hwmon: driver for SMM665 Six-Channel Active DC Output Controller/Monitor

This driver adds support for the monitoring features of the Summit
Microelectronics SMM665 Six-Channel Active DC Output Controller/Monitor.

Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

5 files changed, 923 insertions, 0 deletions

diff --git a/Documentation/hwmon/smm665 b/Documentation/hwmon/smm665
new file mode 100644
index 00000000000..3820fc9ca52
--- /dev/null
+++ b/Documentation/hwmon/smm665
@@ -0,0 +1,157 @@
+Kernel driver smm665
+====================
+
+Supported chips:
+  * Summit Microelectronics SMM465
+    Prefix: 'smm465'
+    Addresses scanned: -
+    Datasheet:
+      http://www.summitmicro.com/prod_select/summary/SMM465/SMM465DS.pdf
+  * Summit Microelectronics SMM665, SMM665B
+    Prefix: 'smm665'
+    Addresses scanned: -
+    Datasheet:
+      http://www.summitmicro.com/prod_select/summary/SMM665/SMM665B_2089_20.pdf
+  * Summit Microelectronics SMM665C
+    Prefix: 'smm665c'
+    Addresses scanned: -
+    Datasheet:
+      http://www.summitmicro.com/prod_select/summary/SMM665C/SMM665C_2125.pdf
+  * Summit Microelectronics SMM764
+    Prefix: 'smm764'
+    Addresses scanned: -
+    Datasheet:
+      http://www.summitmicro.com/prod_select/summary/SMM764/SMM764_2098.pdf
+  * Summit Microelectronics SMM766, SMM766B
+    Prefix: 'smm766'
+    Addresses scanned: -
+    Datasheets:
+      http://www.summitmicro.com/prod_select/summary/SMM766/SMM766_2086.pdf
+      http://www.summitmicro.com/prod_select/summary/SMM766B/SMM766B_2122.pdf
+
+Author: Guenter Roeck <guenter.roeck@ericsson.com>
+
+
+Module Parameters
+-----------------
+
+* vref: int
+  Default: 1250 (mV)
+  Reference voltage on VREF_ADC pin in mV. It should not be necessary to set
+  this parameter unless a non-default reference voltage is used.
+
+
+Description
+-----------
+
+[From datasheet] The SMM665 is an Active DC Output power supply Controller
+that monitors, margins and cascade sequences power. The part monitors six
+power supply channels as well as VDD, 12V input, two general-purpose analog
+inputs and an internal temperature sensor using a 10-bit ADC.
+
+Each monitored channel has its own high and low limits, plus a critical
+limit.
+
+Support for SMM465, SMM764, and SMM766 has been implemented but is untested.
+
+
+Usage Notes
+-----------
+
+This driver does not probe for devices, since there is no register which
+can be safely used to identify the chip. You will have to instantiate
+the devices explicitly. When instantiating the device, you have to specify
+its configuration register address.
+
+Example: the following will load the driver for an SMM665 at address 0x57
+on I2C bus #1:
+$ modprobe smm665
+$ echo smm665 0x57 > /sys/bus/i2c/devices/i2c-1/new_device
+
+
+Sysfs entries
+-------------
+
+This driver uses the values in the datasheet to convert ADC register values
+into the values specified in the sysfs-interface document. All attributes are
+read only.
+
+Min, max, lcrit, and crit values are used by the chip to trigger external signals
+and/or other activity. Triggered signals can include HEALTHY, RST, Power Off,
+or Fault depending on the chip configuration. The driver reports values as lcrit
+or crit if exceeding the limits triggers RST, Power Off, or Fault, and as min or
+max otherwise. For details please see the SMM665 datasheet.
+
+For SMM465 and SMM764, values for Channel E and F are reported but undefined.
