Apple SMC driver (hardware monitoring and control)

This driver provides support for the Apple System Management Controller, which
provides an accelerometer (Apple Sudden Motion Sensor), light sensors,
temperature sensors, keyboard backlight control and fan control. Only
Intel-based Apple's computers are supported (MacBook Pro, MacBook, MacMini).

[bunk@stusta.de: make drivers/hwmon/applesmc.c:backlight_work stati]
[khali@linux-fr.org: fix temperature attribute file names]
Signed-off-by: Nicolas Boichat <nicolas@boichat.ch>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

4 files changed, 1370 insertions, 0 deletions

diff --git a/MAINTAINERS b/MAINTAINERS
index 6d665ac13f99..bb0e832c36ff 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -382,6 +382,12 @@ L:	linux-laptop@vger.kernel.org
 W:      http://www.canb.auug.org.au/~sfr/
 S:      Supported
 
+APPLE SMC DRIVER
+P:      Nicolas Boichat
+M:      nicolas@boichat.ch
+L:      mactel-linux-devel@lists.sourceforge.net
+S:      Maintained
+
 APPLETALK NETWORK LAYER
 P:      Arnaldo Carvalho de Melo
 M:      acme@ghostprotocols.net
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 6d105a1d41b1..25b72a491702 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -594,6 +594,30 @@ config SENSORS_HDAPS
           Say Y here if you have an applicable laptop and want to experience
           the awesome power of hdaps.
 
+config SENSORS_APPLESMC
+        tristate "Apple SMC (Motion sensor, light sensor, keyboard backlight)"
+        depends on HWMON && INPUT && X86
+        select NEW_LEDS
+        select LEDS_CLASS
+        default n
+        help
+          This driver provides support for the Apple System Management
+          Controller, which provides an accelerometer (Apple Sudden Motion
+          Sensor), light sensors, temperature sensors, keyboard backlight
+          control and fan control.
+
+          Only Intel-based Apple's computers are supported (MacBook Pro,
+          MacBook, MacMini).
+
+          Data from the different sensors, keyboard backlight control and fan
+          control are accessible via sysfs.
+
+          This driver also provides an absolute input class device, allowing
+          the laptop to act as a pinball machine-esque joystick.
+
+          Say Y here if you have an applicable laptop and want to experience
+          the awesome power of applesmc.
+
 config HWMON_DEBUG_CHIP
         bool "Hardware Monitoring Chip debugging messages"
         depends on HWMON
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 4165c27a2f25..544f8d8dff4e 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -20,6 +20,7 @@ obj-$(CONFIG_SENSORS_ADM1026)	+= adm1026.o
 obj-$(CONFIG_SENSORS_ADM1029)   += adm1029.o
 obj-$(CONFIG_SENSORS_ADM1031)   += adm1031.o
 obj-$(CONFIG_SENSORS_ADM9240)   += adm9240.o
+obj-$(CONFIG_SENSORS_APPLESMC)  += applesmc.o
 obj-$(CONFIG_SENSORS_AMS)       += ams/
 obj-$(CONFIG_SENSORS_ATXP1)     += atxp1.o
 obj-$(CONFIG_SENSORS_DS1621)    += ds1621.o
diff --git a/drivers/hwmon/applesmc.c b/drivers/hwmon/applesmc.c
new file mode 100644
index 000000000000..3215f9c87f32
--- /dev/null
+++ b/drivers/hwmon/applesmc.c
@@ -0,0 +1,1339 @@
+/*
+ * drivers/hwmon/applesmc.c - driver for Apple's SMC (accelerometer, temperature
+ * sensors, fan control, keyboard backlight control) used in Intel-based Apple
+ * computers.
+ *
+ * Copyright (C) 2007 Nicolas Boichat <nicolas@boichat.ch>
+ *
+ * Based on hdaps.c driver:
+ * Copyright (C) 2005 Robert Love <rml@novell.com>
+ * Copyright (C) 2005 Jesper Juhl <jesper.juhl@gmail.com>
+ *
+ * Fan control based on smcFanControl:
+ * Copyright (C) 2006 Hendrik Holtmann <holtmann@mac.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License v2 as published by the
+ * Free Software Foundation.
+ *
+ * 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.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
+ */
+
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+#include <linux/input.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/timer.h>
+#include <linux/dmi.h>
+#include <linux/mutex.h>
+#include <linux/hwmon-sysfs.h>
+#include <asm/io.h>
+#include <linux/leds.h>
+#include <linux/hwmon.h>
+#include <linux/workqueue.h>
+
+/* data port used by Apple SMC */
+#define APPLESMC_DATA_PORT      0x300
+/* command/status port used by Apple SMC */
+#define APPLESMC_CMD_PORT       0x304
+
+#define APPLESMC_NR_PORTS       32 /* 0x300-0x31f */
+
+#define APPLESMC_MAX_DATA_LENGTH 32
+
+#define APPLESMC_STATUS_MASK    0x0f
+#define APPLESMC_READ_CMD       0x10
+#define APPLESMC_WRITE_CMD      0x11
+#define APPLESMC_GET_KEY_BY_INDEX_CMD   0x12
+#define APPLESMC_GET_KEY_TYPE_CMD       0x13
+
+#define KEY_COUNT_KEY           "#KEY" /* r-o ui32 */
+
+#define LIGHT_SENSOR_LEFT_KEY   "ALV0" /* r-o {alv (6 bytes) */
+#define LIGHT_SENSOR_RIGHT_KEY  "ALV1" /* r-o {alv (6 bytes) */
+#define BACKLIGHT_KEY           "LKSB" /* w-o {lkb (2 bytes) */
+
+#define CLAMSHELL_KEY           "MSLD" /* r-o ui8 (unused) */
+
+#define MOTION_SENSOR_X_KEY     "MO_X" /* r-o sp78 (2 bytes) */
+#define MOTION_SENSOR_Y_KEY     "MO_Y" /* r-o sp78 (2 bytes) */
+#define MOTION_SENSOR_Z_KEY     "MO_Z" /* r-o sp78 (2 bytes) */
+#define MOTION_SENSOR_KEY       "MOCN" /* r/w ui16 */
+
+#define FANS_COUNT              "FNum" /* r-o ui8 */
+#define FANS_MANUAL             "FS! " /* r-w ui16 */
+#define FAN_ACTUAL_SPEED        "F0Ac" /* r-o fpe2 (2 bytes) */
+#define FAN_MIN_SPEED           "F0Mn" /* r-o fpe2 (2 bytes) */
+#define FAN_MAX_SPEED           "F0Mx" /* r-o fpe2 (2 bytes) */
+#define FAN_SAFE_SPEED          "F0Sf" /* r-o fpe2 (2 bytes) */
+#define FAN_TARGET_SPEED        "F0Tg" /* r-w fpe2 (2 bytes) */
+#define FAN_POSITION            "F0ID" /* r-o char[16] */
+
+/*
+ * Temperature sensors keys (sp78 - 2 bytes).
