asus_atk0110.c

Go to the documentation of this file.

/*
 * Copyright (C) 2007-2009 Luca Tettamanti <[email protected]>
 *
 * This file is released under the GPLv2
 * See COPYING in the top level directory of the kernel tree.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/debugfs.h>
#include <linux/kernel.h>
#include <linux/hwmon.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/dmi.h>
#include <linux/jiffies.h>
#include <linux/err.h>

#include <acpi/acpi.h>
#include <acpi/acpixf.h>
#include <acpi/acpi_drivers.h>
#include <acpi/acpi_bus.h>


#define ATK_HID "ATK0110"

static bool new_if;
module_param(new_if, bool, 0);
MODULE_PARM_DESC(new_if, "Override detection heuristic and force the use of the new ATK0110 interface");

static const struct dmi_system_id __initconst atk_force_new_if[] = {
    {
        /* Old interface has broken MCH temp monitoring */
        .ident = "Asus Sabertooth X58",
        .matches = {
            DMI_MATCH(DMI_BOARD_NAME, "SABERTOOTH X58")
        }
    }, {
        /* Old interface reads the same sensor for fan0 and fan1 */
        .ident = "Asus M5A78L",
        .matches = {
            DMI_MATCH(DMI_BOARD_NAME, "M5A78L")
        }
    },
    { }
};

/*
 * Minimum time between readings, enforced in order to avoid
 * hogging the CPU.
 */
#define CACHE_TIME      HZ

#define BOARD_ID        "MBIF"
#define METHOD_ENUMERATE    "GGRP"
#define METHOD_READ     "GITM"
#define METHOD_WRITE        "SITM"
#define METHOD_OLD_READ_TMP "RTMP"
#define METHOD_OLD_READ_VLT "RVLT"
#define METHOD_OLD_READ_FAN "RFAN"
#define METHOD_OLD_ENUM_TMP "TSIF"
#define METHOD_OLD_ENUM_VLT "VSIF"
#define METHOD_OLD_ENUM_FAN "FSIF"

#define ATK_MUX_HWMON       0x00000006ULL
#define ATK_MUX_MGMT        0x00000011ULL

#define ATK_CLASS_MASK      0xff000000ULL
#define ATK_CLASS_FREQ_CTL  0x03000000ULL
#define ATK_CLASS_FAN_CTL   0x04000000ULL
#define ATK_CLASS_HWMON     0x06000000ULL
#define ATK_CLASS_MGMT      0x11000000ULL

#define ATK_TYPE_MASK       0x00ff0000ULL
#define HWMON_TYPE_VOLT     0x00020000ULL
#define HWMON_TYPE_TEMP     0x00030000ULL
#define HWMON_TYPE_FAN      0x00040000ULL

#define ATK_ELEMENT_ID_MASK 0x0000ffffULL

#define ATK_EC_ID       0x11060004ULL

enum atk_pack_member {
    HWMON_PACK_FLAGS,
    HWMON_PACK_NAME,
    HWMON_PACK_LIMIT1,
    HWMON_PACK_LIMIT2,
    HWMON_PACK_ENABLE
};

/* New package format */
#define _HWMON_NEW_PACK_SIZE    7
#define _HWMON_NEW_PACK_FLAGS   0
#define _HWMON_NEW_PACK_NAME    1
#define _HWMON_NEW_PACK_UNK1    2
#define _HWMON_NEW_PACK_UNK2    3
#define _HWMON_NEW_PACK_LIMIT1  4
#define _HWMON_NEW_PACK_LIMIT2  5
#define _HWMON_NEW_PACK_ENABLE  6

/* Old package format */
#define _HWMON_OLD_PACK_SIZE    5
#define _HWMON_OLD_PACK_FLAGS   0
#define _HWMON_OLD_PACK_NAME    1
#define _HWMON_OLD_PACK_LIMIT1  2
#define _HWMON_OLD_PACK_LIMIT2  3
#define _HWMON_OLD_PACK_ENABLE  4


struct atk_data {
    struct device *hwmon_dev;
    acpi_handle atk_handle;
    struct acpi_device *acpi_dev;

    bool old_interface;

    /* old interface */
    acpi_handle rtmp_handle;
    acpi_handle rvlt_handle;
    acpi_handle rfan_handle;
    /* new inteface */
    acpi_handle enumerate_handle;
    acpi_handle read_handle;
    acpi_handle write_handle;

    bool disable_ec;

    int voltage_count;
    int temperature_count;
    int fan_count;
    struct list_head sensor_list;

    struct {
        struct dentry *root;
        u32 id;
    } debugfs;
};


typedef ssize_t (*sysfs_show_func)(struct device *dev,
            struct device_attribute *attr, char *buf);

static const struct acpi_device_id atk_ids[] = {
    {ATK_HID, 0},
    {"", 0},
};
MODULE_DEVICE_TABLE(acpi, atk_ids);

#define ATTR_NAME_SIZE 16 /* Worst case is "tempN_input" */

struct atk_sensor_data {
    struct list_head list;
    struct atk_data *data;
    struct device_attribute label_attr;
    struct device_attribute input_attr;
    struct device_attribute limit1_attr;
    struct device_attribute limit2_attr;
    char label_attr_name[ATTR_NAME_SIZE];
    char input_attr_name[ATTR_NAME_SIZE];
    char limit1_attr_name[ATTR_NAME_SIZE];
    char limit2_attr_name[ATTR_NAME_SIZE];
    u64 id;
    u64 type;
    u64 limit1;
    u64 limit2;
    u64 cached_value;
    unsigned long last_updated; /* in jiffies */
    bool is_valid;
    char const *acpi_name;
};

