hwmon: Driver for Maxim MAX6697 and compatibles

Add support for MAX6581, MAX6602, MAX6622, MAX6636, MAX6689, MAX6693,
MAX6694, MAX6697, MAX6698, and MAX6699 temperature sensors
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Jean Delvare <khali@linux-fr.org>

Documentation/devicetree/bindings/i2c/max6697.txt

+max6697 properties
+
+Required properties:
+- compatible:
+	Should be one of
+		maxim,max6581
+		maxim,max6602
+		maxim,max6622
+		maxim,max6636
+		maxim,max6689
+		maxim,max6693
+		maxim,max6694
+		maxim,max6697
+		maxim,max6698
+		maxim,max6699
+- reg: I2C address
+
+Optional properties:
+
+- smbus-timeout-disable
+	Set to disable SMBus timeout. If not specified, SMBus timeout will be
+	enabled.
+- extended-range-enable
+	Only valid for MAX6581. Set to enable extended temperature range.
+	Extended temperature will be disabled if not specified.
+- beta-compensation-enable
+	Only valid for MAX6693 and MX6694. Set to enable beta compensation on
+	remote temperature channel 1.
+	Beta compensation will be disabled if not specified.
+- alert-mask
+	Alert bit mask. Alert disabled for bits set.
+	Select bit 0 for local temperature, bit 1..7 for remote temperatures.
+	If not specified, alert will be enabled for all channels.
+- over-temperature-mask
+	Over-temperature bit mask. Over-temperature reporting disabled for
+	bits set.
+	Select bit 0 for local temperature, bit 1..7 for remote temperatures.
+	If not specified, over-temperature reporting will be enabled for all
+	channels.
+- resistance-cancellation
+	Boolean for all chips other than MAX6581. Set to enable resistance
+	cancellation on remote temperature channel 1.
+	For MAX6581, resistance cancellation enabled for all channels if
+	specified as boolean, otherwise as per bit mask specified.
+	Only supported for remote temperatures (bit 1..7).
+	If not specified, resistance cancellation will be disabled for all
+	channels.
+- transistor-ideality
+	For MAX6581 only. Two values; first is bit mask, second is ideality
+	select value as per MAX6581 data sheet. Select bit 1..7 for remote
+	channels.
+	Transistor ideality will be initialized to default (1.008) if not
+	specified.
+
+Example:
+
+temp-sensor@1a {
+	compatible = "maxim,max6697";
+	reg = <0x1a>;
+	smbus-timeout-disable;
+	resistance-cancellation;
+	alert-mask = <0x72>;
+	over-temperature-mask = <0x7f>;
+};

Documentation/hwmon/max6697

+Kernel driver max6697
+=====================
+
+Supported chips:
+  * Maxim MAX6581
+    Prefix: 'max6581'
+    Datasheet: http://datasheets.maximintegrated.com/en/ds/MAX6581.pdf
+  * Maxim MAX6602
+    Prefix: 'max6602'
+    Datasheet: http://datasheets.maximintegrated.com/en/ds/MAX6602.pdf
+  * Maxim MAX6622
+    Prefix: 'max6622'
+    Datasheet: http://datasheets.maximintegrated.com/en/ds/MAX6622.pdf
+  * Maxim MAX6636
+    Prefix: 'max6636'
+    Datasheet: http://datasheets.maximintegrated.com/en/ds/MAX6636.pdf
+  * Maxim MAX6689
+    Prefix: 'max6689'
+    Datasheet: http://datasheets.maximintegrated.com/en/ds/MAX6689.pdf
+  * Maxim MAX6693
+    Prefix: 'max6693'
+    Datasheet: http://datasheets.maximintegrated.com/en/ds/MAX6693.pdf
+  * Maxim MAX6694
+    Prefix: 'max6694'
+    Datasheet: http://datasheets.maximintegrated.com/en/ds/MAX6694.pdf
+  * Maxim MAX6697
+    Prefix: 'max6697'
+    Datasheet: http://datasheets.maximintegrated.com/en/ds/MAX6697.pdf
+  * Maxim MAX6698
+    Prefix: 'max6698'
+    Datasheet: http://datasheets.maximintegrated.com/en/ds/MAX6698.pdf
+  * Maxim MAX6699
+    Prefix: 'max6699'
+    Datasheet: http://datasheets.maximintegrated.com/en/ds/MAX6699.pdf
+
+Author:
+    Guenter Roeck <linux@roeck-us.net>
+
+Description
+-----------
+
+This driver implements support for several MAX6697 compatible temperature sensor
+chips. The chips support one local temperature sensor plus four, six, or seven
+remote temperature sensors. Remote temperature sensors are diode-connected
+thermal transitors, except for MAX6698 which supports three diode-connected
+thermal transistors plus three thermistors in addition to the local temperature
+sensor.