+ * First set for Macbook(Pro), second for Macmini.
+ */
+static const char* temperature_sensors_sets[][13] = {
+        { "TA0P", "TB0T", "TC0D", "TC0P", "TG0H", "TG0P", "TG0T", "Th0H",
+          "Th1H", "Tm0P", "Ts0P", "Ts1P", NULL },
+        { "TC0D", "TC0P", NULL }
+};
+
+/* List of keys used to read/write fan speeds */
+static const char* fan_speed_keys[] = {
+        FAN_ACTUAL_SPEED,
+        FAN_MIN_SPEED,
+        FAN_MAX_SPEED,
+        FAN_SAFE_SPEED,
+        FAN_TARGET_SPEED
+};
+
+#define INIT_TIMEOUT_MSECS      5000    /* wait up to 5s for device init ... */
+#define INIT_WAIT_MSECS         50      /* ... in 50ms increments */
+
+#define APPLESMC_POLL_PERIOD    (HZ/20) /* poll for input every 1/20s */
+#define APPLESMC_INPUT_FUZZ     4       /* input event threshold */
+#define APPLESMC_INPUT_FLAT     4
+
+#define SENSOR_X 0
+#define SENSOR_Y 1
+#define SENSOR_Z 2
+
+/* Structure to be passed to DMI_MATCH function */
+struct dmi_match_data {
+/* Indicates whether this computer has an accelerometer. */
+        int accelerometer;
+/* Indicates whether this computer has light sensors and keyboard backlight. */
+        int light;
+/* Indicates which temperature sensors set to use. */
+        int temperature_set;
+};
+
+static const int debug;
+static struct platform_device *pdev;
+static s16 rest_x;
+static s16 rest_y;
+static struct timer_list applesmc_timer;
+static struct input_dev *applesmc_idev;
+static struct class_device *hwmon_class_dev;
+
+/* Indicates whether this computer has an accelerometer. */
+static unsigned int applesmc_accelerometer;
+
+/* Indicates whether this computer has light sensors and keyboard backlight. */
+static unsigned int applesmc_light;
+
+/* Indicates which temperature sensors set to use. */
+static unsigned int applesmc_temperature_set;
+
+static struct mutex applesmc_lock;
+
+/*
+ * Last index written to key_at_index sysfs file, and value to use for all other
+ * key_at_index_* sysfs files.
+ */
+static unsigned int key_at_index;
+
+static struct workqueue_struct *applesmc_led_wq;
+
+/*
+ * __wait_status - Wait up to 2ms for the status port to get a certain value
+ * (masked with 0x0f), returning zero if the value is obtained.  Callers must
+ * hold applesmc_lock.
+ */
+static int __wait_status(u8 val)
+{
+        unsigned int i;
+
+        val = val & APPLESMC_STATUS_MASK;
+
+        for (i = 0; i < 200; i++) {
+                if ((inb(APPLESMC_CMD_PORT) & APPLESMC_STATUS_MASK) == val) {
+                        if (debug)
+                                printk(KERN_DEBUG
+                                                "Waited %d us for status %x\n",
+                                                i*10, val);
+                        return 0;
+                }
+                udelay(10);
+        }
+
+        printk(KERN_WARNING "applesmc: wait status failed: %x != %x\n",
+                                                val, inb(APPLESMC_CMD_PORT));
+
+        return -EIO;
+}
+
+/*
+ * applesmc_read_key - reads len bytes from a given key, and put them in buffer.
+ * Returns zero on success or a negative error on failure. Callers must
+ * hold applesmc_lock.
+ */
+static int applesmc_read_key(const char* key, u8* buffer, u8 len)
+{
+        int i;
+
+        if (len > APPLESMC_MAX_DATA_LENGTH) {
+                printk(KERN_ERR "applesmc_read_key: cannot read more than "
+                                        "%d bytes\n", APPLESMC_MAX_DATA_LENGTH);
+                return -EINVAL;
+        }
+
+        outb(APPLESMC_READ_CMD, APPLESMC_CMD_PORT);
+        if (__wait_status(0x0c))
+                return -EIO;
+
+        for (i = 0; i < 4; i++) {
+                outb(key[i], APPLESMC_DATA_PORT);
+                if (__wait_status(0x04))
+                        return -EIO;
+        }
+        if (debug)
+                printk(KERN_DEBUG "<%s", key);
+
+        outb(len, APPLESMC_DATA_PORT);
+        if (debug)
+                printk(KERN_DEBUG ">%x", len);
+
+        for (i = 0; i < len; i++) {
+                if (__wait_status(0x05))
+                        return -EIO;
+                buffer[i] = inb(APPLESMC_DATA_PORT);
+                if (debug)
+                        printk(KERN_DEBUG "<%x", buffer[i]);
+        }
+        if (debug)
+                printk(KERN_DEBUG "\n");
+
+        return 0;
+}
+
+/*
+ * applesmc_write_key - writes len bytes from buffer to a given key.
+ * Returns zero on success or a negative error on failure. Callers must
+ * hold applesmc_lock.
+ */
+static int applesmc_write_key(const char* key, u8* buffer, u8 len)
+{
+        int i;
+
+        if (len > APPLESMC_MAX_DATA_LENGTH) {
+                printk(KERN_ERR "applesmc_write_key: cannot write more than "
+                                        "%d bytes\n", APPLESMC_MAX_DATA_LENGTH);
+                return -EINVAL;
+        }
+
+        outb(APPLESMC_WRITE_CMD, APPLESMC_CMD_PORT);
+        if (__wait_status(0x0c))
+                return -EIO;
+
+        for (i = 0; i < 4; i++) {
+                outb(key[i], APPLESMC_DATA_PORT);
+                if (__wait_status(0x04))
+                        return -EIO;
+        }
+
+        outb(len, APPLESMC_DATA_PORT);
+
+        for (i = 0; i < len; i++) {
+                if (__wait_status(0x04))
+                        return -EIO;
+                outb(buffer[i], APPLESMC_DATA_PORT);
+        }
+
+        return 0;
+}
+
+/*
+ * applesmc_get_key_at_index - get key at index, and put the result in key
+ * (char[6]). Returns zero on success or a negative error on failure. Callers
+ * must hold applesmc_lock.
