v4.19.13 snapshot.
diff --git a/drivers/hwmon/lm83.c b/drivers/hwmon/lm83.c
new file mode 100644
index 0000000..cbfd0bb
--- /dev/null
+++ b/drivers/hwmon/lm83.c
@@ -0,0 +1,389 @@
+/*
+ * lm83.c - Part of lm_sensors, Linux kernel modules for hardware
+ *          monitoring
+ * Copyright (C) 2003-2009  Jean Delvare <jdelvare@suse.de>
+ *
+ * Heavily inspired from the lm78, lm75 and adm1021 drivers. The LM83 is
+ * a sensor chip made by National Semiconductor. It reports up to four
+ * temperatures (its own plus up to three external ones) with a 1 deg
+ * resolution and a 3-4 deg accuracy. Complete datasheet can be obtained
+ * from National's website at:
+ *   http://www.national.com/pf/LM/LM83.html
+ * Since the datasheet omits to give the chip stepping code, I give it
+ * here: 0x03 (at register 0xff).
+ *
+ * Also supports the LM82 temp sensor, which is basically a stripped down
+ * model of the LM83.  Datasheet is here:
+ * http://www.national.com/pf/LM/LM82.html
+ *
+ * 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.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/jiffies.h>
+#include <linux/i2c.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/hwmon.h>
+#include <linux/err.h>
+#include <linux/mutex.h>
+#include <linux/sysfs.h>
+
+/*
+ * Addresses to scan
+ * Address is selected using 2 three-level pins, resulting in 9 possible
+ * addresses.
+ */
+
+static const unsigned short normal_i2c[] = {
+	0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b, 0x4c, 0x4d, 0x4e, I2C_CLIENT_END };
+
+enum chips { lm83, lm82 };
+
+/*
+ * The LM83 registers
+ * Manufacturer ID is 0x01 for National Semiconductor.
+ */
+
+#define LM83_REG_R_MAN_ID		0xFE
+#define LM83_REG_R_CHIP_ID		0xFF
+#define LM83_REG_R_CONFIG		0x03
+#define LM83_REG_W_CONFIG		0x09
+#define LM83_REG_R_STATUS1		0x02
+#define LM83_REG_R_STATUS2		0x35
+#define LM83_REG_R_LOCAL_TEMP		0x00
+#define LM83_REG_R_LOCAL_HIGH		0x05
+#define LM83_REG_W_LOCAL_HIGH		0x0B
+#define LM83_REG_R_REMOTE1_TEMP		0x30
+#define LM83_REG_R_REMOTE1_HIGH		0x38
+#define LM83_REG_W_REMOTE1_HIGH		0x50
+#define LM83_REG_R_REMOTE2_TEMP		0x01
+#define LM83_REG_R_REMOTE2_HIGH		0x07
+#define LM83_REG_W_REMOTE2_HIGH		0x0D
+#define LM83_REG_R_REMOTE3_TEMP		0x31
+#define LM83_REG_R_REMOTE3_HIGH		0x3A
+#define LM83_REG_W_REMOTE3_HIGH		0x52
+#define LM83_REG_R_TCRIT		0x42
+#define LM83_REG_W_TCRIT		0x5A
+
+/*
+ * Conversions and various macros
+ * The LM83 uses signed 8-bit values with LSB = 1 degree Celsius.
+ */
+
+#define TEMP_FROM_REG(val)	((val) * 1000)
+#define TEMP_TO_REG(val)	((val) <= -128000 ? -128 : \
+				 (val) >= 127000 ? 127 : \
+				 (val) < 0 ? ((val) - 500) / 1000 : \
+				 ((val) + 500) / 1000)
+
+static const u8 LM83_REG_R_TEMP[] = {
+	LM83_REG_R_LOCAL_TEMP,
+	LM83_REG_R_REMOTE1_TEMP,
+	LM83_REG_R_REMOTE2_TEMP,
+	LM83_REG_R_REMOTE3_TEMP,
+	LM83_REG_R_LOCAL_HIGH,
+	LM83_REG_R_REMOTE1_HIGH,
+	LM83_REG_R_REMOTE2_HIGH,
+	LM83_REG_R_REMOTE3_HIGH,
+	LM83_REG_R_TCRIT,
+};
+
+static const u8 LM83_REG_W_HIGH[] = {
+	LM83_REG_W_LOCAL_HIGH,
+	LM83_REG_W_REMOTE1_HIGH,
+	LM83_REG_W_REMOTE2_HIGH,
+	LM83_REG_W_REMOTE3_HIGH,
+	LM83_REG_W_TCRIT,
+};
+
+/*
+ * Client data (each client gets its own)
+ */
+
+struct lm83_data {
+	struct i2c_client *client;
+	const struct attribute_group *groups[3];
+	struct mutex update_lock;
+	char valid; /* zero until following fields are valid */
+	unsigned long last_updated; /* in jiffies */
+
+	/* registers values */
+	s8 temp[9];	/* 0..3: input 1-4,
+			   4..7: high limit 1-4,
+			   8   : critical limit */
+	u16 alarms; /* bitvector, combined */
+};
+
+static struct lm83_data *lm83_update_device(struct device *dev)
+{
+	struct lm83_data *data = dev_get_drvdata(dev);
+	struct i2c_client *client = data->client;
+
+	mutex_lock(&data->update_lock);
+
+	if (time_after(jiffies, data->last_updated + HZ * 2) || !data->valid) {
+		int nr;
+
