diff --git a/drivers/hwmon/applesmc.c b/drivers/hwmon/applesmc.c
new file mode 100644
index 0000000..5c677ba
--- /dev/null
+++ b/drivers/hwmon/applesmc.c
@@ -0,0 +1,1388 @@
+/*
+ * 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>
+ * Copyright (C) 2010 Henrik Rydberg <rydberg@euromail.se>
+ *
+ * Based on hdaps.c driver:
+ * Copyright (C) 2005 Robert Love <rml@novell.com>
+ * Copyright (C) 2005 Jesper Juhl <jj@chaosbits.net>
+ *
+ * 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
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+#include <linux/input-polldev.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/timer.h>
+#include <linux/dmi.h>
+#include <linux/mutex.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/io.h>
+#include <linux/leds.h>
+#include <linux/hwmon.h>
+#include <linux/workqueue.h>
+#include <linux/err.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
+
+/* wait up to 128 ms for a status change. */
+#define APPLESMC_MIN_WAIT	0x0010
+#define APPLESMC_RETRY_WAIT	0x0100
+#define APPLESMC_MAX_WAIT	0x20000
+
+#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 (6-10 bytes) */
+#define LIGHT_SENSOR_RIGHT_KEY	"ALV1" /* r-o {alv (6-10 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_ID_FMT		"F%dID" /* r-o char[16] */
+
+#define TEMP_SENSOR_TYPE	"sp78"
+
+/* List of keys used to read/write fan speeds */
+static const char *const fan_speed_fmt[] = {
+	"F%dAc",		/* actual speed */
+	"F%dMn",		/* minimum speed (rw) */
+	"F%dMx",		/* maximum speed */
+	"F%dSf",		/* safe speed - not all models */
+	"F%dTg",		/* target speed (manual: rw) */
+};
+
+#define INIT_TIMEOUT_MSECS	5000	/* wait up to 5s for device init ... */
+#define INIT_WAIT_MSECS		50	/* ... in 50ms increments */
+
+#define APPLESMC_POLL_INTERVAL	50	/* msecs */
+#define APPLESMC_INPUT_FUZZ	4	/* input event threshold */
+#define APPLESMC_INPUT_FLAT	4
+
+#define to_index(attr) (to_sensor_dev_attr(attr)->index & 0xffff)
+#define to_option(attr) (to_sensor_dev_attr(attr)->index >> 16)
+
+/* Dynamic device node attributes */
+struct applesmc_dev_attr {
+	struct sensor_device_attribute sda;	/* hwmon attributes */
+	char name[32];				/* room for node file name */
+};
+
+/* Dynamic device node group */
+struct applesmc_node_group {
+	char *format;				/* format string */
+	void *show;				/* show function */
+	void *store;				/* store function */
+	int option;				/* function argument */
+	struct applesmc_dev_attr *nodes;	/* dynamic node array */
+};
+
+/* AppleSMC entry - cached register information */
+struct applesmc_entry {
+	char key[5];		/* four-letter key code */
+	u8 valid;		/* set when entry is successfully read once */
+	u8 len;			/* bounded by APPLESMC_MAX_DATA_LENGTH */
+	char type[5];		/* four-letter type code */
+	u8 flags;		/* 0x10: func; 0x40: write; 0x80: read */
+};
+
+/* Register lookup and registers common to all SMCs */
+static struct applesmc_registers {
+	struct mutex mutex;		/* register read/write mutex */
+	unsigned int key_count;		/* number of SMC registers */
+	unsigned int fan_count;		/* number of fans */
+	unsigned int temp_count;	/* number of temperature registers */
+	unsigned int temp_begin;	/* temperature lower index bound */
+	unsigned int temp_end;		/* temperature upper index bound */
+	unsigned int index_count;	/* size of temperature index array */
+	int num_light_sensors;		/* number of light sensors */
+	bool has_accelerometer;		/* has motion sensor */
+	bool has_key_backlight;		/* has keyboard backlight */
+	bool init_complete;		/* true when fully initialized */
+	struct applesmc_entry *cache;	/* cached key entries */
+	const char **index;		/* temperature key index */
+} smcreg = {
+	.mutex = __MUTEX_INITIALIZER(smcreg.mutex),
+};
+
+static const int debug;
+static struct platform_device *pdev;
+static s16 rest_x;
+static s16 rest_y;
+static u8 backlight_state[2];
+
+static struct device *hwmon_dev;
+static struct input_polled_dev *applesmc_idev;
+
+/*
+ * 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_read - Wait for a byte to appear on SMC port. Callers must
+ * hold applesmc_lock.
+ */
+static int wait_read(void)
+{
+	u8 status;
+	int us;
+	for (us = APPLESMC_MIN_WAIT; us < APPLESMC_MAX_WAIT; us <<= 1) {
+		udelay(us);
+		status = inb(APPLESMC_CMD_PORT);
+		/* read: wait for smc to settle */
+		if (status & 0x01)
+			return 0;
+	}
+
+	pr_warn("wait_read() fail: 0x%02x\n", status);
+	return -EIO;
+}
+
+/*
+ * send_byte - Write to SMC port, retrying when necessary. Callers
+ * must hold applesmc_lock.
