diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 89ac1cb..cb4879c 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -423,6 +423,16 @@ config SENSORS_G760A
 	  This driver can also be built as a module.  If so, the module
 	  will be called g760a.
 
+config SENSORS_G762
+	tristate "GMT G762 and G763"
+	depends on I2C
+	help
+	  If you say yes here you get support for Global Mixed-mode
+	  Technology Inc G762 and G763 fan speed PWM controller chips.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called g762.
+
 config SENSORS_GL518SM
 	tristate "Genesys Logic GL518SM"
 	depends on I2C
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 8d6d97e..4b49504 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -57,6 +57,7 @@ obj-$(CONFIG_SENSORS_F75375S)	+= f75375s.o
 obj-$(CONFIG_SENSORS_FAM15H_POWER) += fam15h_power.o
 obj-$(CONFIG_SENSORS_FSCHMD)	+= fschmd.o
 obj-$(CONFIG_SENSORS_G760A)	+= g760a.o
+obj-$(CONFIG_SENSORS_G762)	+= g762.o
 obj-$(CONFIG_SENSORS_GL518SM)	+= gl518sm.o
 obj-$(CONFIG_SENSORS_GL520SM)	+= gl520sm.o
 obj-$(CONFIG_SENSORS_GPIO_FAN)	+= gpio-fan.o
diff --git a/drivers/hwmon/g762.c b/drivers/hwmon/g762.c
new file mode 100644
index 0000000..810b019
--- /dev/null
+++ b/drivers/hwmon/g762.c
@@ -0,0 +1,1058 @@
+/*
+ * g762 - Driver for the Global Mixed-mode Technology Inc. fan speed PWM
+ *        controller chips from G762 family, i.e. G762 and G763
+ *
+ * Copyright (C) 2013, Arnaud EBALARD <arno@natisbad.org>
+ *
+ * This work is based on a basic version for 2.6.31 kernel developed
+ * by Olivier Mouchet for LaCie NAS. Updates have been performed to run
+ * on recent kernels. Additional features have been added. Ability to
+ * configure various characteristics via .dts file has been added.
+ * Detailed datasheet on which this development is based is available
+ * here:
+ *
+ *  http://natisbad.org/NAS/refs/GMT_EDS-762_763-080710-0.2.pdf
+ *
+ * Headers from previous developments have been kept below:
+ *
+ * Copyright (c) 2009 LaCie
+ *
+ * Author: Olivier Mouchet <olivier.mouchet@gmail.com>
+ *
+ * based on g760a code written by Herbert Valerio Riedel <hvr@gnu.org>
+ * Copyright (C) 2007  Herbert Valerio Riedel <hvr@gnu.org>
+ *
+ * g762: minimal datasheet available at:
+ *       http://www.gmt.com.tw/product/datasheet/EDS-762_3.pdf
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/jiffies.h>
+#include <linux/i2c.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/err.h>
+#include <linux/mutex.h>
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+
+#define DRVNAME "g762"
+
+static const struct i2c_device_id g762_id[] = {
+	{ "g762", 0 },
+	{ "g763", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, g762_id);
+
+enum g762_regs {
+	G762_REG_SET_CNT  = 0x00,
+	G762_REG_ACT_CNT  = 0x01,
+	G762_REG_FAN_STA  = 0x02,
+	G762_REG_SET_OUT  = 0x03,
+	G762_REG_FAN_CMD1 = 0x04,
+	G762_REG_FAN_CMD2 = 0x05,
+};
+
+/* Config register bits */
+#define G762_REG_FAN_CMD1_DET_FAN_FAIL  0x80 /* enable fan_fail signal */
+#define G762_REG_FAN_CMD1_DET_FAN_OOC   0x40 /* enable fan_out_of_control */
+#define G762_REG_FAN_CMD1_OUT_MODE      0x20 /* out mode, pwm or dac */
+#define G762_REG_FAN_CMD1_FAN_MODE      0x10 /* fan mode: close or open loop */
+#define G762_REG_FAN_CMD1_CLK_DIV_ID1   0x08 /* clock divisor value */
+#define G762_REG_FAN_CMD1_CLK_DIV_ID0   0x04
+#define G762_REG_FAN_CMD1_PWM_POLARITY  0x02 /* pwm polarity */
+#define G762_REG_FAN_CMD1_PULSE_PER_REV 0x01 /* pulse per fan revolution */
+
+#define G762_REG_FAN_CMD2_GEAR_MODE_1   0x08 /* fan gear mode */
+#define G762_REG_FAN_CMD2_GEAR_MODE_0   0x04
+#define G762_REG_FAN_CMD2_FAN_STARTV_1  0x02 /* fan startup voltage */
+#define G762_REG_FAN_CMD2_FAN_STARTV_0  0x01
+
+#define G762_REG_FAN_STA_FAIL           0x02 /* fan fail */
+#define G762_REG_FAN_STA_OOC            0x01 /* fan out of control */
+
+/* config register values */
+#define OUT_MODE_PWM            1
+#define OUT_MODE_DAC            0
+
+#define FAN_MODE_CLOSED_LOOP    2
+#define FAN_MODE_OPEN_LOOP      1
+
+/* register data is read (and cached) at most once per second */
+#define G762_UPDATE_INTERVAL (HZ)
+
+/*
+ * extract pulse count per fan revolution value (2 or 4) from given
+ * FAN_CMD1 register value
+ */
+#define PULSE_FROM_REG(reg) \
+	((((reg) & G762_REG_FAN_CMD1_PULSE_PER_REV)+1) << 1)