/*
 * Return buffer format:
 * [0-3] "value" is valid flag
 * [4-7] value
 * [8- ] unknown stuff on newer mobos
 */
struct atk_acpi_ret_buffer {
    u32 flags;
    u32 value;
    u8 data[];
};

/* Input buffer used for GITM and SITM methods */
struct atk_acpi_input_buf {
    u32 id;
    u32 param1;
    u32 param2;
};

static int atk_add(struct acpi_device *device);
static int atk_remove(struct acpi_device *device, int type);
static void atk_print_sensor(struct atk_data *data, union acpi_object *obj);
static int atk_read_value(struct atk_sensor_data *sensor, u64 *value);
static void atk_free_sensors(struct atk_data *data);

static struct acpi_driver atk_driver = {
    .name   = ATK_HID,
    .class  = "hwmon",
    .ids    = atk_ids,
    .ops    = {
        .add    = atk_add,
        .remove = atk_remove,
    },
};

#define input_to_atk_sensor(attr) \
    container_of(attr, struct atk_sensor_data, input_attr)

#define label_to_atk_sensor(attr) \
    container_of(attr, struct atk_sensor_data, label_attr)

#define limit1_to_atk_sensor(attr) \
    container_of(attr, struct atk_sensor_data, limit1_attr)

#define limit2_to_atk_sensor(attr) \
    container_of(attr, struct atk_sensor_data, limit2_attr)

static ssize_t atk_input_show(struct device *dev,
        struct device_attribute *attr, char *buf)
{
    struct atk_sensor_data *s = input_to_atk_sensor(attr);
    u64 value;
    int err;

    err = atk_read_value(s, &value);
    if (err)
        return err;

    if (s->type == HWMON_TYPE_TEMP)
        /* ACPI returns decidegree */
        value *= 100;

    return sprintf(buf, "%llu\n", value);
}

static ssize_t atk_label_show(struct device *dev,
        struct device_attribute *attr, char *buf)
{
    struct atk_sensor_data *s = label_to_atk_sensor(attr);

    return sprintf(buf, "%s\n", s->acpi_name);
}

static ssize_t atk_limit1_show(struct device *dev,
        struct device_attribute *attr, char *buf)
{
    struct atk_sensor_data *s = limit1_to_atk_sensor(attr);
    u64 value = s->limit1;

    if (s->type == HWMON_TYPE_TEMP)
        value *= 100;

    return sprintf(buf, "%lld\n", value);
}

static ssize_t atk_limit2_show(struct device *dev,
        struct device_attribute *attr, char *buf)
{
    struct atk_sensor_data *s = limit2_to_atk_sensor(attr);
    u64 value = s->limit2;

    if (s->type == HWMON_TYPE_TEMP)
        value *= 100;

    return sprintf(buf, "%lld\n", value);
}

static ssize_t atk_name_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
    return sprintf(buf, "atk0110\n");
}
static struct device_attribute atk_name_attr =
        __ATTR(name, 0444, atk_name_show, NULL);

static void atk_init_attribute(struct device_attribute *attr, char *name,
        sysfs_show_func show)
{
    sysfs_attr_init(&attr->attr);
    attr->attr.name = name;
    attr->attr.mode = 0444;
    attr->show = show;
    attr->store = NULL;
}


static union acpi_object *atk_get_pack_member(struct atk_data *data,
                        union acpi_object *pack,
                        enum atk_pack_member m)
{
    bool old_if = data->old_interface;
    int offset;

    switch (m) {
    case HWMON_PACK_FLAGS:
        offset = old_if ? _HWMON_OLD_PACK_FLAGS : _HWMON_NEW_PACK_FLAGS;
        break;
    case HWMON_PACK_NAME:
        offset = old_if ? _HWMON_OLD_PACK_NAME : _HWMON_NEW_PACK_NAME;
        break;
    case HWMON_PACK_LIMIT1:
        offset = old_if ? _HWMON_OLD_PACK_LIMIT1 :
                  _HWMON_NEW_PACK_LIMIT1;
        break;
    case HWMON_PACK_LIMIT2:
        offset = old_if ? _HWMON_OLD_PACK_LIMIT2 :
                  _HWMON_NEW_PACK_LIMIT2;
        break;
    case HWMON_PACK_ENABLE:
        offset = old_if ? _HWMON_OLD_PACK_ENABLE :
                  _HWMON_NEW_PACK_ENABLE;
        break;
    default:
        return NULL;
    }

    return &pack->package.elements[offset];
}


/*
 * New package format is:
 * - flag (int)
 *  class - used for de-muxing the request to the correct GITn
 *  type (volt, temp, fan)
 *  sensor id |
 *  sensor id - used for de-muxing the request _inside_ the GITn
 * - name (str)
 * - unknown (int)
 * - unknown (int)
 * - limit1 (int)
 * - limit2 (int)
 * - enable (int)
 *
 * The old package has the same format but it's missing the two unknown fields.
 */
static int validate_hwmon_pack(struct atk_data *data, union acpi_object *obj)
{
    struct device *dev = &data->acpi_dev->dev;
    union acpi_object *tmp;
    bool old_if = data->old_interface;
    int const expected_size = old_if ? _HWMON_OLD_PACK_SIZE :
                       _HWMON_NEW_PACK_SIZE;

    if (obj->type != ACPI_TYPE_PACKAGE) {
        dev_warn(dev, "Invalid type: %d\n", obj->type);
        return -EINVAL;
    }

    if (obj->package.count != expected_size) {
        dev_warn(dev, "Invalid package size: %d, expected: %d\n",
                obj->package.count, expected_size);
        return -EINVAL;
    }

    tmp = atk_get_pack_member(data, obj, HWMON_PACK_FLAGS);
    if (tmp->type != ACPI_TYPE_INTEGER) {
        dev_warn(dev, "Invalid type (flag): %d\n", tmp->type);
        return -EINVAL;
    }

    tmp = atk_get_pack_member(data, obj, HWMON_PACK_NAME);
    if (tmp->type != ACPI_TYPE_STRING) {
        dev_warn(dev, "Invalid type (name): %d\n", tmp->type);
        return -EINVAL;
    }