+
+in1_input		12V input voltage (mV)
+in2_input		3.3V (VDD) input voltage (mV)
+in3_input		Channel A voltage (mV)
+in4_input		Channel B voltage (mV)
+in5_input		Channel C voltage (mV)
+in6_input		Channel D voltage (mV)
+in7_input		Channel E voltage (mV)
+in8_input		Channel F voltage (mV)
+in9_input		AIN1 voltage (mV)
+in10_input		AIN2 voltage (mV)
+
+in1_min			12v input minimum voltage (mV)
+in2_min			3.3V (VDD) input minimum voltage (mV)
+in3_min			Channel A minimum voltage (mV)
+in4_min			Channel B minimum voltage (mV)
+in5_min			Channel C minimum voltage (mV)
+in6_min			Channel D minimum voltage (mV)
+in7_min			Channel E minimum voltage (mV)
+in8_min			Channel F minimum voltage (mV)
+in9_min			AIN1 minimum voltage (mV)
+in10_min		AIN2 minimum voltage (mV)
+
+in1_max			12v input maximum voltage (mV)
+in2_max			3.3V (VDD) input maximum voltage (mV)
+in3_max			Channel A maximum voltage (mV)
+in4_max			Channel B maximum voltage (mV)
+in5_max			Channel C maximum voltage (mV)
+in6_max			Channel D maximum voltage (mV)
+in7_max			Channel E maximum voltage (mV)
+in8_max			Channel F maximum voltage (mV)
+in9_max			AIN1 maximum voltage (mV)
+in10_max		AIN2 maximum voltage (mV)
+
+in1_lcrit		12v input critical minimum voltage (mV)
+in2_lcrit		3.3V (VDD) input critical minimum voltage (mV)
+in3_lcrit		Channel A critical minimum voltage (mV)
+in4_lcrit		Channel B critical minimum voltage (mV)
+in5_lcrit		Channel C critical minimum voltage (mV)
+in6_lcrit		Channel D critical minimum voltage (mV)
+in7_lcrit		Channel E critical minimum voltage (mV)
+in8_lcrit		Channel F critical minimum voltage (mV)
+in9_lcrit		AIN1 critical minimum voltage (mV)
+in10_lcrit		AIN2 critical minimum voltage (mV)
+
+in1_crit		12v input critical maximum voltage (mV)
+in2_crit		3.3V (VDD) input critical maximum voltage (mV)
+in3_crit		Channel A critical maximum voltage (mV)
+in4_crit		Channel B critical maximum voltage (mV)
+in5_crit		Channel C critical maximum voltage (mV)
+in6_crit		Channel D critical maximum voltage (mV)
+in7_crit		Channel E critical maximum voltage (mV)
+in8_crit		Channel F critical maximum voltage (mV)
+in9_crit		AIN1 critical maximum voltage (mV)
+in10_crit		AIN2 critical maximum voltage (mV)
+
+in1_crit_alarm		12v input critical alarm
+in2_crit_alarm		3.3V (VDD) input critical alarm
+in3_crit_alarm		Channel A critical alarm
+in4_crit_alarm		Channel B critical alarm
+in5_crit_alarm		Channel C critical alarm
+in6_crit_alarm		Channel D critical alarm
+in7_crit_alarm		Channel E critical alarm
+in8_crit_alarm		Channel F critical alarm
+in9_crit_alarm		AIN1 critical alarm
+in10_crit_alarm		AIN2 critical alarm
+
+temp1_input		Chip tempererature
+temp1_min		Mimimum chip tempererature
+temp1_max		Maximum chip tempererature
+temp1_crit		Critical chip tempererature
+temp1_crit_alarm	Temperature critical alarm
diff --git a/MAINTAINERS b/MAINTAINERS
index c71d2c5bffa..caacbcc3b64 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5251,6 +5251,13 @@ M:	Nicolas Pitre <nico@fluxnic.net>
 S:	Odd Fixes
 F:	drivers/net/smc91x.*
 
+SMM665 HARDWARE MONITOR DRIVER
+M:	Guenter Roeck <linux@roeck-us.net>
+L:	lm-sensors@lm-sensors.org
+S:	Maintained
+F:	Documentation/hwmon/smm665
+F:	drivers/hwmon/smm665.c
+
 SMSC47B397 HARDWARE MONITOR DRIVER
 M:	"Mark M. Hoffman" <mhoffman@lightlink.com>
 L:	lm-sensors@lm-sensors.org
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 4d382ae5309..c80ba4943b8 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -756,6 +756,21 @@ config SENSORS_SIS5595
 	  This driver can also be built as a module.  If so, the module
 	  will be called sis5595.
 
+config SENSORS_SMM665
+	tristate "Summit Microelectronics SMM665"
+	depends on I2C && EXPERIMENTAL
+	default n
+	help
+	  If you say yes here you get support for the hardware monitoring
+	  features of the Summit Microelectronics SMM665/SMM665B Six-Channel
+	  Active DC Output Controller / Monitor.
+
+	  Other supported chips are SMM465, SMM665C, SMM764, and SMM766.
+	  Support for those chips is untested.
+
+	  This driver can also be built as a module. If so, the module will
+	  be called smm665.
+
 config SENSORS_DME1737
 	tristate "SMSC DME1737, SCH311x and compatibles"
 	depends on I2C && EXPERIMENTAL
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 9103bd6ea73..db24fa1aa8b 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -88,6 +88,7 @@ obj-$(CONFIG_SENSORS_PCF8591)	+= pcf8591.o
 obj-$(CONFIG_SENSORS_S3C)	+= s3c-hwmon.o
 obj-$(CONFIG_SENSORS_SHT15)	+= sht15.o
 obj-$(CONFIG_SENSORS_SIS5595)	+= sis5595.o
+obj-$(CONFIG_SENSORS_SMM665)	+= smm665.o
 obj-$(CONFIG_SENSORS_SMSC47B397)+= smsc47b397.o
 obj-$(CONFIG_SENSORS_SMSC47M1)	+= smsc47m1.o
 obj-$(CONFIG_SENSORS_SMSC47M192)+= smsc47m192.o
diff --git a/drivers/hwmon/smm665.c b/drivers/hwmon/smm665.c
new file mode 100644
index 00000000000..425df5bccd4
--- /dev/null
+++ b/drivers/hwmon/smm665.c
@@ -0,0 +1,743 @@
+/*
+ * Driver for SMM665 Power Controller / Monitor
+ *
+ * Copyright (C) 2010 Ericsson AB.
+ *
+ * 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; version 2 of the License.
+ *
+ * This driver should also work for SMM465, SMM764, and SMM766, but is untested
+ * for those chips. Only monitoring functionality is implemented.