+ */
+static int send_byte(u8 cmd, u16 port)
+{
+	u8 status;
+	int us;
+
+	outb(cmd, port);
+	for (us = APPLESMC_MIN_WAIT; us < APPLESMC_MAX_WAIT; us <<= 1) {
+		udelay(us);
+		status = inb(APPLESMC_CMD_PORT);
+		/* write: wait for smc to settle */
+		if (status & 0x02)
+			continue;
+		/* ready: cmd accepted, return */
+		if (status & 0x04)
+			return 0;
+		/* timeout: give up */
+		if (us << 1 == APPLESMC_MAX_WAIT)
+			break;
+		/* busy: long wait and resend */
+		udelay(APPLESMC_RETRY_WAIT);
+		outb(cmd, port);
+	}
+
+	pr_warn("send_byte(0x%02x, 0x%04x) fail: 0x%02x\n", cmd, port, status);
+	return -EIO;
+}
+
+static int send_command(u8 cmd)
+{
+	return send_byte(cmd, APPLESMC_CMD_PORT);
+}
+
+static int send_argument(const char *key)
+{
+	int i;
+
+	for (i = 0; i < 4; i++)
+		if (send_byte(key[i], APPLESMC_DATA_PORT))
+			return -EIO;
+	return 0;
+}
+
+static int read_smc(u8 cmd, const char *key, u8 *buffer, u8 len)
+{
+	u8 status, data = 0;
+	int i;
+
+	if (send_command(cmd) || send_argument(key)) {
+		pr_warn("%.4s: read arg fail\n", key);
+		return -EIO;
+	}
+
+	/* This has no effect on newer (2012) SMCs */
+	if (send_byte(len, APPLESMC_DATA_PORT)) {
+		pr_warn("%.4s: read len fail\n", key);
+		return -EIO;
+	}
+
+	for (i = 0; i < len; i++) {
+		if (wait_read()) {
+			pr_warn("%.4s: read data[%d] fail\n", key, i);
+			return -EIO;
+		}
+		buffer[i] = inb(APPLESMC_DATA_PORT);
+	}
+
+	/* Read the data port until bit0 is cleared */
+	for (i = 0; i < 16; i++) {
+		udelay(APPLESMC_MIN_WAIT);
+		status = inb(APPLESMC_CMD_PORT);
+		if (!(status & 0x01))
+			break;
+		data = inb(APPLESMC_DATA_PORT);
+	}
+	if (i)
+		pr_warn("flushed %d bytes, last value is: %d\n", i, data);
+
+	return 0;
+}
+
+static int write_smc(u8 cmd, const char *key, const u8 *buffer, u8 len)
+{
+	int i;
+
+	if (send_command(cmd) || send_argument(key)) {
+		pr_warn("%s: write arg fail\n", key);
+		return -EIO;
+	}
+
+	if (send_byte(len, APPLESMC_DATA_PORT)) {
+		pr_warn("%.4s: write len fail\n", key);
+		return -EIO;
+	}
+
+	for (i = 0; i < len; i++) {
+		if (send_byte(buffer[i], APPLESMC_DATA_PORT)) {
+			pr_warn("%s: write data fail\n", key);
+			return -EIO;
+		}
+	}
+
+	return 0;
+}
+
+static int read_register_count(unsigned int *count)
+{
+	__be32 be;
+	int ret;
+
+	ret = read_smc(APPLESMC_READ_CMD, KEY_COUNT_KEY, (u8 *)&be, 4);
+	if (ret)
+		return ret;
+
+	*count = be32_to_cpu(be);
+	return 0;
+}
+
+/*
+ * Serialized I/O
+ *
+ * Returns zero on success or a negative error on failure.
+ * All functions below are concurrency safe - callers should NOT hold lock.
