hwmon_dev);
                data->hwmon_dev = NULL;
                goto exit_detach;
        }

        /*
         * We take the data_mutex lock early so that watchdog_open() cannot
         * run when misc_register() has completed, but we've not yet added
         * our data to the watchdog_data_list (and set the default timeout)
         */
        mutex_lock(&watchdog_data_mutex);
        for (i = 0; i < ARRAY_SIZE(watchdog_minors); i++) {
                /* Register our watchdog part */
                snprintf(data->watchdog_name, sizeof(data->watchdog_name),
                        "watchdog%c", (i == 0) ? '\0' : ('0' + i));
                data->watchdog_miscdev.name = data->watchdog_name;
                data->watchdog_miscdev.fops = &watchdog_fops;
                data->watchdog_miscdev.minor = watchdog_minors[i];
                err = misc_register(&data->watchdog_miscdev);
                if (err == -EBUSY)
                        continue;
                if (err) {
                        data->watchdog_miscdev.minor = 0;
                        dev_err(&client->dev,
                                "Registering watchdog chardev: %d\n", err);
                        break;
                }

                list_add(&data->list, &watchdog_data_list);
                watchdog_set_timeout(data, 60);
                dev_info(&client->dev,
                        "Registered watchdog chardev major 10, minor: %d\n",
                        watchdog_minors[i]);
                break;
        }
        if (i == ARRAY_SIZE(watchdog_minors)) {
                data->watchdog_miscdev.minor = 0;
                dev_warn(&client->dev,
                         "Couldn't register watchdog chardev (due to no free minor)\n");
        }
        mutex_unlock(&watchdog_data_mutex);

        dev_info(&client->dev, "Detected FSC %s chip, revision: %d\n",
                names[data->kind], (int) data->revision);

        return 0;

exit_detach:
        fschmd_remove(client); /* will also free data for us */
        return err;
}

static void fschmd_remove(struct i2c_client *client)
{
        struct fschmd_data *data = i2c_get_clientdata(client);
        int i;

        /* Unregister the watchdog (if registered) */
        if (data->watchdog_miscdev.minor) {
                misc_deregister(&data->watchdog_miscdev);
                if (data->watchdog_is_open) {
                        dev_warn(&client->dev,
                                "i2c client detached with watchdog open! "
                                "Stopping watchdog.\n");
                        watchdog_stop(data);
                }
                mutex_lock(&watchdog_data_mutex);
                list_del(&data->list);
                mutex_unlock(&watchdog_data_mutex);
                /* Tell the watchdog code the client is gone */
                mutex_lock(&data->watchdog_lock);
                data->client = NULL;
                mutex_unlock(&data->watchdog_lock);
        }

        /*
         * Check if registered in case we're called from fschmd_detect
         * to cleanup after an error
         */
        if (data->hwmon_dev)
                hwmon_device_unregister(data->hwmon_dev);

        device_remove_file(&client->dev, &dev_attr_alert_led);
        for (i = 0; i < (FSCHMD_NO_VOLT_SENSORS[data->kind]); i++)
                device_remove_file(&client->dev, &fschmd_attr[i].dev_attr);
        for (i = 0; i < (FSCHMD_NO_TEMP_SENSORS[data->kind] * 4); i++)
                device_remove_file(&client->dev,
                                        &fschmd_temp_attr[i].dev_attr);
        for (i = 0; i < (FSCHMD_NO_FAN_SENSORS[data->kind] * 5); i++)
                device_remove_file(&client->dev,
                                        &fschmd_fan_attr[i].dev_attr);

        mutex_lock(&watchdog_data_mutex);
        kref_put(&data->kref, fschmd_release_resources);
        mutex_unlock(&watchdog_data_mutex);
}

static struct fschmd_data *fschmd_update_device(struct device *dev)
{
        struct i2c_client *client = to_i2c_client(dev);
        struct fschmd_data *data = i2c_get_clientdata(client);
        int i;

        mutex_lock(&data->update_lock);

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

                for (i = 0; i < FSCHMD_NO_TEMP_SENSORS[data->kind]; i++) {
                        data->temp_act[i] = i2c_smbus_read_byte_data(client,
                                        FSCHMD_REG_TEMP_ACT[data->kind][i]);
                        data->temp_status[i] = i2c_smbus_read_byte_data(client,
                                        FSCHMD_REG_TEMP_STATE[data->kind][i]);

                        /* The fscpos doesn't have TEMP_LIMIT registers */
                        if (FSCHMD_REG_TEMP_LIMIT[data->kind][i])
                                data->temp_max[i] = i2c_smbus_read_byte_data(
                                        client,
                                        FSCHMD_REG_TEMP_LIMIT[data->kind][i]);

                        /*
                         * reset alarm if the alarm condition is gone,
                         * the chip doesn't do this itself
                         */
                        if ((data->temp_status[i] & FSCHMD_TEMP_ALARM_MASK) ==
                                        FSCHMD_TEMP_ALARM_MASK &&
                                        data->temp_act[i] < data->temp_max[i])
                                i2c_smbus_write_byte_data(client,
                                        FSCHMD_REG_TEMP_STATE[data->kind][i],
                                        data->temp_status[i]);
                }

                for (i = 0; i < FSCHMD_NO_FAN_SENSORS[data->kind]; i++) {
                        data->fan_act[i] = i2c_smbus_read_byte_data(client,
                                        FSCHMD_REG_FAN_ACT[data->kind][i]);
                        data->fan_status[i] = i2c_smbus_read_byte_data(client,
                                        FSCHMD_REG_FAN_STATE[data->kind][i]);
                        data->fan_ripple[i] = i2c_smbus_read_byte_data(client,
                                        FSCHMD_REG_FAN_RIPPLE[data->kind][i]);

                        /* The fscpos third fan doesn't have a fan_min */
                        if (FSCHMD_REG_FAN_MIN[data->kind][i])
                                data->fan_min[i] = i2c_smbus_read_byte_data(
                                        client,
                                        FSCHMD_REG_FAN_MIN[data->kind][i]);

                        /* reset fan status if speed is back to > 0 */
                        if ((data->fan_status[i] & FSCHMD_FAN_ALARM) &&
                                        data->fan_act[i])
                                i2c_smbus_write_byte_data(client,
                                        FSCHMD_REG_FAN_STATE[data->kind][i],
                                        data->fan_status[i]);
                }

                for (i = 0; i < FSCHMD_NO_VOLT_SENSORS[data->kind]; i++)
                        data->volt[i] = i2c_smbus_read_byte_data(client,
                                               FSCHMD_REG_VOLT[data->kind][i]);

                data->last_updated = jiffies;
                data->valid = true;
        }

        mutex_unlock(&data->update_lock);

        return data;
}

module_i2c_driver(fschmd_driver);

MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
MODULE_DESCRIPTION("FSC Poseidon, Hermes, Scylla, Heracles, Heimdall, Hades "
                        "and Syleus driver");
MODULE_LICENSE("GPL");