+ *
+ * Datasheets:
+ * http://www.summitmicro.com/prod_select/summary/SMM665/SMM665B_2089_20.pdf
+ * http://www.summitmicro.com/prod_select/summary/SMM766B/SMM766B_2122.pdf
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/delay.h>
+
+/* Internal reference voltage (VREF, x 1000 */
+#define SMM665_VREF_ADC_X1000	1250
+
+/* module parameters */
+static int vref = SMM665_VREF_ADC_X1000;
+module_param(vref, int, 0);
+MODULE_PARM_DESC(vref, "Reference voltage in mV");
+
+enum chips { smm465, smm665, smm665c, smm764, smm766 };
+
+/*
+ * ADC channel addresses
+ */
+#define	SMM665_MISC16_ADC_DATA_A	0x00
+#define	SMM665_MISC16_ADC_DATA_B	0x01
+#define	SMM665_MISC16_ADC_DATA_C	0x02
+#define	SMM665_MISC16_ADC_DATA_D	0x03
+#define	SMM665_MISC16_ADC_DATA_E	0x04
+#define	SMM665_MISC16_ADC_DATA_F	0x05
+#define	SMM665_MISC16_ADC_DATA_VDD	0x06
+#define	SMM665_MISC16_ADC_DATA_12V	0x07
+#define	SMM665_MISC16_ADC_DATA_INT_TEMP	0x08
+#define	SMM665_MISC16_ADC_DATA_AIN1	0x09
+#define	SMM665_MISC16_ADC_DATA_AIN2	0x0a
+
+/*
+ * Command registers
+ */
+#define	SMM665_MISC8_CMD_STS		0x80
+#define	SMM665_MISC8_STATUS1		0x81
+#define	SMM665_MISC8_STATUSS2		0x82
+#define	SMM665_MISC8_IO_POLARITY	0x83
+#define	SMM665_MISC8_PUP_POLARITY	0x84
+#define	SMM665_MISC8_ADOC_STATUS1	0x85
+#define	SMM665_MISC8_ADOC_STATUS2	0x86
+#define	SMM665_MISC8_WRITE_PROT		0x87
+#define	SMM665_MISC8_STS_TRACK		0x88
+
+/*
+ * Configuration registers and register groups
+ */
+#define SMM665_ADOC_ENABLE		0x0d
+#define SMM665_LIMIT_BASE		0x80	/* First limit register */
+
+/*
+ * Limit register bit masks
+ */
+#define SMM665_TRIGGER_RST		0x8000
+#define SMM665_TRIGGER_HEALTHY		0x4000
+#define SMM665_TRIGGER_POWEROFF		0x2000
+#define SMM665_TRIGGER_SHUTDOWN		0x1000
+#define SMM665_ADC_MASK			0x03ff
+
+#define smm665_is_critical(lim)	((lim) & (SMM665_TRIGGER_RST \
+					| SMM665_TRIGGER_POWEROFF \
+					| SMM665_TRIGGER_SHUTDOWN))
+/*
+ * Fault register bit definitions
+ * Values are merged from status registers 1/2,
+ * with status register 1 providing the upper 8 bits.
+ */
+#define SMM665_FAULT_A		0x0001
+#define SMM665_FAULT_B		0x0002
+#define SMM665_FAULT_C		0x0004
+#define SMM665_FAULT_D		0x0008
+#define SMM665_FAULT_E		0x0010
+#define SMM665_FAULT_F		0x0020
+#define SMM665_FAULT_VDD	0x0040
+#define SMM665_FAULT_12V	0x0080
+#define SMM665_FAULT_TEMP	0x0100
+#define SMM665_FAULT_AIN1	0x0200
+#define SMM665_FAULT_AIN2	0x0400
+
+/*
+ * I2C Register addresses
+ *
+ * The configuration register needs to be the configured base register.
+ * The command/status register address is derived from it.
+ */
+#define SMM665_REGMASK		0x78
+#define SMM665_CMDREG_BASE	0x48
+#define SMM665_CONFREG_BASE	0x50
+
+/*
+ *  Equations given by chip manufacturer to calculate voltage/temperature values
+ *  vref = Reference voltage on VREF_ADC pin (module parameter)
+ *  adc  = 10bit ADC value read back from registers
+ */
+
+/* Voltage A-F and VDD */
+#define SMM665_VMON_ADC_TO_VOLTS(adc)  ((adc) * vref / 256)
+
+/* Voltage 12VIN */
+#define SMM665_12VIN_ADC_TO_VOLTS(adc) ((adc) * vref * 3 / 256)
+
+/* Voltage AIN1, AIN2 */
+#define SMM665_AIN_ADC_TO_VOLTS(adc)   ((adc) * vref / 512)
+
+/* Temp Sensor */
+#define SMM665_TEMP_ADC_TO_CELSIUS(adc) ((adc) <= 511) ?		   \
+					 ((int)(adc) * 1000 / 4) :	   \
+					 (((int)(adc) - 0x400) * 1000 / 4)
+
+#define SMM665_NUM_ADC		11
+
+/*
+ * Chip dependent ADC conversion time, in uS
+ */
+#define SMM665_ADC_WAIT_SMM665	70
+#define SMM665_ADC_WAIT_SMM766	185
+
+struct smm665_data {
+	enum chips type;
+	int conversion_time;		/* ADC conversion time */
+	struct device *hwmon_dev;
+	struct mutex update_lock;
+	bool valid;
+	unsigned long last_updated;	/* in jiffies */
+	u16 adc[SMM665_NUM_ADC];	/* adc values (raw) */
+	u16 faults;			/* fault status */
+	/* The following values are in mV */
+	int critical_min_limit[SMM665_NUM_ADC];
+	int alarm_min_limit[SMM665_NUM_ADC];
+	int critical_max_limit[SMM665_NUM_ADC];
+	int alarm_max_limit[SMM665_NUM_ADC];
+	struct i2c_client *cmdreg;
+};
+
+/*
+ * smm665_read16()
+ *
+ * Read 16 bit value from <reg>, <reg+1>. Upper 8 bits are in <reg>.