+ */
+
+static int applesmc_read_entry(const struct applesmc_entry *entry,
+			       u8 *buf, u8 len)
+{
+	int ret;
+
+	if (entry->len != len)
+		return -EINVAL;
+	mutex_lock(&smcreg.mutex);
+	ret = read_smc(APPLESMC_READ_CMD, entry->key, buf, len);
+	mutex_unlock(&smcreg.mutex);
+
+	return ret;
+}
+
+static int applesmc_write_entry(const struct applesmc_entry *entry,
+				const u8 *buf, u8 len)
+{
+	int ret;
+
+	if (entry->len != len)
+		return -EINVAL;
+	mutex_lock(&smcreg.mutex);
+	ret = write_smc(APPLESMC_WRITE_CMD, entry->key, buf, len);
+	mutex_unlock(&smcreg.mutex);
+	return ret;
+}
+
+static const struct applesmc_entry *applesmc_get_entry_by_index(int index)
+{
+	struct applesmc_entry *cache = &smcreg.cache[index];
+	u8 key[4], info[6];
+	__be32 be;
+	int ret = 0;
+
+	if (cache->valid)
+		return cache;
+
+	mutex_lock(&smcreg.mutex);
+
+	if (cache->valid)
+		goto out;
+	be = cpu_to_be32(index);
+	ret = read_smc(APPLESMC_GET_KEY_BY_INDEX_CMD, (u8 *)&be, key, 4);
+	if (ret)
+		goto out;
+	ret = read_smc(APPLESMC_GET_KEY_TYPE_CMD, key, info, 6);
+	if (ret)
+		goto out;
+
+	memcpy(cache->key, key, 4);
+	cache->len = info[0];
+	memcpy(cache->type, &info[1], 4);
+	cache->flags = info[5];
+	cache->valid = 1;
+
+out:
+	mutex_unlock(&smcreg.mutex);
+	if (ret)
+		return ERR_PTR(ret);
+	return cache;
+}
+
+static int applesmc_get_lower_bound(unsigned int *lo, const char *key)
+{
+	int begin = 0, end = smcreg.key_count;
+	const struct applesmc_entry *entry;
+
+	while (begin != end) {
+		int middle = begin + (end - begin) / 2;
+		entry = applesmc_get_entry_by_index(middle);
+		if (IS_ERR(entry)) {
+			*lo = 0;
+			return PTR_ERR(entry);
+		}
+		if (strcmp(entry->key, key) < 0)
+			begin = middle + 1;
+		else
+			end = middle;
+	}
+
+	*lo = begin;
+	return 0;
+}
+
+static int applesmc_get_upper_bound(unsigned int *hi, const char *key)
+{
+	int begin = 0, end = smcreg.key_count;
+	const struct applesmc_entry *entry;
+
+	while (begin != end) {
+		int middle = begin + (end - begin) / 2;
+		entry = applesmc_get_entry_by_index(middle);
+		if (IS_ERR(entry)) {
+			*hi = smcreg.key_count;
+			return PTR_ERR(entry);
+		}
+		if (strcmp(key, entry->key) < 0)
+			end = middle;
+		else
+			begin = middle + 1;
+	}
+
+	*hi = begin;
+	return 0;
+}
+
+static const struct applesmc_entry *applesmc_get_entry_by_key(const char *key)
+{
+	int begin, end;
+	int ret;
+
+	ret = applesmc_get_lower_bound(&begin, key);
+	if (ret)
+		return ERR_PTR(ret);
+	ret = applesmc_get_upper_bound(&end, key);
+	if (ret)
+		return ERR_PTR(ret);
+	if (end - begin != 1)
+		return ERR_PTR(-EINVAL);
+
+	return applesmc_get_entry_by_index(begin);
+}
+
+static int applesmc_read_key(const char *key, u8 *buffer, u8 len)
+{
+	const struct applesmc_entry *entry;
+
+	entry = applesmc_get_entry_by_key(key);
+	if (IS_ERR(entry))
+		return PTR_ERR(entry);
+
+	return applesmc_read_entry(entry, buffer, len);
+}
+
+static int applesmc_write_key(const char *key, const u8 *buffer, u8 len)
+{
+	const struct applesmc_entry *entry;
+
+	entry = applesmc_get_entry_by_key(key);
+	if (IS_ERR(entry))
+		return PTR_ERR(entry);
+
+	return applesmc_write_entry(entry, buffer, len);
+}
+
+static int applesmc_has_key(const char *key, bool *value)
+{
+	const struct applesmc_entry *entry;
+
+	entry = applesmc_get_entry_by_key(key);
+	if (IS_ERR(entry) && PTR_ERR(entry) != -EINVAL)
+		return PTR_ERR(entry);
+
+	*value = !IS_ERR(entry);
+	return 0;
+}
+
+/*
+ * applesmc_read_s16 - Read 16-bit signed big endian register
+ */
+static int applesmc_read_s16(const char *key, s16 *value)
+{
+	u8 buffer[2];
+	int ret;
+
+	ret = applesmc_read_key(key, buffer, 2);
+	if (ret)
+		return ret;
+
+	*value = ((s16)buffer[0] << 8) | buffer[1];
+	return 0;
+}
+
+/*
+ * applesmc_device_init - initialize the accelerometer.  Can sleep.
+ */
+static void applesmc_device_init(void)
+{
+	int total;
+	u8 buffer[2];
+
+	if (!smcreg.has_accelerometer)
+		return;
+
+	for (total = INIT_TIMEOUT_MSECS; total > 0; total -= INIT_WAIT_MSECS) {
+		if (!applesmc_read_key(MOTION_SENSOR_KEY, buffer, 2) &&
+				(buffer[0] != 0x00 || buffer[1] != 0x00))
+			return;
+		buffer[0] = 0xe0;
+		buffer[1] = 0x00;
+		applesmc_write_key(MOTION_SENSOR_KEY, buffer, 2);
+		msleep(INIT_WAIT_MSECS);
+	}
+
+	pr_warn("failed to init the device\n");
+}
+
+static int applesmc_init_index(struct applesmc_registers *s)
+{
+	const struct applesmc_entry *entry;
+	unsigned int i;
+
+	if (s->index)
+		return 0;
+
+	s->index = kcalloc(s->temp_count, sizeof(s->index[0]), GFP_KERNEL);
+	if (!s->index)
+		return -ENOMEM;
+
+	for (i = s->temp_begin; i < s->temp_end; i++) {
+		entry = applesmc_get_entry_by_index(i);
+		if (IS_ERR(entry))
+			continue;
+		if (strcmp(entry->type, TEMP_SENSOR_TYPE))
+			continue;
+		s->index[s->index_count++] = entry->key;
+	}
+
+	return 0;
+}
+
+/*
+ * applesmc_init_smcreg_try - Try to initialize register cache. Idempotent.