    /* Don't check... we don't know what they're useful for anyway */
#if 0
    tmp = &obj->package.elements[HWMON_PACK_UNK1];
    if (tmp->type != ACPI_TYPE_INTEGER) {
        dev_warn(dev, "Invalid type (unk1): %d\n", tmp->type);
        return -EINVAL;
    }

    tmp = &obj->package.elements[HWMON_PACK_UNK2];
    if (tmp->type != ACPI_TYPE_INTEGER) {
        dev_warn(dev, "Invalid type (unk2): %d\n", tmp->type);
        return -EINVAL;
    }
#endif

    tmp = atk_get_pack_member(data, obj, HWMON_PACK_LIMIT1);
    if (tmp->type != ACPI_TYPE_INTEGER) {
        dev_warn(dev, "Invalid type (limit1): %d\n", tmp->type);
        return -EINVAL;
    }

    tmp = atk_get_pack_member(data, obj, HWMON_PACK_LIMIT2);
    if (tmp->type != ACPI_TYPE_INTEGER) {
        dev_warn(dev, "Invalid type (limit2): %d\n", tmp->type);
        return -EINVAL;
    }

    tmp = atk_get_pack_member(data, obj, HWMON_PACK_ENABLE);
    if (tmp->type != ACPI_TYPE_INTEGER) {
        dev_warn(dev, "Invalid type (enable): %d\n", tmp->type);
        return -EINVAL;
    }

    atk_print_sensor(data, obj);

    return 0;
}

#ifdef DEBUG
static char const *atk_sensor_type(union acpi_object *flags)
{
    u64 type = flags->integer.value & ATK_TYPE_MASK;
    char const *what;

    switch (type) {
    case HWMON_TYPE_VOLT:
        what = "voltage";
        break;
    case HWMON_TYPE_TEMP:
        what = "temperature";
        break;
    case HWMON_TYPE_FAN:
        what = "fan";
        break;
    default:
        what = "unknown";
        break;
    }

    return what;
}
#endif

static void atk_print_sensor(struct atk_data *data, union acpi_object *obj)
{
#ifdef DEBUG
    struct device *dev = &data->acpi_dev->dev;
    union acpi_object *flags;
    union acpi_object *name;
    union acpi_object *limit1;
    union acpi_object *limit2;
    union acpi_object *enable;
    char const *what;

    flags = atk_get_pack_member(data, obj, HWMON_PACK_FLAGS);
    name = atk_get_pack_member(data, obj, HWMON_PACK_NAME);
    limit1 = atk_get_pack_member(data, obj, HWMON_PACK_LIMIT1);
    limit2 = atk_get_pack_member(data, obj, HWMON_PACK_LIMIT2);
    enable = atk_get_pack_member(data, obj, HWMON_PACK_ENABLE);

    what = atk_sensor_type(flags);

    dev_dbg(dev, "%s: %#llx %s [%llu-%llu] %s\n", what,
            flags->integer.value,
            name->string.pointer,
            limit1->integer.value, limit2->integer.value,
            enable->integer.value ? "enabled" : "disabled");
#endif
}

static int atk_read_value_old(struct atk_sensor_data *sensor, u64 *value)
{
    struct atk_data *data = sensor->data;
    struct device *dev = &data->acpi_dev->dev;
    struct acpi_object_list params;
    union acpi_object id;
    acpi_status status;
    acpi_handle method;

    switch (sensor->type) {
    case HWMON_TYPE_VOLT:
        method = data->rvlt_handle;
        break;
    case HWMON_TYPE_TEMP:
        method = data->rtmp_handle;
        break;
    case HWMON_TYPE_FAN:
        method = data->rfan_handle;
        break;
    default:
        return -EINVAL;
    }

    id.type = ACPI_TYPE_INTEGER;
    id.integer.value = sensor->id;

    params.count = 1;
    params.pointer = &id;

    status = acpi_evaluate_integer(method, NULL, &params, value);
    if (status != AE_OK) {
        dev_warn(dev, "%s: ACPI exception: %s\n", __func__,
                acpi_format_exception(status));
        return -EIO;
    }

    return 0;
}

static union acpi_object *atk_ggrp(struct atk_data *data, u16 mux)
{
    struct device *dev = &data->acpi_dev->dev;
    struct acpi_buffer buf;
    acpi_status ret;
    struct acpi_object_list params;
    union acpi_object id;
    union acpi_object *pack;

    id.type = ACPI_TYPE_INTEGER;
    id.integer.value = mux;
    params.count = 1;
    params.pointer = &id;

    buf.length = ACPI_ALLOCATE_BUFFER;
    ret = acpi_evaluate_object(data->enumerate_handle, NULL, &params, &buf);
    if (ret != AE_OK) {
        dev_err(dev, "GGRP[%#x] ACPI exception: %s\n", mux,
                acpi_format_exception(ret));
        return ERR_PTR(-EIO);
    }
    pack = buf.pointer;
    if (pack->type != ACPI_TYPE_PACKAGE) {
        /* Execution was successful, but the id was not found */
        ACPI_FREE(pack);
        return ERR_PTR(-ENOENT);
    }