+
+The driver provides the following sysfs attributes. temp1 is the local (chip)
+temperature, temp[2..n] are remote temperatures. The actually supported
+per-channel attributes are chip type and channel dependent.
+
+tempX_input      RO temperature
+tempX_max        RW temperature maximum threshold
+tempX_max_alarm  RO temperature maximum threshold alarm
+tempX_crit       RW temperature critical threshold
+tempX_crit_alarm RO temperature critical threshold alarm
+tempX_fault      RO temperature diode fault (remote sensors only)

drivers/hwmon/Kconfig

@@ -854,6 +854,17 @@ config SENSORS_MAX6650
 	  This driver can also be built as a module.  If so, the module
 	  will be called max6650.
 
+config SENSORS_MAX6697
+	tristate "Maxim MAX6697 and compatibles"
+	depends on I2C
+	help
+	  If you say yes here you get support for MAX6581, MAX6602, MAX6622,
+	  MAX6636, MAX6689, MAX6693, MAX6694, MAX6697, MAX6698, and MAX6699
+	  temperature sensor chips.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called max6697.
+
 config SENSORS_MCP3021
 	tristate "Microchip MCP3021 and compatibles"
 	depends on I2C

drivers/hwmon/Makefile

@@ -99,6 +99,7 @@ obj-$(CONFIG_SENSORS_MAX197)	+= max197.o
 obj-$(CONFIG_SENSORS_MAX6639)	+= max6639.o
 obj-$(CONFIG_SENSORS_MAX6642)	+= max6642.o
 obj-$(CONFIG_SENSORS_MAX6650)	+= max6650.o
+obj-$(CONFIG_SENSORS_MAX6697)	+= max6697.o
 obj-$(CONFIG_SENSORS_MC13783_ADC)+= mc13783-adc.o
 obj-$(CONFIG_SENSORS_MCP3021)	+= mcp3021.o
 obj-$(CONFIG_SENSORS_NTC_THERMISTOR)	+= ntc_thermistor.o

drivers/hwmon/max6697.c

+/*
+ * Copyright (c) 2012 Guenter Roeck <linux@roeck-us.net>
+ *
+ * based on max1668.c
+ * Copyright (c) 2011 David George <david.george@ska.ac.za>
+ *
+ * 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.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/err.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+
+#include <linux/platform_data/max6697.h>
+
+enum chips { max6581, max6602, max6622, max6636, max6689, max6693, max6694,
+	     max6697, max6698, max6699 };
+
+/* Report local sensor as temp1 */
+
+static const u8 MAX6697_REG_TEMP[] = {
+			0x07, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x08 };
+static const u8 MAX6697_REG_TEMP_EXT[] = {
+			0x57, 0x09, 0x52, 0x53, 0x54, 0x55, 0x56, 0 };
+static const u8 MAX6697_REG_MAX[] = {
+			0x17, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x18 };
+static const u8 MAX6697_REG_CRIT[] = {
+			0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27 };
+
+/*
+ * Map device tree / platform data register bit map to chip bit map.
+ * Applies to alert register and over-temperature register.
+ */
+#define MAX6697_MAP_BITS(reg)	((((reg) & 0x7e) >> 1) | \
+				 (((reg) & 0x01) << 6) | ((reg) & 0x80))
+
+#define MAX6697_REG_STAT(n)		(0x44 + (n))
+
+#define MAX6697_REG_CONFIG		0x41
+#define MAX6581_CONF_EXTENDED		(1 << 1)
+#define MAX6693_CONF_BETA		(1 << 2)
+#define MAX6697_CONF_RESISTANCE		(1 << 3)
+#define MAX6697_CONF_TIMEOUT		(1 << 5)
+#define MAX6697_REG_ALERT_MASK		0x42
+#define MAX6697_REG_OVERT_MASK		0x43
+
+#define MAX6581_REG_RESISTANCE		0x4a
+#define MAX6581_REG_IDEALITY		0x4b
+#define MAX6581_REG_IDEALITY_SELECT	0x4c
+#define MAX6581_REG_OFFSET		0x4d
+#define MAX6581_REG_OFFSET_SELECT	0x4e
+
+#define MAX6697_CONV_TIME		156	/* ms per channel, worst case */
+
+struct max6697_chip_data {
+	int channels;
+	u32 have_ext;
+	u32 have_crit;
+	u32 have_fault;
+	u8 valid_conf;
+	const u8 *alarm_map;
+};
+
+struct max6697_data {