+ */
+static int applesmc_get_key_at_index(int index, char* key)
+{
+        int i;
+        u8 readkey[4];
+        readkey[0] = index >> 24;
+        readkey[1] = index >> 16;
+        readkey[2] = index >> 8;
+        readkey[3] = index;
+
+        outb(APPLESMC_GET_KEY_BY_INDEX_CMD, APPLESMC_CMD_PORT);
+        if (__wait_status(0x0c))
+                return -EIO;
+
+        for (i = 0; i < 4; i++) {
+                outb(readkey[i], APPLESMC_DATA_PORT);
+                if (__wait_status(0x04))
+                        return -EIO;
+        }
+
+        outb(4, APPLESMC_DATA_PORT);
+
+        for (i = 0; i < 4; i++) {
+                if (__wait_status(0x05))
+                        return -EIO;
+                key[i] = inb(APPLESMC_DATA_PORT);
+        }
+        key[4] = 0;
+
+        return 0;
+}
+
+/*
+ * applesmc_get_key_type - get key type, and put the result in type (char[6]).
+ * Returns zero on success or a negative error on failure. Callers must
+ * hold applesmc_lock.
+ */
+static int applesmc_get_key_type(char* key, char* type)
+{
+        int i;
+
+        outb(APPLESMC_GET_KEY_TYPE_CMD, APPLESMC_CMD_PORT);
+        if (__wait_status(0x0c))
+                return -EIO;
+
+        for (i = 0; i < 4; i++) {
+                outb(key[i], APPLESMC_DATA_PORT);
+                if (__wait_status(0x04))
+                        return -EIO;
+        }
+
+        outb(5, APPLESMC_DATA_PORT);
+
+        for (i = 0; i < 6; i++) {
+                if (__wait_status(0x05))
+                        return -EIO;
+                type[i] = inb(APPLESMC_DATA_PORT);
+        }
+        type[5] = 0;
+
+        return 0;
+}
+
+/*
+ * applesmc_read_motion_sensor - Read motion sensor (X, Y or Z). Callers must
+ * hold applesmc_lock.
+ */
+static int applesmc_read_motion_sensor(int index, s16* value)
+{
+        u8 buffer[2];
+        int ret;
+
+        switch (index) {
+        case SENSOR_X:
+                ret = applesmc_read_key(MOTION_SENSOR_X_KEY, buffer, 2);
+                break;
+        case SENSOR_Y:
+                ret = applesmc_read_key(MOTION_SENSOR_Y_KEY, buffer, 2);
+                break;
+        case SENSOR_Z:
+                ret = applesmc_read_key(MOTION_SENSOR_Z_KEY, buffer, 2);
+                break;
+        default:
+                ret = -EINVAL;
+        }
+
+        *value = ((s16)buffer[0] << 8) | buffer[1];
+
+        return ret;
+}
+
+/*
+ * applesmc_device_init - initialize the accelerometer.  Returns zero on success
+ * and negative error code on failure.  Can sleep.
+ */
+static int applesmc_device_init(void)
+{
+        int total, ret = -ENXIO;
+        u8 buffer[2];
+
+        if (!applesmc_accelerometer)
+                return 0;
+
+        mutex_lock(&applesmc_lock);
+
+        for (total = INIT_TIMEOUT_MSECS; total > 0; total -= INIT_WAIT_MSECS) {
+                if (debug)
+                        printk(KERN_DEBUG "applesmc try %d\n", total);
+                if (!applesmc_read_key(MOTION_SENSOR_KEY, buffer, 2) &&
+                                (buffer[0] != 0x00 || buffer[1] != 0x00)) {
+                        if (total == INIT_TIMEOUT_MSECS) {
+                                printk(KERN_DEBUG "applesmc: device has"
+                                                " already been initialized"
+                                                " (0x%02x, 0x%02x).\n",
+                                                buffer[0], buffer[1]);
+                        } else {
+                                printk(KERN_DEBUG "applesmc: device"
+                                                " successfully initialized"
+                                                " (0x%02x, 0x%02x).\n",
+                                                buffer[0], buffer[1]);
+                        }
+                        ret = 0;
+                        goto out;
+                }
+                buffer[0] = 0xe0;
+                buffer[1] = 0x00;
+                applesmc_write_key(MOTION_SENSOR_KEY, buffer, 2);
+                msleep(INIT_WAIT_MSECS);
+        }
+
+        printk(KERN_WARNING "applesmc: failed to init the device\n");
+
+out:
+        mutex_unlock(&applesmc_lock);
+        return ret;
+}
+
+/*
+ * applesmc_get_fan_count - get the number of fans. Callers must NOT hold
+ * applesmc_lock.
+ */
+static int applesmc_get_fan_count(void)
+{
+        int ret;
+        u8 buffer[1];
+
+        mutex_lock(&applesmc_lock);
+
+        ret = applesmc_read_key(FANS_COUNT, buffer, 1);
+
+        mutex_unlock(&applesmc_lock);
+        if (ret)
+                return ret;
+        else
+                return buffer[0];
+}
+
+/* Device model stuff */
+static int applesmc_probe(struct platform_device *dev)
+{
+        int ret;
+
+        ret = applesmc_device_init();
+        if (ret)
+                return ret;
+
+        printk(KERN_INFO "applesmc: device successfully initialized.\n");
+        return 0;
+}
+
+static int applesmc_resume(struct platform_device *dev)
+{
+        return applesmc_device_init();
+}
+
+static struct platform_driver applesmc_driver = {
+        .probe = applesmc_probe,
+        .resume = applesmc_resume,
+        .driver = {
+                .name = "applesmc",
+                .owner = THIS_MODULE,
+        },
+};
+
+/*
+ * applesmc_calibrate - Set our "resting" values.  Callers must
+ * hold applesmc_lock.