    if (pack->package.count < 1) {
        dev_err(dev, "GGRP[%#x] package is too small\n", mux);
        ACPI_FREE(pack);
        return ERR_PTR(-EIO);
    }
    return pack;
}

static union acpi_object *atk_gitm(struct atk_data *data, u64 id)
{
    struct device *dev = &data->acpi_dev->dev;
    struct atk_acpi_input_buf buf;
    union acpi_object tmp;
    struct acpi_object_list params;
    struct acpi_buffer ret;
    union acpi_object *obj;
    acpi_status status;

    buf.id = id;
    buf.param1 = 0;
    buf.param2 = 0;

    tmp.type = ACPI_TYPE_BUFFER;
    tmp.buffer.pointer = (u8 *)&buf;
    tmp.buffer.length = sizeof(buf);

    params.count = 1;
    params.pointer = (void *)&tmp;

    ret.length = ACPI_ALLOCATE_BUFFER;
    status = acpi_evaluate_object_typed(data->read_handle, NULL, &params,
            &ret, ACPI_TYPE_BUFFER);
    if (status != AE_OK) {
        dev_warn(dev, "GITM[%#llx] ACPI exception: %s\n", id,
                acpi_format_exception(status));
        return ERR_PTR(-EIO);
    }
    obj = ret.pointer;

    /* Sanity check */
    if (obj->buffer.length < 8) {
        dev_warn(dev, "Unexpected ASBF length: %u\n",
                obj->buffer.length);
        ACPI_FREE(obj);
        return ERR_PTR(-EIO);
    }
    return obj;
}

static union acpi_object *atk_sitm(struct atk_data *data,
        struct atk_acpi_input_buf *buf)
{
    struct device *dev = &data->acpi_dev->dev;
    struct acpi_object_list params;
    union acpi_object tmp;
    struct acpi_buffer ret;
    union acpi_object *obj;
    acpi_status status;

    tmp.type = ACPI_TYPE_BUFFER;
    tmp.buffer.pointer = (u8 *)buf;
    tmp.buffer.length = sizeof(*buf);

    params.count = 1;
    params.pointer = &tmp;

    ret.length = ACPI_ALLOCATE_BUFFER;
    status = acpi_evaluate_object_typed(data->write_handle, NULL, &params,
            &ret, ACPI_TYPE_BUFFER);
    if (status != AE_OK) {
        dev_warn(dev, "SITM[%#x] ACPI exception: %s\n", buf->id,
                acpi_format_exception(status));
        return ERR_PTR(-EIO);
    }
    obj = ret.pointer;

    /* Sanity check */
    if (obj->buffer.length < 8) {
        dev_warn(dev, "Unexpected ASBF length: %u\n",
                obj->buffer.length);
        ACPI_FREE(obj);
        return ERR_PTR(-EIO);
    }
    return obj;
}

static int atk_read_value_new(struct atk_sensor_data *sensor, u64 *value)
{
    struct atk_data *data = sensor->data;
    struct device *dev = &data->acpi_dev->dev;
    union acpi_object *obj;
    struct atk_acpi_ret_buffer *buf;
    int err = 0;

    obj = atk_gitm(data, sensor->id);
    if (IS_ERR(obj))
        return PTR_ERR(obj);

    buf = (struct atk_acpi_ret_buffer *)obj->buffer.pointer;
    if (buf->flags == 0) {
        /*
         * The reading is not valid, possible causes:
         * - sensor failure
         * - enumeration was FUBAR (and we didn't notice)
         */
        dev_warn(dev, "Read failed, sensor = %#llx\n", sensor->id);
        err = -EIO;
        goto out;
    }

    *value = buf->value;
out:
    ACPI_FREE(obj);
    return err;
}

static int atk_read_value(struct atk_sensor_data *sensor, u64 *value)
{
    int err;

    if (!sensor->is_valid ||
        time_after(jiffies, sensor->last_updated + CACHE_TIME)) {
        if (sensor->data->old_interface)
            err = atk_read_value_old(sensor, value);
        else
            err = atk_read_value_new(sensor, value);

        sensor->is_valid = true;
        sensor->last_updated = jiffies;
        sensor->cached_value = *value;
    } else {
        *value = sensor->cached_value;
        err = 0;
    }

    return err;
}

#ifdef CONFIG_DEBUG_FS
static int atk_debugfs_gitm_get(void *p, u64 *val)
{
    struct atk_data *data = p;
    union acpi_object *ret;
    struct atk_acpi_ret_buffer *buf;
    int err = 0;

    if (!data->read_handle)
        return -ENODEV;

    if (!data->debugfs.id)
        return -EINVAL;

    ret = atk_gitm(data, data->debugfs.id);
    if (IS_ERR(ret))
        return PTR_ERR(ret);

    buf = (struct atk_acpi_ret_buffer *)ret->buffer.pointer;
    if (buf->flags)
        *val = buf->value;
    else
        err = -EIO;

