hwmon: Driver for TI ADC128D818

ADC128D818 is a System Monitor with Temperature Sensor. It is similar to LM80
and LM96080, but has 16 bit wide sensor registers and no fan speed monitoring.
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>

Documentation/hwmon/adc128d818

+Kernel driver adc128d818
+========================
+
+Supported chips:
+  * Texas Instruments ADC818D818
+    Prefix: 'adc818d818'
+    Addresses scanned: I2C 0x1d, 0x1e, 0x1f, 0x2d, 0x2e, 0x2f
+    Datasheet: Publicly available at the TI website
+               http://www.ti.com/
+
+Author: Guenter Roeck
+
+Description
+-----------
+
+This driver implements support for the Texas Instruments ADC128D818.
+It is described as 'ADC System Monitor with Temperature Sensor'.
+
+The ADC128D818 implements one temperature sensor and seven voltage sensors.
+
+Temperatures are measured in degrees Celsius. There is one set of limits.
+When the HOT Temperature Limit is crossed, this will cause an alarm that will
+be reasserted until the temperature drops below the HOT Hysteresis.
+Measurements are guaranteed between -55 and +125 degrees. The temperature
+measurement has a resolution of 0.5 degrees; the limits have a resolution
+of 1 degree.
+
+Voltage sensors (also known as IN sensors) report their values in volts.
+An alarm is triggered if the voltage has crossed a programmable minimum
+or maximum limit. Note that minimum in this case always means 'closest to
+zero'; this is important for negative voltage measurements. All voltage
+inputs can measure voltages between 0 and 2.55 volts, with a resolution
+of 0.625 mV.
+
+If an alarm triggers, it will remain triggered until the hardware register
+is read at least once. This means that the cause for the alarm may
+already have disappeared by the time the alarm is read. The driver
+caches the alarm status for each sensor until it is at least reported
+once, to ensure that alarms are reported to user space.
+
+The ADC128D818 only updates its values approximately once per second;
+reading it more often will do no harm, but will return 'old' values.
+
+In addition to the scanned address list, the chip can also be configured for
+addresses 0x35 to 0x37. Those addresses are not scanned. You have to instantiate
+the driver explicitly if the chip is configured for any of those addresses in
+your system.

drivers/hwmon/Kconfig

@@ -1277,6 +1277,16 @@ config SENSORS_SMM665
 	  This driver can also be built as a module. If so, the module will
 	  be called smm665.
 
+config SENSORS_ADC128D818
+	tristate "Texas Instruments ADC128D818"
+	depends on I2C
+	help
+	  If you say yes here you get support for the Texas Instruments
+	  ADC128D818 System Monitor with Temperature Sensor chip.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called adc128d818.
+
 config SENSORS_ADS1015
 	tristate "Texas Instruments ADS1015"
 	depends on I2C

drivers/hwmon/Makefile

@@ -25,6 +25,7 @@ obj-$(CONFIG_SENSORS_ABITUGURU3)+= abituguru3.o
 obj-$(CONFIG_SENSORS_AD7314)	+= ad7314.o
 obj-$(CONFIG_SENSORS_AD7414)	+= ad7414.o
 obj-$(CONFIG_SENSORS_AD7418)	+= ad7418.o
+obj-$(CONFIG_SENSORS_ADC128D818) += adc128d818.o
 obj-$(CONFIG_SENSORS_ADCXX)	+= adcxx.o
 obj-$(CONFIG_SENSORS_ADM1021)	+= adm1021.o
 obj-$(CONFIG_SENSORS_ADM1025)	+= adm1025.o

drivers/hwmon/adc128d818.c

+/*
+ * Driver for TI ADC128D818 System Monitor with Temperature Sensor
+ *
+ * Copyright (c) 2014 Guenter Roeck
+ *
+ * Derived from lm80.c
+ * Copyright (C) 1998, 1999  Frodo Looijaard <frodol@dds.nl>
+ *			     and Philip Edelbrock <phil@netroedge.com>
+ *
+ * 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/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/regulator/consumer.h>
+#include <linux/mutex.h>
+
+/* Addresses to scan
+ * The chip also supports addresses 0x35..0x37. Don't scan those addresses
+ * since they are also used by some EEPROMs, which may result in false
+ * positives.
