// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * smsc47m1.c - Part of lm_sensors, Linux kernel modules
 *              for hardware monitoring
 *
 * Supports the SMSC LPC47B27x, LPC47M10x, LPC47M112, LPC47M13x,
 * LPC47M14x, LPC47M15x, LPC47M192, LPC47M292 and LPC47M997
 * Super-I/O chips.
 *
 * Copyright (C) 2002 Mark D. Studebaker <mdsxyz123@yahoo.com>
 * Copyright (C) 2004-2007 Jean Delvare <jdelvare@suse.de>
 * Ported to Linux 2.6 by Gabriele Gorla <gorlik@yahoo.com>
 *                      and Jean Delvare
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/ioport.h>
#include <linux/jiffies.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/mutex.h>
#include <linux/sysfs.h>
#include <linux/acpi.h>
#include <linux/io.h>

static unsigned short force_id;
module_param(force_id, ushort, 0);
MODULE_PARM_DESC(force_id, "Override the detected device ID");

static struct platform_device *smsc47m1_pdev;

#define DRVNAME "smsc47m1"
enum chips { smsc47m1, smsc47m2 };

/* Super-I/0 registers and commands */

#define REG     0x2e    /* The register to read/write */
#define VAL     0x2f    /* The value to read/write */

static inline void
superio_outb(int reg, int val)
{
        outb(reg, REG);
        outb(val, VAL);
}

static inline int
superio_inb(int reg)
{
        outb(reg, REG);
        return inb(VAL);
}

/* logical device for fans is 0x0A */
#define superio_select() superio_outb(0x07, 0x0A)

static inline int
superio_enter(void)
{
        if (!request_muxed_region(REG, 2, DRVNAME))
                return -EBUSY;

        outb(0x55, REG);
        return 0;
}

static inline void
superio_exit(void)
{
        outb(0xAA, REG);
        release_region(REG, 2);
}

#define SUPERIO_REG_ACT         0x30
#define SUPERIO_REG_BASE        0x60
#define SUPERIO_REG_DEVID       0x20
#define SUPERIO_REG_DEVREV      0x21

/* Logical device registers */

#define SMSC_EXTENT             0x80

/* nr is 0 or 1 in the macros below */
#define SMSC47M1_REG_ALARM              0x04
#define SMSC47M1_REG_TPIN(nr)           (0x34 - (nr))
#define SMSC47M1_REG_PPIN(nr)           (0x36 - (nr))
#define SMSC47M1_REG_FANDIV             0x58

static const u8 SMSC47M1_REG_FAN[3]             = { 0x59, 0x5a, 0x6b };
static const u8 SMSC47M1_REG_FAN_PRELOAD[3]     = { 0x5b, 0x5c, 0x6c };
static const u8 SMSC47M1_REG_PWM[3]             = { 0x56, 0x57, 0x69 };

#define SMSC47M2_REG_ALARM6             0x09
#define SMSC47M2_REG_TPIN1              0x38
#define SMSC47M2_REG_TPIN2              0x37
#define SMSC47M2_REG_TPIN3              0x2d
#define SMSC47M2_REG_PPIN3              0x2c
#define SMSC47M2_REG_FANDIV3            0x6a

#define MIN_FROM_REG(reg, div)          ((reg) >= 192 ? 0 : \
                                         983040 / ((192 - (reg)) * (div)))
#define FAN_FROM_REG(reg, div, preload) ((reg) <= (preload) || (reg) == 255 ? \
                                         0 : \
                                         983040 / (((reg) - (preload)) * (div)))
#define DIV_FROM_REG(reg)               (1 << (reg))
#define PWM_FROM_REG(reg)               (((reg) & 0x7E) << 1)
#define PWM_EN_FROM_REG(reg)            ((~(reg)) & 0x01)
#define PWM_TO_REG(reg)                 (((reg) >> 1) & 0x7E)

struct smsc47m1_data {
        unsigned short addr;
        const char *name;
        enum chips type;
        struct device *hwmon_dev;

        struct mutex update_lock;
        unsigned long last_updated;     /* In jiffies */

        u8 fan[3];              /* Register value */
        u8 fan_preload[3];      /* Register value */
        u8 fan_div[3];          /* Register encoding, shifted right */
        u8 alarms;              /* Register encoding */
        u8 pwm[3];              /* Register value (bit 0 is disable) */
};

