hwmon: (tmp401) Add support for TI's TMP401 sensor chip

This is a new hwmon driver for TI's TMP401 temperature sensor IC. This driver
was written on behalf of an embedded systems vendor under the
Linux driver project.

It has been tested using a TI TMP401 sample attached to a i2c-tiny-usb adapter.
Which was provided by Till Harbaum, many thanks to him for this!

Signed-off-by: Hans de Goede <[e-mail]>
Signed-off-by: Jean Delvare <[e-mail]>

drivers/hwmon/Kconfig

···
 	  This driver can also be built as a module.  If so, the module
 	  will be called thmc50.
 
+config SENSORS_TMP401
+	tristate "Texas Instruments TMP401 and compatibles"
+	depends on I2C && EXPERIMENTAL
+	help
+	  If you say yes here you get support for Texas Instruments TMP401 and
+	  TMP411 temperature sensor chips.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called tmp401.
+
 config SENSORS_VIA686A
 	tristate "VIA686A"
 	depends on PCI

drivers/hwmon/Makefile

···
 obj-$(CONFIG_SENSORS_SMSC47M1)	+= smsc47m1.o
 obj-$(CONFIG_SENSORS_SMSC47M192)+= smsc47m192.o
 obj-$(CONFIG_SENSORS_THMC50)	+= thmc50.o
+obj-$(CONFIG_SENSORS_TMP401)	+= tmp401.o
 obj-$(CONFIG_SENSORS_VIA686A)	+= via686a.o
 obj-$(CONFIG_SENSORS_VT1211)	+= vt1211.o
 obj-$(CONFIG_SENSORS_VT8231)	+= vt8231.o