+ */
+static const unsigned short normal_i2c[] = {
+	0x1d, 0x1e, 0x1f, 0x2d, 0x2e, 0x2f, I2C_CLIENT_END };
+
+/* registers */
+#define ADC128_REG_IN_MAX(nr)		(0x2a + (nr) * 2)
+#define ADC128_REG_IN_MIN(nr)		(0x2b + (nr) * 2)
+#define ADC128_REG_IN(nr)		(0x20 + (nr))
+
+#define ADC128_REG_TEMP			0x27
+#define ADC128_REG_TEMP_MAX		0x38
+#define ADC128_REG_TEMP_HYST		0x39
+
+#define ADC128_REG_CONFIG		0x00
+#define ADC128_REG_ALARM		0x01
+#define ADC128_REG_MASK			0x03
+#define ADC128_REG_CONV_RATE		0x07
+#define ADC128_REG_ONESHOT		0x09
+#define ADC128_REG_SHUTDOWN		0x0a
+#define ADC128_REG_CONFIG_ADV		0x0b
+#define ADC128_REG_BUSY_STATUS		0x0c
+
+#define ADC128_REG_MAN_ID		0x3e
+#define ADC128_REG_DEV_ID		0x3f
+
+struct adc128_data {
+	struct i2c_client *client;
+	struct regulator *regulator;
+	int vref;		/* Reference voltage in mV */
+	struct mutex update_lock;
+	bool valid;		/* true if following fields are valid */
+	unsigned long last_updated;	/* In jiffies */
+
+	u16 in[3][7];		/* Register value, normalized to 12 bit
+				 * 0: input voltage
+				 * 1: min limit
+				 * 2: max limit
+				 */
+	s16 temp[3];		/* Register value, normalized to 9 bit
+				 * 0: sensor 1: limit 2: hyst
+				 */
+	u8 alarms;		/* alarm register value */
+};
+
+static struct adc128_data *adc128_update_device(struct device *dev)
+{
+	struct adc128_data *data = dev_get_drvdata(dev);
+	struct i2c_client *client = data->client;
+	struct adc128_data *ret = data;
+	int i, rv;
+
+	mutex_lock(&data->update_lock);
+
+	if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
+		for (i = 0; i < 7; i++) {
+			rv = i2c_smbus_read_word_swapped(client,
+							 ADC128_REG_IN(i));
+			if (rv < 0)
+				goto abort;
+			data->in[0][i] = rv >> 4;
+
+			rv = i2c_smbus_read_byte_data(client,
+						      ADC128_REG_IN_MIN(i));
+			if (rv < 0)
+				goto abort;
+			data->in[1][i] = rv << 4;
+
+			rv = i2c_smbus_read_byte_data(client,
+						      ADC128_REG_IN_MAX(i));
+			if (rv < 0)
+				goto abort;
+			data->in[2][i] = rv << 4;
+		}
+
+		rv = i2c_smbus_read_word_swapped(client, ADC128_REG_TEMP);
+		if (rv < 0)
+			goto abort;
+		data->temp[0] = rv >> 7;
+
+		rv = i2c_smbus_read_byte_data(client, ADC128_REG_TEMP_MAX);
+		if (rv < 0)
+			goto abort;
+		data->temp[1] = rv << 1;
+
+		rv = i2c_smbus_read_byte_data(client, ADC128_REG_TEMP_HYST);
+		if (rv < 0)
+			goto abort;
+		data->temp[2] = rv << 1;
+
+		rv = i2c_smbus_read_byte_data(client, ADC128_REG_ALARM);
+		if (rv < 0)
+			goto abort;
+		data->alarms |= rv;
+
+		data->last_updated = jiffies;
+		data->valid = true;
+	}
+	goto done;
+
+abort:
+	ret = ERR_PTR(rv);
+	data->valid = false;
+done:
