Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 643 insertions, 0 deletions

diff --git a/drivers/hwmon/max6639.c b/drivers/hwmon/max6639.c
new file mode 100644
index 0000000000..aa7f21ab23
--- /dev/null
+++ b/drivers/hwmon/max6639.c
@@ -0,0 +1,643 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * max6639.c - Support for Maxim MAX6639
+ *
+ * 2-Channel Temperature Monitor with Dual PWM Fan-Speed Controller
+ *
+ * Copyright (C) 2010, 2011 Roland Stigge <stigge@antcom.de>
+ *
+ * based on the initial MAX6639 support from semptian.net
+ * by He Changqing <hechangqing@semptian.com>
+ */
+
+#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/platform_data/max6639.h>
+
+/* Addresses to scan */
+static const unsigned short normal_i2c[] = { 0x2c, 0x2e, 0x2f, I2C_CLIENT_END };
+
+/* The MAX6639 registers, valid channel numbers: 0, 1 */
+#define MAX6639_REG_TEMP(ch)			(0x00 + (ch))
+#define MAX6639_REG_STATUS			0x02
+#define MAX6639_REG_OUTPUT_MASK			0x03
+#define MAX6639_REG_GCONFIG			0x04
+#define MAX6639_REG_TEMP_EXT(ch)		(0x05 + (ch))
+#define MAX6639_REG_ALERT_LIMIT(ch)		(0x08 + (ch))
+#define MAX6639_REG_OT_LIMIT(ch)		(0x0A + (ch))
+#define MAX6639_REG_THERM_LIMIT(ch)		(0x0C + (ch))
+#define MAX6639_REG_FAN_CONFIG1(ch)		(0x10 + (ch) * 4)
+#define MAX6639_REG_FAN_CONFIG2a(ch)		(0x11 + (ch) * 4)
+#define MAX6639_REG_FAN_CONFIG2b(ch)		(0x12 + (ch) * 4)
+#define MAX6639_REG_FAN_CONFIG3(ch)		(0x13 + (ch) * 4)
+#define MAX6639_REG_FAN_CNT(ch)			(0x20 + (ch))
+#define MAX6639_REG_TARGET_CNT(ch)		(0x22 + (ch))
+#define MAX6639_REG_FAN_PPR(ch)			(0x24 + (ch))
+#define MAX6639_REG_TARGTDUTY(ch)		(0x26 + (ch))
+#define MAX6639_REG_FAN_START_TEMP(ch)		(0x28 + (ch))
+#define MAX6639_REG_DEVID			0x3D
+#define MAX6639_REG_MANUID			0x3E
+#define MAX6639_REG_DEVREV			0x3F
+
+/* Register bits */
+#define MAX6639_GCONFIG_STANDBY			0x80
+#define MAX6639_GCONFIG_POR			0x40
+#define MAX6639_GCONFIG_DISABLE_TIMEOUT		0x20
+#define MAX6639_GCONFIG_CH2_LOCAL		0x10
+#define MAX6639_GCONFIG_PWM_FREQ_HI		0x08
+
+#define MAX6639_FAN_CONFIG1_PWM			0x80
+
+#define MAX6639_FAN_CONFIG3_THERM_FULL_SPEED	0x40
+
+static const int rpm_ranges[] = { 2000, 4000, 8000, 16000 };
+
+#define FAN_FROM_REG(val, rpm_range)	((val) == 0 || (val) == 255 ? \
+				0 : (rpm_ranges[rpm_range] * 30) / (val))
+#define TEMP_LIMIT_TO_REG(val)	clamp_val((val) / 1000, 0, 255)
+
+/*
+ * Client data (each client gets its own)
+ */
+struct max6639_data {
+	struct i2c_client *client;
+	struct mutex update_lock;
+	bool valid;		/* true if following fields are valid */
+	unsigned long last_updated;	/* In jiffies */
+
+	/* Register values sampled regularly */
+	u16 temp[2];		/* Temperature, in 1/8 C, 0..255 C */
+	bool temp_fault[2];	/* Detected temperature diode failure */
+	u8 fan[2];		/* Register value: TACH count for fans >=30 */
+	u8 status;		/* Detected channel alarms and fan failures */
+
+	/* Register values only written to */
+	u8 pwm[2];		/* Register value: Duty cycle 0..120 */
+	u8 temp_therm[2];	/* THERM Temperature, 0..255 C (->_max) */
+	u8 temp_alert[2];	/* ALERT Temperature, 0..255 C (->_crit) */