+ */
+static int smm665_read16(struct i2c_client *client, int reg)
+{
+	int rv, val;
+
+	rv = i2c_smbus_read_byte_data(client, reg);
+	if (rv < 0)
+		return rv;
+	val = rv << 8;
+	rv = i2c_smbus_read_byte_data(client, reg + 1);
+	if (rv < 0)
+		return rv;
+	val |= rv;
+	return val;
+}
+
+/*
+ * Read adc value.
+ */
+static int smm665_read_adc(struct smm665_data *data, int adc)
+{
+	struct i2c_client *client = data->cmdreg;
+	int rv;
+	int radc;
+
+	/*
+	 * Algorithm for reading ADC, per SMM665 datasheet
+	 *
+	 *  {[S][addr][W][Ack]} {[offset][Ack]} {[S][addr][R][Nack]}
+	 * [wait conversion time]
+	 *  {[S][addr][R][Ack]} {[datahi][Ack]} {[datalo][Ack][P]}
+	 *
+	 * To implement the first part of this exchange,
+	 * do a full read transaction and expect a failure/Nack.
+	 * This sets up the address pointer on the SMM665
+	 * and starts the ADC conversion.
+	 * Then do a two-byte read transaction.
+	 */
+	rv = i2c_smbus_read_byte_data(client, adc << 3);
+	if (rv != -ENXIO) {
+		/*
+		 * We expect ENXIO to reflect NACK
+		 * (per Documentation/i2c/fault-codes).
+		 * Everything else is an error.
+		 */
+		dev_dbg(&client->dev,
+			"Unexpected return code %d when setting ADC index", rv);
+		return (rv < 0) ? rv : -EIO;
+	}
+
+	udelay(data->conversion_time);
+
+	/*
+	 * Now read two bytes.
+	 *
+	 * Neither i2c_smbus_read_byte() nor
+	 * i2c_smbus_read_block_data() worked here,
+	 * so use i2c_smbus_read_word_data() instead.
+	 * We could also try to use i2c_master_recv(),
+	 * but that is not always supported.
+	 */
+	rv = i2c_smbus_read_word_data(client, 0);
+	if (rv < 0) {
+		dev_dbg(&client->dev, "Failed to read ADC value: error %d", rv);
+		return -1;
+	}
+	/*
+	 * Validate/verify readback adc channel (in bit 11..14).
+	 * High byte is in lower 8 bit of rv, so only shift by 3.
+	 */
+	radc = (rv >> 3) & 0x0f;
+	if (radc != adc) {
+		dev_dbg(&client->dev, "Unexpected RADC: Expected %d got %d",
+			adc, radc);
+		return -EIO;
+	}
+	/*
+	 * Chip replies with H/L, while SMBus expects L/H.
+	 * Thus, byte order is reversed, and we have to swap
+	 * the result.