+
+/*
+ * extract fan clock divisor (1, 2, 4 or 8) from given FAN_CMD1
+ * register value
+ */
+#define CLKDIV_FROM_REG(reg) \
+	(1 << (((reg) & (G762_REG_FAN_CMD1_CLK_DIV_ID0 |	\
+			 G762_REG_FAN_CMD1_CLK_DIV_ID1)) >> 2))
+
+/*
+ * extract fan gear mode value (0, 1 or 2) from given FAN_CMD2
+ * register value
+ */
+#define GEARMODE_FROM_REG(reg) \
+	(1 << (((reg) & (G762_REG_FAN_CMD2_GEAR_MODE_0 |	\
+			 G762_REG_FAN_CMD2_GEAR_MODE_1)) >> 2))
+
+struct g762_data {
+	struct i2c_client *client;
+	struct device *hwmon_dev;
+
+	/* update mutex */
+	struct mutex update_lock;
+
+	/* board specific parameters. */
+	u32 clk; /* default 32kHz */
+
+	/* g762 register cache */
+	bool valid;
+	unsigned long last_updated; /* in jiffies */
+
+	u8 set_cnt;  /* RPM cmd in close loop control */
+	u8 act_cnt;  /* formula: cnt = (CLK * 30)/(rpm * P) */
+	u8 fan_sta;  /* bit 0: set when actual fan speed is more than
+		      *        25% outside requested fan speed
+		      * bit 1: set when no transition occurs on fan
+		      *        pin for 0.7s
+		      */
+	u8 set_out;  /* output voltage/PWM duty in open loop control */
+	u8 fan_cmd1; /*   0: FG_PLS_ID0 FG pulses count per revolution
+		      *      0: 2 counts per revolution
+		      *      1: 4 counts per revolution
+		      *   1: PWM_POLARITY 1: negative_duty
+		      *                   0: positive_duty
+		      * 2,3: [FG_CLOCK_ID0, FG_CLK_ID1]
+		      *         00: Divide fan clock by 1
+		      *         01: Divide fan clock by 2
+		      *         10: Divide fan clock by 4
+		      *         11: Divide fan clock by 8
+		      *   4: FAN_MODE 1:close-loop, 0:open-loop
+		      *   5: OUT_MODE 1:PWM, 0:DAC
+		      *   6: DET_FAN_OOC enable "fan ooc" status
+		      *   7: DET_FAN_FAIL enable "fan fail" status
+		      */
+	u8 fan_cmd2; /* 0,1: FAN_STARTV 0,1,2,3 -> 0,32,64,96 dac_code
+		      * 2,3: FG_GEAR_MODE
+		      *         00: div = 1
+		      *         01: div = 2
+		      *         10: div = 4
+		      *   4: Mask ALERT# (g763 only)
+		      */
+};
+
+/*
+ * sysfs PWM interface uses value from 0 to 255 when g762 FAN_SET_CNT register
+ * uses values from 255 (off) to 0 (full speed).
+ */
+#define PWM_FROM_CNT(cnt)	(0xff-(cnt))
+#define PWM_TO_CNT(pwm)		(0xff-(pwm))
+
+/*
+ * Convert count value from fan controller register into fan speed RPM value.
+ * Note that the datasheet documents a basic formula. Influence of additional
+ * parameters have been infered from examples in the datasheet and tests:
+ * fan clock divisor, fan gear mode.
+ */
+static inline unsigned int rpm_from_cnt(u8 cnt, u32 clk, u16 p,
+					u8 clk_div, u8 gear_mode)
+{
+	if (cnt == 0 || cnt == 0xff)
+		return 0;
+
+	return (clk*30*(gear_mode+1))/(cnt*p*clk_div);
+}
+
+/* Convert fan RPM value from sysfs into count value */
+static inline unsigned char cnt_from_rpm(u32 rpm, u32 clk, u16 p,
+					 u8 clk_div, u8 gear_mode)
+{
+	return (rpm == 0) ? 0xff : (clk*30*(gear_mode+1))/(rpm*p*clk_div);
+}
+
+static inline int g762_read_value(struct i2c_client *client,
+				  enum g762_regs reg)
+{
+	return i2c_smbus_read_byte_data(client, reg);
+}
+
+static inline int g762_write_value(struct i2c_client *client,
+				   enum g762_regs reg, u8 value)
+{
+	return i2c_smbus_write_byte_data(client, reg, value);
+}
+
+/* helper to grab and cache data, at most one time per second */
+static struct g762_data *g762_update_client(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct g762_data *data = i2c_get_clientdata(client);
+
+	mutex_lock(&data->update_lock);
+	if (time_after(jiffies, data->last_updated + G762_UPDATE_INTERVAL) ||
+	    unlikely(!data->valid)) {
+		data->set_cnt =  g762_read_value(client, G762_REG_SET_CNT);
+		data->act_cnt =  g762_read_value(client, G762_REG_ACT_CNT);
+		data->fan_sta =  g762_read_value(client, G762_REG_FAN_STA);
+		data->set_out =  g762_read_value(client, G762_REG_SET_OUT);
+		data->fan_cmd1 = g762_read_value(client, G762_REG_FAN_CMD1);
+		data->fan_cmd2 = g762_read_value(client, G762_REG_FAN_CMD2);
+
+		data->last_updated = jiffies;
+		data->valid = 1;
+	}
+	mutex_unlock(&data->update_lock);
+
+	return data;
+}
+
+
+
+/*
+ * helpers for passing hardware characteristics via DT. Some of those
+ * are also used by sysfs handlers (write function) later in the file.