+	mutex_unlock(&data->update_lock);
+	return ret;
+}
+
+static ssize_t adc128_show_in(struct device *dev, struct device_attribute *attr,
+			      char *buf)
+{
+	struct adc128_data *data = adc128_update_device(dev);
+	int index = to_sensor_dev_attr_2(attr)->index;
+	int nr = to_sensor_dev_attr_2(attr)->nr;
+	int val;
+
+	if (IS_ERR(data))
+		return PTR_ERR(data);
+
+	val = DIV_ROUND_CLOSEST(data->in[index][nr] * data->vref, 4095);
+	return sprintf(buf, "%d\n", val);
+}
+
+static ssize_t adc128_set_in(struct device *dev, struct device_attribute *attr,
+			     const char *buf, size_t count)
+{
+	struct adc128_data *data = dev_get_drvdata(dev);
+	int index = to_sensor_dev_attr_2(attr)->index;
+	int nr = to_sensor_dev_attr_2(attr)->nr;
+	u8 reg, regval;
+	long val;
+	int err;
+
+	err = kstrtol(buf, 10, &val);
+	if (err < 0)
+		return err;
+
+	mutex_lock(&data->update_lock);
+	/* 10 mV LSB on limit registers */
+	regval = clamp_val(DIV_ROUND_CLOSEST(val, 10), 0, 255);
+	data->in[index][nr] = regval << 4;
+	reg = index == 1 ? ADC128_REG_IN_MIN(nr) : ADC128_REG_IN_MAX(nr);
+	i2c_smbus_write_byte_data(data->client, reg, regval);
+	mutex_unlock(&data->update_lock);
+
+	return count;
+}
+
+static ssize_t adc128_show_temp(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct adc128_data *data = adc128_update_device(dev);
+	int index = to_sensor_dev_attr(attr)->index;
+	int temp;
+
+	if (IS_ERR(data))
+		return PTR_ERR(data);
+
+	temp = (data->temp[index] << 7) >> 7;	/* sign extend */
+	return sprintf(buf, "%d\n", temp * 500);/* 0.5 degrees C resolution */
+}
+
+static ssize_t adc128_set_temp(struct device *dev,
+			       struct device_attribute *attr,
+			       const char *buf, size_t count)
+{
+	struct adc128_data *data = dev_get_drvdata(dev);
+	int index = to_sensor_dev_attr(attr)->index;
+	long val;
+	int err;
+	s8 regval;
+
+	err = kstrtol(buf, 10, &val);
+	if (err < 0)
+		return err;
+
+	mutex_lock(&data->update_lock);
+	regval = clamp_val(DIV_ROUND_CLOSEST(val, 1000), -128, 127);
+	data->temp[index] = regval << 1;
+	i2c_smbus_write_byte_data(data->client,
+				  index == 1 ? ADC128_REG_TEMP_MAX
+					     : ADC128_REG_TEMP_HYST,
+				  regval);
+	mutex_unlock(&data->update_lock);
+
+	return count;
+}
+
+static ssize_t adc128_show_alarm(struct device *dev,
+				 struct device_attribute *attr, char *buf)
+{
+	struct adc128_data *data = adc128_update_device(dev);
+	int mask = 1 << to_sensor_dev_attr(attr)->index;
+	u8 alarms;
+
+	if (IS_ERR(data))
+		return PTR_ERR(data);
+
+	/*
+	 * Clear an alarm after reporting it to user space. If it is still
+	 * active, the next update sequence will set the alarm bit again.