+	 */
+	rv = swab16(rv) & SMM665_ADC_MASK;
+
+	return rv;
+}
+
+static struct smm665_data *smm665_update_device(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct smm665_data *data = i2c_get_clientdata(client);
+	struct smm665_data *ret = data;
+
+	mutex_lock(&data->update_lock);
+
+	if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
+		int i, val;
+
+		/*
+		 * read status registers
+		 */
+		val = smm665_read16(client, SMM665_MISC8_STATUS1);
+		if (unlikely(val < 0)) {
+			ret = ERR_PTR(val);
+			goto abort;
+		}
+		data->faults = val;
+
+		/* Read adc registers */
+		for (i = 0; i < SMM665_NUM_ADC; i++) {
+			val = smm665_read_adc(data, i);
+			if (unlikely(val < 0)) {
+				ret = ERR_PTR(val);
+				goto abort;
+			}
+			data->adc[i] = val;
+		}
+		data->last_updated = jiffies;
+		data->valid = 1;
+	}
+abort:
+	mutex_unlock(&data->update_lock);
+	return ret;
+}
+
+/* Return converted value from given adc */
+static int smm665_convert(u16 adcval, int index)
+{
+	int val = 0;
+
+	switch (index) {
+	case SMM665_MISC16_ADC_DATA_12V:
+		val = SMM665_12VIN_ADC_TO_VOLTS(adcval & SMM665_ADC_MASK);
+		break;
+
+	case SMM665_MISC16_ADC_DATA_VDD:
+	case SMM665_MISC16_ADC_DATA_A:
+	case SMM665_MISC16_ADC_DATA_B:
+	case SMM665_MISC16_ADC_DATA_C:
+	case SMM665_MISC16_ADC_DATA_D:
+	case SMM665_MISC16_ADC_DATA_E:
+	case SMM665_MISC16_ADC_DATA_F:
+		val = SMM665_VMON_ADC_TO_VOLTS(adcval & SMM665_ADC_MASK);
+		break;
+
+	case SMM665_MISC16_ADC_DATA_AIN1:
+	case SMM665_MISC16_ADC_DATA_AIN2:
+		val = SMM665_AIN_ADC_TO_VOLTS(adcval & SMM665_ADC_MASK);
+		break;
+
+	case SMM665_MISC16_ADC_DATA_INT_TEMP:
+		val = SMM665_TEMP_ADC_TO_CELSIUS(adcval & SMM665_ADC_MASK);
+		break;
+
+	default:
+		/* If we get here, the developer messed up */
+		WARN_ON_ONCE(1);
+		break;
+	}
+
+	return val;
+}
+
+static int smm665_get_min(struct device *dev, int index)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct smm665_data *data = i2c_get_clientdata(client);
+
+	return data->alarm_min_limit[index];
+}
+
+static int smm665_get_max(struct device *dev, int index)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct smm665_data *data = i2c_get_clientdata(client);
+
+	return data->alarm_max_limit[index];
+}
+
+static int smm665_get_lcrit(struct device *dev, int index)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct smm665_data *data = i2c_get_clientdata(client);
+
+	return data->critical_min_limit[index];
+}
+
+static int smm665_get_crit(struct device *dev, int index)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct smm665_data *data = i2c_get_clientdata(client);
+
+	return data->critical_max_limit[index];
+}
+
+static ssize_t smm665_show_crit_alarm(struct device *dev,
+				      struct device_attribute *da, char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
+	struct smm665_data *data = smm665_update_device(dev);
+	int val = 0;
+
+	if (IS_ERR(data))
+		return PTR_ERR(data);
+
+	if (data->faults & (1 << attr->index))
+		val = 1;
+
+	return snprintf(buf, PAGE_SIZE, "%d\n", val);
+}
+
+static ssize_t smm665_show_input(struct device *dev,
+				 struct device_attribute *da, char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
+	struct smm665_data *data = smm665_update_device(dev);
+	int adc = attr->index;
+	int val;
+
+	if (IS_ERR(data))
+		return PTR_ERR(data);
+
+	val = smm665_convert(data->adc[adc], adc);
+	return snprintf(buf, PAGE_SIZE, "%d\n", val);
+}
+
+#define SMM665_SHOW(what) \
+  static ssize_t smm665_show_##what(struct device *dev, \
+				    struct device_attribute *da, char *buf) \
+{ \
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(da); \
+	const int val = smm665_get_##what(dev, attr->index); \
+	return snprintf(buf, PAGE_SIZE, "%d\n", val); \
+}
+
+SMM665_SHOW(min);
+SMM665_SHOW(max);
+SMM665_SHOW(lcrit);
+SMM665_SHOW(crit);
+
+/* These macros are used below in constructing device attribute objects
+ * for use with sysfs_create_group() to make a sysfs device file
+ * for each register.
+ */
+
+#define SMM665_ATTR(name, type, cmd_idx) \