+	struct device *hwmon_dev;
+
+	enum chips type;
+	const struct max6697_chip_data *chip;
+
+	int update_interval;	/* in milli-seconds */
+	int temp_offset;	/* in degrees C */
+
+	struct mutex update_lock;
+	unsigned long last_updated;	/* In jiffies */
+	bool valid;		/* true if following fields are valid */
+
+	/* 1x local and up to 7x remote */
+	u8 temp[8][4];		/* [nr][0]=temp [1]=ext [2]=max [3]=crit */
+#define MAX6697_TEMP_INPUT	0
+#define MAX6697_TEMP_EXT	1
+#define MAX6697_TEMP_MAX	2
+#define MAX6697_TEMP_CRIT	3
+	u32 alarms;
+};
+
+/* Diode fault status bits on MAX6581 are right shifted by one bit */
+static const u8 max6581_alarm_map[] = {
+	 0, 0, 1, 2, 3, 4, 5, 6, 8, 9, 10, 11, 12, 13, 14, 15,
+	 16, 17, 18, 19, 20, 21, 22, 23 };
+
+static const struct max6697_chip_data max6697_chip_data[] = {
+	[max6581] = {
+		.channels = 8,
+		.have_crit = 0xff,
+		.have_ext = 0x7f,
+		.have_fault = 0xfe,
+		.valid_conf = MAX6581_CONF_EXTENDED | MAX6697_CONF_TIMEOUT,
+		.alarm_map = max6581_alarm_map,
+	},
+	[max6602] = {
+		.channels = 5,
+		.have_crit = 0x12,
+		.have_ext = 0x02,
+		.have_fault = 0x1e,
+		.valid_conf = MAX6697_CONF_RESISTANCE | MAX6697_CONF_TIMEOUT,
+	},
+	[max6622] = {
+		.channels = 5,
+		.have_crit = 0x12,
+		.have_ext = 0x02,
+		.have_fault = 0x1e,
+		.valid_conf = MAX6697_CONF_RESISTANCE | MAX6697_CONF_TIMEOUT,
+	},
+	[max6636] = {
+		.channels = 7,
+		.have_crit = 0x72,
+		.have_ext = 0x02,
+		.have_fault = 0x7e,
+		.valid_conf = MAX6697_CONF_RESISTANCE | MAX6697_CONF_TIMEOUT,
+	},
+	[max6689] = {
+		.channels = 7,
+		.have_crit = 0x72,
+		.have_ext = 0x02,
+		.have_fault = 0x7e,
+		.valid_conf = MAX6697_CONF_RESISTANCE | MAX6697_CONF_TIMEOUT,
+	},
+	[max6693] = {
+		.channels = 7,
+		.have_crit = 0x72,
+		.have_ext = 0x02,
+		.have_fault = 0x7e,
+		.valid_conf = MAX6697_CONF_RESISTANCE | MAX6693_CONF_BETA |
+		  MAX6697_CONF_TIMEOUT,
+	},
+	[max6694] = {
+		.channels = 5,
+		.have_crit = 0x12,
+		.have_ext = 0x02,
+		.have_fault = 0x1e,
+		.valid_conf = MAX6697_CONF_RESISTANCE | MAX6693_CONF_BETA |
+		  MAX6697_CONF_TIMEOUT,
+	},
+	[max6697] = {
+		.channels = 7,
+		.have_crit = 0x72,
+		.have_ext = 0x02,
+		.have_fault = 0x7e,
+		.valid_conf = MAX6697_CONF_RESISTANCE | MAX6697_CONF_TIMEOUT,
+	},
+	[max6698] = {
+		.channels = 7,
+		.have_crit = 0x72,
+		.have_ext = 0x02,
+		.have_fault = 0x0e,
+		.valid_conf = MAX6697_CONF_RESISTANCE | MAX6697_CONF_TIMEOUT,
+	},
+	[max6699] = {
+		.channels = 5,
+		.have_crit = 0x12,
+		.have_ext = 0x02,
+		.have_fault = 0x1e,
+		.valid_conf = MAX6697_CONF_RESISTANCE | MAX6697_CONF_TIMEOUT,
+	},
+};
+
+static struct max6697_data *max6697_update_device(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct max6697_data *data = i2c_get_clientdata(client);
+	struct max6697_data *ret = data;
+	int val;
+	int i;
+	u32 alarms;
+
+	mutex_lock(&data->update_lock);
+
+	if (data->valid &&
+	    !time_after(jiffies, data->last_updated
+			+ msecs_to_jiffies(data->update_interval)))
+		goto abort;
+
+	for (i = 0; i < data->chip->channels; i++) {
+		if (data->chip->have_ext & (1 << i)) {
+			val = i2c_smbus_read_byte_data(client,
+						       MAX6697_REG_TEMP_EXT[i]);
+			if (unlikely(val < 0)) {
+				ret = ERR_PTR(val);
+				goto abort;
+			}
+			data->temp[i][MAX6697_TEMP_EXT] = val;
+		}
+
+		val = i2c_smbus_read_byte_data(client, MAX6697_REG_TEMP[i]);
+		if (unlikely(val < 0)) {
+			ret = ERR_PTR(val);
+			goto abort;
+		}
+		data->temp[i][MAX6697_TEMP_INPUT] = val;
+