+ */
+static void applesmc_calibrate(void)
+{
+        applesmc_read_motion_sensor(SENSOR_X, &rest_x);
+        applesmc_read_motion_sensor(SENSOR_Y, &rest_y);
+        rest_x = -rest_x;
+}
+
+static int applesmc_idev_open(struct input_dev *dev)
+{
+        add_timer(&applesmc_timer);
+
+        return 0;
+}
+
+static void applesmc_idev_close(struct input_dev *dev)
+{
+        del_timer_sync(&applesmc_timer);
+}
+
+static void applesmc_idev_poll(unsigned long unused)
+{
+        s16 x, y;
+
+        /* Cannot sleep.  Try nonblockingly.  If we fail, try again later. */
+        if (!mutex_trylock(&applesmc_lock)) {
+                mod_timer(&applesmc_timer, jiffies + APPLESMC_POLL_PERIOD);
+                return;
+        }
+
+        if (applesmc_read_motion_sensor(SENSOR_X, &x))
+                goto out;
+        if (applesmc_read_motion_sensor(SENSOR_Y, &y))
+                goto out;
+
+        x = -x;
+        input_report_abs(applesmc_idev, ABS_X, x - rest_x);
+        input_report_abs(applesmc_idev, ABS_Y, y - rest_y);
+        input_sync(applesmc_idev);
+
+out:
+        mod_timer(&applesmc_timer, jiffies + APPLESMC_POLL_PERIOD);
+
+        mutex_unlock(&applesmc_lock);
+}
+
+/* Sysfs Files */
+
+static ssize_t applesmc_position_show(struct device *dev,
+                                   struct device_attribute *attr, char *buf)
+{
+        int ret;
+        s16 x, y, z;
+
+        mutex_lock(&applesmc_lock);
+
+        ret = applesmc_read_motion_sensor(SENSOR_X, &x);
+        if (ret)
+                goto out;
+        ret = applesmc_read_motion_sensor(SENSOR_Y, &y);
+        if (ret)
+                goto out;
+        ret = applesmc_read_motion_sensor(SENSOR_Z, &z);
+        if (ret)
+                goto out;
+
+out:
+        mutex_unlock(&applesmc_lock);
+        if (ret)
+                return ret;
+        else
+                return snprintf(buf, PAGE_SIZE, "(%d,%d,%d)\n", x, y, z);
+}
+
+static ssize_t applesmc_light_show(struct device *dev,
+                                struct device_attribute *attr, char *sysfsbuf)
+{
+        int ret;
+        u8 left = 0, right = 0;
+        u8 buffer[6];
+
+        mutex_lock(&applesmc_lock);
+
+        ret = applesmc_read_key(LIGHT_SENSOR_LEFT_KEY, buffer, 6);
+        left = buffer[2];
+        if (ret)
+                goto out;
+        ret = applesmc_read_key(LIGHT_SENSOR_RIGHT_KEY, buffer, 6);
+        right = buffer[2];
+
+out:
+        mutex_unlock(&applesmc_lock);
+        if (ret)
+                return ret;
+        else
+                return snprintf(sysfsbuf, PAGE_SIZE, "(%d,%d)\n", left, right);
+}
+
+/* Displays degree Celsius * 1000 */
+static ssize_t applesmc_show_temperature(struct device *dev,
+                        struct device_attribute *devattr, char *sysfsbuf)
+{
+        int ret;
+        u8 buffer[2];
+        unsigned int temp;
+        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+        const char* key =
+                temperature_sensors_sets[applesmc_temperature_set][attr->index];
+
+        mutex_lock(&applesmc_lock);
+
+        ret = applesmc_read_key(key, buffer, 2);
+        temp = buffer[0]*1000;
+        temp += (buffer[1] >> 6) * 250;
+
+        mutex_unlock(&applesmc_lock);
+
+        if (ret)
+                return ret;
+        else
+                return snprintf(sysfsbuf, PAGE_SIZE, "%u\n", temp);
+}
+
+static ssize_t applesmc_show_fan_speed(struct device *dev,
+                                struct device_attribute *attr, char *sysfsbuf)
+{
+        int ret;
+        unsigned int speed = 0;
+        char newkey[5];
+        u8 buffer[2];
+        struct sensor_device_attribute_2 *sensor_attr =
+                                                to_sensor_dev_attr_2(attr);
+
+        newkey[0] = fan_speed_keys[sensor_attr->nr][0];
+        newkey[1] = '0' + sensor_attr->index;
+        newkey[2] = fan_speed_keys[sensor_attr->nr][2];
+        newkey[3] = fan_speed_keys[sensor_attr->nr][3];
+        newkey[4] = 0;
+
+        mutex_lock(&applesmc_lock);
+
+        ret = applesmc_read_key(newkey, buffer, 2);
+        speed = ((buffer[0] << 8 | buffer[1]) >> 2);
+
+        mutex_unlock(&applesmc_lock);
+        if (ret)
+                return ret;
+        else
+                return snprintf(sysfsbuf, PAGE_SIZE, "%u\n", speed);
+}
+
+static ssize_t applesmc_store_fan_speed(struct device *dev,
+                                        struct device_attribute *attr,
+                                        const char *sysfsbuf, size_t count)
+{
+        int ret;
+        u32 speed;
+        char newkey[5];
+        u8 buffer[2];
+        struct sensor_device_attribute_2 *sensor_attr =
+                                                to_sensor_dev_attr_2(attr);
+
+        speed = simple_strtoul(sysfsbuf, NULL, 10);
+
+        if (speed > 0x4000) /* Bigger than a 14-bit value */
+                return -EINVAL;
+
+        newkey[0] = fan_speed_keys[sensor_attr->nr][0];
+        newkey[1] = '0' + sensor_attr->index;
+        newkey[2] = fan_speed_keys[sensor_attr->nr][2];
+        newkey[3] = fan_speed_keys[sensor_attr->nr][3];
+        newkey[4] = 0;
+
+        mutex_lock(&applesmc_lock);
+
+        buffer[0] = (speed >> 6) & 0xff;
+        buffer[1] = (speed << 2) & 0xff;
+        ret = applesmc_write_key(newkey, buffer, 2);
+