+	static SENSOR_DEVICE_ATTR(name##_##type, S_IRUGO, \
+				  smm665_show_##type, NULL, cmd_idx)
+
+/* Construct a sensor_device_attribute structure for each register */
+
+/* Input voltages */
+SMM665_ATTR(in1, input, SMM665_MISC16_ADC_DATA_12V);
+SMM665_ATTR(in2, input, SMM665_MISC16_ADC_DATA_VDD);
+SMM665_ATTR(in3, input, SMM665_MISC16_ADC_DATA_A);
+SMM665_ATTR(in4, input, SMM665_MISC16_ADC_DATA_B);
+SMM665_ATTR(in5, input, SMM665_MISC16_ADC_DATA_C);
+SMM665_ATTR(in6, input, SMM665_MISC16_ADC_DATA_D);
+SMM665_ATTR(in7, input, SMM665_MISC16_ADC_DATA_E);
+SMM665_ATTR(in8, input, SMM665_MISC16_ADC_DATA_F);
+SMM665_ATTR(in9, input, SMM665_MISC16_ADC_DATA_AIN1);
+SMM665_ATTR(in10, input, SMM665_MISC16_ADC_DATA_AIN2);
+
+/* Input voltages min */
+SMM665_ATTR(in1, min, SMM665_MISC16_ADC_DATA_12V);
+SMM665_ATTR(in2, min, SMM665_MISC16_ADC_DATA_VDD);
+SMM665_ATTR(in3, min, SMM665_MISC16_ADC_DATA_A);
+SMM665_ATTR(in4, min, SMM665_MISC16_ADC_DATA_B);
+SMM665_ATTR(in5, min, SMM665_MISC16_ADC_DATA_C);
+SMM665_ATTR(in6, min, SMM665_MISC16_ADC_DATA_D);
+SMM665_ATTR(in7, min, SMM665_MISC16_ADC_DATA_E);
+SMM665_ATTR(in8, min, SMM665_MISC16_ADC_DATA_F);
+SMM665_ATTR(in9, min, SMM665_MISC16_ADC_DATA_AIN1);
+SMM665_ATTR(in10, min, SMM665_MISC16_ADC_DATA_AIN2);
+
+/* Input voltages max */
+SMM665_ATTR(in1, max, SMM665_MISC16_ADC_DATA_12V);
+SMM665_ATTR(in2, max, SMM665_MISC16_ADC_DATA_VDD);
+SMM665_ATTR(in3, max, SMM665_MISC16_ADC_DATA_A);
+SMM665_ATTR(in4, max, SMM665_MISC16_ADC_DATA_B);
+SMM665_ATTR(in5, max, SMM665_MISC16_ADC_DATA_C);
+SMM665_ATTR(in6, max, SMM665_MISC16_ADC_DATA_D);
+SMM665_ATTR(in7, max, SMM665_MISC16_ADC_DATA_E);
+SMM665_ATTR(in8, max, SMM665_MISC16_ADC_DATA_F);
+SMM665_ATTR(in9, max, SMM665_MISC16_ADC_DATA_AIN1);
+SMM665_ATTR(in10, max, SMM665_MISC16_ADC_DATA_AIN2);
+
+/* Input voltages lcrit */
+SMM665_ATTR(in1, lcrit, SMM665_MISC16_ADC_DATA_12V);
+SMM665_ATTR(in2, lcrit, SMM665_MISC16_ADC_DATA_VDD);
+SMM665_ATTR(in3, lcrit, SMM665_MISC16_ADC_DATA_A);
+SMM665_ATTR(in4, lcrit, SMM665_MISC16_ADC_DATA_B);
+SMM665_ATTR(in5, lcrit, SMM665_MISC16_ADC_DATA_C);
+SMM665_ATTR(in6, lcrit, SMM665_MISC16_ADC_DATA_D);
+SMM665_ATTR(in7, lcrit, SMM665_MISC16_ADC_DATA_E);
+SMM665_ATTR(in8, lcrit, SMM665_MISC16_ADC_DATA_F);
+SMM665_ATTR(in9, lcrit, SMM665_MISC16_ADC_DATA_AIN1);
+SMM665_ATTR(in10, lcrit, SMM665_MISC16_ADC_DATA_AIN2);
+
+/* Input voltages crit */
+SMM665_ATTR(in1, crit, SMM665_MISC16_ADC_DATA_12V);
+SMM665_ATTR(in2, crit, SMM665_MISC16_ADC_DATA_VDD);
+SMM665_ATTR(in3, crit, SMM665_MISC16_ADC_DATA_A);
+SMM665_ATTR(in4, crit, SMM665_MISC16_ADC_DATA_B);
+SMM665_ATTR(in5, crit, SMM665_MISC16_ADC_DATA_C);
+SMM665_ATTR(in6, crit, SMM665_MISC16_ADC_DATA_D);
+SMM665_ATTR(in7, crit, SMM665_MISC16_ADC_DATA_E);
+SMM665_ATTR(in8, crit, SMM665_MISC16_ADC_DATA_F);
+SMM665_ATTR(in9, crit, SMM665_MISC16_ADC_DATA_AIN1);
+SMM665_ATTR(in10, crit, SMM665_MISC16_ADC_DATA_AIN2);
+
+/* critical alarms */
+SMM665_ATTR(in1, crit_alarm, SMM665_FAULT_12V);
+SMM665_ATTR(in2, crit_alarm, SMM665_FAULT_VDD);
+SMM665_ATTR(in3, crit_alarm, SMM665_FAULT_A);
+SMM665_ATTR(in4, crit_alarm, SMM665_FAULT_B);
+SMM665_ATTR(in5, crit_alarm, SMM665_FAULT_C);
+SMM665_ATTR(in6, crit_alarm, SMM665_FAULT_D);
+SMM665_ATTR(in7, crit_alarm, SMM665_FAULT_E);
+SMM665_ATTR(in8, crit_alarm, SMM665_FAULT_F);
+SMM665_ATTR(in9, crit_alarm, SMM665_FAULT_AIN1);
+SMM665_ATTR(in10, crit_alarm, SMM665_FAULT_AIN2);
+
+/* Temperature */
+SMM665_ATTR(temp1, input, SMM665_MISC16_ADC_DATA_INT_TEMP);
+SMM665_ATTR(temp1, min, SMM665_MISC16_ADC_DATA_INT_TEMP);
+SMM665_ATTR(temp1, max, SMM665_MISC16_ADC_DATA_INT_TEMP);
+SMM665_ATTR(temp1, lcrit, SMM665_MISC16_ADC_DATA_INT_TEMP);
+SMM665_ATTR(temp1, crit, SMM665_MISC16_ADC_DATA_INT_TEMP);
+SMM665_ATTR(temp1, crit_alarm, SMM665_FAULT_TEMP);
+
+/*
+ * Finally, construct an array of pointers to members of the above objects,
+ * as required for sysfs_create_group()
+ */
+static struct attribute *smm665_attributes[] = {
+	&sensor_dev_attr_in1_input.dev_attr.attr,
+	&sensor_dev_attr_in1_min.dev_attr.attr,