+ */
+
+
+/* Set pwm mode. Accepts either 0 (pwm mode) or 1 (linear mode) */
+static int do_set_pwm_mode(struct device *dev, unsigned long val)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct g762_data *data = g762_update_client(dev);
+	int ret = 0;
+
+	mutex_lock(&data->update_lock);
+	switch (val) {
+	case OUT_MODE_PWM:
+		data->fan_cmd1 |= G762_REG_FAN_CMD1_OUT_MODE;
+		break;
+	case OUT_MODE_DAC: /* i.e. linear mode */
+		data->fan_cmd1 &= ~G762_REG_FAN_CMD1_OUT_MODE;
+		break;
+	default:
+		ret = -EINVAL;
+		goto out;
+	}
+	g762_write_value(client, G762_REG_FAN_CMD1, data->fan_cmd1);
+ out:
+	mutex_unlock(&data->update_lock);
+
+	return ret;
+}
+
+/*
+ * Set reference clock. Accepted values are between 0 and 0xffffff.
+ * Note that this is an internal parameter, i.e. value is not passed
+ * to the device.
+ */
+static int do_set_pwm_freq(struct device *dev, unsigned long val)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct g762_data *data = i2c_get_clientdata(client);
+	int ret = -EINVAL;
+
+	if (val <= 0xffffff) {
+		data->clk = val;
+		ret = 0;
+	}
+
+	return ret;
+}
+
+/* Set fan clock divisor. Accepted values are 1, 2, 4 and 8. */
+static int do_set_fan_div(struct device *dev, unsigned long val)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct g762_data *data = g762_update_client(dev);
+	int ret = 0;
+
+	mutex_lock(&data->update_lock);
+	switch (val) {
+	case 1:
+		data->fan_cmd1 &= ~G762_REG_FAN_CMD1_CLK_DIV_ID0;
+		data->fan_cmd1 &= ~G762_REG_FAN_CMD1_CLK_DIV_ID1;
+		break;
+	case 2:
+		data->fan_cmd1 |=  G762_REG_FAN_CMD1_CLK_DIV_ID0;
+		data->fan_cmd1 &= ~G762_REG_FAN_CMD1_CLK_DIV_ID1;
+		break;
+	case 4:
+		data->fan_cmd1 &= ~G762_REG_FAN_CMD1_CLK_DIV_ID0;
+		data->fan_cmd1 |=  G762_REG_FAN_CMD1_CLK_DIV_ID1;
+		break;
+	case 8:
+		data->fan_cmd1 |=  G762_REG_FAN_CMD1_CLK_DIV_ID0;
+		data->fan_cmd1 |=  G762_REG_FAN_CMD1_CLK_DIV_ID1;
+		break;
+	default:
+		ret = -EINVAL;
+		goto out;
+	}
+	g762_write_value(client, G762_REG_FAN_CMD1, data->fan_cmd1);
+ out:
+	mutex_unlock(&data->update_lock);
+
+	return ret;
+}
+
+/* Set fan gear mode. Accepted values are either 0, 1 or 2. */
+static int do_set_fan_gear_mode(struct device *dev, unsigned long val)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct g762_data *data = g762_update_client(dev);
+	int ret = 0;
+
+	mutex_lock(&data->update_lock);
+	switch (val) {
+	case 0:
+		data->fan_cmd2 &= ~G762_REG_FAN_CMD2_GEAR_MODE_0;
+		data->fan_cmd2 &= ~G762_REG_FAN_CMD2_GEAR_MODE_1;
+		break;
+	case 1:
+		data->fan_cmd2 |=  G762_REG_FAN_CMD2_GEAR_MODE_0;
+		data->fan_cmd2 &= ~G762_REG_FAN_CMD2_GEAR_MODE_1;
+		break;
+	case 2:
+		data->fan_cmd2 &= ~G762_REG_FAN_CMD2_GEAR_MODE_0;
+		data->fan_cmd2 |=  G762_REG_FAN_CMD2_GEAR_MODE_1;
+		break;
+	default:
+		ret = -EINVAL;
+		goto out;
+	}
+	g762_write_value(client, G762_REG_FAN_CMD2, data->fan_cmd2);
+ out:
+	mutex_unlock(&data->update_lock);
+
+	return ret;
+}
+
+/* Set pulse per revolution value. Accepts either 2 or 4. */
+static int do_set_fan_pulses(struct device *dev, unsigned long val)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct g762_data *data = g762_update_client(dev);
+	int ret = 0;
+
+	mutex_lock(&data->update_lock);
+	switch (val) {
+	case 2:
+		data->fan_cmd1 &= ~G762_REG_FAN_CMD1_PULSE_PER_REV;
+		break;
+	case 4:
+		data->fan_cmd1 |=  G762_REG_FAN_CMD1_PULSE_PER_REV;
+		break;
+	default:
+		ret = -EINVAL;
+		goto out;
+	}
+	g762_write_value(client, G762_REG_FAN_CMD1, data->fan_cmd1);
+ out:
+	mutex_unlock(&data->update_lock);
+
+	return ret;
+}
+
+/* Set fan mode. Accepts either 1 (open loop) or 2 (closed loop). */
+static int do_set_pwm_enable(struct device *dev, unsigned long val)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct g762_data *data = g762_update_client(dev);
+	int ret = 0;
+
+	mutex_lock(&data->update_lock);
+	switch (val) {