+		val = i2c_smbus_read_byte_data(client, MAX6697_REG_MAX[i]);
+		if (unlikely(val < 0)) {
+			ret = ERR_PTR(val);
+			goto abort;
+		}
+		data->temp[i][MAX6697_TEMP_MAX] = val;
+
+		if (data->chip->have_crit & (1 << i)) {
+			val = i2c_smbus_read_byte_data(client,
+						       MAX6697_REG_CRIT[i]);
+			if (unlikely(val < 0)) {
+				ret = ERR_PTR(val);
+				goto abort;
+			}
+			data->temp[i][MAX6697_TEMP_CRIT] = val;
+		}
+	}
+
+	alarms = 0;
+	for (i = 0; i < 3; i++) {
+		val = i2c_smbus_read_byte_data(client, MAX6697_REG_STAT(i));
+		if (unlikely(val < 0)) {
+			ret = ERR_PTR(val);
+			goto abort;
+		}
+		alarms = (alarms << 8) | val;
+	}
+	data->alarms = alarms;
+	data->last_updated = jiffies;
+	data->valid = true;
+abort:
+	mutex_unlock(&data->update_lock);
+
+	return ret;
+}
+
+static ssize_t show_temp_input(struct device *dev,
+			       struct device_attribute *devattr, char *buf)
+{
+	int index = to_sensor_dev_attr(devattr)->index;
+	struct max6697_data *data = max6697_update_device(dev);
+	int temp;
+
+	if (IS_ERR(data))
+		return PTR_ERR(data);
+
+	temp = (data->temp[index][MAX6697_TEMP_INPUT] - data->temp_offset) << 3;
+	temp |= data->temp[index][MAX6697_TEMP_EXT] >> 5;
+
+	return sprintf(buf, "%d\n", temp * 125);
+}
+
+static ssize_t show_temp(struct device *dev,
+			 struct device_attribute *devattr, char *buf)
+{
+	int nr = to_sensor_dev_attr_2(devattr)->nr;
+	int index = to_sensor_dev_attr_2(devattr)->index;
+	struct max6697_data *data = max6697_update_device(dev);
+	int temp;
+
+	if (IS_ERR(data))
+		return PTR_ERR(data);
+
+	temp = data->temp[nr][index];
+	temp -= data->temp_offset;
+
+	return sprintf(buf, "%d\n", temp * 1000);
+}
+
+static ssize_t show_alarm(struct device *dev, struct device_attribute *attr,
+			  char *buf)
+{
+	int index = to_sensor_dev_attr(attr)->index;
+	struct max6697_data *data = max6697_update_device(dev);
+
+	if (IS_ERR(data))
+		return PTR_ERR(data);
+
+	if (data->chip->alarm_map)
+		index = data->chip->alarm_map[index];
+
+	return sprintf(buf, "%u\n", (data->alarms >> index) & 0x1);
+}
+
+static ssize_t set_temp(struct device *dev,
+			struct device_attribute *devattr,
+			const char *buf, size_t count)
+{
+	int nr = to_sensor_dev_attr_2(devattr)->nr;
+	int index = to_sensor_dev_attr_2(devattr)->index;
+	struct i2c_client *client = to_i2c_client(dev);
+	struct max6697_data *data = i2c_get_clientdata(client);
+	long temp;
+	int ret;
+
+	ret = kstrtol(buf, 10, &temp);
+	if (ret < 0)
+		return ret;
+
+	mutex_lock(&data->update_lock);
+	temp = DIV_ROUND_CLOSEST(temp, 1000) + data->temp_offset;
+	temp = clamp_val(temp, 0, data->type == max6581 ? 255 : 127);
+	data->temp[nr][index] = temp;
+	ret = i2c_smbus_write_byte_data(client,
+					index == 2 ? MAX6697_REG_MAX[nr]
+						   : MAX6697_REG_CRIT[nr],
+					temp);
+	mutex_unlock(&data->update_lock);
+
+	return ret < 0 ? ret : count;
+}
+
+static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_input, NULL, 0);
+static SENSOR_DEVICE_ATTR_2(temp1_max, S_IRUGO | S_IWUSR, show_temp, set_temp,
+			    0, MAX6697_TEMP_MAX);
+static SENSOR_DEVICE_ATTR_2(temp1_crit, S_IRUGO | S_IWUSR, show_temp, set_temp,
+			    0, MAX6697_TEMP_CRIT);
+
+static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp_input, NULL, 1);
+static SENSOR_DEVICE_ATTR_2(temp2_max, S_IRUGO | S_IWUSR, show_temp, set_temp,
+			    1, MAX6697_TEMP_MAX);
+static SENSOR_DEVICE_ATTR_2(temp2_crit, S_IRUGO | S_IWUSR, show_temp, set_temp,
+			    1, MAX6697_TEMP_CRIT);
+