+		dev_dbg(&client->dev, "Updating lm83 data.\n");
+		for (nr = 0; nr < 9; nr++) {
+			data->temp[nr] =
+			    i2c_smbus_read_byte_data(client,
+			    LM83_REG_R_TEMP[nr]);
+		}
+		data->alarms =
+		    i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS1)
+		    + (i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS2)
+		    << 8);
+
+		data->last_updated = jiffies;
+		data->valid = 1;
+	}
+
+	mutex_unlock(&data->update_lock);
+
+	return data;
+}
+
+/*
+ * Sysfs stuff
+ */
+
+static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
+			 char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct lm83_data *data = lm83_update_device(dev);
+	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[attr->index]));
+}
+
+static ssize_t set_temp(struct device *dev, struct device_attribute *devattr,
+			const char *buf, size_t count)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct lm83_data *data = dev_get_drvdata(dev);
+	struct i2c_client *client = data->client;
+	long val;
+	int nr = attr->index;
+	int err;
+
+	err = kstrtol(buf, 10, &val);
+	if (err < 0)
+		return err;
+
+	mutex_lock(&data->update_lock);
+	data->temp[nr] = TEMP_TO_REG(val);
+	i2c_smbus_write_byte_data(client, LM83_REG_W_HIGH[nr - 4],
+				  data->temp[nr]);
+	mutex_unlock(&data->update_lock);
+	return count;
+}
+
+static ssize_t alarms_show(struct device *dev, struct device_attribute *dummy,
+			   char *buf)
+{
+	struct lm83_data *data = lm83_update_device(dev);
+	return sprintf(buf, "%d\n", data->alarms);
+}
+
+static ssize_t show_alarm(struct device *dev, struct device_attribute
+			  *devattr, char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct lm83_data *data = lm83_update_device(dev);
+	int bitnr = attr->index;
+
+	return sprintf(buf, "%d\n", (data->alarms >> bitnr) & 1);
+}
+
+static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
+static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp, NULL, 1);
+static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_temp, NULL, 2);
+static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, show_temp, NULL, 3);
+static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp,
+	set_temp, 4);
+static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp,
+	set_temp, 5);
+static SENSOR_DEVICE_ATTR(temp3_max, S_IWUSR | S_IRUGO, show_temp,
+	set_temp, 6);
+static SENSOR_DEVICE_ATTR(temp4_max, S_IWUSR | S_IRUGO, show_temp,
+	set_temp, 7);
+static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO, show_temp, NULL, 8);
+static SENSOR_DEVICE_ATTR(temp2_crit, S_IRUGO, show_temp, NULL, 8);
+static SENSOR_DEVICE_ATTR(temp3_crit, S_IWUSR | S_IRUGO, show_temp,
+	set_temp, 8);
+static SENSOR_DEVICE_ATTR(temp4_crit, S_IRUGO, show_temp, NULL, 8);
+
+/* Individual alarm files */
+static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 0);
+static SENSOR_DEVICE_ATTR(temp3_crit_alarm, S_IRUGO, show_alarm, NULL, 1);
+static SENSOR_DEVICE_ATTR(temp3_fault, S_IRUGO, show_alarm, NULL, 2);
+static SENSOR_DEVICE_ATTR(temp3_max_alarm, S_IRUGO, show_alarm, NULL, 4);
+static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 6);
+static SENSOR_DEVICE_ATTR(temp2_crit_alarm, S_IRUGO, show_alarm, NULL, 8);
+static SENSOR_DEVICE_ATTR(temp4_crit_alarm, S_IRUGO, show_alarm, NULL, 9);
+static SENSOR_DEVICE_ATTR(temp4_fault, S_IRUGO, show_alarm, NULL, 10);
+static SENSOR_DEVICE_ATTR(temp4_max_alarm, S_IRUGO, show_alarm, NULL, 12);
+static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_alarm, NULL, 13);
+static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_alarm, NULL, 15);
+/* Raw alarm file for compatibility */
+static DEVICE_ATTR_RO(alarms);
+
+static struct attribute *lm83_attributes[] = {
+	&sensor_dev_attr_temp1_input.dev_attr.attr,
+	&sensor_dev_attr_temp3_input.dev_attr.attr,
+	&sensor_dev_attr_temp1_max.dev_attr.attr,
+	&sensor_dev_attr_temp3_max.dev_attr.attr,
+	&sensor_dev_attr_temp1_crit.dev_attr.attr,