    ACPI_FREE(ret);
    return err;
}

DEFINE_SIMPLE_ATTRIBUTE(atk_debugfs_gitm,
            atk_debugfs_gitm_get,
            NULL,
            "0x%08llx\n")

static int atk_acpi_print(char *buf, size_t sz, union acpi_object *obj)
{
    int ret = 0;

    switch (obj->type) {
    case ACPI_TYPE_INTEGER:
        ret = snprintf(buf, sz, "0x%08llx\n", obj->integer.value);
        break;
    case ACPI_TYPE_STRING:
        ret = snprintf(buf, sz, "%s\n", obj->string.pointer);
        break;
    }

    return ret;
}

static void atk_pack_print(char *buf, size_t sz, union acpi_object *pack)
{
    int ret;
    int i;

    for (i = 0; i < pack->package.count; i++) {
        union acpi_object *obj = &pack->package.elements[i];

        ret = atk_acpi_print(buf, sz, obj);
        if (ret >= sz)
            break;
        buf += ret;
        sz -= ret;
    }
}

static int atk_debugfs_ggrp_open(struct inode *inode, struct file *file)
{
    struct atk_data *data = inode->i_private;
    char *buf = NULL;
    union acpi_object *ret;
    u8 cls;
    int i;

    if (!data->enumerate_handle)
        return -ENODEV;
    if (!data->debugfs.id)
        return -EINVAL;

    cls = (data->debugfs.id & 0xff000000) >> 24;
    ret = atk_ggrp(data, cls);
    if (IS_ERR(ret))
        return PTR_ERR(ret);

    for (i = 0; i < ret->package.count; i++) {
        union acpi_object *pack = &ret->package.elements[i];
        union acpi_object *id;

        if (pack->type != ACPI_TYPE_PACKAGE)
            continue;
        if (!pack->package.count)
            continue;
        id = &pack->package.elements[0];
        if (id->integer.value == data->debugfs.id) {
            /* Print the package */
            buf = kzalloc(512, GFP_KERNEL);
            if (!buf) {
                ACPI_FREE(ret);
                return -ENOMEM;
            }
            atk_pack_print(buf, 512, pack);
            break;
        }
    }
    ACPI_FREE(ret);

    if (!buf)
        return -EINVAL;

    file->private_data = buf;

    return nonseekable_open(inode, file);
}

static ssize_t atk_debugfs_ggrp_read(struct file *file, char __user *buf,
        size_t count, loff_t *pos)
{
    char *str = file->private_data;
    size_t len = strlen(str);

    return simple_read_from_buffer(buf, count, pos, str, len);
}

static int atk_debugfs_ggrp_release(struct inode *inode, struct file *file)
{
    kfree(file->private_data);
    return 0;
}

static const struct file_operations atk_debugfs_ggrp_fops = {
    .read       = atk_debugfs_ggrp_read,
    .open       = atk_debugfs_ggrp_open,
    .release    = atk_debugfs_ggrp_release,
    .llseek     = no_llseek,
};

static void atk_debugfs_init(struct atk_data *data)
{
    struct dentry *d;
    struct dentry *f;

    data->debugfs.id = 0;

    d = debugfs_create_dir("asus_atk0110", NULL);
    if (!d || IS_ERR(d))
        return;

    f = debugfs_create_x32("id", S_IRUSR | S_IWUSR, d, &data->debugfs.id);
    if (!f || IS_ERR(f))
        goto cleanup;

    f = debugfs_create_file("gitm", S_IRUSR, d, data,
            &atk_debugfs_gitm);
    if (!f || IS_ERR(f))
        goto cleanup;

    f = debugfs_create_file("ggrp", S_IRUSR, d, data,
            &atk_debugfs_ggrp_fops);
    if (!f || IS_ERR(f))
        goto cleanup;

    data->debugfs.root = d;

    return;
cleanup:
    debugfs_remove_recursive(d);
}

static void atk_debugfs_cleanup(struct atk_data *data)
{
    debugfs_remove_recursive(data->debugfs.root);
}

#else /* CONFIG_DEBUG_FS */

static void atk_debugfs_init(struct atk_data *data)
{
}

static void atk_debugfs_cleanup(struct atk_data *data)
{
}
#endif

static int atk_add_sensor(struct atk_data *data, union acpi_object *obj)
{
    struct device *dev = &data->acpi_dev->dev;
    union acpi_object *flags;
    union acpi_object *name;
    union acpi_object *limit1;
    union acpi_object *limit2;
    union acpi_object *enable;
    struct atk_sensor_data *sensor;
    char const *base_name;
    char const *limit1_name;
    char const *limit2_name;
    u64 type;
    int err;
    int *num;
    int start;

    if (obj->type != ACPI_TYPE_PACKAGE) {
        /* wft is this? */
        dev_warn(dev, "Unknown type for ACPI object: (%d)\n",
                obj->type);
        return -EINVAL;
    }

    err = validate_hwmon_pack(data, obj);
    if (err)
        return err;

    /* Ok, we have a valid hwmon package */
    type = atk_get_pack_member(data, obj, HWMON_PACK_FLAGS)->integer.value
           & ATK_TYPE_MASK;

    switch (type) {
    case HWMON_TYPE_VOLT:
        base_name = "in";
        limit1_name = "min";
        limit2_name = "max";
        num = &data->voltage_count;
        start = 0;
        break;
    case HWMON_TYPE_TEMP:
        base_name = "temp";
        limit1_name = "max";
        limit2_name = "crit";
        num = &data->temperature_count;
        start = 1;
        break;
    case HWMON_TYPE_FAN:
        base_name = "fan";
        limit1_name = "min";
        limit2_name = "max";
        num = &data->fan_count;
        start = 1;
        break;
    default:
        dev_warn(dev, "Unknown sensor type: %#llx\n", type);
        return -EINVAL;
    }

    enable = atk_get_pack_member(data, obj, HWMON_PACK_ENABLE);
    if (!enable->integer.value)
        /* sensor is disabled */
        return 0;

    flags = atk_get_pack_member(data, obj, HWMON_PACK_FLAGS);
    name = atk_get_pack_member(data, obj, HWMON_PACK_NAME);
    limit1 = atk_get_pack_member(data, obj, HWMON_PACK_LIMIT1);
    limit2 = atk_get_pack_member(data, obj, HWMON_PACK_LIMIT2);

    sensor = kzalloc(sizeof(*sensor), GFP_KERNEL);
    if (!sensor)
        return -ENOMEM;

    sensor->acpi_name = kstrdup(name->string.pointer, GFP_KERNEL);
    if (!sensor->acpi_name) {
        err = -ENOMEM;
        goto out;
    }