+	case FAN_MODE_OPEN_LOOP:
+		data->fan_cmd1 &= ~G762_REG_FAN_CMD1_FAN_MODE;
+		break;
+	case FAN_MODE_CLOSED_LOOP:
+		data->fan_cmd1 |=  G762_REG_FAN_CMD1_FAN_MODE;
+		break;
+	default:
+		ret = -EINVAL;
+		goto out;
+	}
+
+	g762_write_value(client, G762_REG_FAN_CMD1, data->fan_cmd1);
+ out:
+	mutex_unlock(&data->update_lock);
+
+	return ret;
+}
+
+/* Set pwm polarity (0 for negative duty, 1 for positive duty) */
+static int do_set_pwm_polarity(struct device *dev, unsigned long val)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct g762_data *data = g762_update_client(dev);
+	int ret = 0;
+
+	mutex_lock(&data->update_lock);
+	switch (val) {
+	case 0: /* i.e. negative duty */
+		data->fan_cmd1 &= ~G762_REG_FAN_CMD1_PWM_POLARITY;
+		break;
+	case 1: /* i.e. positive duty */
+		data->fan_cmd1 |=  G762_REG_FAN_CMD1_PWM_POLARITY;
+		break;
+	default:
+		ret = -EINVAL;
+		goto out;
+	}
+	g762_write_value(client, G762_REG_FAN_CMD1, data->fan_cmd1);
+ out:
+	mutex_unlock(&data->update_lock);
+
+	return ret;
+}
+
+/*
+ * Set pwm value. Accepted values are between 0 and 255. Note that the
+ * internal register used for setting the value depends ont the fan
+ * mode of the device.
+ */
+static int do_set_pwm(struct device *dev, unsigned long val)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct g762_data *data = g762_update_client(dev);
+	int ret = -EINVAL;
+
+	mutex_lock(&data->update_lock);
+	if (val > 255)
+		goto out;
+
+	if (data->fan_cmd1 & G762_REG_FAN_CMD1_FAN_MODE) { /* closed-loop */
+		data->set_cnt = PWM_TO_CNT(val);
+		g762_write_value(client, G762_REG_SET_CNT, (u8)val);
+	} else {                                           /* open-loop */
+		data->set_out = val;
+		g762_write_value(client, G762_REG_SET_OUT, (u8)val);
+	}
+
+	ret = 0;
+ out:
+	mutex_unlock(&data->update_lock);
+
+	return ret;
+}
+
+/* Set fan RPM value. This only makes sense in closed-loop mode. */
+static int do_set_fan_target(struct device *dev, unsigned long val)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct g762_data *data = g762_update_client(dev);
+	int ret = -EINVAL;
+
+	mutex_lock(&data->update_lock);
+	if (data->fan_cmd1 & G762_REG_FAN_CMD1_FAN_MODE) { /* closed-loop */
+		data->set_cnt = cnt_from_rpm(val, data->clk,
+					     PULSE_FROM_REG(data->fan_cmd1),
+					     CLKDIV_FROM_REG(data->fan_cmd1),
+					     GEARMODE_FROM_REG(data->fan_cmd2));
+		g762_write_value(client, G762_REG_SET_CNT, data->set_cnt);
+		ret = 0;
+	}
+	mutex_unlock(&data->update_lock);
+
+	return ret;
+}
+
+/* Enable/disable fan failure detection. Accepted values are 1 and 0. */
+static int do_fan_failure_detection_toggle(struct device *dev,
+					   unsigned long enable)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct g762_data *data = g762_update_client(dev);
+	int ret = 0;
+
+	mutex_lock(&data->update_lock);
+	switch (enable) {
+	case 0:
+		data->fan_cmd1 &= ~G762_REG_FAN_CMD1_DET_FAN_FAIL;
+		break;
+	case 1:
+		data->fan_cmd1 |=  G762_REG_FAN_CMD1_DET_FAN_FAIL;
+		break;
+	default:
+		ret = -EINVAL;
+		goto out;
+	}
+	g762_write_value(client, G762_REG_FAN_CMD1, data->fan_cmd1);
+ out:
+	mutex_unlock(&data->update_lock);
+
+	return ret;
+}
+
+/* Enable/disable fan out of control detection. Accepted values are 1 and 0 */
+static int do_fan_ooc_detection_toggle(struct device *dev, unsigned int enable)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct g762_data *data = g762_update_client(dev);
+	int ret = 0;
+
+	mutex_lock(&data->update_lock);
+	switch (enable) {
+	case 0:
+		data->fan_cmd1 &= ~G762_REG_FAN_CMD1_DET_FAN_OOC;
+		break;
+	case 1:
+		data->fan_cmd1 |=  G762_REG_FAN_CMD1_DET_FAN_OOC;
+		break;
+	default:
+		ret = -EINVAL;
+		goto out;
+	}
+	g762_write_value(client, G762_REG_FAN_CMD1, data->fan_cmd1);
+ out:
+	mutex_unlock(&data->update_lock);
+
+	return ret;
+}
+
+/* Set startup voltage. Accepted values are either 0, 1, 2 or 3. */