struct smsc47m1_sio_data {
        enum chips type;
        u8 activate;            /* Remember initial device state */
};

static inline int smsc47m1_read_value(struct smsc47m1_data *data, u8 reg)
{
        return inb_p(data->addr + reg);
}

static inline void smsc47m1_write_value(struct smsc47m1_data *data, u8 reg,
                u8 value)
{
        outb_p(value, data->addr + reg);
}

static struct smsc47m1_data *smsc47m1_update_device(struct device *dev,
                int init)
{
        struct smsc47m1_data *data = dev_get_drvdata(dev);

        mutex_lock(&data->update_lock);

        if (time_after(jiffies, data->last_updated + HZ + HZ / 2) || init) {
                int i, fan_nr;
                fan_nr = data->type == smsc47m2 ? 3 : 2;

                for (i = 0; i < fan_nr; i++) {
                        data->fan[i] = smsc47m1_read_value(data,
                                       SMSC47M1_REG_FAN[i]);
                        data->fan_preload[i] = smsc47m1_read_value(data,
                                               SMSC47M1_REG_FAN_PRELOAD[i]);
                        data->pwm[i] = smsc47m1_read_value(data,
                                       SMSC47M1_REG_PWM[i]);
                }

                i = smsc47m1_read_value(data, SMSC47M1_REG_FANDIV);
                data->fan_div[0] = (i >> 4) & 0x03;
                data->fan_div[1] = i >> 6;

                data->alarms = smsc47m1_read_value(data,
                               SMSC47M1_REG_ALARM) >> 6;
                /* Clear alarms if needed */
                if (data->alarms)
                        smsc47m1_write_value(data, SMSC47M1_REG_ALARM, 0xC0);

                if (fan_nr >= 3) {
                        data->fan_div[2] = (smsc47m1_read_value(data,
                                            SMSC47M2_REG_FANDIV3) >> 4) & 0x03;
                        data->alarms |= (smsc47m1_read_value(data,
                                         SMSC47M2_REG_ALARM6) & 0x40) >> 4;
                        /* Clear alarm if needed */
                        if (data->alarms & 0x04)
                                smsc47m1_write_value(data,
                                                     SMSC47M2_REG_ALARM6,
                                                     0x40);
                }

                data->last_updated = jiffies;
        }

        mutex_unlock(&data->update_lock);
        return data;
}

static ssize_t fan_show(struct device *dev, struct device_attribute *devattr,
                        char *buf)
{
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct smsc47m1_data *data = smsc47m1_update_device(dev, 0);
        int nr = attr->index;
        /*
         * This chip (stupidly) stops monitoring fan speed if PWM is
         * enabled and duty cycle is 0%. This is fine if the monitoring
         * and control concern the same fan, but troublesome if they are
         * not (which could as well happen).
         */
        int rpm = (data->pwm[nr] & 0x7F) == 0x00 ? 0 :
                  FAN_FROM_REG(data->fan[nr],
                               DIV_FROM_REG(data->fan_div[nr]),
                               data->fan_preload[nr]);
        return sprintf(buf, "%d\n", rpm);
}

static ssize_t fan_min_show(struct device *dev,
                            struct device_attribute *devattr, char *buf)
{
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct smsc47m1_data *data = smsc47m1_update_device(dev, 0);
        int nr = attr->index;
        int rpm = MIN_FROM_REG(data->fan_preload[nr],
                               DIV_FROM_REG(data->fan_div[nr]));
        return sprintf(buf, "%d\n", rpm);
}

static ssize_t fan_div_show(struct device *dev,
                            struct device_attribute *devattr, char *buf)
{
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct smsc47m1_data *data = smsc47m1_update_device(dev, 0);
        return sprintf(buf, "%d\n", DIV_FROM_REG(data->fan_div[attr->index]));
}

static ssize_t fan_alarm_show(struct device *dev,
                              struct device_attribute *devattr, char *buf)
{
        int bitnr = to_sensor_dev_attr(devattr)->index;
        struct smsc47m1_data *data = smsc47m1_update_device(dev, 0);
        return sprintf(buf, "%u\n", (data->alarms >> bitnr) & 1);
}