+	u8 temp_ot[2];		/* OT Temperature, 0..255 C (->_emergency) */
+
+	/* Register values initialized only once */
+	u8 ppr;			/* Pulses per rotation 0..3 for 1..4 ppr */
+	u8 rpm_range;		/* Index in above rpm_ranges table */
+
+	/* Optional regulator for FAN supply */
+	struct regulator *reg;
+};
+
+static struct max6639_data *max6639_update_device(struct device *dev)
+{
+	struct max6639_data *data = dev_get_drvdata(dev);
+	struct i2c_client *client = data->client;
+	struct max6639_data *ret = data;
+	int i;
+	int status_reg;
+
+	mutex_lock(&data->update_lock);
+
+	if (time_after(jiffies, data->last_updated + 2 * HZ) || !data->valid) {
+		int res;
+
+		dev_dbg(&client->dev, "Starting max6639 update\n");
+
+		status_reg = i2c_smbus_read_byte_data(client,
+						      MAX6639_REG_STATUS);
+		if (status_reg < 0) {
+			ret = ERR_PTR(status_reg);
+			goto abort;
+		}
+
+		data->status = status_reg;
+
+		for (i = 0; i < 2; i++) {
+			res = i2c_smbus_read_byte_data(client,
+					MAX6639_REG_FAN_CNT(i));
+			if (res < 0) {
+				ret = ERR_PTR(res);
+				goto abort;
+			}
+			data->fan[i] = res;
+
+			res = i2c_smbus_read_byte_data(client,
+					MAX6639_REG_TEMP_EXT(i));
+			if (res < 0) {
+				ret = ERR_PTR(res);
+				goto abort;
+			}
+			data->temp[i] = res >> 5;
+			data->temp_fault[i] = res & 0x01;
+
+			res = i2c_smbus_read_byte_data(client,
+					MAX6639_REG_TEMP(i));
+			if (res < 0) {
+				ret = ERR_PTR(res);
+				goto abort;
+			}
+			data->temp[i] |= res << 3;
+		}
+
+		data->last_updated = jiffies;
+		data->valid = true;
+	}
+abort:
+	mutex_unlock(&data->update_lock);
+
+	return ret;
+}
+
+static ssize_t temp_input_show(struct device *dev,
+			       struct device_attribute *dev_attr, char *buf)
+{
+	long temp;
+	struct max6639_data *data = max6639_update_device(dev);
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
+
+	if (IS_ERR(data))
+		return PTR_ERR(data);
+
+	temp = data->temp[attr->index] * 125;
+	return sprintf(buf, "%ld\n", temp);
+}
+
+static ssize_t temp_fault_show(struct device *dev,
+			       struct device_attribute *dev_attr, char *buf)
+{
+	struct max6639_data *data = max6639_update_device(dev);
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
+
+	if (IS_ERR(data))
+		return PTR_ERR(data);
+
+	return sprintf(buf, "%d\n", data->temp_fault[attr->index]);
+}
+
+static ssize_t temp_max_show(struct device *dev,
+			     struct device_attribute *dev_attr, char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
+	struct max6639_data *data = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%d\n", (data->temp_therm[attr->index] * 1000));
+}
+
+static ssize_t temp_max_store(struct device *dev,
+			      struct device_attribute *dev_attr,
+			      const char *buf, size_t count)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
+	struct max6639_data *data = dev_get_drvdata(dev);
+	struct i2c_client *client = data->client;
+	unsigned long val;
+	int res;
+
+	res = kstrtoul(buf, 10, &val);
+	if (res)
+		return res;
+
+	mutex_lock(&data->update_lock);
+	data->temp_therm[attr->index] = TEMP_LIMIT_TO_REG(val);
+	i2c_smbus_write_byte_data(client,