+ */
+static int applesmc_init_smcreg_try(void)
+{
+	struct applesmc_registers *s = &smcreg;
+	bool left_light_sensor = 0, right_light_sensor = 0;
+	unsigned int count;
+	u8 tmp[1];
+	int ret;
+
+	if (s->init_complete)
+		return 0;
+
+	ret = read_register_count(&count);
+	if (ret)
+		return ret;
+
+	if (s->cache && s->key_count != count) {
+		pr_warn("key count changed from %d to %d\n",
+			s->key_count, count);
+		kfree(s->cache);
+		s->cache = NULL;
+	}
+	s->key_count = count;
+
+	if (!s->cache)
+		s->cache = kcalloc(s->key_count, sizeof(*s->cache), GFP_KERNEL);
+	if (!s->cache)
+		return -ENOMEM;
+
+	ret = applesmc_read_key(FANS_COUNT, tmp, 1);
+	if (ret)
+		return ret;
+	s->fan_count = tmp[0];
+	if (s->fan_count > 10)
+		s->fan_count = 10;
+
+	ret = applesmc_get_lower_bound(&s->temp_begin, "T");
+	if (ret)
+		return ret;
+	ret = applesmc_get_lower_bound(&s->temp_end, "U");
+	if (ret)
+		return ret;
+	s->temp_count = s->temp_end - s->temp_begin;
+
+	ret = applesmc_init_index(s);
+	if (ret)
+		return ret;
+
+	ret = applesmc_has_key(LIGHT_SENSOR_LEFT_KEY, &left_light_sensor);
+	if (ret)
+		return ret;
+	ret = applesmc_has_key(LIGHT_SENSOR_RIGHT_KEY, &right_light_sensor);
+	if (ret)
+		return ret;
+	ret = applesmc_has_key(MOTION_SENSOR_KEY, &s->has_accelerometer);
+	if (ret)
+		return ret;
+	ret = applesmc_has_key(BACKLIGHT_KEY, &s->has_key_backlight);
+	if (ret)
+		return ret;
+
+	s->num_light_sensors = left_light_sensor + right_light_sensor;
+	s->init_complete = true;
+
+	pr_info("key=%d fan=%d temp=%d index=%d acc=%d lux=%d kbd=%d\n",
+	       s->key_count, s->fan_count, s->temp_count, s->index_count,
+	       s->has_accelerometer,
+	       s->num_light_sensors,
+	       s->has_key_backlight);
+
+	return 0;
+}
+
+static void applesmc_destroy_smcreg(void)
+{
+	kfree(smcreg.index);
+	smcreg.index = NULL;
+	kfree(smcreg.cache);
+	smcreg.cache = NULL;
+	smcreg.init_complete = false;
+}
+
+/*
+ * applesmc_init_smcreg - Initialize register cache.
+ *
+ * Retries until initialization is successful, or the operation times out.
+ *
+ */
+static int applesmc_init_smcreg(void)
+{
+	int ms, ret;
+
+	for (ms = 0; ms < INIT_TIMEOUT_MSECS; ms += INIT_WAIT_MSECS) {
+		ret = applesmc_init_smcreg_try();
+		if (!ret) {
+			if (ms)
+				pr_info("init_smcreg() took %d ms\n", ms);
+			return 0;
+		}
+		msleep(INIT_WAIT_MSECS);
+	}
+
+	applesmc_destroy_smcreg();
+
+	return ret;
+}
+
+/* Device model stuff */
+static int applesmc_probe(struct platform_device *dev)
+{
+	int ret;
+
+	ret = applesmc_init_smcreg();
+	if (ret)
+		return ret;
+
+	applesmc_device_init();
+
+	return 0;
+}
+
+/* Synchronize device with memorized backlight state */
+static int applesmc_pm_resume(struct device *dev)
+{
+	if (smcreg.has_key_backlight)
+		applesmc_write_key(BACKLIGHT_KEY, backlight_state, 2);
+	return 0;
+}
+
+/* Reinitialize device on resume from hibernation */
+static int applesmc_pm_restore(struct device *dev)
+{
+	applesmc_device_init();
+	return applesmc_pm_resume(dev);
+}
+
+static const struct dev_pm_ops applesmc_pm_ops = {
+	.resume = applesmc_pm_resume,
+	.restore = applesmc_pm_restore,
+};
+
+static struct platform_driver applesmc_driver = {
+	.probe = applesmc_probe,
+	.driver	= {
+		.name = "applesmc",
+		.pm = &applesmc_pm_ops,
+	},
+};
+
+/*
+ * applesmc_calibrate - Set our "resting" values.  Callers must
+ * hold applesmc_lock.