drivers/hwmon/tmp401.c

···
+/* tmp401.c
+ *
+ * Copyright (C) 2007,2008 Hans de Goede <[e-mail]>
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+/*
+ * Driver for the Texas Instruments TMP401 SMBUS temperature sensor IC.
+ *
+ * Note this IC is in some aspect similar to the LM90, but it has quite a
+ * few differences too, for example the local temp has a higher resolution
+ * and thus has 16 bits registers for its value and limit instead of 8 bits.
+ */
+
+#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/sysfs.h>
+
+/* Addresses to scan */
+static const unsigned short normal_i2c[] = { 0x4c, I2C_CLIENT_END };
+
+/* Insmod parameters */
+I2C_CLIENT_INSMOD_1(tmp401);
+
+
+/*
+ * The TMP401 registers, note some registers have different addresses for
+ * reading and writing
+ */
+#define TMP401_STATUS				0x02
+#define TMP401_CONFIG_READ			0x03
+#define TMP401_CONFIG_WRITE			0x09
+#define TMP401_CONVERSION_RATE_READ		0x04
+#define TMP401_CONVERSION_RATE_WRITE		0x0A
+#define TMP401_TEMP_CRIT_HYST			0x21
+#define TMP401_CONSECUTIVE_ALERT		0x22
+#define TMP401_MANUFACTURER_ID_REG		0xFE
+#define TMP401_DEVICE_ID_REG			0xFF
+
+static const u8 TMP401_TEMP_MSB[2]			= { 0x00, 0x01 };
+static const u8 TMP401_TEMP_LSB[2]			= { 0x15, 0x10 };
+static const u8 TMP401_TEMP_LOW_LIMIT_MSB_READ[2]	= { 0x06, 0x08 };
+static const u8 TMP401_TEMP_LOW_LIMIT_MSB_WRITE[2]	= { 0x0C, 0x0E };
+static const u8 TMP401_TEMP_LOW_LIMIT_LSB[2]		= { 0x17, 0x14 };
+static const u8 TMP401_TEMP_HIGH_LIMIT_MSB_READ[2]	= { 0x05, 0x07 };
+static const u8 TMP401_TEMP_HIGH_LIMIT_MSB_WRITE[2]	= { 0x0B, 0x0D };
+static const u8 TMP401_TEMP_HIGH_LIMIT_LSB[2]		= { 0x16, 0x13 };
+/* These are called the THERM limit / hysteresis / mask in the datasheet */
+static const u8 TMP401_TEMP_CRIT_LIMIT[2]		= { 0x20, 0x19 };
+
+/* Flags */
+#define TMP401_CONFIG_RANGE		0x04
+#define TMP401_CONFIG_SHUTDOWN		0x40
+#define TMP401_STATUS_LOCAL_CRIT		0x01
+#define TMP401_STATUS_REMOTE_CRIT		0x02
+#define TMP401_STATUS_REMOTE_OPEN		0x04
+#define TMP401_STATUS_REMOTE_LOW		0x08
+#define TMP401_STATUS_REMOTE_HIGH		0x10
+#define TMP401_STATUS_LOCAL_LOW		0x20
+#define TMP401_STATUS_LOCAL_HIGH		0x40
+
+/* Manufacturer / Device ID's */
+#define TMP401_MANUFACTURER_ID			0x55
+#define TMP401_DEVICE_ID			0x11
+
+/*
+ * Functions declarations
+ */
+
+static int tmp401_probe(struct i2c_client *client,
+			const struct i2c_device_id *id);
+static int tmp401_detect(struct i2c_client *client, int kind,
+			 struct i2c_board_info *info);
+static int tmp401_remove(struct i2c_client *client);
+static struct tmp401_data *tmp401_update_device(struct device *dev);
+
+/*
+ * Driver data (common to all clients)
+ */
+
+static const struct i2c_device_id tmp401_id[] = {
+	{ "tmp401", tmp401 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, tmp401_id);
+
+static struct i2c_driver tmp401_driver = {
+	.class		= I2C_CLASS_HWMON,
+	.driver = {
+		.name	= "tmp401",
+	},
+	.probe		= tmp401_probe,
+	.remove		= tmp401_remove,
+	.id_table	= tmp401_id,
+	.detect		= tmp401_detect,
+	.address_data	= &addr_data,
+};
+
+/*
+ * Client data (each client gets its own)
+ */
+
+struct tmp401_data {
+	struct device *hwmon_dev;
+	struct mutex update_lock;
+	char valid; /* zero until following fields are valid */
+	unsigned long last_updated; /* in jiffies */
+