+static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_temp_input, NULL, 2);
+static SENSOR_DEVICE_ATTR_2(temp3_max, S_IRUGO | S_IWUSR, show_temp, set_temp,
+			    2, MAX6697_TEMP_MAX);
+static SENSOR_DEVICE_ATTR_2(temp3_crit, S_IRUGO | S_IWUSR, show_temp, set_temp,
+			    2, MAX6697_TEMP_CRIT);
+
+static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, show_temp_input, NULL, 3);
+static SENSOR_DEVICE_ATTR_2(temp4_max, S_IRUGO | S_IWUSR, show_temp, set_temp,
+			    3, MAX6697_TEMP_MAX);
+static SENSOR_DEVICE_ATTR_2(temp4_crit, S_IRUGO | S_IWUSR, show_temp, set_temp,
+			    3, MAX6697_TEMP_CRIT);
+
+static SENSOR_DEVICE_ATTR(temp5_input, S_IRUGO, show_temp_input, NULL, 4);
+static SENSOR_DEVICE_ATTR_2(temp5_max, S_IRUGO | S_IWUSR, show_temp, set_temp,
+			    4, MAX6697_TEMP_MAX);
+static SENSOR_DEVICE_ATTR_2(temp5_crit, S_IRUGO | S_IWUSR, show_temp, set_temp,
+			    4, MAX6697_TEMP_CRIT);
+
+static SENSOR_DEVICE_ATTR(temp6_input, S_IRUGO, show_temp_input, NULL, 5);
+static SENSOR_DEVICE_ATTR_2(temp6_max, S_IRUGO | S_IWUSR, show_temp, set_temp,
+			    5, MAX6697_TEMP_MAX);
+static SENSOR_DEVICE_ATTR_2(temp6_crit, S_IRUGO | S_IWUSR, show_temp, set_temp,
+			    5, MAX6697_TEMP_CRIT);
+
+static SENSOR_DEVICE_ATTR(temp7_input, S_IRUGO, show_temp_input, NULL, 6);
+static SENSOR_DEVICE_ATTR_2(temp7_max, S_IRUGO | S_IWUSR, show_temp, set_temp,
+			    6, MAX6697_TEMP_MAX);
+static SENSOR_DEVICE_ATTR_2(temp7_crit, S_IRUGO | S_IWUSR, show_temp, set_temp,
+			    6, MAX6697_TEMP_CRIT);
+
+static SENSOR_DEVICE_ATTR(temp8_input, S_IRUGO, show_temp_input, NULL, 7);
+static SENSOR_DEVICE_ATTR_2(temp8_max, S_IRUGO | S_IWUSR, show_temp, set_temp,
+			    7, MAX6697_TEMP_MAX);
+static SENSOR_DEVICE_ATTR_2(temp8_crit, S_IRUGO | S_IWUSR, show_temp, set_temp,
+			    7, MAX6697_TEMP_CRIT);
+
+static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 22);
+static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_alarm, NULL, 16);
+static SENSOR_DEVICE_ATTR(temp3_max_alarm, S_IRUGO, show_alarm, NULL, 17);
+static SENSOR_DEVICE_ATTR(temp4_max_alarm, S_IRUGO, show_alarm, NULL, 18);
+static SENSOR_DEVICE_ATTR(temp5_max_alarm, S_IRUGO, show_alarm, NULL, 19);
+static SENSOR_DEVICE_ATTR(temp6_max_alarm, S_IRUGO, show_alarm, NULL, 20);
+static SENSOR_DEVICE_ATTR(temp7_max_alarm, S_IRUGO, show_alarm, NULL, 21);
+static SENSOR_DEVICE_ATTR(temp8_max_alarm, S_IRUGO, show_alarm, NULL, 23);
+
+static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 14);
+static SENSOR_DEVICE_ATTR(temp2_crit_alarm, S_IRUGO, show_alarm, NULL, 8);
+static SENSOR_DEVICE_ATTR(temp3_crit_alarm, S_IRUGO, show_alarm, NULL, 9);
+static SENSOR_DEVICE_ATTR(temp4_crit_alarm, S_IRUGO, show_alarm, NULL, 10);
+static SENSOR_DEVICE_ATTR(temp5_crit_alarm, S_IRUGO, show_alarm, NULL, 11);
+static SENSOR_DEVICE_ATTR(temp6_crit_alarm, S_IRUGO, show_alarm, NULL, 12);
+static SENSOR_DEVICE_ATTR(temp7_crit_alarm, S_IRUGO, show_alarm, NULL, 13);
+static SENSOR_DEVICE_ATTR(temp8_crit_alarm, S_IRUGO, show_alarm, NULL, 15);
+
+static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_alarm, NULL, 1);
+static SENSOR_DEVICE_ATTR(temp3_fault, S_IRUGO, show_alarm, NULL, 2);
+static SENSOR_DEVICE_ATTR(temp4_fault, S_IRUGO, show_alarm, NULL, 3);
+static SENSOR_DEVICE_ATTR(temp5_fault, S_IRUGO, show_alarm, NULL, 4);
+static SENSOR_DEVICE_ATTR(temp6_fault, S_IRUGO, show_alarm, NULL, 5);
+static SENSOR_DEVICE_ATTR(temp7_fault, S_IRUGO, show_alarm, NULL, 6);