+				  MAX6639_REG_THERM_LIMIT(attr->index),
+				  data->temp_therm[attr->index]);
+	mutex_unlock(&data->update_lock);
+	return count;
+}
+
+static ssize_t temp_crit_show(struct device *dev,
+			      struct device_attribute *dev_attr, char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
+	struct max6639_data *data = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%d\n", (data->temp_alert[attr->index] * 1000));
+}
+
+static ssize_t temp_crit_store(struct device *dev,
+			       struct device_attribute *dev_attr,
+			       const char *buf, size_t count)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
+	struct max6639_data *data = dev_get_drvdata(dev);
+	struct i2c_client *client = data->client;
+	unsigned long val;
+	int res;
+
+	res = kstrtoul(buf, 10, &val);
+	if (res)
+		return res;
+
+	mutex_lock(&data->update_lock);
+	data->temp_alert[attr->index] = TEMP_LIMIT_TO_REG(val);
+	i2c_smbus_write_byte_data(client,
+				  MAX6639_REG_ALERT_LIMIT(attr->index),
+				  data->temp_alert[attr->index]);
+	mutex_unlock(&data->update_lock);
+	return count;
+}
+
+static ssize_t temp_emergency_show(struct device *dev,
+				   struct device_attribute *dev_attr,
+				   char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
+	struct max6639_data *data = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%d\n", (data->temp_ot[attr->index] * 1000));
+}
+
+static ssize_t temp_emergency_store(struct device *dev,
+				    struct device_attribute *dev_attr,
+				    const char *buf, size_t count)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
+	struct max6639_data *data = dev_get_drvdata(dev);
+	struct i2c_client *client = data->client;
+	unsigned long val;
+	int res;
+
+	res = kstrtoul(buf, 10, &val);
+	if (res)
+		return res;
+
+	mutex_lock(&data->update_lock);
+	data->temp_ot[attr->index] = TEMP_LIMIT_TO_REG(val);
+	i2c_smbus_write_byte_data(client,
+				  MAX6639_REG_OT_LIMIT(attr->index),
+				  data->temp_ot[attr->index]);
+	mutex_unlock(&data->update_lock);
+	return count;
+}
+
+static ssize_t pwm_show(struct device *dev, struct device_attribute *dev_attr,
+			char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
+	struct max6639_data *data = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%d\n", data->pwm[attr->index] * 255 / 120);
+}
+
+static ssize_t pwm_store(struct device *dev,
+			 struct device_attribute *dev_attr, const char *buf,
+			 size_t count)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
+	struct max6639_data *data = dev_get_drvdata(dev);
+	struct i2c_client *client = data->client;
+	unsigned long val;
+	int res;
+
+	res = kstrtoul(buf, 10, &val);
+	if (res)
+		return res;
+
+	val = clamp_val(val, 0, 255);
+
+	mutex_lock(&data->update_lock);
+	data->pwm[attr->index] = (u8)(val * 120 / 255);
+	i2c_smbus_write_byte_data(client,
+				  MAX6639_REG_TARGTDUTY(attr->index),
+				  data->pwm[attr->index]);
+	mutex_unlock(&data->update_lock);
+	return count;
+}
+
+static ssize_t fan_input_show(struct device *dev,
+			      struct device_attribute *dev_attr, char *buf)
+{
+	struct max6639_data *data = max6639_update_device(dev);