    INIT_LIST_HEAD(&sensor->list);
    sensor->type = type;
    sensor->data = data;
    sensor->id = flags->integer.value;
    sensor->limit1 = limit1->integer.value;
    if (data->old_interface)
        sensor->limit2 = limit2->integer.value;
    else
        /* The upper limit is expressed as delta from lower limit */
        sensor->limit2 = sensor->limit1 + limit2->integer.value;

    snprintf(sensor->input_attr_name, ATTR_NAME_SIZE,
            "%s%d_input", base_name, start + *num);
    atk_init_attribute(&sensor->input_attr,
            sensor->input_attr_name,
            atk_input_show);

    snprintf(sensor->label_attr_name, ATTR_NAME_SIZE,
            "%s%d_label", base_name, start + *num);
    atk_init_attribute(&sensor->label_attr,
            sensor->label_attr_name,
            atk_label_show);

    snprintf(sensor->limit1_attr_name, ATTR_NAME_SIZE,
            "%s%d_%s", base_name, start + *num, limit1_name);
    atk_init_attribute(&sensor->limit1_attr,
            sensor->limit1_attr_name,
            atk_limit1_show);

    snprintf(sensor->limit2_attr_name, ATTR_NAME_SIZE,
            "%s%d_%s", base_name, start + *num, limit2_name);
    atk_init_attribute(&sensor->limit2_attr,
            sensor->limit2_attr_name,
            atk_limit2_show);

    list_add(&sensor->list, &data->sensor_list);
    (*num)++;

    return 1;
out:
    kfree(sensor);
    return err;
}

static int atk_enumerate_old_hwmon(struct atk_data *data)
{
    struct device *dev = &data->acpi_dev->dev;
    struct acpi_buffer buf;
    union acpi_object *pack;
    acpi_status status;
    int i, ret;
    int count = 0;

    /* Voltages */
    buf.length = ACPI_ALLOCATE_BUFFER;
    status = acpi_evaluate_object_typed(data->atk_handle,
            METHOD_OLD_ENUM_VLT, NULL, &buf, ACPI_TYPE_PACKAGE);
    if (status != AE_OK) {
        dev_warn(dev, METHOD_OLD_ENUM_VLT ": ACPI exception: %s\n",
                acpi_format_exception(status));

        return -ENODEV;
    }

    pack = buf.pointer;
    for (i = 1; i < pack->package.count; i++) {
        union acpi_object *obj = &pack->package.elements[i];

        ret = atk_add_sensor(data, obj);
        if (ret > 0)
            count++;
    }
    ACPI_FREE(buf.pointer);

    /* Temperatures */
    buf.length = ACPI_ALLOCATE_BUFFER;
    status = acpi_evaluate_object_typed(data->atk_handle,
            METHOD_OLD_ENUM_TMP, NULL, &buf, ACPI_TYPE_PACKAGE);
    if (status != AE_OK) {
        dev_warn(dev, METHOD_OLD_ENUM_TMP ": ACPI exception: %s\n",
                acpi_format_exception(status));

        ret = -ENODEV;
        goto cleanup;
    }

    pack = buf.pointer;
    for (i = 1; i < pack->package.count; i++) {
        union acpi_object *obj = &pack->package.elements[i];

        ret = atk_add_sensor(data, obj);
        if (ret > 0)
            count++;
    }
    ACPI_FREE(buf.pointer);

    /* Fans */
    buf.length = ACPI_ALLOCATE_BUFFER;
    status = acpi_evaluate_object_typed(data->atk_handle,
            METHOD_OLD_ENUM_FAN, NULL, &buf, ACPI_TYPE_PACKAGE);
    if (status != AE_OK) {
        dev_warn(dev, METHOD_OLD_ENUM_FAN ": ACPI exception: %s\n",
                acpi_format_exception(status));

        ret = -ENODEV;
        goto cleanup;
    }

    pack = buf.pointer;
    for (i = 1; i < pack->package.count; i++) {
        union acpi_object *obj = &pack->package.elements[i];

        ret = atk_add_sensor(data, obj);
        if (ret > 0)
            count++;
    }
    ACPI_FREE(buf.pointer);

    return count;
cleanup:
    atk_free_sensors(data);
    return ret;
}

static int atk_ec_present(struct atk_data *data)
{
    struct device *dev = &data->acpi_dev->dev;
    union acpi_object *pack;
    union acpi_object *ec;
    int ret;
    int i;

    pack = atk_ggrp(data, ATK_MUX_MGMT);
    if (IS_ERR(pack)) {
        if (PTR_ERR(pack) == -ENOENT) {
            /* The MGMT class does not exists - that's ok */
            dev_dbg(dev, "Class %#llx not found\n", ATK_MUX_MGMT);
            return 0;
        }
        return PTR_ERR(pack);
    }

    /* Search the EC */
    ec = NULL;
    for (i = 0; i < pack->package.count; i++) {
        union acpi_object *obj = &pack->package.elements[i];
        union acpi_object *id;

        if (obj->type != ACPI_TYPE_PACKAGE)
            continue;

        id = &obj->package.elements[0];
        if (id->type != ACPI_TYPE_INTEGER)
            continue;

        if (id->integer.value == ATK_EC_ID) {
            ec = obj;
            break;
        }
    }

    ret = (ec != NULL);
    if (!ret)
        /* The system has no EC */
        dev_dbg(dev, "EC not found\n");