+	&sensor_dev_attr_in1_max.dev_attr.attr,
+	&sensor_dev_attr_in1_lcrit.dev_attr.attr,
+	&sensor_dev_attr_in1_crit.dev_attr.attr,
+	&sensor_dev_attr_in1_crit_alarm.dev_attr.attr,
+
+	&sensor_dev_attr_in2_input.dev_attr.attr,
+	&sensor_dev_attr_in2_min.dev_attr.attr,
+	&sensor_dev_attr_in2_max.dev_attr.attr,
+	&sensor_dev_attr_in2_lcrit.dev_attr.attr,
+	&sensor_dev_attr_in2_crit.dev_attr.attr,
+	&sensor_dev_attr_in2_crit_alarm.dev_attr.attr,
+
+	&sensor_dev_attr_in3_input.dev_attr.attr,
+	&sensor_dev_attr_in3_min.dev_attr.attr,
+	&sensor_dev_attr_in3_max.dev_attr.attr,
+	&sensor_dev_attr_in3_lcrit.dev_attr.attr,
+	&sensor_dev_attr_in3_crit.dev_attr.attr,
+	&sensor_dev_attr_in3_crit_alarm.dev_attr.attr,
+
+	&sensor_dev_attr_in4_input.dev_attr.attr,
+	&sensor_dev_attr_in4_min.dev_attr.attr,
+	&sensor_dev_attr_in4_max.dev_attr.attr,
+	&sensor_dev_attr_in4_lcrit.dev_attr.attr,
+	&sensor_dev_attr_in4_crit.dev_attr.attr,
+	&sensor_dev_attr_in4_crit_alarm.dev_attr.attr,
+
+	&sensor_dev_attr_in5_input.dev_attr.attr,
+	&sensor_dev_attr_in5_min.dev_attr.attr,
+	&sensor_dev_attr_in5_max.dev_attr.attr,
+	&sensor_dev_attr_in5_lcrit.dev_attr.attr,
+	&sensor_dev_attr_in5_crit.dev_attr.attr,
+	&sensor_dev_attr_in5_crit_alarm.dev_attr.attr,
+
+	&sensor_dev_attr_in6_input.dev_attr.attr,
+	&sensor_dev_attr_in6_min.dev_attr.attr,
+	&sensor_dev_attr_in6_max.dev_attr.attr,
+	&sensor_dev_attr_in6_lcrit.dev_attr.attr,
+	&sensor_dev_attr_in6_crit.dev_attr.attr,
+	&sensor_dev_attr_in6_crit_alarm.dev_attr.attr,
+
+	&sensor_dev_attr_in7_input.dev_attr.attr,
+	&sensor_dev_attr_in7_min.dev_attr.attr,
+	&sensor_dev_attr_in7_max.dev_attr.attr,
+	&sensor_dev_attr_in7_lcrit.dev_attr.attr,
+	&sensor_dev_attr_in7_crit.dev_attr.attr,
+	&sensor_dev_attr_in7_crit_alarm.dev_attr.attr,
+
+	&sensor_dev_attr_in8_input.dev_attr.attr,
+	&sensor_dev_attr_in8_min.dev_attr.attr,
+	&sensor_dev_attr_in8_max.dev_attr.attr,
+	&sensor_dev_attr_in8_lcrit.dev_attr.attr,
+	&sensor_dev_attr_in8_crit.dev_attr.attr,
+	&sensor_dev_attr_in8_crit_alarm.dev_attr.attr,
+
+	&sensor_dev_attr_in9_input.dev_attr.attr,
+	&sensor_dev_attr_in9_min.dev_attr.attr,
+	&sensor_dev_attr_in9_max.dev_attr.attr,
+	&sensor_dev_attr_in9_lcrit.dev_attr.attr,
+	&sensor_dev_attr_in9_crit.dev_attr.attr,
+	&sensor_dev_attr_in9_crit_alarm.dev_attr.attr,
+
+	&sensor_dev_attr_in10_input.dev_attr.attr,
+	&sensor_dev_attr_in10_min.dev_attr.attr,
+	&sensor_dev_attr_in10_max.dev_attr.attr,
+	&sensor_dev_attr_in10_lcrit.dev_attr.attr,
+	&sensor_dev_attr_in10_crit.dev_attr.attr,
+	&sensor_dev_attr_in10_crit_alarm.dev_attr.attr,
+
+	&sensor_dev_attr_temp1_input.dev_attr.attr,
+	&sensor_dev_attr_temp1_min.dev_attr.attr,
+	&sensor_dev_attr_temp1_max.dev_attr.attr,
+	&sensor_dev_attr_temp1_lcrit.dev_attr.attr,
+	&sensor_dev_attr_temp1_crit.dev_attr.attr,
+	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
+
+	NULL,
+};
+
+static const struct attribute_group smm665_group = {
+	.attrs = smm665_attributes,
+};
+
+static int smm665_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
+{
+	struct i2c_adapter *adapter = client->adapter;
+	struct smm665_data *data;
+	int i, ret;
+
+	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
+				     | I2C_FUNC_SMBUS_WORD_DATA))
+		return -ENODEV;
+
+	if (i2c_smbus_read_byte_data(client, SMM665_ADOC_ENABLE) < 0)
+		return -ENODEV;
+
+	ret = -ENOMEM;
+	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	if (!data)
+		goto out_return;
+
+	i2c_set_clientdata(client, data);
+	mutex_init(&data->update_lock);
+
+	data->type = id->driver_data;
+	data->cmdreg = i2c_new_dummy(adapter, (client->addr & ~SMM665_REGMASK)
+				     | SMM665_CMDREG_BASE);
+	if (!data->cmdreg)
+		goto out_kfree;
+
+	switch (data->type) {
+	case smm465:
+	case smm665:
+		data->conversion_time = SMM665_ADC_WAIT_SMM665;
+		break;
+	case smm665c:
+	case smm764:
+	case smm766:
+		data->conversion_time = SMM665_ADC_WAIT_SMM766;
+		break;
+	}
+
+	ret = -ENODEV;
+	if (i2c_smbus_read_byte_data(data->cmdreg, SMM665_MISC8_CMD_STS) < 0)
+		goto out_unregister;
+
+	/*
+	 * Read limits.