+	/* register values */
+	u8 status;
+	u8 config;
+	u16 temp[2];
+	u16 temp_low[2];
+	u16 temp_high[2];
+	u8 temp_crit[2];
+	u8 temp_crit_hyst;
+};
+
+/*
+ * Sysfs attr show / store functions
+ */
+
+static int tmp401_register_to_temp(u16 reg, u8 config)
+{
+	int temp = reg;
+
+	if (config & TMP401_CONFIG_RANGE)
+		temp -= 64 * 256;
+
+	return (temp * 625 + 80) / 160;
+}
+
+static u16 tmp401_temp_to_register(long temp, u8 config)
+{
+	if (config & TMP401_CONFIG_RANGE) {
+		temp = SENSORS_LIMIT(temp, -64000, 191000);
+		temp += 64000;
+	} else
+		temp = SENSORS_LIMIT(temp, 0, 127000);
+
+	return (temp * 160 + 312) / 625;
+}
+
+static int tmp401_crit_register_to_temp(u8 reg, u8 config)
+{
+	int temp = reg;
+
+	if (config & TMP401_CONFIG_RANGE)
+		temp -= 64;
+
+	return temp * 1000;
+}
+
+static u8 tmp401_crit_temp_to_register(long temp, u8 config)
+{
+	if (config & TMP401_CONFIG_RANGE) {
+		temp = SENSORS_LIMIT(temp, -64000, 191000);
+		temp += 64000;
+	} else
+		temp = SENSORS_LIMIT(temp, 0, 127000);
+
+	return (temp + 500) / 1000;
+}
+
+static ssize_t show_temp_value(struct device *dev,
+	struct device_attribute *devattr, char *buf)
+{
+	int index = to_sensor_dev_attr(devattr)->index;
+	struct tmp401_data *data = tmp401_update_device(dev);
+
+	return sprintf(buf, "%d\n",
+		tmp401_register_to_temp(data->temp[index], data->config));
+}
+
+static ssize_t show_temp_min(struct device *dev,
+	struct device_attribute *devattr, char *buf)
+{
+	int index = to_sensor_dev_attr(devattr)->index;
+	struct tmp401_data *data = tmp401_update_device(dev);
+
+	return sprintf(buf, "%d\n",
+		tmp401_register_to_temp(data->temp_low[index], data->config));
+}
+
+static ssize_t show_temp_max(struct device *dev,
+	struct device_attribute *devattr, char *buf)
+{
+	int index = to_sensor_dev_attr(devattr)->index;
+	struct tmp401_data *data = tmp401_update_device(dev);
+
+	return sprintf(buf, "%d\n",
+		tmp401_register_to_temp(data->temp_high[index], data->config));
+}
+
+static ssize_t show_temp_crit(struct device *dev,
+	struct device_attribute *devattr, char *buf)
+{
+	int index = to_sensor_dev_attr(devattr)->index;
+	struct tmp401_data *data = tmp401_update_device(dev);
+
+	return sprintf(buf, "%d\n",
+			tmp401_crit_register_to_temp(data->temp_crit[index],
+							data->config));
+}
+
+static ssize_t show_temp_crit_hyst(struct device *dev,
+	struct device_attribute *devattr, char *buf)
+{
+	int temp, index = to_sensor_dev_attr(devattr)->index;
+	struct tmp401_data *data = tmp401_update_device(dev);
+
+	mutex_lock(&data->update_lock);
+	temp = tmp401_crit_register_to_temp(data->temp_crit[index],
+						data->config);
+	temp -= data->temp_crit_hyst * 1000;
+	mutex_unlock(&data->update_lock);
+
+	return sprintf(buf, "%d\n", temp);
+}
+
+static ssize_t show_status(struct device *dev,
+	struct device_attribute *devattr, char *buf)
+{
+	int mask = to_sensor_dev_attr(devattr)->index;
+	struct tmp401_data *data = tmp401_update_device(dev);
+
+	if (data->status & mask)
+		return sprintf(buf, "1\n");
+	else
+		return sprintf(buf, "0\n");
+}
+
+static ssize_t store_temp_min(struct device *dev, struct device_attribute
+	*devattr, const char *buf, size_t count)
+{
+	int index = to_sensor_dev_attr(devattr)->index;
+	struct tmp401_data *data = tmp401_update_device(dev);
+	long val;
+	u16 reg;
+