static ssize_t pwm_show(struct device *dev, struct device_attribute *devattr,
                        char *buf)
{
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct smsc47m1_data *data = smsc47m1_update_device(dev, 0);
        return sprintf(buf, "%d\n", PWM_FROM_REG(data->pwm[attr->index]));
}

static ssize_t pwm_en_show(struct device *dev,
                           struct device_attribute *devattr, char *buf)
{
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct smsc47m1_data *data = smsc47m1_update_device(dev, 0);
        return sprintf(buf, "%d\n", PWM_EN_FROM_REG(data->pwm[attr->index]));
}

static ssize_t alarms_show(struct device *dev,
                           struct device_attribute *devattr, char *buf)
{
        struct smsc47m1_data *data = smsc47m1_update_device(dev, 0);
        return sprintf(buf, "%d\n", data->alarms);
}

static ssize_t fan_min_store(struct device *dev,
                             struct device_attribute *devattr,
                             const char *buf, size_t count)
{
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct smsc47m1_data *data = dev_get_drvdata(dev);
        int nr = attr->index;
        long rpmdiv;
        long val;
        int err;

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

        mutex_lock(&data->update_lock);
        rpmdiv = val * DIV_FROM_REG(data->fan_div[nr]);

        if (983040 > 192 * rpmdiv || 2 * rpmdiv > 983040) {
                mutex_unlock(&data->update_lock);
                return -EINVAL;
        }

        data->fan_preload[nr] = 192 - ((983040 + rpmdiv / 2) / rpmdiv);
        smsc47m1_write_value(data, SMSC47M1_REG_FAN_PRELOAD[nr],
                             data->fan_preload[nr]);
        mutex_unlock(&data->update_lock);

        return count;
}

/*
 * Note: we save and restore the fan minimum here, because its value is
 * determined in part by the fan clock divider.  This follows the principle
 * of least surprise; the user doesn't expect the fan minimum to change just
 * because the divider changed.
 */
static ssize_t fan_div_store(struct device *dev,
                             struct device_attribute *devattr,
                             const char *buf, size_t count)
{
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct smsc47m1_data *data = dev_get_drvdata(dev);
        int nr = attr->index;
        long new_div;
        int err;
        long tmp;
        u8 old_div = DIV_FROM_REG(data->fan_div[nr]);

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

        if (new_div == old_div) /* No change */
                return count;

        mutex_lock(&data->update_lock);
        switch (new_div) {
        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:
                mutex_unlock(&data->update_lock);
                return -EINVAL;
        }

        switch (nr) {
        case 0:
        case 1:
                tmp = smsc47m1_read_value(data, SMSC47M1_REG_FANDIV)
                      & ~(0x03 << (4 + 2 * nr));
                tmp |= data->fan_div[nr] << (4 + 2 * nr);
                smsc47m1_write_value(data, SMSC47M1_REG_FANDIV, tmp);
                break;
        case 2:
                tmp = smsc47m1_read_value(data, SMSC47M2_REG_FANDIV3) & 0xCF;
                tmp |= data->fan_div[2] << 4;
                smsc47m1_write_value(data, SMSC47M2_REG_FANDIV3, tmp);
                break;
        default:
                BUG();
        }

        /* Preserve fan min */
        tmp = 192 - (old_div * (192 - data->fan_preload[nr])
                     + new_div / 2) / new_div;
        data->fan_preload[nr] = clamp_val(tmp, 0, 191);
        smsc47m1_write_value(data, SMSC47M1_REG_FAN_PRELOAD[nr],
                             data->fan_preload[nr]);
        mutex_unlock(&data->update_lock);

        return count;
}

static ssize_t pwm_store(struct device *dev, struct device_attribute *devattr,
                         const char *buf, size_t count)
{
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct smsc47m1_data *data = dev_get_drvdata(dev);
        int nr = attr->index;
        long val;
        int err;

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

        if (val < 0 || val > 255)
                return -EINVAL;

        mutex_lock(&data->update_lock);
        data->pwm[nr] &= 0x81; /* Preserve additional bits */
        data->pwm[nr] |= PWM_TO_REG(val);
        smsc47m1_write_value(data, SMSC47M1_REG_PWM[nr],
                             data->pwm[nr]);
        mutex_unlock(&data->update_lock);

        return count;
}

static ssize_t pwm_en_store(struct device *dev,
                            struct device_attribute *devattr, const char *buf,
                            size_t count)
{
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct smsc47m1_data *data = dev_get_drvdata(dev);
        int nr = attr->index;
        unsigned long val;
        int err;