    ACPI_FREE(pack);
    return ret;
}

static int atk_ec_enabled(struct atk_data *data)
{
    struct device *dev = &data->acpi_dev->dev;
    union acpi_object *obj;
    struct atk_acpi_ret_buffer *buf;
    int err;

    obj = atk_gitm(data, ATK_EC_ID);
    if (IS_ERR(obj)) {
        dev_err(dev, "Unable to query EC status\n");
        return PTR_ERR(obj);
    }
    buf = (struct atk_acpi_ret_buffer *)obj->buffer.pointer;

    if (buf->flags == 0) {
        dev_err(dev, "Unable to query EC status\n");
        err = -EIO;
    } else {
        err = (buf->value != 0);
        dev_dbg(dev, "EC is %sabled\n",
                err ? "en" : "dis");
    }

    ACPI_FREE(obj);
    return err;
}

static int atk_ec_ctl(struct atk_data *data, int enable)
{
    struct device *dev = &data->acpi_dev->dev;
    union acpi_object *obj;
    struct atk_acpi_input_buf sitm;
    struct atk_acpi_ret_buffer *ec_ret;
    int err = 0;

    sitm.id = ATK_EC_ID;
    sitm.param1 = enable;
    sitm.param2 = 0;

    obj = atk_sitm(data, &sitm);
    if (IS_ERR(obj)) {
        dev_err(dev, "Failed to %sable the EC\n",
                enable ? "en" : "dis");
        return PTR_ERR(obj);
    }
    ec_ret = (struct atk_acpi_ret_buffer *)obj->buffer.pointer;
    if (ec_ret->flags == 0) {
        dev_err(dev, "Failed to %sable the EC\n",
                enable ? "en" : "dis");
        err = -EIO;
    } else {
        dev_info(dev, "EC %sabled\n",
                enable ? "en" : "dis");
    }

    ACPI_FREE(obj);
    return err;
}

static int atk_enumerate_new_hwmon(struct atk_data *data)
{
    struct device *dev = &data->acpi_dev->dev;
    union acpi_object *pack;
    int err;
    int i;

    err = atk_ec_present(data);
    if (err < 0)
        return err;
    if (err) {
        err = atk_ec_enabled(data);
        if (err < 0)
            return err;
        /* If the EC was disabled we will disable it again on unload */
        data->disable_ec = err;

        err = atk_ec_ctl(data, 1);
        if (err) {
            data->disable_ec = false;
            return err;
        }
    }

    dev_dbg(dev, "Enumerating hwmon sensors\n");

    pack = atk_ggrp(data, ATK_MUX_HWMON);
    if (IS_ERR(pack))
        return PTR_ERR(pack);

    for (i = 0; i < pack->package.count; i++) {
        union acpi_object *obj = &pack->package.elements[i];

        atk_add_sensor(data, obj);
    }

    err = data->voltage_count + data->temperature_count + data->fan_count;

    ACPI_FREE(pack);
    return err;
}

static int atk_create_files(struct atk_data *data)
{
    struct atk_sensor_data *s;
    int err;

    list_for_each_entry(s, &data->sensor_list, list) {
        err = device_create_file(data->hwmon_dev, &s->input_attr);
        if (err)
            return err;
        err = device_create_file(data->hwmon_dev, &s->label_attr);
        if (err)
            return err;
        err = device_create_file(data->hwmon_dev, &s->limit1_attr);
        if (err)
            return err;
        err = device_create_file(data->hwmon_dev, &s->limit2_attr);
        if (err)
            return err;
    }

    err = device_create_file(data->hwmon_dev, &atk_name_attr);

    return err;
}

static void atk_remove_files(struct atk_data *data)
{
    struct atk_sensor_data *s;

    list_for_each_entry(s, &data->sensor_list, list) {
        device_remove_file(data->hwmon_dev, &s->input_attr);
        device_remove_file(data->hwmon_dev, &s->label_attr);
        device_remove_file(data->hwmon_dev, &s->limit1_attr);
        device_remove_file(data->hwmon_dev, &s->limit2_attr);
    }
    device_remove_file(data->hwmon_dev, &atk_name_attr);
}

static void atk_free_sensors(struct atk_data *data)
{
    struct list_head *head = &data->sensor_list;
    struct atk_sensor_data *s, *tmp;

    list_for_each_entry_safe(s, tmp, head, list) {
        kfree(s->acpi_name);
        kfree(s);
    }
}

static int atk_register_hwmon(struct atk_data *data)
{
    struct device *dev = &data->acpi_dev->dev;
    int err;

    dev_dbg(dev, "registering hwmon device\n");
    data->hwmon_dev = hwmon_device_register(dev);
    if (IS_ERR(data->hwmon_dev))
        return PTR_ERR(data->hwmon_dev);

    dev_dbg(dev, "populating sysfs directory\n");
    err = atk_create_files(data);
    if (err)
        goto remove;

    return 0;
remove:
    /* Cleanup the registered files */
    atk_remove_files(data);
    hwmon_device_unregister(data->hwmon_dev);
    return err;
}

static int atk_probe_if(struct atk_data *data)
{
    struct device *dev = &data->acpi_dev->dev;
    acpi_handle ret;
    acpi_status status;
    int err = 0;

    /* RTMP: read temperature */
    status = acpi_get_handle(data->atk_handle, METHOD_OLD_READ_TMP, &ret);
    if (ACPI_SUCCESS(status))
        data->rtmp_handle = ret;
    else
        dev_dbg(dev, "method " METHOD_OLD_READ_TMP " not found: %s\n",
                acpi_format_exception(status));