+ */
+static void applesmc_calibrate(void)
+{
+	applesmc_read_s16(MOTION_SENSOR_X_KEY, &rest_x);
+	applesmc_read_s16(MOTION_SENSOR_Y_KEY, &rest_y);
+	rest_x = -rest_x;
+}
+
+static void applesmc_idev_poll(struct input_polled_dev *dev)
+{
+	struct input_dev *idev = dev->input;
+	s16 x, y;
+
+	if (applesmc_read_s16(MOTION_SENSOR_X_KEY, &x))
+		return;
+	if (applesmc_read_s16(MOTION_SENSOR_Y_KEY, &y))
+		return;
+
+	x = -x;
+	input_report_abs(idev, ABS_X, x - rest_x);
+	input_report_abs(idev, ABS_Y, y - rest_y);
+	input_sync(idev);
+}
+
+/* Sysfs Files */
+
+static ssize_t applesmc_name_show(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	return snprintf(buf, PAGE_SIZE, "applesmc\n");
+}
+
+static ssize_t applesmc_position_show(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	int ret;
+	s16 x, y, z;
+
+	ret = applesmc_read_s16(MOTION_SENSOR_X_KEY, &x);
+	if (ret)
+		goto out;
+	ret = applesmc_read_s16(MOTION_SENSOR_Y_KEY, &y);
+	if (ret)
+		goto out;
+	ret = applesmc_read_s16(MOTION_SENSOR_Z_KEY, &z);
+	if (ret)
+		goto out;
+
+out:
+	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)
+{
+	const struct applesmc_entry *entry;
+	static int data_length;
+	int ret;
+	u8 left = 0, right = 0;
+	u8 buffer[10];
+
+	if (!data_length) {
+		entry = applesmc_get_entry_by_key(LIGHT_SENSOR_LEFT_KEY);
+		if (IS_ERR(entry))
+			return PTR_ERR(entry);
+		if (entry->len > 10)
+			return -ENXIO;
+		data_length = entry->len;
+		pr_info("light sensor data length set to %d\n", data_length);
+	}
+
+	ret = applesmc_read_key(LIGHT_SENSOR_LEFT_KEY, buffer, data_length);
+	/* newer macbooks report a single 10-bit bigendian value */
+	if (data_length == 10) {
+		left = be16_to_cpu(*(__be16 *)(buffer + 6)) >> 2;
+		goto out;
+	}
+	left = buffer[2];
+	if (ret)
+		goto out;
+	ret = applesmc_read_key(LIGHT_SENSOR_RIGHT_KEY, buffer, data_length);
+	right = buffer[2];
+
+out:
+	if (ret)
+		return ret;
+	else
+		return snprintf(sysfsbuf, PAGE_SIZE, "(%d,%d)\n", left, right);
+}
+
+/* Displays sensor key as label */
+static ssize_t applesmc_show_sensor_label(struct device *dev,
+			struct device_attribute *devattr, char *sysfsbuf)
+{
+	const char *key = smcreg.index[to_index(devattr)];
+
+	return snprintf(sysfsbuf, PAGE_SIZE, "%s\n", key);
+}
+
+/* Displays degree Celsius * 1000 */
+static ssize_t applesmc_show_temperature(struct device *dev,
+			struct device_attribute *devattr, char *sysfsbuf)
+{
+	const char *key = smcreg.index[to_index(devattr)];
+	int ret;
+	s16 value;
+	int temp;
+
+	ret = applesmc_read_s16(key, &value);
+	if (ret)
+		return ret;
+
+	temp = 250 * (value >> 6);
+
+	return snprintf(sysfsbuf, PAGE_SIZE, "%d\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];
+
+	scnprintf(newkey, sizeof(newkey), fan_speed_fmt[to_option(attr)],
+		  to_index(attr));
+
+	ret = applesmc_read_key(newkey, buffer, 2);
+	speed = ((buffer[0] << 8 | buffer[1]) >> 2);
+
+	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;
+	unsigned long speed;
+	char newkey[5];
+	u8 buffer[2];
+
+	if (kstrtoul(sysfsbuf, 10, &speed) < 0 || speed >= 0x4000)
+		return -EINVAL;		/* Bigger than a 14-bit value */
+
+	scnprintf(newkey, sizeof(newkey), fan_speed_fmt[to_option(attr)],
+		  to_index(attr));
+
+	buffer[0] = (speed >> 6) & 0xff;
+	buffer[1] = (speed << 2) & 0xff;
+	ret = applesmc_write_key(newkey, buffer, 2);
+
+	if (ret)
+		return ret;
+	else
+		return count;
+}
+
+static ssize_t applesmc_show_fan_manual(struct device *dev,
+			struct device_attribute *attr, char *sysfsbuf)
+{
+	int ret;
+	u16 manual = 0;
+	u8 buffer[2];
+
+	ret = applesmc_read_key(FANS_MANUAL, buffer, 2);
+	manual = ((buffer[0] << 8 | buffer[1]) >> to_index(attr)) & 0x01;
+
+	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 *attr,
+					 const char *sysfsbuf, size_t count)
+{
+	int ret;
+	u8 buffer[2];
+	unsigned long input;
+	u16 val;
+
+	if (kstrtoul(sysfsbuf, 10, &input) < 0)
+		return -EINVAL;
+
+	ret = applesmc_read_key(FANS_MANUAL, buffer, 2);
+	val = (buffer[0] << 8 | buffer[1]);
+	if (ret)
+		goto out;
+
+	if (input)
+		val = val | (0x01 << to_index(attr));