+        mutex_unlock(&applesmc_lock);
+        if (ret)
+                return ret;
+        else
+                return count;
+}
+
+static ssize_t applesmc_show_fan_manual(struct device *dev,
+                        struct device_attribute *devattr, char *sysfsbuf)
+{
+        int ret;
+        u16 manual = 0;
+        u8 buffer[2];
+        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+
+        mutex_lock(&applesmc_lock);
+
+        ret = applesmc_read_key(FANS_MANUAL, buffer, 2);
+        manual = ((buffer[0] << 8 | buffer[1]) >> attr->index) & 0x01;
+
+        mutex_unlock(&applesmc_lock);
+        if (ret)
+                return ret;
+        else
+                return snprintf(sysfsbuf, PAGE_SIZE, "%d\n", manual);
+}
+
+static ssize_t applesmc_store_fan_manual(struct device *dev,
+                                         struct device_attribute *devattr,
+                                         const char *sysfsbuf, size_t count)
+{
+        int ret;
+        u8 buffer[2];
+        u32 input;
+        u16 val;
+        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+
+        input = simple_strtoul(sysfsbuf, NULL, 10);
+
+        mutex_lock(&applesmc_lock);
+
+        ret = applesmc_read_key(FANS_MANUAL, buffer, 2);
+        val = (buffer[0] << 8 | buffer[1]);
+        if (ret)
+                goto out;
+
+        if (input)
+                val = val | (0x01 << attr->index);
+        else
+                val = val & ~(0x01 << attr->index);
+
+        buffer[0] = (val >> 8) & 0xFF;
+        buffer[1] = val & 0xFF;
+
+        ret = applesmc_write_key(FANS_MANUAL, buffer, 2);
+
+out:
+        mutex_unlock(&applesmc_lock);
+        if (ret)
+                return ret;
+        else
+                return count;
+}
+
+static ssize_t applesmc_show_fan_position(struct device *dev,
+                                struct device_attribute *attr, char *sysfsbuf)
+{
+        int ret;
+        char newkey[5];
+        u8 buffer[17];
+        struct sensor_device_attribute_2 *sensor_attr =
+                                                to_sensor_dev_attr_2(attr);
+
+        newkey[0] = FAN_POSITION[0];
+        newkey[1] = '0' + sensor_attr->index;
+        newkey[2] = FAN_POSITION[2];
+        newkey[3] = FAN_POSITION[3];
+        newkey[4] = 0;
+
+        mutex_lock(&applesmc_lock);
+
+        ret = applesmc_read_key(newkey, buffer, 16);
+        buffer[16] = 0;
+
+        mutex_unlock(&applesmc_lock);
+        if (ret)
+                return ret;
+        else
+                return snprintf(sysfsbuf, PAGE_SIZE, "%s\n", buffer+4);
+}
+
+static ssize_t applesmc_calibrate_show(struct device *dev,
+                                struct device_attribute *attr, char *sysfsbuf)
+{
+        return snprintf(sysfsbuf, PAGE_SIZE, "(%d,%d)\n", rest_x, rest_y);
+}
+
+static ssize_t applesmc_calibrate_store(struct device *dev,
+        struct device_attribute *attr, const char *sysfsbuf, size_t count)
+{
+        mutex_lock(&applesmc_lock);
+        applesmc_calibrate();
+        mutex_unlock(&applesmc_lock);
+
+        return count;
+}
+
+/* Store the next backlight value to be written by the work */
+static unsigned int backlight_value;
+
+static void applesmc_backlight_set(struct work_struct *work)
+{
+        u8 buffer[2];
+
+        mutex_lock(&applesmc_lock);
+        buffer[0] = backlight_value;
+        buffer[1] = 0x00;
+        applesmc_write_key(BACKLIGHT_KEY, buffer, 2);
+        mutex_unlock(&applesmc_lock);
+}
+static DECLARE_WORK(backlight_work, &applesmc_backlight_set);
+
+static void applesmc_brightness_set(struct led_classdev *led_cdev,
+                                                enum led_brightness value)
+{
+        int ret;
+
+        backlight_value = value;
+        ret = queue_work(applesmc_led_wq, &backlight_work);
+
+        if (debug && (!ret))
+                printk(KERN_DEBUG "applesmc: work was already on the queue.\n");
+}
+
+static ssize_t applesmc_key_count_show(struct device *dev,
+                                struct device_attribute *attr, char *sysfsbuf)
+{
+        int ret;
+        u8 buffer[4];
+        u32 count;
+
+        mutex_lock(&applesmc_lock);
+
+        ret = applesmc_read_key(KEY_COUNT_KEY, buffer, 4);
+        count = ((u32)buffer[0]<<24) + ((u32)buffer[1]<<16) +
+                                                ((u32)buffer[2]<<8) + buffer[3];
+
+        mutex_unlock(&applesmc_lock);
+        if (ret)
+                return ret;
+        else
+                return snprintf(sysfsbuf, PAGE_SIZE, "%d\n", count);
+}
+
+static ssize_t applesmc_key_at_index_read_show(struct device *dev,
+                                struct device_attribute *attr, char *sysfsbuf)
+{
+        char key[5];
+        char info[6];
+        int ret;
+
+        mutex_lock(&applesmc_lock);
+
+        ret = applesmc_get_key_at_index(key_at_index, key);
+
+        if (ret || !key[0]) {
+                mutex_unlock(&applesmc_lock);
+
+                return -EINVAL;
+        }
+
+        ret = applesmc_get_key_type(key, info);
+
+        if (ret) {
+                mutex_unlock(&applesmc_lock);
+
+                return ret;
+        }
+
+        /*
+         * info[0] maximum value (APPLESMC_MAX_DATA_LENGTH) is much lower than
+         * PAGE_SIZE, so we don't need any checks before writing to sysfsbuf.