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
+
+	if (IS_ERR(data))
+		return PTR_ERR(data);
+
+	return sprintf(buf, "%d\n", FAN_FROM_REG(data->fan[attr->index],
+		       data->rpm_range));
+}
+
+static ssize_t alarm_show(struct device *dev,
+			  struct device_attribute *dev_attr, char *buf)
+{
+	struct max6639_data *data = max6639_update_device(dev);
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
+
+	if (IS_ERR(data))
+		return PTR_ERR(data);
+
+	return sprintf(buf, "%d\n", !!(data->status & (1 << attr->index)));
+}
+
+static SENSOR_DEVICE_ATTR_RO(temp1_input, temp_input, 0);
+static SENSOR_DEVICE_ATTR_RO(temp2_input, temp_input, 1);
+static SENSOR_DEVICE_ATTR_RO(temp1_fault, temp_fault, 0);
+static SENSOR_DEVICE_ATTR_RO(temp2_fault, temp_fault, 1);
+static SENSOR_DEVICE_ATTR_RW(temp1_max, temp_max, 0);
+static SENSOR_DEVICE_ATTR_RW(temp2_max, temp_max, 1);
+static SENSOR_DEVICE_ATTR_RW(temp1_crit, temp_crit, 0);
+static SENSOR_DEVICE_ATTR_RW(temp2_crit, temp_crit, 1);
+static SENSOR_DEVICE_ATTR_RW(temp1_emergency, temp_emergency, 0);
+static SENSOR_DEVICE_ATTR_RW(temp2_emergency, temp_emergency, 1);
+static SENSOR_DEVICE_ATTR_RW(pwm1, pwm, 0);
+static SENSOR_DEVICE_ATTR_RW(pwm2, pwm, 1);
+static SENSOR_DEVICE_ATTR_RO(fan1_input, fan_input, 0);
+static SENSOR_DEVICE_ATTR_RO(fan2_input, fan_input, 1);
+static SENSOR_DEVICE_ATTR_RO(fan1_fault, alarm, 1);
+static SENSOR_DEVICE_ATTR_RO(fan2_fault, alarm, 0);
+static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, alarm, 3);
+static SENSOR_DEVICE_ATTR_RO(temp2_max_alarm, alarm, 2);
+static SENSOR_DEVICE_ATTR_RO(temp1_crit_alarm, alarm, 7);
+static SENSOR_DEVICE_ATTR_RO(temp2_crit_alarm, alarm, 6);
+static SENSOR_DEVICE_ATTR_RO(temp1_emergency_alarm, alarm, 5);
+static SENSOR_DEVICE_ATTR_RO(temp2_emergency_alarm, alarm, 4);
+
+
+static struct attribute *max6639_attrs[] = {
+	&sensor_dev_attr_temp1_input.dev_attr.attr,
+	&sensor_dev_attr_temp2_input.dev_attr.attr,
+	&sensor_dev_attr_temp1_fault.dev_attr.attr,
+	&sensor_dev_attr_temp2_fault.dev_attr.attr,
+	&sensor_dev_attr_temp1_max.dev_attr.attr,
+	&sensor_dev_attr_temp2_max.dev_attr.attr,
+	&sensor_dev_attr_temp1_crit.dev_attr.attr,
+	&sensor_dev_attr_temp2_crit.dev_attr.attr,
+	&sensor_dev_attr_temp1_emergency.dev_attr.attr,
+	&sensor_dev_attr_temp2_emergency.dev_attr.attr,
+	&sensor_dev_attr_pwm1.dev_attr.attr,
+	&sensor_dev_attr_pwm2.dev_attr.attr,
+	&sensor_dev_attr_fan1_input.dev_attr.attr,
+	&sensor_dev_attr_fan2_input.dev_attr.attr,
+	&sensor_dev_attr_fan1_fault.dev_attr.attr,
+	&sensor_dev_attr_fan2_fault.dev_attr.attr,
+	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
+	&sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
+	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
+	&sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
+	&sensor_dev_attr_temp1_emergency_alarm.dev_attr.attr,
+	&sensor_dev_attr_temp2_emergency_alarm.dev_attr.attr,
+	NULL
+};
+ATTRIBUTE_GROUPS(max6639);
+
+/*
+ *  returns respective index in rpm_ranges table
+ *  1 by default on invalid range
+ */