+	 */
+	alarms = data->alarms;
+	data->alarms &= ~mask;
+
+	return sprintf(buf, "%u\n", !!(alarms & mask));
+}
+
+static SENSOR_DEVICE_ATTR_2(in0_input, S_IWUSR | S_IRUGO,
+			    adc128_show_in, adc128_set_in, 0, 0);
+static SENSOR_DEVICE_ATTR_2(in0_min, S_IWUSR | S_IRUGO,
+			    adc128_show_in, adc128_set_in, 0, 1);
+static SENSOR_DEVICE_ATTR_2(in0_max, S_IWUSR | S_IRUGO,
+			    adc128_show_in, adc128_set_in, 0, 2);
+
+static SENSOR_DEVICE_ATTR_2(in1_input, S_IWUSR | S_IRUGO,
+			    adc128_show_in, adc128_set_in, 1, 0);
+static SENSOR_DEVICE_ATTR_2(in1_min, S_IWUSR | S_IRUGO,
+			    adc128_show_in, adc128_set_in, 1, 1);
+static SENSOR_DEVICE_ATTR_2(in1_max, S_IWUSR | S_IRUGO,
+			    adc128_show_in, adc128_set_in, 1, 2);
+
+static SENSOR_DEVICE_ATTR_2(in2_input, S_IWUSR | S_IRUGO,
+			    adc128_show_in, adc128_set_in, 2, 0);
+static SENSOR_DEVICE_ATTR_2(in2_min, S_IWUSR | S_IRUGO,
+			    adc128_show_in, adc128_set_in, 2, 1);
+static SENSOR_DEVICE_ATTR_2(in2_max, S_IWUSR | S_IRUGO,
+			    adc128_show_in, adc128_set_in, 2, 2);
+
+static SENSOR_DEVICE_ATTR_2(in3_input, S_IWUSR | S_IRUGO,
+			    adc128_show_in, adc128_set_in, 3, 0);
+static SENSOR_DEVICE_ATTR_2(in3_min, S_IWUSR | S_IRUGO,
+			    adc128_show_in, adc128_set_in, 3, 1);
+static SENSOR_DEVICE_ATTR_2(in3_max, S_IWUSR | S_IRUGO,
+			    adc128_show_in, adc128_set_in, 3, 2);
+
+static SENSOR_DEVICE_ATTR_2(in4_input, S_IWUSR | S_IRUGO,
+			    adc128_show_in, adc128_set_in, 4, 0);
+static SENSOR_DEVICE_ATTR_2(in4_min, S_IWUSR | S_IRUGO,
+			    adc128_show_in, adc128_set_in, 4, 1);
+static SENSOR_DEVICE_ATTR_2(in4_max, S_IWUSR | S_IRUGO,
+			    adc128_show_in, adc128_set_in, 4, 2);
+
+static SENSOR_DEVICE_ATTR_2(in5_input, S_IWUSR | S_IRUGO,
+			    adc128_show_in, adc128_set_in, 5, 0);
+static SENSOR_DEVICE_ATTR_2(in5_min, S_IWUSR | S_IRUGO,
+			    adc128_show_in, adc128_set_in, 5, 1);
+static SENSOR_DEVICE_ATTR_2(in5_max, S_IWUSR | S_IRUGO,
+			    adc128_show_in, adc128_set_in, 5, 2);
+
+static SENSOR_DEVICE_ATTR_2(in6_input, S_IWUSR | S_IRUGO,
+			    adc128_show_in, adc128_set_in, 6, 0);
+static SENSOR_DEVICE_ATTR_2(in6_min, S_IWUSR | S_IRUGO,
+			    adc128_show_in, adc128_set_in, 6, 1);
+static SENSOR_DEVICE_ATTR_2(in6_max, S_IWUSR | S_IRUGO,
+			    adc128_show_in, adc128_set_in, 6, 2);
+
+static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, adc128_show_temp, NULL, 0);
+static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
+			  adc128_show_temp, adc128_set_temp, 1);
+static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO,
+			  adc128_show_temp, adc128_set_temp, 2);
+
+static SENSOR_DEVICE_ATTR(in0_alarm, S_IRUGO, adc128_show_alarm, NULL, 0);
+static SENSOR_DEVICE_ATTR(in1_alarm, S_IRUGO, adc128_show_alarm, NULL, 1);
+static SENSOR_DEVICE_ATTR(in2_alarm, S_IRUGO, adc128_show_alarm, NULL, 2);
+static SENSOR_DEVICE_ATTR(in3_alarm, S_IRUGO, adc128_show_alarm, NULL, 3);
+static SENSOR_DEVICE_ATTR(in4_alarm, S_IRUGO, adc128_show_alarm, NULL, 4);