+static SENSOR_DEVICE_ATTR(temp8_fault, S_IRUGO, show_alarm, NULL, 7);
+
+static struct attribute *max6697_attributes[8][7] = {
+	{
+		&sensor_dev_attr_temp1_input.dev_attr.attr,
+		&sensor_dev_attr_temp1_max.dev_attr.attr,
+		&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
+		&sensor_dev_attr_temp1_crit.dev_attr.attr,
+		&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
+		NULL
+	}, {
+		&sensor_dev_attr_temp2_input.dev_attr.attr,
+		&sensor_dev_attr_temp2_max.dev_attr.attr,
+		&sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
+		&sensor_dev_attr_temp2_crit.dev_attr.attr,
+		&sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
+		&sensor_dev_attr_temp2_fault.dev_attr.attr,
+		NULL
+	}, {
+		&sensor_dev_attr_temp3_input.dev_attr.attr,
+		&sensor_dev_attr_temp3_max.dev_attr.attr,
+		&sensor_dev_attr_temp3_max_alarm.dev_attr.attr,
+		&sensor_dev_attr_temp3_crit.dev_attr.attr,
+		&sensor_dev_attr_temp3_crit_alarm.dev_attr.attr,
+		&sensor_dev_attr_temp3_fault.dev_attr.attr,
+		NULL
+	}, {
+		&sensor_dev_attr_temp4_input.dev_attr.attr,
+		&sensor_dev_attr_temp4_max.dev_attr.attr,
+		&sensor_dev_attr_temp4_max_alarm.dev_attr.attr,
+		&sensor_dev_attr_temp4_crit.dev_attr.attr,
+		&sensor_dev_attr_temp4_crit_alarm.dev_attr.attr,
+		&sensor_dev_attr_temp4_fault.dev_attr.attr,
+		NULL
+	}, {
+		&sensor_dev_attr_temp5_input.dev_attr.attr,
+		&sensor_dev_attr_temp5_max.dev_attr.attr,
+		&sensor_dev_attr_temp5_max_alarm.dev_attr.attr,
+		&sensor_dev_attr_temp5_crit.dev_attr.attr,
+		&sensor_dev_attr_temp5_crit_alarm.dev_attr.attr,
+		&sensor_dev_attr_temp5_fault.dev_attr.attr,
+		NULL
+	}, {
+		&sensor_dev_attr_temp6_input.dev_attr.attr,
+		&sensor_dev_attr_temp6_max.dev_attr.attr,
+		&sensor_dev_attr_temp6_max_alarm.dev_attr.attr,
+		&sensor_dev_attr_temp6_crit.dev_attr.attr,
+		&sensor_dev_attr_temp6_crit_alarm.dev_attr.attr,
+		&sensor_dev_attr_temp6_fault.dev_attr.attr,
+		NULL
+	}, {
+		&sensor_dev_attr_temp7_input.dev_attr.attr,
+		&sensor_dev_attr_temp7_max.dev_attr.attr,
+		&sensor_dev_attr_temp7_max_alarm.dev_attr.attr,
+		&sensor_dev_attr_temp7_crit.dev_attr.attr,
+		&sensor_dev_attr_temp7_crit_alarm.dev_attr.attr,
+		&sensor_dev_attr_temp7_fault.dev_attr.attr,
+		NULL
+	}, {
+		&sensor_dev_attr_temp8_input.dev_attr.attr,
+		&sensor_dev_attr_temp8_max.dev_attr.attr,
+		&sensor_dev_attr_temp8_max_alarm.dev_attr.attr,
+		&sensor_dev_attr_temp8_crit.dev_attr.attr,
+		&sensor_dev_attr_temp8_crit_alarm.dev_attr.attr,
+		&sensor_dev_attr_temp8_fault.dev_attr.attr,
+		NULL
+	}
+};
+
+static const struct attribute_group max6697_group[8] = {
+	{ .attrs = max6697_attributes[0] },
+	{ .attrs = max6697_attributes[1] },
+	{ .attrs = max6697_attributes[2] },
+	{ .attrs = max6697_attributes[3] },
+	{ .attrs = max6697_attributes[4] },
+	{ .attrs = max6697_attributes[5] },
+	{ .attrs = max6697_attributes[6] },
+	{ .attrs = max6697_attributes[7] },
+};
+
+static void max6697_get_config_of(struct device_node *node,
+				  struct max6697_platform_data *pdata)
+{
+	int len;
+	const __be32 *prop;
+
+	prop = of_get_property(node, "smbus-timeout-disable", &len);
+	if (prop)
+		pdata->smbus_timeout_disable = true;
+	prop = of_get_property(node, "extended-range-enable", &len);
+	if (prop)
+		pdata->extended_range_enable = true;
+	prop = of_get_property(node, "beta-compensation-enable", &len);
+	if (prop)
+		pdata->beta_compensation = true;
+	prop = of_get_property(node, "alert-mask", &len);
+	if (prop && len == sizeof(u32))
+		pdata->alert_mask = be32_to_cpu(prop[0]);