+	else
+		val = val & ~(0x01 << to_index(attr));
+
+	buffer[0] = (val >> 8) & 0xFF;
+	buffer[1] = val & 0xFF;
+
+	ret = applesmc_write_key(FANS_MANUAL, buffer, 2);
+
+out:
+	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];
+
+	scnprintf(newkey, sizeof(newkey), FAN_ID_FMT, to_index(attr));
+
+	ret = applesmc_read_key(newkey, buffer, 16);
+	buffer[16] = 0;
+
+	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)
+{
+	applesmc_calibrate();
+
+	return count;
+}
+
+static void applesmc_backlight_set(struct work_struct *work)
+{
+	applesmc_write_key(BACKLIGHT_KEY, backlight_state, 2);
+}
+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_state[0] = value;
+	ret = queue_work(applesmc_led_wq, &backlight_work);
+
+	if (debug && (!ret))
+		dev_dbg(led_cdev->dev, "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;
+
+	ret = applesmc_read_key(KEY_COUNT_KEY, buffer, 4);
+	count = ((u32)buffer[0]<<24) + ((u32)buffer[1]<<16) +
+						((u32)buffer[2]<<8) + buffer[3];
+
+	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)
+{
+	const struct applesmc_entry *entry;
+	int ret;
+
+	entry = applesmc_get_entry_by_index(key_at_index);
+	if (IS_ERR(entry))
+		return PTR_ERR(entry);
+	ret = applesmc_read_entry(entry, sysfsbuf, entry->len);
+	if (ret)
+		return ret;
+
+	return entry->len;
+}
+
+static ssize_t applesmc_key_at_index_data_length_show(struct device *dev,
+				struct device_attribute *attr, char *sysfsbuf)
+{
+	const struct applesmc_entry *entry;
+
+	entry = applesmc_get_entry_by_index(key_at_index);
+	if (IS_ERR(entry))
+		return PTR_ERR(entry);
+
+	return snprintf(sysfsbuf, PAGE_SIZE, "%d\n", entry->len);
+}
+
+static ssize_t applesmc_key_at_index_type_show(struct device *dev,
+				struct device_attribute *attr, char *sysfsbuf)
+{
+	const struct applesmc_entry *entry;
+
+	entry = applesmc_get_entry_by_index(key_at_index);
+	if (IS_ERR(entry))
+		return PTR_ERR(entry);
+
+	return snprintf(sysfsbuf, PAGE_SIZE, "%s\n", entry->type);
+}
+
+static ssize_t applesmc_key_at_index_name_show(struct device *dev,
+				struct device_attribute *attr, char *sysfsbuf)
+{
+	const struct applesmc_entry *entry;
+
+	entry = applesmc_get_entry_by_index(key_at_index);
+	if (IS_ERR(entry))
+		return PTR_ERR(entry);
+
+	return snprintf(sysfsbuf, PAGE_SIZE, "%s\n", entry->key);
+}
+
+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)
+{
+	unsigned long newkey;
+
+	if (kstrtoul(sysfsbuf, 10, &newkey) < 0
+	    || newkey >= smcreg.key_count)
+		return -EINVAL;
+
+	key_at_index = newkey;
+	return count;
+}
+
+static struct led_classdev applesmc_backlight = {
+	.name			= "smc::kbd_backlight",
+	.default_trigger	= "nand-disk",
+	.brightness_set		= applesmc_brightness_set,
+};
+
+static struct applesmc_node_group info_group[] = {
+	{ "name", applesmc_name_show },
+	{ "key_count", applesmc_key_count_show },
+	{ "key_at_index", applesmc_key_at_index_show, applesmc_key_at_index_store },
+	{ "key_at_index_name", applesmc_key_at_index_name_show },
+	{ "key_at_index_type", applesmc_key_at_index_type_show },
+	{ "key_at_index_data_length", applesmc_key_at_index_data_length_show },
+	{ "key_at_index_data", applesmc_key_at_index_read_show },
+	{ }
+};
+
+static struct applesmc_node_group accelerometer_group[] = {
+	{ "position", applesmc_position_show },
+	{ "calibrate", applesmc_calibrate_show, applesmc_calibrate_store },
+	{ }
+};
+
+static struct applesmc_node_group light_sensor_group[] = {
+	{ "light", applesmc_light_show },
+	{ }
+};
+
+static struct applesmc_node_group fan_group[] = {
+	{ "fan%d_label", applesmc_show_fan_position },
+	{ "fan%d_input", applesmc_show_fan_speed, NULL, 0 },
+	{ "fan%d_min", applesmc_show_fan_speed, applesmc_store_fan_speed, 1 },
+	{ "fan%d_max", applesmc_show_fan_speed, NULL, 2 },
+	{ "fan%d_safe", applesmc_show_fan_speed, NULL, 3 },
+	{ "fan%d_output", applesmc_show_fan_speed, applesmc_store_fan_speed, 4 },
+	{ "fan%d_manual", applesmc_show_fan_manual, applesmc_store_fan_manual },
+	{ }
+};
+
+static struct applesmc_node_group temp_group[] = {