+	&sensor_dev_attr_temp3_crit.dev_attr.attr,
+
+	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
+	&sensor_dev_attr_temp3_crit_alarm.dev_attr.attr,
+	&sensor_dev_attr_temp3_fault.dev_attr.attr,
+	&sensor_dev_attr_temp3_max_alarm.dev_attr.attr,
+	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
+	&dev_attr_alarms.attr,
+	NULL
+};
+
+static const struct attribute_group lm83_group = {
+	.attrs = lm83_attributes,
+};
+
+static struct attribute *lm83_attributes_opt[] = {
+	&sensor_dev_attr_temp2_input.dev_attr.attr,
+	&sensor_dev_attr_temp4_input.dev_attr.attr,
+	&sensor_dev_attr_temp2_max.dev_attr.attr,
+	&sensor_dev_attr_temp4_max.dev_attr.attr,
+	&sensor_dev_attr_temp2_crit.dev_attr.attr,
+	&sensor_dev_attr_temp4_crit.dev_attr.attr,
+
+	&sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
+	&sensor_dev_attr_temp4_crit_alarm.dev_attr.attr,
+	&sensor_dev_attr_temp4_fault.dev_attr.attr,
+	&sensor_dev_attr_temp4_max_alarm.dev_attr.attr,
+	&sensor_dev_attr_temp2_fault.dev_attr.attr,
+	&sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
+	NULL
+};
+
+static const struct attribute_group lm83_group_opt = {
+	.attrs = lm83_attributes_opt,
+};
+
+/*
+ * Real code
+ */
+
+/* Return 0 if detection is successful, -ENODEV otherwise */
+static int lm83_detect(struct i2c_client *new_client,
+		       struct i2c_board_info *info)
+{
+	struct i2c_adapter *adapter = new_client->adapter;
+	const char *name;
+	u8 man_id, chip_id;
+
+	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
+		return -ENODEV;
+
+	/* Detection */
+	if ((i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS1) & 0xA8) ||
+	    (i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS2) & 0x48) ||
+	    (i2c_smbus_read_byte_data(new_client, LM83_REG_R_CONFIG) & 0x41)) {
+		dev_dbg(&adapter->dev, "LM83 detection failed at 0x%02x\n",
+			new_client->addr);
+		return -ENODEV;
+	}
+
+	/* Identification */
+	man_id = i2c_smbus_read_byte_data(new_client, LM83_REG_R_MAN_ID);
+	if (man_id != 0x01)	/* National Semiconductor */
+		return -ENODEV;
+
+	chip_id = i2c_smbus_read_byte_data(new_client, LM83_REG_R_CHIP_ID);
+	switch (chip_id) {
+	case 0x03:
+		name = "lm83";
+		break;
+	case 0x01:
+		name = "lm82";
+		break;
+	default:
+		/* identification failed */
+		dev_info(&adapter->dev,
+			 "Unsupported chip (man_id=0x%02X, chip_id=0x%02X)\n",
+			 man_id, chip_id);
+		return -ENODEV;
+	}
+
+	strlcpy(info->type, name, I2C_NAME_SIZE);
+
+	return 0;
+}
+
+static int lm83_probe(struct i2c_client *new_client,
+		      const struct i2c_device_id *id)
+{
+	struct device *hwmon_dev;
+	struct lm83_data *data;
+
+	data = devm_kzalloc(&new_client->dev, sizeof(struct lm83_data),
+			    GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->client = new_client;
+	mutex_init(&data->update_lock);
+
+	/*
+	 * Register sysfs hooks
+	 * The LM82 can only monitor one external diode which is
+	 * at the same register as the LM83 temp3 entry - so we
+	 * declare 1 and 3 common, and then 2 and 4 only for the LM83.
+	 */
+	data->groups[0] = &lm83_group;
+	if (id->driver_data == lm83)
+		data->groups[1] = &lm83_group_opt;
+
+	hwmon_dev = devm_hwmon_device_register_with_groups(&new_client->dev,
+							   new_client->name,
+							   data, data->groups);
+	return PTR_ERR_OR_ZERO(hwmon_dev);
+}
+
+/*
+ * Driver data (common to all clients)
+ */
+
+static const struct i2c_device_id lm83_id[] = {
+	{ "lm83", lm83 },
+	{ "lm82", lm82 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, lm83_id);
+
+static struct i2c_driver lm83_driver = {
+	.class		= I2C_CLASS_HWMON,
+	.driver = {
+		.name	= "lm83",
+	},
+	.probe		= lm83_probe,
+	.id_table	= lm83_id,
+	.detect		= lm83_detect,
+	.address_list	= normal_i2c,
+};
+
+module_i2c_driver(lm83_driver);
+
+MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>");
+MODULE_DESCRIPTION("LM83 driver");
+MODULE_LICENSE("GPL");