+static int do_set_fan_startv(struct device *dev, unsigned long val)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct g762_data *data = g762_update_client(dev);
+	int ret = 0;
+
+	mutex_lock(&data->update_lock);
+	switch (val) {
+	case 0:
+		data->fan_cmd2 &= ~G762_REG_FAN_CMD2_FAN_STARTV_0;
+		data->fan_cmd2 &= ~G762_REG_FAN_CMD2_FAN_STARTV_1;
+		break;
+	case 1:
+		data->fan_cmd2 |=  G762_REG_FAN_CMD2_FAN_STARTV_0;
+		data->fan_cmd2 &= ~G762_REG_FAN_CMD2_FAN_STARTV_1;
+		break;
+	case 2:
+		data->fan_cmd2 &= ~G762_REG_FAN_CMD2_FAN_STARTV_0;
+		data->fan_cmd2 |=  G762_REG_FAN_CMD2_FAN_STARTV_1;
+		break;
+	case 3:
+		data->fan_cmd2 |=  G762_REG_FAN_CMD2_FAN_STARTV_0;
+		data->fan_cmd2 |=  G762_REG_FAN_CMD2_FAN_STARTV_1;
+		break;
+	default:
+		ret = -EINVAL;
+		goto out;
+	}
+	g762_write_value(client, G762_REG_FAN_CMD2, data->fan_cmd2);
+ out:
+	mutex_unlock(&data->update_lock);
+
+	return ret;
+}
+
+
+
+/*
+ * Configuration-related definitions
+ */
+
+struct g762_config {
+	u32 fan_startv;
+	u32 fan_gear_mode;
+	u32 fan_div;
+	u32 fan_pulses;
+	u32 fan_target;
+	u32 pwm_polarity;
+	u32 pwm_enable;
+	u32 pwm_freq;
+	u32 pwm_mode;
+};
+
+/*
+ * g762 default values: it is assumed that the fan is set for a 32KHz clock
+ * source, a fan clock divisor of 1 and two pulses per revolution. Default
+ * fan driving mode is linear mode (g762/g763 also support PWM mode). Note
+ * the specific init value for properties which may be left unmodified.
+ */
+#define G762_DEFAULT_CLK            32768
+#define G762_DEFAULT_FAN_DIV        1
+#define G762_DEFAULT_FAN_PULSES     2
+#define G762_DEFAULT_OUT_MODE       0
+#define G762_DEFAULT_FAN_MODE       2
+#define G762_DEFAULT_FAN_STARTV     1
+#define G762_DEFAULT_FAN_GEAR_MODE  0
+#define G762_DEFAULT_FAN_POLARITY   0
+#define G762_UNTOUCHED_VAL          0xffffffff
+
+static void g762_config_init(struct g762_config *conf)
+{
+	conf->pwm_enable = G762_DEFAULT_FAN_MODE;
+	conf->pwm_mode = G762_DEFAULT_OUT_MODE;
+	conf->pwm_freq = G762_DEFAULT_CLK;
+	conf->pwm_polarity = G762_DEFAULT_FAN_POLARITY;
+	conf->fan_pulses = G762_DEFAULT_FAN_PULSES;
+	conf->fan_div = G762_DEFAULT_FAN_DIV;
+	conf->fan_startv = G762_DEFAULT_FAN_STARTV;
+	conf->fan_gear_mode = G762_DEFAULT_FAN_GEAR_MODE;
+	conf->fan_target = G762_UNTOUCHED_VAL;
+}
+
+static inline int g762_one_prop_commit(struct i2c_client *client,
+				       u32 pval, const char *pname,
+				       int (*psetter)(struct device *dev,
+						      unsigned long val))
+{
+	int ret = 0;
+
+	if ((pval != G762_UNTOUCHED_VAL) && (*psetter)(&client->dev, pval)) {
+		dev_info(&client->dev, "unable to set %s (%d)\n", pname, pval);
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+static int g762_config_commit(struct i2c_client *client,
+			      struct g762_config *conf)
+{
+	int ret = 0;
+
+	if (g762_one_prop_commit(client, conf->pwm_mode,
+				 "pwm_mode", &do_set_pwm_mode) ||
+	    g762_one_prop_commit(client, conf->pwm_enable,
+				 "pwm_enable", &do_set_pwm_enable) ||
+	    g762_one_prop_commit(client, conf->fan_div,
+				 "fan_div", &do_set_fan_div) ||
+	    g762_one_prop_commit(client, conf->fan_pulses,
+				 "fan_pulses", &do_set_fan_pulses) ||
+	    g762_one_prop_commit(client, conf->pwm_freq,
+				 "pwm_freq", &do_set_pwm_freq) ||
+	    g762_one_prop_commit(client, conf->fan_gear_mode,
+				 "fan_gear_mode", &do_set_fan_gear_mode) ||
+	    g762_one_prop_commit(client, conf->pwm_polarity,
+				 "pwm_polarity", &do_set_pwm_polarity) ||
+	    g762_one_prop_commit(client, conf->fan_startv,
+				 "fan_startv", &do_set_fan_startv) ||
+	    g762_one_prop_commit(client, conf->fan_target,
+				 "fan_target", &do_set_fan_target)) {
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+
+/*
+ * Helpers to import hardware characteristics from .dts file and overload
+ * default config values.