+	 *
+	 * Limit registers start with register SMM665_LIMIT_BASE.
+	 * Each channel uses 8 registers, providing four limit values
+	 * per channel. Each limit value requires two registers, with the
+	 * high byte in the first register and the low byte in the second
+	 * register. The first two limits are under limit values, followed
+	 * by two over limit values.
+	 *
+	 * Limit register order matches the ADC register order, so we use
+	 * ADC register defines throughout the code to index limit registers.
+	 *
+	 * We save the first retrieved value both as "critical" and "alarm"
+	 * value. The second value overwrites either the critical or the
+	 * alarm value, depending on its configuration. This ensures that both
+	 * critical and alarm values are initialized, even if both registers are
+	 * configured as critical or non-critical.
+	 */
+	for (i = 0; i < SMM665_NUM_ADC; i++) {
+		int val;
+
+		val = smm665_read16(client, SMM665_LIMIT_BASE + i * 8);
+		if (unlikely(val < 0))
+			goto out_unregister;
+		data->critical_min_limit[i] = data->alarm_min_limit[i]
+		  = smm665_convert(val, i);
+		val = smm665_read16(client, SMM665_LIMIT_BASE + i * 8 + 2);
+		if (unlikely(val < 0))
+			goto out_unregister;
+		if (smm665_is_critical(val))
+			data->critical_min_limit[i] = smm665_convert(val, i);
+		else
+			data->alarm_min_limit[i] = smm665_convert(val, i);
+		val = smm665_read16(client, SMM665_LIMIT_BASE + i * 8 + 4);
+		if (unlikely(val < 0))
+			goto out_unregister;
+		data->critical_max_limit[i] = data->alarm_max_limit[i]
+		  = smm665_convert(val, i);
+		val = smm665_read16(client, SMM665_LIMIT_BASE + i * 8 + 6);
+		if (unlikely(val < 0))
+			goto out_unregister;
+		if (smm665_is_critical(val))
+			data->critical_max_limit[i] = smm665_convert(val, i);
+		else
+			data->alarm_max_limit[i] = smm665_convert(val, i);
+	}
+
+	/* Register sysfs hooks */
+	ret = sysfs_create_group(&client->dev.kobj, &smm665_group);
+	if (ret)
+		goto out_unregister;
+
+	data->hwmon_dev = hwmon_device_register(&client->dev);
+	if (IS_ERR(data->hwmon_dev)) {
+		ret = PTR_ERR(data->hwmon_dev);
+		goto out_remove_group;
+	}
+
+	return 0;
+
+out_remove_group:
+	sysfs_remove_group(&client->dev.kobj, &smm665_group);
+out_unregister:
+	i2c_unregister_device(data->cmdreg);
+out_kfree:
+	kfree(data);
+out_return:
+	return ret;
+}
+
+static int smm665_remove(struct i2c_client *client)
+{
+	struct smm665_data *data = i2c_get_clientdata(client);
+
+	i2c_unregister_device(data->cmdreg);
+	hwmon_device_unregister(data->hwmon_dev);
+	sysfs_remove_group(&client->dev.kobj, &smm665_group);
+
+	kfree(data);
+
+	return 0;
+}
+
+static const struct i2c_device_id smm665_id[] = {
+	{"smm465", smm465},
+	{"smm665", smm665},
+	{"smm665c", smm665c},
+	{"smm764", smm764},
+	{"smm766", smm766},
+	{}
+};
+
+MODULE_DEVICE_TABLE(i2c, smm665_id);
+
+/* This is the driver that will be inserted */
+static struct i2c_driver smm665_driver = {
+	.driver = {
+		   .name = "smm665",
+		   },
+	.probe = smm665_probe,
+	.remove = smm665_remove,
+	.id_table = smm665_id,
+};
+
+static int __init smm665_init(void)
+{
+	return i2c_add_driver(&smm665_driver);
+}
+
+static void __exit smm665_exit(void)
+{
+	i2c_del_driver(&smm665_driver);
+}
+
+MODULE_AUTHOR("Guenter Roeck");
+MODULE_DESCRIPTION("SMM665 driver");
+MODULE_LICENSE("GPL");
+
+module_init(smm665_init);
+module_exit(smm665_exit);