+	if (strict_strtol(buf, 10, &val))
+		return -EINVAL;
+
+	reg = tmp401_temp_to_register(val, data->config);
+
+	mutex_lock(&data->update_lock);
+
+	i2c_smbus_write_byte_data(to_i2c_client(dev),
+		TMP401_TEMP_LOW_LIMIT_MSB_WRITE[index], reg >> 8);
+	i2c_smbus_write_byte_data(to_i2c_client(dev),
+		TMP401_TEMP_LOW_LIMIT_LSB[index], reg & 0xFF);
+
+	data->temp_low[index] = reg;
+
+	mutex_unlock(&data->update_lock);
+
+	return count;
+}
+
+static ssize_t store_temp_max(struct device *dev, struct device_attribute
+	*devattr, const char *buf, size_t count)
+{
+	int index = to_sensor_dev_attr(devattr)->index;
+	struct tmp401_data *data = tmp401_update_device(dev);
+	long val;
+	u16 reg;
+
+	if (strict_strtol(buf, 10, &val))
+		return -EINVAL;
+
+	reg = tmp401_temp_to_register(val, data->config);
+
+	mutex_lock(&data->update_lock);
+
+	i2c_smbus_write_byte_data(to_i2c_client(dev),
+		TMP401_TEMP_HIGH_LIMIT_MSB_WRITE[index], reg >> 8);
+	i2c_smbus_write_byte_data(to_i2c_client(dev),
+		TMP401_TEMP_HIGH_LIMIT_LSB[index], reg & 0xFF);
+
+	data->temp_high[index] = reg;
+
+	mutex_unlock(&data->update_lock);
+
+	return count;
+}
+
+static ssize_t store_temp_crit(struct device *dev, struct device_attribute
+	*devattr, const char *buf, size_t count)
+{
+	int index = to_sensor_dev_attr(devattr)->index;
+	struct tmp401_data *data = tmp401_update_device(dev);
+	long val;
+	u8 reg;
+
+	if (strict_strtol(buf, 10, &val))
+		return -EINVAL;
+
+	reg = tmp401_crit_temp_to_register(val, data->config);
+
+	mutex_lock(&data->update_lock);
+
+	i2c_smbus_write_byte_data(to_i2c_client(dev),
+		TMP401_TEMP_CRIT_LIMIT[index], reg);
+
+	data->temp_crit[index] = reg;
+
+	mutex_unlock(&data->update_lock);
+
+	return count;
+}
+
+static ssize_t store_temp_crit_hyst(struct device *dev, struct device_attribute
+	*devattr, const char *buf, size_t count)
+{
+	int temp, index = to_sensor_dev_attr(devattr)->index;
+	struct tmp401_data *data = tmp401_update_device(dev);
+	long val;
+	u8 reg;
+
+	if (strict_strtol(buf, 10, &val))
+		return -EINVAL;
+
+	if (data->config & TMP401_CONFIG_RANGE)
+		val = SENSORS_LIMIT(val, -64000, 191000);
+	else
+		val = SENSORS_LIMIT(val, 0, 127000);
+
+	mutex_lock(&data->update_lock);
+	temp = tmp401_crit_register_to_temp(data->temp_crit[index],
+						data->config);
+	val = SENSORS_LIMIT(val, temp - 255000, temp);
+	reg = ((temp - val) + 500) / 1000;
+
+	i2c_smbus_write_byte_data(to_i2c_client(dev),
+		TMP401_TEMP_CRIT_HYST, reg);
+
+	data->temp_crit_hyst = reg;
+
+	mutex_unlock(&data->update_lock);
+
+	return count;
+}
+
+static struct sensor_device_attribute tmp401_attr[] = {
+	SENSOR_ATTR(temp1_input, 0444, show_temp_value, NULL, 0),
+	SENSOR_ATTR(temp1_min, 0644, show_temp_min, store_temp_min, 0),
+	SENSOR_ATTR(temp1_max, 0644, show_temp_max, store_temp_max, 0),
+	SENSOR_ATTR(temp1_crit, 0644, show_temp_crit, store_temp_crit, 0),
+	SENSOR_ATTR(temp1_crit_hyst, 0644, show_temp_crit_hyst,
+		    store_temp_crit_hyst, 0),
+	SENSOR_ATTR(temp1_min_alarm, 0444, show_status, NULL,
+		    TMP401_STATUS_LOCAL_LOW),
+	SENSOR_ATTR(temp1_max_alarm, 0444, show_status, NULL,
+		    TMP401_STATUS_LOCAL_HIGH),
+	SENSOR_ATTR(temp1_crit_alarm, 0444, show_status, NULL,
+		    TMP401_STATUS_LOCAL_CRIT),
+	SENSOR_ATTR(temp2_input, 0444, show_temp_value, NULL, 1),
+	SENSOR_ATTR(temp2_min, 0644, show_temp_min, store_temp_min, 1),