+         */
+        ret = applesmc_read_key(key, sysfsbuf, info[0]);
+
+        mutex_unlock(&applesmc_lock);
+
+        if (!ret) {
+                return info[0];
+        }
+        else {
+                return ret;
+        }
+}
+
+static ssize_t applesmc_key_at_index_data_length_show(struct device *dev,
+                                struct device_attribute *attr, char *sysfsbuf)
+{
+        char key[5];
+        char info[6];
+        int ret;
+
+        mutex_lock(&applesmc_lock);
+
+        ret = applesmc_get_key_at_index(key_at_index, key);
+
+        if (ret || !key[0]) {
+                mutex_unlock(&applesmc_lock);
+
+                return -EINVAL;
+        }
+
+        ret = applesmc_get_key_type(key, info);
+
+        mutex_unlock(&applesmc_lock);
+
+        if (!ret)
+                return snprintf(sysfsbuf, PAGE_SIZE, "%d\n", info[0]);
+        else
+                return ret;
+}
+
+static ssize_t applesmc_key_at_index_type_show(struct device *dev,
+                                struct device_attribute *attr, char *sysfsbuf)
+{
+        char key[5];
+        char info[6];
+        int ret;
+
+        mutex_lock(&applesmc_lock);
+
+        ret = applesmc_get_key_at_index(key_at_index, key);
+
+        if (ret || !key[0]) {
+                mutex_unlock(&applesmc_lock);
+
+                return -EINVAL;
+        }
+
+        ret = applesmc_get_key_type(key, info);
+
+        mutex_unlock(&applesmc_lock);
+
+        if (!ret)
+                return snprintf(sysfsbuf, PAGE_SIZE, "%s\n", info+1);
+        else
+                return ret;
+}
+
+static ssize_t applesmc_key_at_index_name_show(struct device *dev,
+                                struct device_attribute *attr, char *sysfsbuf)
+{
+        char key[5];
+        int ret;
+
+        mutex_lock(&applesmc_lock);
+
+        ret = applesmc_get_key_at_index(key_at_index, key);
+
+        mutex_unlock(&applesmc_lock);
+
+        if (!ret && key[0])
+                return snprintf(sysfsbuf, PAGE_SIZE, "%s\n", key);
+        else
+                return -EINVAL;
+}
+
+static ssize_t applesmc_key_at_index_show(struct device *dev,
+                                struct device_attribute *attr, char *sysfsbuf)
+{
+        return snprintf(sysfsbuf, PAGE_SIZE, "%d\n", key_at_index);
+}
+
+static ssize_t applesmc_key_at_index_store(struct device *dev,
+        struct device_attribute *attr, const char *sysfsbuf, size_t count)
+{
+        mutex_lock(&applesmc_lock);
+
+        key_at_index = simple_strtoul(sysfsbuf, NULL, 10);
+
+        mutex_unlock(&applesmc_lock);
+
+        return count;
+}
+
+static struct led_classdev applesmc_backlight = {
+        .name                   = "smc:kbd_backlight",
+        .default_trigger        = "nand-disk",
+        .brightness_set         = applesmc_brightness_set,
+};
+
+static DEVICE_ATTR(position, 0444, applesmc_position_show, NULL);
+static DEVICE_ATTR(calibrate, 0644,
+                        applesmc_calibrate_show, applesmc_calibrate_store);
+
+static struct attribute *accelerometer_attributes[] = {
+        &dev_attr_position.attr,
+        &dev_attr_calibrate.attr,
+        NULL
+};
+
+static const struct attribute_group accelerometer_attributes_group =
+        { .attrs = accelerometer_attributes };
+
+static DEVICE_ATTR(light, 0444, applesmc_light_show, NULL);
+
+static DEVICE_ATTR(key_count, 0444, applesmc_key_count_show, NULL);
+static DEVICE_ATTR(key_at_index, 0644,
+                applesmc_key_at_index_show, applesmc_key_at_index_store);
+static DEVICE_ATTR(key_at_index_name, 0444,
+                                        applesmc_key_at_index_name_show, NULL);
+static DEVICE_ATTR(key_at_index_type, 0444,
+                                        applesmc_key_at_index_type_show, NULL);
+static DEVICE_ATTR(key_at_index_data_length, 0444,
+                                applesmc_key_at_index_data_length_show, NULL);
+static DEVICE_ATTR(key_at_index_data, 0444,
+                                applesmc_key_at_index_read_show, NULL);
+
+static struct attribute *key_enumeration_attributes[] = {
+        &dev_attr_key_count.attr,
+        &dev_attr_key_at_index.attr,
+        &dev_attr_key_at_index_name.attr,
+        &dev_attr_key_at_index_type.attr,
+        &dev_attr_key_at_index_data_length.attr,
+        &dev_attr_key_at_index_data.attr,
+        NULL
+};
+
+static const struct attribute_group key_enumeration_group =
+        { .attrs = key_enumeration_attributes };
+
+/*
+ * Macro defining SENSOR_DEVICE_ATTR for a fan sysfs entries.
+ *  - show actual speed
+ *  - show/store minimum speed
+ *  - show maximum speed
+ *  - show safe speed
+ *  - show/store target speed
+ *  - show/store manual mode
+ */
+#define sysfs_fan_speeds_offset(offset) \
+static SENSOR_DEVICE_ATTR_2(fan##offset##_input, S_IRUGO, \
+                        applesmc_show_fan_speed, NULL, 0, offset-1); \
+\
+static SENSOR_DEVICE_ATTR_2(fan##offset##_min, S_IRUGO | S_IWUSR, \
+        applesmc_show_fan_speed, applesmc_store_fan_speed, 1, offset-1); \
+\
+static SENSOR_DEVICE_ATTR_2(fan##offset##_max, S_IRUGO, \
+                        applesmc_show_fan_speed, NULL, 2, offset-1); \
+\
+static SENSOR_DEVICE_ATTR_2(fan##offset##_safe, S_IRUGO, \
+                        applesmc_show_fan_speed, NULL, 3, offset-1); \
+\
+static SENSOR_DEVICE_ATTR_2(fan##offset##_output, S_IRUGO | S_IWUSR, \
+        applesmc_show_fan_speed, applesmc_store_fan_speed, 4, offset-1); \
+\
+static SENSOR_DEVICE_ATTR(fan##offset##_manual, S_IRUGO | S_IWUSR, \
+        applesmc_show_fan_manual, applesmc_store_fan_manual, offset-1); \
+\
+static SENSOR_DEVICE_ATTR(fan##offset##_position, S_IRUGO, \
+        applesmc_show_fan_position, NULL, offset-1); \
+\
+static struct attribute *fan##offset##_attributes[] = { \
+        &sensor_dev_attr_fan##offset##_input.dev_attr.attr, \
+        &sensor_dev_attr_fan##offset##_min.dev_attr.attr, \
+        &sensor_dev_attr_fan##offset##_max.dev_attr.attr, \
+        &sensor_dev_attr_fan##offset##_safe.dev_attr.attr, \
+        &sensor_dev_attr_fan##offset##_output.dev_attr.attr, \
+        &sensor_dev_attr_fan##offset##_manual.dev_attr.attr, \
+        &sensor_dev_attr_fan##offset##_position.dev_attr.attr, \
+        NULL \
+};
+
+/*
+ * Create the needed functions for each fan using the macro defined above
+ * (2 fans are supported)
+ */
+sysfs_fan_speeds_offset(1);
+sysfs_fan_speeds_offset(2);
+
+static const struct attribute_group fan_attribute_groups[] = {
+        { .attrs = fan1_attributes },
+        { .attrs = fan2_attributes }
+};
+
+/*
+ * Temperature sensors sysfs entries.