+	{ "temp%d_label", applesmc_show_sensor_label },
+	{ "temp%d_input", applesmc_show_temperature },
+	{ }
+};
+
+/* Module stuff */
+
+/*
+ * applesmc_destroy_nodes - remove files and free associated memory
+ */
+static void applesmc_destroy_nodes(struct applesmc_node_group *groups)
+{
+	struct applesmc_node_group *grp;
+	struct applesmc_dev_attr *node;
+
+	for (grp = groups; grp->nodes; grp++) {
+		for (node = grp->nodes; node->sda.dev_attr.attr.name; node++)
+			sysfs_remove_file(&pdev->dev.kobj,
+					  &node->sda.dev_attr.attr);
+		kfree(grp->nodes);
+		grp->nodes = NULL;
+	}
+}
+
+/*
+ * applesmc_create_nodes - create a two-dimensional group of sysfs files
+ */
+static int applesmc_create_nodes(struct applesmc_node_group *groups, int num)
+{
+	struct applesmc_node_group *grp;
+	struct applesmc_dev_attr *node;
+	struct attribute *attr;
+	int ret, i;
+
+	for (grp = groups; grp->format; grp++) {
+		grp->nodes = kcalloc(num + 1, sizeof(*node), GFP_KERNEL);
+		if (!grp->nodes) {
+			ret = -ENOMEM;
+			goto out;
+		}
+		for (i = 0; i < num; i++) {
+			node = &grp->nodes[i];
+			scnprintf(node->name, sizeof(node->name), grp->format,
+				  i + 1);
+			node->sda.index = (grp->option << 16) | (i & 0xffff);
+			node->sda.dev_attr.show = grp->show;
+			node->sda.dev_attr.store = grp->store;
+			attr = &node->sda.dev_attr.attr;
+			sysfs_attr_init(attr);
+			attr->name = node->name;
+			attr->mode = S_IRUGO | (grp->store ? S_IWUSR : 0);
+			ret = sysfs_create_file(&pdev->dev.kobj, attr);
+			if (ret) {
+				attr->name = NULL;
+				goto out;
+			}
+		}
+	}
+
+	return 0;
+out:
+	applesmc_destroy_nodes(groups);
+	return ret;
+}
+
+/* Create accelerometer resources */
+static int applesmc_create_accelerometer(void)
+{
+	struct input_dev *idev;
+	int ret;
+
+	if (!smcreg.has_accelerometer)
+		return 0;
+
+	ret = applesmc_create_nodes(accelerometer_group, 1);
+	if (ret)
+		goto out;
+
+	applesmc_idev = input_allocate_polled_device();
+	if (!applesmc_idev) {
+		ret = -ENOMEM;
+		goto out_sysfs;
+	}
+
+	applesmc_idev->poll = applesmc_idev_poll;
+	applesmc_idev->poll_interval = APPLESMC_POLL_INTERVAL;
+
+	/* initial calibrate for the input device */
+	applesmc_calibrate();
+
+	/* initialize the input device */
+	idev = applesmc_idev->input;
+	idev->name = "applesmc";
+	idev->id.bustype = BUS_HOST;
+	idev->dev.parent = &pdev->dev;
+	idev->evbit[0] = BIT_MASK(EV_ABS);
+	input_set_abs_params(idev, ABS_X,
+			-256, 256, APPLESMC_INPUT_FUZZ, APPLESMC_INPUT_FLAT);
+	input_set_abs_params(idev, ABS_Y,
+			-256, 256, APPLESMC_INPUT_FUZZ, APPLESMC_INPUT_FLAT);
+
+	ret = input_register_polled_device(applesmc_idev);
+	if (ret)
+		goto out_idev;
+
+	return 0;
+
+out_idev:
+	input_free_polled_device(applesmc_idev);
+
+out_sysfs:
+	applesmc_destroy_nodes(accelerometer_group);
+
+out:
+	pr_warn("driver init failed (ret=%d)!\n", ret);
+	return ret;
+}
+
+/* Release all resources used by the accelerometer */
+static void applesmc_release_accelerometer(void)
+{
+	if (!smcreg.has_accelerometer)
+		return;
+	input_unregister_polled_device(applesmc_idev);
+	input_free_polled_device(applesmc_idev);
+	applesmc_destroy_nodes(accelerometer_group);
+}
+
+static int applesmc_create_light_sensor(void)
+{
+	if (!smcreg.num_light_sensors)
+		return 0;
+	return applesmc_create_nodes(light_sensor_group, 1);
+}
+
+static void applesmc_release_light_sensor(void)
+{
+	if (!smcreg.num_light_sensors)
+		return;
+	applesmc_destroy_nodes(light_sensor_group);
+}
+
+static int applesmc_create_key_backlight(void)
+{
+	if (!smcreg.has_key_backlight)
+		return 0;
+	applesmc_led_wq = create_singlethread_workqueue("applesmc-led");
+	if (!applesmc_led_wq)
+		return -ENOMEM;
+	return led_classdev_register(&pdev->dev, &applesmc_backlight);
+}
+
+static void applesmc_release_key_backlight(void)
+{
+	if (!smcreg.has_key_backlight)
+		return;
+	led_classdev_unregister(&applesmc_backlight);
+	destroy_workqueue(applesmc_led_wq);
+}
+
+static int applesmc_dmi_match(const struct dmi_system_id *id)
+{
+	return 1;
+}
+
+/*
+ * Note that DMI_MATCH(...,"MacBook") will match "MacBookPro1,1".