+static SENSOR_DEVICE_ATTR(in5_alarm, S_IRUGO, adc128_show_alarm, NULL, 5);
+static SENSOR_DEVICE_ATTR(in6_alarm, S_IRUGO, adc128_show_alarm, NULL, 6);
+static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, adc128_show_alarm, NULL, 7);
+
+static struct attribute *adc128_attrs[] = {
+	&sensor_dev_attr_in0_min.dev_attr.attr,
+	&sensor_dev_attr_in1_min.dev_attr.attr,
+	&sensor_dev_attr_in2_min.dev_attr.attr,
+	&sensor_dev_attr_in3_min.dev_attr.attr,
+	&sensor_dev_attr_in4_min.dev_attr.attr,
+	&sensor_dev_attr_in5_min.dev_attr.attr,
+	&sensor_dev_attr_in6_min.dev_attr.attr,
+	&sensor_dev_attr_in0_max.dev_attr.attr,
+	&sensor_dev_attr_in1_max.dev_attr.attr,
+	&sensor_dev_attr_in2_max.dev_attr.attr,
+	&sensor_dev_attr_in3_max.dev_attr.attr,
+	&sensor_dev_attr_in4_max.dev_attr.attr,
+	&sensor_dev_attr_in5_max.dev_attr.attr,
+	&sensor_dev_attr_in6_max.dev_attr.attr,
+	&sensor_dev_attr_in0_input.dev_attr.attr,
+	&sensor_dev_attr_in1_input.dev_attr.attr,
+	&sensor_dev_attr_in2_input.dev_attr.attr,
+	&sensor_dev_attr_in3_input.dev_attr.attr,
+	&sensor_dev_attr_in4_input.dev_attr.attr,
+	&sensor_dev_attr_in5_input.dev_attr.attr,
+	&sensor_dev_attr_in6_input.dev_attr.attr,
+	&sensor_dev_attr_temp1_input.dev_attr.attr,
+	&sensor_dev_attr_temp1_max.dev_attr.attr,
+	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
+	&sensor_dev_attr_in0_alarm.dev_attr.attr,
+	&sensor_dev_attr_in1_alarm.dev_attr.attr,
+	&sensor_dev_attr_in2_alarm.dev_attr.attr,
+	&sensor_dev_attr_in3_alarm.dev_attr.attr,
+	&sensor_dev_attr_in4_alarm.dev_attr.attr,
+	&sensor_dev_attr_in5_alarm.dev_attr.attr,
+	&sensor_dev_attr_in6_alarm.dev_attr.attr,
+	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
+	NULL
+};
+ATTRIBUTE_GROUPS(adc128);
+
+static int adc128_detect(struct i2c_client *client, struct i2c_board_info *info)
+{
+	int man_id, dev_id;
+
+	if (!i2c_check_functionality(client->adapter,
+				     I2C_FUNC_SMBUS_BYTE_DATA |
+				     I2C_FUNC_SMBUS_WORD_DATA))
+		return -ENODEV;
+
+	man_id = i2c_smbus_read_byte_data(client, ADC128_REG_MAN_ID);
+	dev_id = i2c_smbus_read_byte_data(client, ADC128_REG_DEV_ID);
+	if (man_id != 0x01 || dev_id != 0x09)
+		return -ENODEV;
+
+	/* Check unused bits for confirmation */
+	if (i2c_smbus_read_byte_data(client, ADC128_REG_CONFIG) & 0xf4)
+		return -ENODEV;
+	if (i2c_smbus_read_byte_data(client, ADC128_REG_CONV_RATE) & 0xfe)
+		return -ENODEV;
+	if (i2c_smbus_read_byte_data(client, ADC128_REG_ONESHOT) & 0xfe)
+		return -ENODEV;
+	if (i2c_smbus_read_byte_data(client, ADC128_REG_SHUTDOWN) & 0xfe)
+		return -ENODEV;
+	if (i2c_smbus_read_byte_data(client, ADC128_REG_CONFIG_ADV) & 0xf8)
+		return -ENODEV;
+	if (i2c_smbus_read_byte_data(client, ADC128_REG_BUSY_STATUS) & 0xfc)
+		return -ENODEV;
+
+	strlcpy(info->type, "adc128d818", I2C_NAME_SIZE);
+
+	return 0;
+}
+
+static int adc128_init_client(struct adc128_data *data)
+{
+	struct i2c_client *client = data->client;
+	int err;
+
+	/*
+	 * Reset chip to defaults.