+ */
+
+#ifdef CONFIG_OF
+static struct of_device_id g762_dt_match[] = {
+	{ .compatible = "gmt,g762" },
+	{ .compatible = "gmt,g763" },
+	{ },
+};
+
+static inline void g762_of_import_one_prop(struct i2c_client *client,
+					   u32 *dest, const char *pname)
+{
+	const __be32 *prop;
+	int len;
+
+	prop = of_get_property(client->dev.of_node, pname, &len);
+	if (prop && len == sizeof(u32)) {
+		*dest = be32_to_cpu(prop[0]);
+		dev_info(&client->dev, "found %s (%d)\n", pname, *dest);
+	}
+}
+
+static void g762_config_of_overload(struct i2c_client *client,
+				    struct g762_config *conf)
+{
+	if (!client->dev.of_node)
+		return;
+
+	g762_of_import_one_prop(client, &conf->fan_gear_mode, "fan_gear_mode");
+	g762_of_import_one_prop(client, &conf->pwm_polarity, "pwm_polarity");
+	g762_of_import_one_prop(client, &conf->fan_startv, "fan_startv");
+	g762_of_import_one_prop(client, &conf->pwm_freq, "pwm_freq");
+	g762_of_import_one_prop(client, &conf->fan_div, "fan_div");
+	g762_of_import_one_prop(client, &conf->fan_pulses, "fan_pulses");
+	g762_of_import_one_prop(client, &conf->pwm_mode, "pwm_mode");
+	g762_of_import_one_prop(client, &conf->fan_target, "fan_target");
+	g762_of_import_one_prop(client, &conf->pwm_enable, "pwm_enable");
+}
+#else
+static void g762_config_of_overload(struct i2c_client *client,
+				    struct g762_config *conf) { };
+#endif
+
+
+
+/*
+ * sysfs attributes
+ */
+
+
+/*
+ * Read function for fan1_input sysfs file. Return current fan RPM value, or
+ * 0 if fan is out of control
+ */
+static ssize_t get_fan_rpm(struct device *dev, struct device_attribute *da,
+			   char *buf)
+{
+	struct g762_data *data = g762_update_client(dev);
+	unsigned int rpm = 0;
+
+	mutex_lock(&data->update_lock);
+	/* reverse logic: fan out of control reporting is enabled low */
+	if (data->fan_sta & G762_REG_FAN_STA_OOC) {
+		rpm = rpm_from_cnt(data->act_cnt, data->clk,
+				   PULSE_FROM_REG(data->fan_cmd1),
+				   CLKDIV_FROM_REG(data->fan_cmd1),
+				   GEARMODE_FROM_REG(data->fan_cmd2));
+	}
+	mutex_unlock(&data->update_lock);
+
+	return sprintf(buf, "%u\n", rpm);
+}
+
+
+/*
+ * Read and write functions for pwm1_mode sysfs file. Get and set fan speed
+ * control mode i.e. pwm (1) or linear (0).