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

        if (val > 1)
                return -EINVAL;

        mutex_lock(&data->update_lock);
        data->pwm[nr] &= 0xFE; /* preserve the other bits */
        data->pwm[nr] |= !val;
        smsc47m1_write_value(data, SMSC47M1_REG_PWM[nr],
                             data->pwm[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(fan1_alarm, fan_alarm, 0);
static SENSOR_DEVICE_ATTR_RW(pwm1, pwm, 0);
static SENSOR_DEVICE_ATTR_RW(pwm1_enable, pwm_en, 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);
static SENSOR_DEVICE_ATTR_RO(fan2_alarm, fan_alarm, 1);
static SENSOR_DEVICE_ATTR_RW(pwm2, pwm, 1);
static SENSOR_DEVICE_ATTR_RW(pwm2_enable, pwm_en, 1);
static SENSOR_DEVICE_ATTR_RO(fan3_input, fan, 2);
static SENSOR_DEVICE_ATTR_RW(fan3_min, fan_min, 2);
static SENSOR_DEVICE_ATTR_RW(fan3_div, fan_div, 2);
static SENSOR_DEVICE_ATTR_RO(fan3_alarm, fan_alarm, 2);
static SENSOR_DEVICE_ATTR_RW(pwm3, pwm, 2);
static SENSOR_DEVICE_ATTR_RW(pwm3_enable, pwm_en, 2);

static DEVICE_ATTR_RO(alarms);

static ssize_t name_show(struct device *dev, struct device_attribute
                         *devattr, char *buf)
{
        struct smsc47m1_data *data = dev_get_drvdata(dev);

        return sprintf(buf, "%s\n", data->name);
}
static DEVICE_ATTR_RO(name);

static struct attribute *smsc47m1_attributes_fan1[] = {
        &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,
        NULL
};

static const struct attribute_group smsc47m1_group_fan1 = {
        .attrs = smsc47m1_attributes_fan1,
};

static struct attribute *smsc47m1_attributes_fan2[] = {
        &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,
        NULL
};

static const struct attribute_group smsc47m1_group_fan2 = {
        .attrs = smsc47m1_attributes_fan2,
};

static struct attribute *smsc47m1_attributes_fan3[] = {
        &sensor_dev_attr_fan3_input.dev_attr.attr,
        &sensor_dev_attr_fan3_min.dev_attr.attr,
        &sensor_dev_attr_fan3_div.dev_attr.attr,
        &sensor_dev_attr_fan3_alarm.dev_attr.attr,
        NULL
};

static const struct attribute_group smsc47m1_group_fan3 = {
        .attrs = smsc47m1_attributes_fan3,
};

static struct attribute *smsc47m1_attributes_pwm1[] = {
        &sensor_dev_attr_pwm1.dev_attr.attr,
        &sensor_dev_attr_pwm1_enable.dev_attr.attr,
        NULL
};

static const struct attribute_group smsc47m1_group_pwm1 = {
        .attrs = smsc47m1_attributes_pwm1,
};

static struct attribute *smsc47m1_attributes_pwm2[] = {
        &sensor_dev_attr_pwm2.dev_attr.attr,
        &sensor_dev_attr_pwm2_enable.dev_attr.attr,
        NULL
};

static const struct attribute_group smsc47m1_group_pwm2 = {
        .attrs = smsc47m1_attributes_pwm2,
};

static struct attribute *smsc47m1_attributes_pwm3[] = {
        &sensor_dev_attr_pwm3.dev_attr.attr,
        &sensor_dev_attr_pwm3_enable.dev_attr.attr,
        NULL
};

static const struct attribute_group smsc47m1_group_pwm3 = {
        .attrs = smsc47m1_attributes_pwm3,
};

static struct attribute *smsc47m1_attributes[] = {
        &dev_attr_alarms.attr,
        &dev_attr_name.attr,
        NULL
};

static const struct attribute_group smsc47m1_group = {
        .attrs = smsc47m1_attributes,
};

static int __init smsc47m1_find(struct smsc47m1_sio_data *sio_data)
{
        u8 val;
        unsigned short addr;
        int err;

        err = superio_enter();
        if (err)
                return err;

        val = force_id ? force_id : superio_inb(SUPERIO_REG_DEVID);