+	prop = of_get_property(node, "over-temperature-mask", &len);
+	if (prop && len == sizeof(u32))
+		pdata->over_temperature_mask = be32_to_cpu(prop[0]);
+	prop = of_get_property(node, "resistance-cancellation", &len);
+	if (prop) {
+		if (len == sizeof(u32))
+			pdata->resistance_cancellation = be32_to_cpu(prop[0]);
+		else
+			pdata->resistance_cancellation = 0xfe;
+	}
+	prop = of_get_property(node, "transistor-ideality", &len);
+	if (prop && len == 2 * sizeof(u32)) {
+			pdata->ideality_mask = be32_to_cpu(prop[0]);
+			pdata->ideality_value = be32_to_cpu(prop[1]);
+	}
+}
+
+static int max6697_init_chip(struct i2c_client *client)
+{
+	struct max6697_data *data = i2c_get_clientdata(client);
+	struct max6697_platform_data *pdata = dev_get_platdata(&client->dev);
+	struct max6697_platform_data p;
+	const struct max6697_chip_data *chip = data->chip;
+	int factor = chip->channels;
+	int ret, reg;
+
+	/*
+	 * Don't touch configuration if neither platform data nor OF
+	 * configuration was specified. If that is the case, use the
+	 * current chip configuration.
+	 */
+	if (!pdata && !client->dev.of_node) {
+		reg = i2c_smbus_read_byte_data(client, MAX6697_REG_CONFIG);
+		if (reg < 0)
+			return reg;
+		if (data->type == max6581) {
+			if (reg & MAX6581_CONF_EXTENDED)
+				data->temp_offset = 64;
+			reg = i2c_smbus_read_byte_data(client,
+						       MAX6581_REG_RESISTANCE);
+			if (reg < 0)
+				return reg;
+			factor += hweight8(reg);
+		} else {
+			if (reg & MAX6697_CONF_RESISTANCE)
+				factor++;
+		}
+		goto done;
+	}
+
+	if (client->dev.of_node) {
+		memset(&p, 0, sizeof(p));
+		max6697_get_config_of(client->dev.of_node, &p);
+		pdata = &p;
+	}
+
+	reg = 0;
+	if (pdata->smbus_timeout_disable &&
+	    (chip->valid_conf & MAX6697_CONF_TIMEOUT)) {
+		reg |= MAX6697_CONF_TIMEOUT;
+	}
+	if (pdata->extended_range_enable &&
+	    (chip->valid_conf & MAX6581_CONF_EXTENDED)) {
+		reg |= MAX6581_CONF_EXTENDED;
+		data->temp_offset = 64;
+	}
+	if (pdata->resistance_cancellation &&
+	    (chip->valid_conf & MAX6697_CONF_RESISTANCE)) {
+		reg |= MAX6697_CONF_RESISTANCE;
+		factor++;
+	}
+	if (pdata->beta_compensation &&
+	    (chip->valid_conf & MAX6693_CONF_BETA)) {
+		reg |= MAX6693_CONF_BETA;
+	}
+
+	ret = i2c_smbus_write_byte_data(client, MAX6697_REG_CONFIG, reg);
+	if (ret < 0)
+		return ret;
+
+	ret = i2c_smbus_write_byte_data(client, MAX6697_REG_ALERT_MASK,
+					MAX6697_MAP_BITS(pdata->alert_mask));
+	if (ret < 0)
+		return ret;
+
+	ret = i2c_smbus_write_byte_data(client, MAX6697_REG_OVERT_MASK,
+				MAX6697_MAP_BITS(pdata->over_temperature_mask));
+	if (ret < 0)
+		return ret;
+
+	if (data->type == max6581) {
+		factor += hweight8(pdata->resistance_cancellation >> 1);
+		ret = i2c_smbus_write_byte_data(client, MAX6581_REG_RESISTANCE,
+					pdata->resistance_cancellation >> 1);
+		if (ret < 0)
+			return ret;
+		ret = i2c_smbus_write_byte_data(client, MAX6581_REG_IDEALITY,
+						pdata->ideality_mask >> 1);
+		if (ret < 0)
+			return ret;
+		ret = i2c_smbus_write_byte_data(client,
+						MAX6581_REG_IDEALITY_SELECT,
+						pdata->ideality_value);
+		if (ret < 0)
+			return ret;
+	}
+done:
+	data->update_interval = factor * MAX6697_CONV_TIME;
+	return 0;
+}
+
+static void max6697_remove_files(struct i2c_client *client)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(max6697_group); i++)
+		sysfs_remove_group(&client->dev.kobj, &max6697_group[i]);
+}
+
+static int max6697_probe(struct i2c_client *client,