+ * So we need to put "Apple MacBook Pro" before "Apple MacBook".
+ */
+static const struct dmi_system_id applesmc_whitelist[] __initconst = {
+	{ applesmc_dmi_match, "Apple MacBook Air", {
+	  DMI_MATCH(DMI_BOARD_VENDOR, "Apple"),
+	  DMI_MATCH(DMI_PRODUCT_NAME, "MacBookAir") },
+	},
+	{ applesmc_dmi_match, "Apple MacBook Pro", {
+	  DMI_MATCH(DMI_BOARD_VENDOR, "Apple"),
+	  DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro") },
+	},
+	{ applesmc_dmi_match, "Apple MacBook", {
+	  DMI_MATCH(DMI_BOARD_VENDOR, "Apple"),
+	  DMI_MATCH(DMI_PRODUCT_NAME, "MacBook") },
+	},
+	{ applesmc_dmi_match, "Apple Macmini", {
+	  DMI_MATCH(DMI_BOARD_VENDOR, "Apple"),
+	  DMI_MATCH(DMI_PRODUCT_NAME, "Macmini") },
+	},
+	{ applesmc_dmi_match, "Apple MacPro", {
+	  DMI_MATCH(DMI_BOARD_VENDOR, "Apple"),
+	  DMI_MATCH(DMI_PRODUCT_NAME, "MacPro") },
+	},
+	{ applesmc_dmi_match, "Apple iMac", {
+	  DMI_MATCH(DMI_BOARD_VENDOR, "Apple"),
+	  DMI_MATCH(DMI_PRODUCT_NAME, "iMac") },
+	},
+	{ .ident = NULL }
+};
+
+static int __init applesmc_init(void)
+{
+	int ret;
+
+	if (!dmi_check_system(applesmc_whitelist)) {
+		pr_warn("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", APPLESMC_DATA_PORT,
+					       NULL, 0);
+	if (IS_ERR(pdev)) {
+		ret = PTR_ERR(pdev);
+		goto out_driver;
+	}
+
+	/* create register cache */
+	ret = applesmc_init_smcreg();
+	if (ret)
+		goto out_device;
+
+	ret = applesmc_create_nodes(info_group, 1);
+	if (ret)
+		goto out_smcreg;
+
+	ret = applesmc_create_nodes(fan_group, smcreg.fan_count);
+	if (ret)
+		goto out_info;
+
+	ret = applesmc_create_nodes(temp_group, smcreg.index_count);
+	if (ret)
+		goto out_fans;
+
+	ret = applesmc_create_accelerometer();
+	if (ret)
+		goto out_temperature;
+
+	ret = applesmc_create_light_sensor();
+	if (ret)
+		goto out_accelerometer;
+
+	ret = applesmc_create_key_backlight();
+	if (ret)
+		goto out_light_sysfs;
+
+	hwmon_dev = hwmon_device_register(&pdev->dev);
+	if (IS_ERR(hwmon_dev)) {
+		ret = PTR_ERR(hwmon_dev);
+		goto out_light_ledclass;
+	}
+
+	return 0;
+
+out_light_ledclass:
+	applesmc_release_key_backlight();
+out_light_sysfs:
+	applesmc_release_light_sensor();
+out_accelerometer:
+	applesmc_release_accelerometer();
+out_temperature:
+	applesmc_destroy_nodes(temp_group);
+out_fans:
+	applesmc_destroy_nodes(fan_group);
+out_info:
+	applesmc_destroy_nodes(info_group);
+out_smcreg:
+	applesmc_destroy_smcreg();
+out_device:
+	platform_device_unregister(pdev);
+out_driver:
+	platform_driver_unregister(&applesmc_driver);
+out_region:
+	release_region(APPLESMC_DATA_PORT, APPLESMC_NR_PORTS);
+out:
+	pr_warn("driver init failed (ret=%d)!\n", ret);
+	return ret;
+}
+
+static void __exit applesmc_exit(void)
+{
+	hwmon_device_unregister(hwmon_dev);
+	applesmc_release_key_backlight();
+	applesmc_release_light_sensor();
+	applesmc_release_accelerometer();
+	applesmc_destroy_nodes(temp_group);
+	applesmc_destroy_nodes(fan_group);
+	applesmc_destroy_nodes(info_group);
+	applesmc_destroy_smcreg();
+	platform_device_unregister(pdev);
+	platform_driver_unregister(&applesmc_driver);
+	release_region(APPLESMC_DATA_PORT, APPLESMC_NR_PORTS);
+}
+
+module_init(applesmc_init);
+module_exit(applesmc_exit);
+
+MODULE_AUTHOR("Nicolas Boichat");
+MODULE_DESCRIPTION("Apple SMC");
+MODULE_LICENSE("GPL v2");
+MODULE_DEVICE_TABLE(dmi, applesmc_whitelist);