+ */
+static ssize_t get_pwm_mode(struct device *dev, struct device_attribute *da,
+			    char *buf)
+{
+	struct g762_data *data = g762_update_client(dev);
+	int pwm_mode;
+
+	pwm_mode = (data->fan_cmd1 & G762_REG_FAN_CMD1_OUT_MODE) ? 1 : 0;
+
+	return sprintf(buf, "%d\n", pwm_mode);
+}
+
+static ssize_t set_pwm_mode(struct device *dev, struct device_attribute *da,
+			    const char *buf, size_t count)
+{
+	unsigned long val;
+
+	if (kstrtoul(buf, 10, &val) || do_set_pwm_mode(dev, val))
+		return -EINVAL;
+
+	return count;
+}
+
+
+/*
+ * Read and write functions for fan1_div sysfs file. Get and set fan
+ * controller prescaler value
+ */
+static ssize_t get_fan_div(struct device *dev,
+			       struct device_attribute *da, char *buf)
+{
+	struct g762_data *data = g762_update_client(dev);
+
+	return sprintf(buf, "%d\n", CLKDIV_FROM_REG(data->fan_cmd1));
+}
+
+static ssize_t set_fan_div(struct device *dev,
+			       struct device_attribute *da,
+			       const char *buf, size_t count)
+{
+	unsigned long val;
+
+	if (kstrtoul(buf, 10, &val) || do_set_fan_div(dev, val))
+		return -EINVAL;
+
+	return count;
+}
+
+
+/*
+ * Following documentation about hwmon's sysfs interface, a pwm1_enable node
+ * should accept followings:
+ *
+ *  0 : no fan speed control (i.e. fan at full speed)
+ *  1 : manual fan speed control enabled (use pwm[1-*]) (open-loop)
+ *  2+: automatic fan speed control enabled (use fan[1-*]_enable)(close-loop)
+ *
+ * but we do not accept 0 as "no-control" mode is not supported by g762,
+ * -EINVAL is returned in this case.
+ */
+static ssize_t get_pwm_enable(struct device *dev,
+			      struct device_attribute *da, char *buf)
+{
+	struct g762_data *data = g762_update_client(dev);
+	int fan_mode;
+
+	fan_mode = (data->fan_cmd1 & G762_REG_FAN_CMD1_FAN_MODE) ? 2 : 1;
+
+	return sprintf(buf, "%d\n", fan_mode);
+}
+
+static ssize_t set_pwm_enable(struct device *dev,
+			      struct device_attribute *da,
+			      const char *buf, size_t count)
+{
+	unsigned long val;
+
+	if (kstrtoul(buf, 10, &val) || do_set_pwm_enable(dev, val))
+		return -EINVAL;
+
+	return count;
+}
+
+
+/*
+ * Get/set the fan speed in open-loop mode using pwm1 sysfs file. Speed is
+ * given as a relative value from 0 to 255, where 255 is maximum speed. Note
+ * that this is done by writing directly to the chip's DAC, it won't change
+ * the closed loop speed set by fan1_target. Also note that due to rounding
+ * errors it is possible that you don't read back exactly the value you have
+ * set.
+ */
+static ssize_t get_pwm(struct device *dev, struct device_attribute *da,
+		       char *buf)
+{
+	struct g762_data *data = g762_update_client(dev);
+	int val;
+
+	mutex_lock(&data->update_lock);
+	if (data->fan_cmd1 & G762_REG_FAN_CMD1_FAN_MODE) { /* closed-loop */
+		val = PWM_FROM_CNT(data->set_cnt);
+	} else {                                            /* open-loop */
+		val = data->set_out;
+	}
+	mutex_unlock(&data->update_lock);
+
+	return sprintf(buf, "%d\n", val);
+}
+
+static ssize_t set_pwm(struct device *dev, struct device_attribute *da,
+		       const char *buf, size_t count)
+{
+	unsigned long val;
+
+	if (kstrtoul(buf, 10, &val) || do_set_pwm(dev, val))
+		return -EINVAL;
+
+	return count;
+}
+
+
+/*
+ * Get/set the fan speed in closed-loop mode using fan1_target sysfs file. Speed
+ * is given as a rpm value, then G762 will automatically regulate the fan speed
+ * using pulses from fan tachometer.
+ *
+ * Refer to rpm_from_cnt implementation to get info about count number
+ * calculation.
+ *
+ * Also note that due to rounding errors it is possible that you don't read
+ * back exactly the value you have set.