+	 * This makes most other initializations unnecessary.
+	 */
+	err = i2c_smbus_write_byte_data(client, ADC128_REG_CONFIG, 0x80);
+	if (err)
+		return err;
+
+	/* Start monitoring */
+	err = i2c_smbus_write_byte_data(client, ADC128_REG_CONFIG, 0x01);
+	if (err)
+		return err;
+
+	/* If external vref is selected, configure the chip to use it */
+	if (data->regulator) {
+		err = i2c_smbus_write_byte_data(client,
+						ADC128_REG_CONFIG_ADV, 0x01);
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+
+static int adc128_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
+{
+	struct device *dev = &client->dev;
+	struct regulator *regulator;
+	struct device *hwmon_dev;
+	struct adc128_data *data;
+	int err, vref;
+
+	data = devm_kzalloc(dev, sizeof(struct adc128_data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	/* vref is optional. If specified, is used as chip reference voltage */
+	regulator = devm_regulator_get_optional(dev, "vref");
+	if (!IS_ERR(regulator)) {
+		data->regulator = regulator;
+		err = regulator_enable(regulator);
+		if (err < 0)
+			return err;
+		vref = regulator_get_voltage(regulator);
+		if (vref < 0) {
+			err = vref;
+			goto error;
+		}
+		data->vref = DIV_ROUND_CLOSEST(vref, 1000);
+	} else {
+		data->vref = 2560;	/* 2.56V, in mV */
+	}
+
+	data->client = client;
+	i2c_set_clientdata(client, data);
+	mutex_init(&data->update_lock);
+
+	/* Initialize the chip */
+	err = adc128_init_client(data);
+	if (err < 0)
+		goto error;
+
+	hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
+							   data, adc128_groups);
+	if (IS_ERR(hwmon_dev)) {
+		err = PTR_ERR(hwmon_dev);
+		goto error;
+	}
+
+	return 0;
+
+error:
+	if (data->regulator)
+		regulator_disable(data->regulator);
+	return err;
+}
+
+static int adc128_remove(struct i2c_client *client)
+{
+	struct adc128_data *data = i2c_get_clientdata(client);
+
+	if (data->regulator)
+		regulator_disable(data->regulator);
+
+	return 0;
+}
+
+static const struct i2c_device_id adc128_id[] = {
+	{ "adc128d818", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, adc128_id);
+
+static struct i2c_driver adc128_driver = {
+	.class		= I2C_CLASS_HWMON,
+	.driver = {
+		.name	= "adc128d818",
+	},
+	.probe		= adc128_probe,
+	.remove		= adc128_remove,
+	.id_table	= adc128_id,
+	.detect		= adc128_detect,
+	.address_list	= normal_i2c,
+};
+
+module_i2c_driver(adc128_driver);
+
+MODULE_AUTHOR("Guenter Roeck");
+MODULE_DESCRIPTION("Driver for ADC128D818");
+MODULE_LICENSE("GPL");