]> www.pilppa.org Git - linux-2.6-omap-h63xx.git/blobdiff - drivers/hwmon/asus_atk0110.c
Merge branch 'hwmon-for-linus' of git://jdelvare.pck.nerim.net/jdelvare-2.6
[linux-2.6-omap-h63xx.git] / drivers / hwmon / asus_atk0110.c
diff --git a/drivers/hwmon/asus_atk0110.c b/drivers/hwmon/asus_atk0110.c
new file mode 100644 (file)
index 0000000..0897ede
--- /dev/null
@@ -0,0 +1,1009 @@
+/*
+ * Copyright (C) 2007-2009 Luca Tettamanti <kronos.it@gmail.com>
+ *
+ * This file is released under the GPLv2
+ * See COPYING in the top level directory of the kernel tree.
+ */
+
+#include <linux/kernel.h>
+#include <linux/hwmon.h>
+#include <linux/list.h>
+#include <linux/module.h>
+
+#include <acpi/acpi.h>
+#include <acpi/acpixf.h>
+#include <acpi/acpi_drivers.h>
+#include <acpi/acpi_bus.h>
+
+
+#define ATK_HID "ATK0110"
+
+/* 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_CLASS_MASK         0xff000000ULL
+#define ATK_CLASS_FREQ_CTL     0x03000000ULL
+#define ATK_CLASS_FAN_CTL      0x04000000ULL
+#define ATK_CLASS_HWMON                0x06000000ULL
+
+#define ATK_TYPE_MASK          0x00ff0000ULL
+#define HWMON_TYPE_VOLT                0x00020000ULL
+#define HWMON_TYPE_TEMP                0x00030000ULL
+#define HWMON_TYPE_FAN         0x00040000ULL
+
+#define HWMON_SENSOR_ID_MASK   0x0000ffffULL
+
+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;
+
+       int voltage_count;
+       int temperature_count;
+       int fan_count;
+       struct list_head sensor_list;
+};
+
+
+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;
+};
+
+struct atk_acpi_buffer_u64 {
+       union acpi_object buf;
+       u64 value;
+};
+
+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)
+{
+       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;
+}
+
+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;
+}
+
+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 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;
+       struct acpi_object_list params;
+       struct acpi_buffer ret;
+       union acpi_object id;
+       struct atk_acpi_buffer_u64 tmp;
+       acpi_status status;
+
+       id.type = ACPI_TYPE_INTEGER;
+       id.integer.value = sensor->id;
+
+       params.count = 1;
+       params.pointer = &id;
+
+       tmp.buf.type = ACPI_TYPE_BUFFER;
+       tmp.buf.buffer.pointer = (u8 *)&tmp.value;
+       tmp.buf.buffer.length = sizeof(u64);
+       ret.length = sizeof(tmp);
+       ret.pointer = &tmp;
+
+       status = acpi_evaluate_object_typed(data->read_handle, NULL, &params,
+                       &ret, ACPI_TYPE_BUFFER);
+       if (status != AE_OK) {
+               dev_warn(dev, "%s: ACPI exception: %s\n", __func__,
+                               acpi_format_exception(status));
+               return -EIO;
+       }
+
+       /* Return buffer format:
+        * [0-3] "value" is valid flag
+        * [4-7] value
+        */
+       if (!(tmp.value & 0xffffffff)) {
+               /* The reading is not valid, possible causes:
+                * - sensor failure
+                * - enumeration was FUBAR (and we didn't notice)
+                */
+               dev_info(dev, "Failure: %#llx\n", tmp.value);
+               return -EIO;
+       }
+
+       *value = (tmp.value & 0xffffffff00000000ULL) >> 32;
+
+       return 0;
+}
+
+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;
+}
+
+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;
+       sensor->limit2 = 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->acpi_name);
+       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_enumerate_new_hwmon(struct atk_data *data)
+{
+       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;
+       int err;
+       int i;
+
+       dev_dbg(dev, "Enumerating hwmon sensors\n");
+
+       id.type = ACPI_TYPE_INTEGER;
+       id.integer.value = ATK_MUX_HWMON;
+       params.count = 1;
+       params.pointer = &id;
+
+       buf.length = ACPI_ALLOCATE_BUFFER;
+       ret = acpi_evaluate_object_typed(data->enumerate_handle, NULL, &params,
+                       &buf, ACPI_TYPE_PACKAGE);
+       if (ret != AE_OK) {
+               dev_warn(dev, METHOD_ENUMERATE ": ACPI exception: %s\n",
+                               acpi_format_exception(ret));
+               return -ENODEV;
+       }
+
+       /* Result must be a package */
