smsc47m1.c

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/*
 * 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 <[email protected]>
 * Copyright (C) 2004-2007 Jean Delvare <[email protected]>
 * Ported to Linux 2.6 by Gabriele Gorla <[email protected]>
 *          and Jean Delvare
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#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 *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 void
superio_enter(void)
{
    outb(0x55, REG);
}

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

#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 int __exit smsc47m1_remove(struct platform_device *pdev);
static struct smsc47m1_data *smsc47m1_update_device(struct device *dev,
        int init);

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 platform_driver smsc47m1_driver = {
    .driver = {
        .owner  = THIS_MODULE,
        .name   = DRVNAME,
    },
    .remove     = __exit_p(smsc47m1_remove),
};

static ssize_t get_fan(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 get_fan_min(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 get_fan_div(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 get_fan_alarm(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 get_pwm(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 get_pwm_en(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 get_alarms(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 set_fan_min(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 set_fan_div(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;
    }

    /* Preserve fan min */
    tmp = 192 - (old_div * (192 - data->fan_preload[nr])
             + new_div / 2) / new_div;
    data->fan_preload[nr] = SENSORS_LIMIT(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 set_pwm(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 set_pwm_en(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;
}

#define fan_present(offset)                     \
static SENSOR_DEVICE_ATTR(fan##offset##_input, S_IRUGO, get_fan,    \
        NULL, offset - 1);                  \
static SENSOR_DEVICE_ATTR(fan##offset##_min, S_IRUGO | S_IWUSR,     \
        get_fan_min, set_fan_min, offset - 1);          \
static SENSOR_DEVICE_ATTR(fan##offset##_div, S_IRUGO | S_IWUSR,     \
        get_fan_div, set_fan_div, offset - 1);          \
static SENSOR_DEVICE_ATTR(fan##offset##_alarm, S_IRUGO, get_fan_alarm,  \
        NULL, offset - 1);                  \
static SENSOR_DEVICE_ATTR(pwm##offset, S_IRUGO | S_IWUSR,       \
        get_pwm, set_pwm, offset - 1);              \
static SENSOR_DEVICE_ATTR(pwm##offset##_enable, S_IRUGO | S_IWUSR,  \
        get_pwm_en, set_pwm_en, offset - 1)

fan_present(1);
fan_present(2);
fan_present(3);

static DEVICE_ATTR(alarms, S_IRUGO, get_alarms, NULL);

static ssize_t show_name(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(name, S_IRUGO, show_name, NULL);

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;

    superio_enter();
    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) {
        superio_enter();
        superio_select();

        pr_info("Disabling device\n");
        superio_outb(SUPERIO_REG_ACT, sio_data->activate);

        superio_exit();
    }
}

#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%hx-0x%hx 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->platform_data;
    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 int __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);

    return 0;
}

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 int __init smsc47m1_device_add(unsigned short address,
                      const struct smsc47m1_sio_data *sio_data)
{
    struct resource res = {
        .start  = address,
        .end    = address + SMSC_EXTENT - 1,
        .name   = DRVNAME,
        .flags  = IORESOURCE_IO,
    };
    int err;

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

    pdev = platform_device_alloc(DRVNAME, 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_data(pdev, sio_data,
                       sizeof(struct smsc47m1_sio_data));
    if (err) {
        pr_err("Platform data allocation failed\n");
        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 __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 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(pdev);
    smsc47m1_restore(&sio_data);
    return err;
}

static void __exit sm_smsc47m1_exit(void)
{
    platform_driver_unregister(&smsc47m1_driver);
    smsc47m1_restore(pdev->dev.platform_data);
    platform_device_unregister(pdev);
}

MODULE_AUTHOR("Mark D. Studebaker <[email protected]>");
MODULE_DESCRIPTION("SMSC LPC47M1xx fan sensors driver");
MODULE_LICENSE("GPL");

module_init(sm_smsc47m1_init);
module_exit(sm_smsc47m1_exit);