+static int rpm_range_to_reg(int range)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(rpm_ranges); i++) {
+		if (rpm_ranges[i] == range)
+			return i;
+	}
+
+	return 1; /* default: 4000 RPM */
+}
+
+static int max6639_init_client(struct i2c_client *client,
+			       struct max6639_data *data)
+{
+	struct max6639_platform_data *max6639_info =
+		dev_get_platdata(&client->dev);
+	int i;
+	int rpm_range = 1; /* default: 4000 RPM */
+	int err;
+
+	/* Reset chip to default values, see below for GCONFIG setup */
+	err = i2c_smbus_write_byte_data(client, MAX6639_REG_GCONFIG,
+				  MAX6639_GCONFIG_POR);
+	if (err)
+		goto exit;
+
+	/* Fans pulse per revolution is 2 by default */
+	if (max6639_info && max6639_info->ppr > 0 &&
+			max6639_info->ppr < 5)
+		data->ppr = max6639_info->ppr;
+	else
+		data->ppr = 2;
+	data->ppr -= 1;
+
+	if (max6639_info)
+		rpm_range = rpm_range_to_reg(max6639_info->rpm_range);
+	data->rpm_range = rpm_range;
+
+	for (i = 0; i < 2; i++) {
+
+		/* Set Fan pulse per revolution */
+		err = i2c_smbus_write_byte_data(client,
+				MAX6639_REG_FAN_PPR(i),
+				data->ppr << 6);
+		if (err)
+			goto exit;
+
+		/* Fans config PWM, RPM */
+		err = i2c_smbus_write_byte_data(client,
+			MAX6639_REG_FAN_CONFIG1(i),
+			MAX6639_FAN_CONFIG1_PWM | rpm_range);
+		if (err)
+			goto exit;
+
+		/* Fans PWM polarity high by default */
+		if (max6639_info && max6639_info->pwm_polarity == 0)
+			err = i2c_smbus_write_byte_data(client,
+				MAX6639_REG_FAN_CONFIG2a(i), 0x00);
+		else
+			err = i2c_smbus_write_byte_data(client,
+				MAX6639_REG_FAN_CONFIG2a(i), 0x02);
+		if (err)
+			goto exit;
+
+		/*
+		 * /THERM full speed enable,
+		 * PWM frequency 25kHz, see also GCONFIG below
+		 */
+		err = i2c_smbus_write_byte_data(client,
+			MAX6639_REG_FAN_CONFIG3(i),
+			MAX6639_FAN_CONFIG3_THERM_FULL_SPEED | 0x03);
+		if (err)
+			goto exit;
+
+		/* Max. temp. 80C/90C/100C */
+		data->temp_therm[i] = 80;
+		data->temp_alert[i] = 90;
+		data->temp_ot[i] = 100;
+		err = i2c_smbus_write_byte_data(client,
+				MAX6639_REG_THERM_LIMIT(i),
+				data->temp_therm[i]);
+		if (err)
+			goto exit;
+		err = i2c_smbus_write_byte_data(client,
+				MAX6639_REG_ALERT_LIMIT(i),
+				data->temp_alert[i]);
+		if (err)
+			goto exit;
+		err = i2c_smbus_write_byte_data(client,
+				MAX6639_REG_OT_LIMIT(i), data->temp_ot[i]);
+		if (err)
+			goto exit;
+
+		/* PWM 120/120 (i.e. 100%) */
+		data->pwm[i] = 120;
+		err = i2c_smbus_write_byte_data(client,
+				MAX6639_REG_TARGTDUTY(i), data->pwm[i]);
+		if (err)
+			goto exit;
+	}
+	/* Start monitoring */
+	err = i2c_smbus_write_byte_data(client, MAX6639_REG_GCONFIG,
+		MAX6639_GCONFIG_DISABLE_TIMEOUT | MAX6639_GCONFIG_CH2_LOCAL |
+		MAX6639_GCONFIG_PWM_FREQ_HI);
+exit:
+	return err;
+}
+
+/* Return 0 if detection is successful, -ENODEV otherwise */
+static int max6639_detect(struct i2c_client *client,
+			  struct i2c_board_info *info)
+{
+	struct i2c_adapter *adapter = client->adapter;
+	int dev_id, manu_id;
+
+	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
+		return -ENODEV;
+
+	/* Actual detection via device and manufacturer ID */