+ */
+static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO,
+                                        applesmc_show_temperature, NULL, 0);
+static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO,
+                                        applesmc_show_temperature, NULL, 1);
+static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO,
+                                        applesmc_show_temperature, NULL, 2);
+static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO,
+                                        applesmc_show_temperature, NULL, 3);
+static SENSOR_DEVICE_ATTR(temp5_input, S_IRUGO,
+                                        applesmc_show_temperature, NULL, 4);
+static SENSOR_DEVICE_ATTR(temp6_input, S_IRUGO,
+                                        applesmc_show_temperature, NULL, 5);
+static SENSOR_DEVICE_ATTR(temp7_input, S_IRUGO,
+                                        applesmc_show_temperature, NULL, 6);
+static SENSOR_DEVICE_ATTR(temp8_input, S_IRUGO,
+                                        applesmc_show_temperature, NULL, 7);
+static SENSOR_DEVICE_ATTR(temp9_input, S_IRUGO,
+                                        applesmc_show_temperature, NULL, 8);
+static SENSOR_DEVICE_ATTR(temp10_input, S_IRUGO,
+                                        applesmc_show_temperature, NULL, 9);
+static SENSOR_DEVICE_ATTR(temp11_input, S_IRUGO,
+                                        applesmc_show_temperature, NULL, 10);
+static SENSOR_DEVICE_ATTR(temp12_input, S_IRUGO,
+                                        applesmc_show_temperature, NULL, 11);
+
+static struct attribute *temperature_attributes[] = {
+        &sensor_dev_attr_temp1_input.dev_attr.attr,
+        &sensor_dev_attr_temp2_input.dev_attr.attr,
+        &sensor_dev_attr_temp3_input.dev_attr.attr,
+        &sensor_dev_attr_temp4_input.dev_attr.attr,
+        &sensor_dev_attr_temp5_input.dev_attr.attr,
+        &sensor_dev_attr_temp6_input.dev_attr.attr,
+        &sensor_dev_attr_temp7_input.dev_attr.attr,
+        &sensor_dev_attr_temp8_input.dev_attr.attr,
+        &sensor_dev_attr_temp9_input.dev_attr.attr,
+        &sensor_dev_attr_temp10_input.dev_attr.attr,
+        &sensor_dev_attr_temp11_input.dev_attr.attr,
+        &sensor_dev_attr_temp12_input.dev_attr.attr,
+        NULL
+};
+
+static const struct attribute_group temperature_attributes_group =
+        { .attrs = temperature_attributes };
+
+/* Module stuff */
+
+/*
+ * applesmc_dmi_match - found a match.  return one, short-circuiting the hunt.
+ */
+static int applesmc_dmi_match(struct dmi_system_id *id)
+{
+        int i = 0;
+        struct dmi_match_data* dmi_data = id->driver_data;
+        printk(KERN_INFO "applesmc: %s detected:\n", id->ident);
+        applesmc_accelerometer = dmi_data->accelerometer;
+        printk(KERN_INFO "applesmc:  - Model %s accelerometer\n",
+                                applesmc_accelerometer ? "with" : "without");
+        applesmc_light = dmi_data->light;
+        printk(KERN_INFO "applesmc:  - Model %s light sensors and backlight\n",
+                                        applesmc_light ? "with" : "without");
+
+        applesmc_temperature_set =  dmi_data->temperature_set;
+        while (temperature_sensors_sets[applesmc_temperature_set][i] != NULL)
+                i++;
+        printk(KERN_INFO "applesmc:  - Model with %d temperature sensors\n", i);
+        return 1;
+}
+
+/* Create accelerometer ressources */
+static int applesmc_create_accelerometer(void)
+{
+        int ret;
+
+        ret = sysfs_create_group(&pdev->dev.kobj,
+                                        &accelerometer_attributes_group);
+        if (ret)
+                goto out;
+
+        applesmc_idev = input_allocate_device();
+        if (!applesmc_idev) {
+                ret = -ENOMEM;
+                goto out_sysfs;
+        }
+
+        /* initial calibrate for the input device */
+        applesmc_calibrate();
+
+        /* initialize the input class */
+        applesmc_idev->name = "applesmc";
+        applesmc_idev->id.bustype = BUS_HOST;
+        applesmc_idev->cdev.dev = &pdev->dev;
+        applesmc_idev->evbit[0] = BIT(EV_ABS);
+        applesmc_idev->open = applesmc_idev_open;
+        applesmc_idev->close = applesmc_idev_close;
+        input_set_abs_params(applesmc_idev, ABS_X,
+                        -256, 256, APPLESMC_INPUT_FUZZ, APPLESMC_INPUT_FLAT);
+        input_set_abs_params(applesmc_idev, ABS_Y,
+                        -256, 256, APPLESMC_INPUT_FUZZ, APPLESMC_INPUT_FLAT);
+
+        ret = input_register_device(applesmc_idev);
+        if (ret)
+                goto out_idev;
+
+        /* start up our timer for the input device */
+        init_timer(&applesmc_timer);
+        applesmc_timer.function = applesmc_idev_poll;
+        applesmc_timer.expires = jiffies + APPLESMC_POLL_PERIOD;
+
+        return 0;
+
+out_idev:
+        input_free_device(applesmc_idev);
+
+out_sysfs:
+        sysfs_remove_group(&pdev->dev.kobj, &accelerometer_attributes_group);
+
+out:
+        printk(KERN_WARNING "applesmc: driver init failed (ret=%d)!\n", ret);
+        return ret;
+}
+
+/* Release all ressources used by the accelerometer */
+static void applesmc_release_accelerometer(void)
+{
+        del_timer_sync(&applesmc_timer);
+        input_unregister_device(applesmc_idev);
+        sysfs_remove_group(&pdev->dev.kobj, &accelerometer_attributes_group);
+}
+
+static __initdata struct dmi_match_data applesmc_dmi_data[] = {
+/* MacBook Pro: accelerometer, backlight and temperature set 0 */
+        { .accelerometer = 1, .light = 1, .temperature_set = 0 },
+/* MacBook: accelerometer and temperature set 0 */
+        { .accelerometer = 1, .light = 0, .temperature_set = 0 },
+/* MacBook: temperature set 1 */
+        { .accelerometer = 0, .light = 0, .temperature_set = 1 }
+};
+
+/* Note that DMI_MATCH(...,"MacBook") will match "MacBookPro1,1".