        /*
         * SMSC LPC47M10x/LPC47M112/LPC47M13x (device id 0x59), LPC47M14x
         * (device id 0x5F) and LPC47B27x (device id 0x51) have fan control.
         * The LPC47M15x and LPC47M192 chips "with hardware monitoring block"
         * can do much more besides (device id 0x60).
         * The LPC47M997 is undocumented, but seems to be compatible with
         * the LPC47M192, and has the same device id.
         * The LPC47M292 (device id 0x6B) is somewhat compatible, but it
         * supports a 3rd fan, and the pin configuration registers are
         * unfortunately different.
         * The LPC47M233 has the same device id (0x6B) but is not compatible.
         * We check the high bit of the device revision register to
         * differentiate them.
         */
        switch (val) {
        case 0x51:
                pr_info("Found SMSC LPC47B27x\n");
                sio_data->type = smsc47m1;
                break;
        case 0x59:
                pr_info("Found SMSC LPC47M10x/LPC47M112/LPC47M13x\n");
                sio_data->type = smsc47m1;
                break;
        case 0x5F:
                pr_info("Found SMSC LPC47M14x\n");
                sio_data->type = smsc47m1;
                break;
        case 0x60:
                pr_info("Found SMSC LPC47M15x/LPC47M192/LPC47M997\n");
                sio_data->type = smsc47m1;
                break;
        case 0x6B:
                if (superio_inb(SUPERIO_REG_DEVREV) & 0x80) {
                        pr_debug("Found SMSC LPC47M233, unsupported\n");
                        superio_exit();
                        return -ENODEV;
                }

                pr_info("Found SMSC LPC47M292\n");
                sio_data->type = smsc47m2;
                break;
        default:
                superio_exit();
                return -ENODEV;
        }

        superio_select();
        addr = (superio_inb(SUPERIO_REG_BASE) << 8)
              |  superio_inb(SUPERIO_REG_BASE + 1);
        if (addr == 0) {
                pr_info("Device address not set, will not use\n");
                superio_exit();
                return -ENODEV;
        }

        /*
         * Enable only if address is set (needed at least on the
         * Compaq Presario S4000NX)
         */
        sio_data->activate = superio_inb(SUPERIO_REG_ACT);
        if ((sio_data->activate & 0x01) == 0) {
                pr_info("Enabling device\n");
                superio_outb(SUPERIO_REG_ACT, sio_data->activate | 0x01);
        }

        superio_exit();
        return addr;
}

/* Restore device to its initial state */
static void smsc47m1_restore(const struct smsc47m1_sio_data *sio_data)
{
        if ((sio_data->activate & 0x01) == 0) {
                if (!superio_enter()) {
                        superio_select();
                        pr_info("Disabling device\n");
                        superio_outb(SUPERIO_REG_ACT, sio_data->activate);
                        superio_exit();
                } else {
                        pr_warn("Failed to disable device\n");
                }
        }
}

#define CHECK           1
#define REQUEST         2

/*
 * This function can be used to:
 *  - test for resource conflicts with ACPI
 *  - request the resources
 * We only allocate the I/O ports we really need, to minimize the risk of
 * conflicts with ACPI or with other drivers.
 */
static int __init smsc47m1_handle_resources(unsigned short address,
                                            enum chips type, int action,
                                            struct device *dev)
{
        static const u8 ports_m1[] = {
                /* register, region length */
                0x04, 1,
                0x33, 4,
                0x56, 7,
        };

        static const u8 ports_m2[] = {
                /* register, region length */
                0x04, 1,
                0x09, 1,
                0x2c, 2,
                0x35, 4,
                0x56, 7,
                0x69, 4,
        };

        int i, ports_size, err;
        const u8 *ports;

        switch (type) {
        case smsc47m1:
        default:
                ports = ports_m1;
                ports_size = ARRAY_SIZE(ports_m1);
                break;
        case smsc47m2:
                ports = ports_m2;
                ports_size = ARRAY_SIZE(ports_m2);
                break;
        }

        for (i = 0; i + 1 < ports_size; i += 2) {
                unsigned short start = address + ports[i];
                unsigned short len = ports[i + 1];