+			 const struct i2c_device_id *id)
+{
+	struct i2c_adapter *adapter = client->adapter;
+	struct device *dev = &client->dev;
+	struct max6697_data *data;
+	int i, err;
+
+	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
+		return -ENODEV;
+
+	data = devm_kzalloc(dev, sizeof(struct max6697_data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->type = id->driver_data;
+	data->chip = &max6697_chip_data[data->type];
+
+	i2c_set_clientdata(client, data);
+	mutex_init(&data->update_lock);
+
+	err = max6697_init_chip(client);
+	if (err)
+		return err;
+
+	for (i = 0; i < data->chip->channels; i++) {
+		err = sysfs_create_file(&dev->kobj,
+					max6697_attributes[i][0]);
+		if (err)
+			goto error;
+		err = sysfs_create_file(&dev->kobj,
+					max6697_attributes[i][1]);
+		if (err)
+			goto error;
+		err = sysfs_create_file(&dev->kobj,
+					max6697_attributes[i][2]);
+		if (err)
+			goto error;
+
+		if (data->chip->have_crit & (1 << i)) {
+			err = sysfs_create_file(&dev->kobj,
+						max6697_attributes[i][3]);
+			if (err)
+				goto error;
+			err = sysfs_create_file(&dev->kobj,
+						max6697_attributes[i][4]);
+			if (err)
+				goto error;
+		}
+		if (data->chip->have_fault & (1 << i)) {
+			err = sysfs_create_file(&dev->kobj,
+						max6697_attributes[i][5]);
+			if (err)
+				goto error;
+		}
+	}
+
+	data->hwmon_dev = hwmon_device_register(dev);
+	if (IS_ERR(data->hwmon_dev)) {
+		err = PTR_ERR(data->hwmon_dev);
+		goto error;
+	}
+
+	return 0;
+
+error:
+	max6697_remove_files(client);
+	return err;
+}
+
+static int max6697_remove(struct i2c_client *client)
+{
+	struct max6697_data *data = i2c_get_clientdata(client);
+
+	hwmon_device_unregister(data->hwmon_dev);
+	max6697_remove_files(client);
+
+	return 0;
+}
+
+static const struct i2c_device_id max6697_id[] = {
+	{ "max6581", max6581 },
+	{ "max6602", max6602 },
+	{ "max6622", max6622 },
+	{ "max6636", max6636 },
+	{ "max6689", max6689 },
+	{ "max6693", max6693 },
+	{ "max6694", max6694 },
+	{ "max6697", max6697 },
+	{ "max6698", max6698 },
+	{ "max6699", max6699 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, max6697_id);
+
+static struct i2c_driver max6697_driver = {
+	.class = I2C_CLASS_HWMON,
+	.driver = {
+		.name	= "max6697",
+	},
+	.probe = max6697_probe,
+	.remove	= max6697_remove,
+	.id_table = max6697_id,
+};
+
+module_i2c_driver(max6697_driver);
+
+MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>");
+MODULE_DESCRIPTION("MAX6697 temperature sensor driver");
+MODULE_LICENSE("GPL");

include/linux/platform_data/max6697.h

+/*
+ * max6697.h
+ *     Copyright (c) 2012 Guenter Roeck <linux@roeck-us.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef MAX6697_H
+#define MAX6697_H
+
+#include <linux/types.h>
+
+/*
+ * For all bit masks:
+ * bit 0:    local temperature
+ * bit 1..7: remote temperatures
+ */
+struct max6697_platform_data {
+	bool smbus_timeout_disable;	/* set to disable SMBus timeouts */
+	bool extended_range_enable;	/* set to enable extended temp range */
+	bool beta_compensation;		/* set to enable beta compensation */
+	u8 alert_mask;			/* set bit to 1 to disable alert */
+	u8 over_temperature_mask;	/* set bit to 1 to disable */
+	u8 resistance_cancellation;	/* set bit to 0 to disable
+					 * bit mask for MAX6581,
+					 * boolean for other chips
+					 */
+	u8 ideality_mask;		/* set bit to 0 to disable */
+	u8 ideality_value;		/* transistor ideality as per
+					 * MAX6581 datasheet
+					 */
+};
+
+#endif /* MAX6697_H */