+ * So we need to put "Apple MacBook Pro" before "Apple MacBook". */
+static __initdata struct dmi_system_id applesmc_whitelist[] = {
+        { applesmc_dmi_match, "Apple MacBook Pro", {
+          DMI_MATCH(DMI_BOARD_VENDOR,"Apple"),
+          DMI_MATCH(DMI_PRODUCT_NAME,"MacBookPro") },
+                (void*)&applesmc_dmi_data[0]},
+        { applesmc_dmi_match, "Apple MacBook", {
+          DMI_MATCH(DMI_BOARD_VENDOR,"Apple"),
+          DMI_MATCH(DMI_PRODUCT_NAME,"MacBook") },
+                (void*)&applesmc_dmi_data[1]},
+        { applesmc_dmi_match, "Apple Macmini", {
+          DMI_MATCH(DMI_BOARD_VENDOR,"Apple"),
+          DMI_MATCH(DMI_PRODUCT_NAME,"Macmini") },
+                (void*)&applesmc_dmi_data[2]},
+        { .ident = NULL }
+};
+
+static int __init applesmc_init(void)
+{
+        int ret;
+        int count;
+        int i;
+
+        mutex_init(&applesmc_lock);
+
+        if (!dmi_check_system(applesmc_whitelist)) {
+                printk(KERN_WARNING "applesmc: supported laptop not found!\n");
+                ret = -ENODEV;
+                goto out;
+        }
+
+        if (!request_region(APPLESMC_DATA_PORT, APPLESMC_NR_PORTS,
+                                                                "applesmc")) {
+                ret = -ENXIO;
+                goto out;
+        }
+
+        ret = platform_driver_register(&applesmc_driver);
+        if (ret)
+                goto out_region;
+
+        pdev = platform_device_register_simple("applesmc", -1, NULL, 0);
+        if (IS_ERR(pdev)) {
+                ret = PTR_ERR(pdev);
+                goto out_driver;
+        }
+
+        /* Create key enumeration sysfs files */
+        ret = sysfs_create_group(&pdev->dev.kobj, &key_enumeration_group);
+        if (ret)
+                goto out_device;
+
+        /* create fan files */
+        count = applesmc_get_fan_count();
+        if (count < 0) {
+                printk(KERN_ERR "applesmc: Cannot get the number of fans.\n");
+        } else {
+                printk(KERN_INFO "applesmc: %d fans found.\n", count);
+
+                switch (count) {
+                default:
+                        printk(KERN_WARNING "applesmc: More than 2 fans found,"
+                                        " but at most 2 fans are supported"
+                                                " by the driver.\n");
+                case 2:
+                        ret = sysfs_create_group(&pdev->dev.kobj,
+                                                 &fan_attribute_groups[1]);
+                        if (ret)
+                                goto out_key_enumeration;
+                case 1:
+                        ret = sysfs_create_group(&pdev->dev.kobj,
+                                                 &fan_attribute_groups[0]);
+                        if (ret)
+                                goto out_fan_1;
+                case 0:
+                        ;
+                }
+        }
+
+        for (i = 0;
+             temperature_sensors_sets[applesmc_temperature_set][i] != NULL;
+             i++) {
+                if (temperature_attributes[i] == NULL) {
+                        printk(KERN_ERR "applesmc: More temperature sensors "
+                                "in temperature_sensors_sets (at least %i)"
+                                "than available sysfs files in "
+                                "temperature_attributes (%i), please report "
+                                "this bug.\n", i, i-1);
+                        goto out_temperature;
+                }
+                ret = sysfs_create_file(&pdev->dev.kobj,
+                                                temperature_attributes[i]);
+                if (ret)
+                        goto out_temperature;
+        }
+
+        if (applesmc_accelerometer) {
+                ret = applesmc_create_accelerometer();
+                if (ret)
+                        goto out_temperature;
+        }
+
+        if (applesmc_light) {
+                /* Add light sensor file */
+                ret = sysfs_create_file(&pdev->dev.kobj, &dev_attr_light.attr);
+                if (ret)
+                        goto out_accelerometer;
+
+                /* Create the workqueue */
+                applesmc_led_wq = create_singlethread_workqueue("applesmc-led");
+                if (!applesmc_led_wq) {
+                        ret = -ENOMEM;
+                        goto out_light_sysfs;
+                }
+
+                /* register as a led device */
+                ret = led_classdev_register(&pdev->dev, &applesmc_backlight);
+                if (ret < 0)
+                        goto out_light_wq;
+        }
+
+        hwmon_class_dev = hwmon_device_register(&pdev->dev);
+        if (IS_ERR(hwmon_class_dev)) {
+                ret = PTR_ERR(hwmon_class_dev);
+                goto out_light_ledclass;
+        }
+
+        printk(KERN_INFO "applesmc: driver successfully loaded.\n");
+
+        return 0;
+
+out_light_ledclass:
+        if (applesmc_light)
+                led_classdev_unregister(&applesmc_backlight);
+out_light_wq:
+        if (applesmc_light)
+                destroy_workqueue(applesmc_led_wq);
+out_light_sysfs:
+        if (applesmc_light)
+                sysfs_remove_file(&pdev->dev.kobj, &dev_attr_light.attr);
+out_accelerometer:
+        if (applesmc_accelerometer)
+                applesmc_release_accelerometer();
+out_temperature:
+        sysfs_remove_group(&pdev->dev.kobj, &temperature_attributes_group);
+        sysfs_remove_group(&pdev->dev.kobj, &fan_attribute_groups[0]);
+out_fan_1:
+        sysfs_remove_group(&pdev->dev.kobj, &fan_attribute_groups[1]);
+out_key_enumeration:
+        sysfs_remove_group(&pdev->dev.kobj, &key_enumeration_group);
+out_device:
+        platform_device_unregister(pdev);
+out_driver:
+        platform_driver_unregister(&applesmc_driver);
+out_region:
+        release_region(APPLESMC_DATA_PORT, APPLESMC_NR_PORTS);
+out:
+        printk(KERN_WARNING "applesmc: driver init failed (ret=%d)!\n", ret);
+        return ret;
+}
+
+static void __exit applesmc_exit(void)
+{
+        hwmon_device_unregister(hwmon_class_dev);
+        if (applesmc_light) {
+                led_classdev_unregister(&applesmc_backlight);
+                destroy_workqueue(applesmc_led_wq);
+                sysfs_remove_file(&pdev->dev.kobj, &dev_attr_light.attr);
+        }
+        if (applesmc_accelerometer)
+                applesmc_release_accelerometer();
+        sysfs_remove_group(&pdev->dev.kobj, &temperature_attributes_group);
+        sysfs_remove_group(&pdev->dev.kobj, &fan_attribute_groups[0]);
+        sysfs_remove_group(&pdev->dev.kobj, &fan_attribute_groups[1]);
+        sysfs_remove_group(&pdev->dev.kobj, &key_enumeration_group);
+        platform_device_unregister(pdev);
+        platform_driver_unregister(&applesmc_driver);
+        release_region(APPLESMC_DATA_PORT, APPLESMC_NR_PORTS);
+
+        printk(KERN_INFO "applesmc: driver unloaded.\n");
+}
+
+module_init(applesmc_init);
+module_exit(applesmc_exit);
+
+MODULE_AUTHOR("Nicolas Boichat");
+MODULE_DESCRIPTION("Apple SMC");
+MODULE_LICENSE("GPL v2");