                switch (action) {
                case CHECK:
                        /* Only check for conflicts */
                        err = acpi_check_region(start, len, DRVNAME);
                        if (err)
                                return err;
                        break;
                case REQUEST:
                        /* Request the resources */
                        if (!devm_request_region(dev, start, len, DRVNAME)) {
                                dev_err(dev,
                                        "Region 0x%x-0x%x already in use!\n",
                                        start, start + len);
                                return -EBUSY;
                        }
                        break;
                }
        }

        return 0;
}

static void smsc47m1_remove_files(struct device *dev)
{
        sysfs_remove_group(&dev->kobj, &smsc47m1_group);
        sysfs_remove_group(&dev->kobj, &smsc47m1_group_fan1);
        sysfs_remove_group(&dev->kobj, &smsc47m1_group_fan2);
        sysfs_remove_group(&dev->kobj, &smsc47m1_group_fan3);
        sysfs_remove_group(&dev->kobj, &smsc47m1_group_pwm1);
        sysfs_remove_group(&dev->kobj, &smsc47m1_group_pwm2);
        sysfs_remove_group(&dev->kobj, &smsc47m1_group_pwm3);
}

static int __init smsc47m1_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct smsc47m1_sio_data *sio_data = dev_get_platdata(dev);
        struct smsc47m1_data *data;
        struct resource *res;
        int err;
        int fan1, fan2, fan3, pwm1, pwm2, pwm3;

        static const char * const names[] = {
                "smsc47m1",
                "smsc47m2",
        };

        res = platform_get_resource(pdev, IORESOURCE_IO, 0);
        err = smsc47m1_handle_resources(res->start, sio_data->type,
                                        REQUEST, dev);
        if (err < 0)
                return err;

        data = devm_kzalloc(dev, sizeof(struct smsc47m1_data), GFP_KERNEL);
        if (!data)
                return -ENOMEM;

        data->addr = res->start;
        data->type = sio_data->type;
        data->name = names[sio_data->type];
        mutex_init(&data->update_lock);
        platform_set_drvdata(pdev, data);

        /*
         * If no function is properly configured, there's no point in
         * actually registering the chip.
         */
        pwm1 = (smsc47m1_read_value(data, SMSC47M1_REG_PPIN(0)) & 0x05)
               == 0x04;
        pwm2 = (smsc47m1_read_value(data, SMSC47M1_REG_PPIN(1)) & 0x05)
               == 0x04;
        if (data->type == smsc47m2) {
                fan1 = (smsc47m1_read_value(data, SMSC47M2_REG_TPIN1)
                        & 0x0d) == 0x09;
                fan2 = (smsc47m1_read_value(data, SMSC47M2_REG_TPIN2)
                        & 0x0d) == 0x09;
                fan3 = (smsc47m1_read_value(data, SMSC47M2_REG_TPIN3)
                        & 0x0d) == 0x0d;
                pwm3 = (smsc47m1_read_value(data, SMSC47M2_REG_PPIN3)
                        & 0x0d) == 0x08;
        } else {
                fan1 = (smsc47m1_read_value(data, SMSC47M1_REG_TPIN(0))
                        & 0x05) == 0x05;
                fan2 = (smsc47m1_read_value(data, SMSC47M1_REG_TPIN(1))
                        & 0x05) == 0x05;
                fan3 = 0;
                pwm3 = 0;
        }
        if (!(fan1 || fan2 || fan3 || pwm1 || pwm2 || pwm3)) {
                dev_warn(dev, "Device not configured, will not use\n");
                return -ENODEV;
        }

        /*
         * Some values (fan min, clock dividers, pwm registers) may be
         * needed before any update is triggered, so we better read them
         * at least once here. We don't usually do it that way, but in
         * this particular case, manually reading 5 registers out of 8
         * doesn't make much sense and we're better using the existing
         * function.
         */
        smsc47m1_update_device(dev, 1);