+	dev_id = i2c_smbus_read_byte_data(client, MAX6639_REG_DEVID);
+	manu_id = i2c_smbus_read_byte_data(client, MAX6639_REG_MANUID);
+	if (dev_id != 0x58 || manu_id != 0x4D)
+		return -ENODEV;
+
+	strscpy(info->type, "max6639", I2C_NAME_SIZE);
+
+	return 0;
+}
+
+static void max6639_regulator_disable(void *data)
+{
+	regulator_disable(data);
+}
+
+static int max6639_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct max6639_data *data;
+	struct device *hwmon_dev;
+	int err;
+
+	data = devm_kzalloc(dev, sizeof(struct max6639_data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->client = client;
+
+	data->reg = devm_regulator_get_optional(dev, "fan");
+	if (IS_ERR(data->reg)) {
+		if (PTR_ERR(data->reg) != -ENODEV)
+			return PTR_ERR(data->reg);
+
+		data->reg = NULL;
+	} else {
+		/* Spin up fans */
+		err = regulator_enable(data->reg);
+		if (err) {
+			dev_err(dev, "Failed to enable fan supply: %d\n", err);
+			return err;
+		}
+		err = devm_add_action_or_reset(dev, max6639_regulator_disable,
+					       data->reg);
+		if (err) {
+			dev_err(dev, "Failed to register action: %d\n", err);
+			return err;
+		}
+	}
+
+	mutex_init(&data->update_lock);
+
+	/* Initialize the max6639 chip */
+	err = max6639_init_client(client, data);
+	if (err < 0)
+		return err;
+
+	hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
+							   data,
+							   max6639_groups);
+	return PTR_ERR_OR_ZERO(hwmon_dev);
+}
+
+static int max6639_suspend(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct max6639_data *data = dev_get_drvdata(dev);
+	int ret = i2c_smbus_read_byte_data(client, MAX6639_REG_GCONFIG);
+
+	if (ret < 0)
+		return ret;
+
+	if (data->reg)
+		regulator_disable(data->reg);
+
+	return i2c_smbus_write_byte_data(client,
+			MAX6639_REG_GCONFIG, ret | MAX6639_GCONFIG_STANDBY);
+}
+
+static int max6639_resume(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct max6639_data *data = dev_get_drvdata(dev);
+	int ret;
+
+	if (data->reg) {
+		ret = regulator_enable(data->reg);
+		if (ret) {
+			dev_err(dev, "Failed to enable fan supply: %d\n", ret);
+			return ret;
+		}
+	}
+
+	ret = i2c_smbus_read_byte_data(client, MAX6639_REG_GCONFIG);
+	if (ret < 0)
+		return ret;
+
+	return i2c_smbus_write_byte_data(client,
+			MAX6639_REG_GCONFIG, ret & ~MAX6639_GCONFIG_STANDBY);
+}
+
+static const struct i2c_device_id max6639_id[] = {
+	{"max6639", 0},
+	{ }
+};
+
+MODULE_DEVICE_TABLE(i2c, max6639_id);
+
+static DEFINE_SIMPLE_DEV_PM_OPS(max6639_pm_ops, max6639_suspend, max6639_resume);
+
+static const struct of_device_id max6639_of_match[] = {
+	{ .compatible = "maxim,max6639", },
+	{ },
+};
+
+static struct i2c_driver max6639_driver = {
+	.class = I2C_CLASS_HWMON,
+	.driver = {
+		   .name = "max6639",
+		   .pm = pm_sleep_ptr(&max6639_pm_ops),
+		   .of_match_table = max6639_of_match,
+		   },
+	.probe = max6639_probe,
+	.id_table = max6639_id,
+	.detect = max6639_detect,
+	.address_list = normal_i2c,
+};
+
+module_i2c_driver(max6639_driver);
+
+MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
+MODULE_DESCRIPTION("max6639 driver");
+MODULE_LICENSE("GPL");