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 000000000000..3820fc9ca52d
--- /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 c71d2c5bffa6..caacbcc3b64f 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 4d382ae53092..c80ba4943b81 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 9103bd6ea73a..db24fa1aa8b7 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 000000000000..425df5bccd45
--- /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);