        /* Register sysfs hooks */
        if (fan1) {
                err = sysfs_create_group(&dev->kobj,
                                         &smsc47m1_group_fan1);
                if (err)
                        goto error_remove_files;
        } else
                dev_dbg(dev, "Fan 1 not enabled by hardware, skipping\n");

        if (fan2) {
                err = sysfs_create_group(&dev->kobj,
                                         &smsc47m1_group_fan2);
                if (err)
                        goto error_remove_files;
        } else
                dev_dbg(dev, "Fan 2 not enabled by hardware, skipping\n");

        if (fan3) {
                err = sysfs_create_group(&dev->kobj,
                                         &smsc47m1_group_fan3);
                if (err)
                        goto error_remove_files;
        } else if (data->type == smsc47m2)
                dev_dbg(dev, "Fan 3 not enabled by hardware, skipping\n");

        if (pwm1) {
                err = sysfs_create_group(&dev->kobj,
                                         &smsc47m1_group_pwm1);
                if (err)
                        goto error_remove_files;
        } else
                dev_dbg(dev, "PWM 1 not enabled by hardware, skipping\n");

        if (pwm2) {
                err = sysfs_create_group(&dev->kobj,
                                         &smsc47m1_group_pwm2);
                if (err)
                        goto error_remove_files;
        } else
                dev_dbg(dev, "PWM 2 not enabled by hardware, skipping\n");

        if (pwm3) {
                err = sysfs_create_group(&dev->kobj,
                                         &smsc47m1_group_pwm3);
                if (err)
                        goto error_remove_files;
        } else if (data->type == smsc47m2)
                dev_dbg(dev, "PWM 3 not enabled by hardware, skipping\n");

        err = sysfs_create_group(&dev->kobj, &smsc47m1_group);
        if (err)
                goto error_remove_files;

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

        return 0;

error_remove_files:
        smsc47m1_remove_files(dev);
        return err;
}

static void __exit smsc47m1_remove(struct platform_device *pdev)
{
        struct smsc47m1_data *data = platform_get_drvdata(pdev);

        hwmon_device_unregister(data->hwmon_dev);
        smsc47m1_remove_files(&pdev->dev);
}

/*
 * smsc47m1_remove() lives in .exit.text. For drivers registered via
 * module_platform_driver_probe() this ok because they cannot get unbound at
 * runtime. The driver needs to be marked with __refdata, otherwise modpost
 * triggers a section mismatch warning.
 */
static struct platform_driver smsc47m1_driver __refdata = {
        .driver = {
                .name   = DRVNAME,
        },
        .remove         = __exit_p(smsc47m1_remove),
};

static int __init smsc47m1_device_add(unsigned short address,
                                      const struct smsc47m1_sio_data *sio_data)
{
        const struct resource res = {
                .start  = address,
                .end    = address + SMSC_EXTENT - 1,
                .name   = DRVNAME,
                .flags  = IORESOURCE_IO,
        };
        const struct platform_device_info pdevinfo = {
                .name = DRVNAME,
                .id = address,
                .res = &res,
                .num_res = 1,
                .data = sio_data,
                .size_data = sizeof(struct smsc47m1_sio_data),
        };
        int err;

        err = smsc47m1_handle_resources(address, sio_data->type, CHECK, NULL);
        if (err)
                return err;

        smsc47m1_pdev = platform_device_register_full(&pdevinfo);
        if (IS_ERR(smsc47m1_pdev)) {
                pr_err("Device allocation failed\n");
                return PTR_ERR(smsc47m1_pdev);
        }

        return 0;
}

static int __init sm_smsc47m1_init(void)
{
        int err;
        unsigned short address;
        struct smsc47m1_sio_data sio_data;

        err = smsc47m1_find(&sio_data);
        if (err < 0)
                return err;
        address = err;

        /* Sets global smsc47m1_pdev as a side effect */
        err = smsc47m1_device_add(address, &sio_data);
        if (err)
                return err;

        err = platform_driver_probe(&smsc47m1_driver, smsc47m1_probe);
        if (err)
                goto exit_device;

        return 0;

exit_device:
        platform_device_unregister(smsc47m1_pdev);
        smsc47m1_restore(&sio_data);
        return err;
}

static void __exit sm_smsc47m1_exit(void)
{
        platform_driver_unregister(&smsc47m1_driver);
        smsc47m1_restore(dev_get_platdata(&smsc47m1_pdev->dev));
        platform_device_unregister(smsc47m1_pdev);
}

MODULE_AUTHOR("Mark D. Studebaker <mdsxyz123@yahoo.com>");
MODULE_DESCRIPTION("SMSC LPC47M1xx fan sensors driver");
MODULE_LICENSE("GPL");

module_init(sm_smsc47m1_init);
module_exit(sm_smsc47m1_exit);