+ */
+static ssize_t get_fan_target(struct device *dev, struct device_attribute *da,
+			      char *buf)
+{
+	struct g762_data *data = g762_update_client(dev);
+	unsigned int rpm;
+	ssize_t err;
+
+	mutex_lock(&data->update_lock);
+	if (data->fan_cmd1 & G762_REG_FAN_CMD1_FAN_MODE) { /* closed-loop */
+		rpm = rpm_from_cnt(data->set_cnt, data->clk,
+				   PULSE_FROM_REG(data->fan_cmd1),
+				   CLKDIV_FROM_REG(data->fan_cmd1),
+				   GEARMODE_FROM_REG(data->fan_cmd2));
+		err = sprintf(buf, "%u\n", rpm);
+	} else {                                           /* open-loop */
+		err = -EINVAL;
+	}
+	mutex_unlock(&data->update_lock);
+
+	return err;
+}
+
+static ssize_t set_fan_target(struct device *dev, struct device_attribute *da,
+			      const char *buf, size_t count)
+{
+	unsigned long val;
+
+	if (kstrtoul(buf, 10, &val) || do_set_fan_target(dev, val))
+		return -EINVAL;
+
+	return count;
+}
+
+
+/* read function for fan1_fault sysfs file. */
+static ssize_t get_fan_failure(struct device *dev, struct device_attribute *da,
+			       char *buf)
+{
+	struct g762_data *data = g762_update_client(dev);
+	unsigned int val;
+
+	val = (data->fan_sta & G762_REG_FAN_STA_FAIL) ? 1 : 0;
+
+	return sprintf(buf, "%u\n", val);
+}
+
+
+/* read function for fan1_alarm sysfs file. */
+static ssize_t get_fan_ooc(struct device *dev, struct device_attribute *da,
+			   char *buf)
+{
+	struct g762_data *data = g762_update_client(dev);
+	unsigned int val;
+
+	/* ooc condition is enabled low */
+	val = (data->fan_sta & G762_REG_FAN_STA_OOC) ? 0 : 1;
+
+	return sprintf(buf, "%u\n", val);
+}
+
+
+static DEVICE_ATTR(pwm1, S_IWUSR | S_IRUGO,
+		   get_pwm, set_pwm);
+static DEVICE_ATTR(pwm1_mode, S_IWUSR | S_IRUGO,
+		   get_pwm_mode, set_pwm_mode);
+static DEVICE_ATTR(pwm1_enable, S_IWUSR | S_IRUGO,
+		   get_pwm_enable, set_pwm_enable);
+
+static DEVICE_ATTR(fan1_input, S_IRUGO,
+		   get_fan_rpm, NULL);
+static DEVICE_ATTR(fan1_alarm, S_IRUGO,
+		   get_fan_ooc, NULL);
+static DEVICE_ATTR(fan1_fault, S_IRUGO,
+		   get_fan_failure, NULL);
+static DEVICE_ATTR(fan1_target, S_IWUSR | S_IRUGO,
+		   get_fan_target, set_fan_target);
+static DEVICE_ATTR(fan1_div, S_IWUSR | S_IRUGO,
+		   get_fan_div, set_fan_div);
+
+/* Driver data */
+static struct attribute *g762_attributes[] = {
+	&dev_attr_fan1_input.attr,
+	&dev_attr_fan1_alarm.attr,
+	&dev_attr_fan1_fault.attr,
+	&dev_attr_fan1_target.attr,
+	&dev_attr_fan1_div.attr,
+	&dev_attr_pwm1.attr,
+	&dev_attr_pwm1_mode.attr,
+	&dev_attr_pwm1_enable.attr,
+	NULL
+};
+
+static const struct attribute_group g762_group = {
+	.attrs = g762_attributes,
+};
+
+static int g762_probe(struct i2c_client *client, const struct i2c_device_id *id)
+{
+	struct g762_data *data;
+	struct g762_config conf;
+	int err = 0;
+
+	if (!i2c_check_functionality(client->adapter,
+				     I2C_FUNC_SMBUS_BYTE_DATA)) {
+		err = -ENODEV;
+		goto out;
+	}
+
+	data = devm_kzalloc(&client->dev, sizeof(struct g762_data), GFP_KERNEL);
+	if (!data) {
+		err = -ENOMEM;
+		goto out;
+	}
+	i2c_set_clientdata(client, data);
+
+	data->client = client;
+	mutex_init(&data->update_lock);
+
+	/* Enable fan protection and fan fail detection by default */
+	do_fan_ooc_detection_toggle(&client->dev, 1);
+	do_fan_failure_detection_toggle(&client->dev, 1);
+
+	/*
+	 * Set default configuration values before passing the structure
+	 * to OF helpers to overload them using those provided by .dts
+	 * file (if any). Final config is then commited.
+	 */
+	g762_config_init(&conf);
+	g762_config_of_overload(client, &conf);
+	err = g762_config_commit(client, &conf);
+	if (err)
+		goto out;
+
+	/* Register sysfs hooks */
+	err = sysfs_create_group(&client->dev.kobj, &g762_group);
+	if (err)
+		goto out;
+
+	data->hwmon_dev = (struct device *)hwmon_device_register(&client->dev);
+	if (IS_ERR(data->hwmon_dev)) {
+		err = PTR_ERR(data->hwmon_dev);
+		sysfs_remove_group(&client->dev.kobj, &g762_group);
+		goto out;
+	}
+
+	dev_info(&data->client->dev, "device successfully initialized\n");
+
+ out:
+	return err;
+}
+
+static int g762_remove(struct i2c_client *client)
+{
+	struct g762_data *data = i2c_get_clientdata(client);
+
+	hwmon_device_unregister(data->hwmon_dev);
+	sysfs_remove_group(&client->dev.kobj, &g762_group);
+
+	dev_info(&data->client->dev, "device successfully removed\n");
+	return 0;
+}
+
+static struct i2c_driver g762_driver = {
+	.driver = {
+		.name = DRVNAME,
+		.owner = THIS_MODULE,
+		.of_match_table = of_match_ptr(g762_dt_match),
+	},
+	.probe	  = g762_probe,
+	.remove	  = g762_remove,
+	.id_table = g762_id,
+};
+
+module_i2c_driver(g762_driver);
+
+MODULE_AUTHOR("Olivier Mouchet <olivier.mouchet@gmail.com>");
+MODULE_DESCRIPTION("GMT G762 driver");
+MODULE_LICENSE("GPL");