+       pack = buf.pointer;
+
+       if (pack->package.count < 1) {
+               dev_dbg(dev, "%s: hwmon package is too small: %d\n", __func__,
+                               pack->package.count);
+               err = -EINVAL;
+               goto out;
+       }
+
+       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;
+
+out:
+       ACPI_FREE(buf.pointer);
+       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_check_old_if(struct atk_data *data)
+{
+       struct device *dev = &data->acpi_dev->dev;
+       acpi_handle ret;
+       acpi_status status;
+
+       /* RTMP: read temperature */
+       status = acpi_get_handle(data->atk_handle, METHOD_OLD_READ_TMP, &ret);
+       if (status != AE_OK) {
+               dev_dbg(dev, "method " METHOD_OLD_READ_TMP " not found: %s\n",
+                               acpi_format_exception(status));
+               return -ENODEV;
+       }
+       data->rtmp_handle = ret;
+
+       /* RVLT: read voltage */
+       status = acpi_get_handle(data->atk_handle, METHOD_OLD_READ_VLT, &ret);
+       if (status != AE_OK) {
+               dev_dbg(dev, "method " METHOD_OLD_READ_VLT " not found: %s\n",
+                               acpi_format_exception(status));
+               return -ENODEV;
+       }
+       data->rvlt_handle = ret;
+
+       /* RFAN: read fan status */
+       status = acpi_get_handle(data->atk_handle, METHOD_OLD_READ_FAN, &ret);
+       if (status != AE_OK) {
+               dev_dbg(dev, "method " METHOD_OLD_READ_FAN " not found: %s\n",
+                               acpi_format_exception(status));
+               return -ENODEV;
+       }
+       data->rfan_handle = ret;
+
+       return 0;
+}
+
+static int atk_check_new_if(struct atk_data *data)
+{
+       struct device *dev = &data->acpi_dev->dev;
+       acpi_handle ret;
+       acpi_status status;
+
+       /* Enumeration */
+       status = acpi_get_handle(data->atk_handle, METHOD_ENUMERATE, &ret);
+       if (status != AE_OK) {
+               dev_dbg(dev, "method " METHOD_ENUMERATE " not found: %s\n",
+                               acpi_format_exception(status));
+               return -ENODEV;
+       }
+       data->enumerate_handle = ret;
+
+       /* De-multiplexer (read) */
+       status = acpi_get_handle(data->atk_handle, METHOD_READ, &ret);
+       if (status != AE_OK) {
+               dev_dbg(dev, "method " METHOD_READ " not found: %s\n",
+                               acpi_format_exception(status));
+               return -ENODEV;
+       }
+       data->read_handle = ret;
+
+       return 0;
+}
+
+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);
+
+       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");
+               err = -ENODEV;
+               goto out;
+       }
+
+       obj = buf.pointer;
+       if (obj->package.count >= 2 &&
+                       obj->package.elements[1].type == ACPI_TYPE_STRING) {
+               dev_dbg(&device->dev, "board ID = %s\n",
+                               obj->package.elements[1].string.pointer);
+       }
+       ACPI_FREE(buf.pointer);
+
+       /* 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.
+        */
+       err = atk_check_old_if(data);
+       if (!err) {
+               dev_dbg(&device->dev, "Using old hwmon interface\n");
+               data->old_interface = true;
+       } else {
+               err = atk_check_new_if(data);
+               if (err)
+                       goto out;
+
+               dev_dbg(&device->dev, "Using new hwmon interface\n");
+               data->old_interface = false;
+       }
+
+       if (data->old_interface)
+               err = atk_enumerate_old_hwmon(data);
+       else
+               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;
+
+       device->driver_data = data;
+       return 0;
+cleanup:
+       atk_free_sensors(data);
+out:
+       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_remove_files(data);
+       atk_free_sensors(data);
+       hwmon_device_unregister(data->hwmon_dev);
+
+       kfree(data);
+
+       return 0;
+}
+
+static int __init atk0110_init(void)
+{
+       int ret;
+
+       ret = acpi_bus_register_driver(&atk_driver);
+       if (ret)
+               pr_info("atk: 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");