    /* RVLT: read voltage */
    status = acpi_get_handle(data->atk_handle, METHOD_OLD_READ_VLT, &ret);
    if (ACPI_SUCCESS(status))
        data->rvlt_handle = ret;
    else
        dev_dbg(dev, "method " METHOD_OLD_READ_VLT " not found: %s\n",
                acpi_format_exception(status));

    /* RFAN: read fan status */
    status = acpi_get_handle(data->atk_handle, METHOD_OLD_READ_FAN, &ret);
    if (ACPI_SUCCESS(status))
        data->rfan_handle = ret;
    else
        dev_dbg(dev, "method " METHOD_OLD_READ_FAN " not found: %s\n",
                acpi_format_exception(status));

    /* Enumeration */
    status = acpi_get_handle(data->atk_handle, METHOD_ENUMERATE, &ret);
    if (ACPI_SUCCESS(status))
        data->enumerate_handle = ret;
    else
        dev_dbg(dev, "method " METHOD_ENUMERATE " not found: %s\n",
                acpi_format_exception(status));

    /* De-multiplexer (read) */
    status = acpi_get_handle(data->atk_handle, METHOD_READ, &ret);
    if (ACPI_SUCCESS(status))
        data->read_handle = ret;
    else
        dev_dbg(dev, "method " METHOD_READ " not found: %s\n",
                acpi_format_exception(status));

    /* De-multiplexer (write) */
    status = acpi_get_handle(data->atk_handle, METHOD_WRITE, &ret);
    if (ACPI_SUCCESS(status))
        data->write_handle = ret;
    else
        dev_dbg(dev, "method " METHOD_WRITE " not found: %s\n",
                 acpi_format_exception(status));

    /*
     * Check for hwmon methods: first check "old" style methods; note that
     * both may be present: in this case we stick to the old interface;
     * analysis of multiple DSDTs indicates that when both interfaces
     * are present the new one (GGRP/GITM) is not functional.
     */
    if (new_if)
        dev_info(dev, "Overriding interface detection\n");
    if (data->rtmp_handle &&
            data->rvlt_handle && data->rfan_handle && !new_if)
        data->old_interface = true;
    else if (data->enumerate_handle && data->read_handle &&
            data->write_handle)
        data->old_interface = false;
    else
        err = -ENODEV;

    return err;
}

static int atk_add(struct acpi_device *device)
{
    acpi_status ret;
    int err;
    struct acpi_buffer buf;
    union acpi_object *obj;
    struct atk_data *data;

    dev_dbg(&device->dev, "adding...\n");

    data = kzalloc(sizeof(*data), GFP_KERNEL);
    if (!data)
        return -ENOMEM;

    data->acpi_dev = device;
    data->atk_handle = device->handle;
    INIT_LIST_HEAD(&data->sensor_list);
    data->disable_ec = false;

    buf.length = ACPI_ALLOCATE_BUFFER;
    ret = acpi_evaluate_object_typed(data->atk_handle, BOARD_ID, NULL,
            &buf, ACPI_TYPE_PACKAGE);
    if (ret != AE_OK) {
        dev_dbg(&device->dev, "atk: method MBIF not found\n");
    } else {
        obj = buf.pointer;
        if (obj->package.count >= 2) {
            union acpi_object *id = &obj->package.elements[1];
            if (id->type == ACPI_TYPE_STRING)
                dev_dbg(&device->dev, "board ID = %s\n",
                    id->string.pointer);
        }
        ACPI_FREE(buf.pointer);
    }

    err = atk_probe_if(data);
    if (err) {
        dev_err(&device->dev, "No usable hwmon interface detected\n");
        goto out;
    }

    if (data->old_interface) {
        dev_dbg(&device->dev, "Using old hwmon interface\n");
        err = atk_enumerate_old_hwmon(data);
    } else {
        dev_dbg(&device->dev, "Using new hwmon interface\n");
        err = atk_enumerate_new_hwmon(data);
    }
    if (err < 0)
        goto out;
    if (err == 0) {
        dev_info(&device->dev,
             "No usable sensor detected, bailing out\n");
        err = -ENODEV;
        goto out;
    }

    err = atk_register_hwmon(data);
    if (err)
        goto cleanup;

    atk_debugfs_init(data);

    device->driver_data = data;
    return 0;
cleanup:
    atk_free_sensors(data);
out:
    if (data->disable_ec)
        atk_ec_ctl(data, 0);
    kfree(data);
    return err;
}

static int atk_remove(struct acpi_device *device, int type)
{
    struct atk_data *data = device->driver_data;
    dev_dbg(&device->dev, "removing...\n");

    device->driver_data = NULL;

    atk_debugfs_cleanup(data);

    atk_remove_files(data);
    atk_free_sensors(data);
    hwmon_device_unregister(data->hwmon_dev);

    if (data->disable_ec) {
        if (atk_ec_ctl(data, 0))
            dev_err(&device->dev, "Failed to disable EC\n");
    }

    kfree(data);

    return 0;
}

static int __init atk0110_init(void)
{
    int ret;

    /* Make sure it's safe to access the device through ACPI */
    if (!acpi_resources_are_enforced()) {
        pr_err("Resources not safely usable due to acpi_enforce_resources kernel parameter\n");
        return -EBUSY;
    }

    if (dmi_check_system(atk_force_new_if))
        new_if = true;

    ret = acpi_bus_register_driver(&atk_driver);
    if (ret)
        pr_info("acpi_bus_register_driver failed: %d\n", ret);

    return ret;
}

static void __exit atk0110_exit(void)
{
    acpi_bus_unregister_driver(&atk_driver);
}

module_init(atk0110_init);
module_exit(atk0110_exit);

MODULE_LICENSE("GPL");