+	SENSOR_ATTR(temp2_max, 0644, show_temp_max, store_temp_max, 1),
+	SENSOR_ATTR(temp2_crit, 0644, show_temp_crit, store_temp_crit, 1),
+	SENSOR_ATTR(temp2_crit_hyst, 0444, show_temp_crit_hyst, NULL, 1),
+	SENSOR_ATTR(temp2_fault, 0444, show_status, NULL,
+		    TMP401_STATUS_REMOTE_OPEN),
+	SENSOR_ATTR(temp2_min_alarm, 0444, show_status, NULL,
+		    TMP401_STATUS_REMOTE_LOW),
+	SENSOR_ATTR(temp2_max_alarm, 0444, show_status, NULL,
+		    TMP401_STATUS_REMOTE_HIGH),
+	SENSOR_ATTR(temp2_crit_alarm, 0444, show_status, NULL,
+		    TMP401_STATUS_REMOTE_CRIT),
+};
+
+/*
+ * Begin non sysfs callback code (aka Real code)
+ */
+
+static void tmp401_init_client(struct i2c_client *client)
+{
+	int config, config_orig;
+
+	/* Set the conversion rate to 2 Hz */
+	i2c_smbus_write_byte_data(client, TMP401_CONVERSION_RATE_WRITE, 5);
+
+	/* Start conversions (disable shutdown if necessary) */
+	config = i2c_smbus_read_byte_data(client, TMP401_CONFIG_READ);
+	if (config < 0) {
+		dev_warn(&client->dev, "Initialization failed!\n");
+		return;
+	}
+
+	config_orig = config;
+	config &= ~TMP401_CONFIG_SHUTDOWN;
+
+	if (config != config_orig)
+		i2c_smbus_write_byte_data(client, TMP401_CONFIG_WRITE, config);
+}
+
+static int tmp401_detect(struct i2c_client *client, int kind,
+			 struct i2c_board_info *info)
+{
+	struct i2c_adapter *adapter = client->adapter;
+
+	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
+		return -ENODEV;
+
+	/* Detect and identify the chip */
+	if (kind <= 0) {
+		u8 reg;
+
+		reg = i2c_smbus_read_byte_data(client,
+					       TMP401_MANUFACTURER_ID_REG);
+		if (reg != TMP401_MANUFACTURER_ID)
+			return -ENODEV;
+
+		reg = i2c_smbus_read_byte_data(client, TMP401_DEVICE_ID_REG);
+		if (reg != TMP401_DEVICE_ID)
+			return -ENODEV;
+
+		reg = i2c_smbus_read_byte_data(client, TMP401_CONFIG_READ);
+		if (reg & 0x1b)
+			return -ENODEV;
+
+		reg = i2c_smbus_read_byte_data(client,
+					       TMP401_CONVERSION_RATE_READ);
+		if (reg > 15)
+			return -ENODEV;
+	}
+	strlcpy(info->type, "tmp401", I2C_NAME_SIZE);
+
+	return 0;
+}
+
+static int tmp401_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
+{
+	int i, err = 0;
+	struct tmp401_data *data;
+
+	data = kzalloc(sizeof(struct tmp401_data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	i2c_set_clientdata(client, data);
+	mutex_init(&data->update_lock);
+
+	/* Initialize the TMP401 chip */
+	tmp401_init_client(client);
+
+	/* Register sysfs hooks */
+	for (i = 0; i < ARRAY_SIZE(tmp401_attr); i++) {
+		err = device_create_file(&client->dev,
+					 &tmp401_attr[i].dev_attr);
+		if (err)
+			goto exit_remove;
+	}
+
+	data->hwmon_dev = hwmon_device_register(&client->dev);
+	if (IS_ERR(data->hwmon_dev)) {
+		err = PTR_ERR(data->hwmon_dev);
+		data->hwmon_dev = NULL;
+		goto exit_remove;
+	}
+
+	dev_info(&client->dev, "Detected TI TMP401 chip\n");
+
+	return 0;
+
+exit_remove:
+	tmp401_remove(client); /* will also free data for us */
+	return err;
+}
+
+static int tmp401_remove(struct i2c_client *client)
+{
+	struct tmp401_data *data = i2c_get_clientdata(client);
+	int i;
+
+	if (data->hwmon_dev)
+		hwmon_device_unregister(data->hwmon_dev);
+
+	for (i = 0; i < ARRAY_SIZE(tmp401_attr); i++)
+		device_remove_file(&client->dev, &tmp401_attr[i].dev_attr);
+
+	kfree(data);
+	return 0;
+}
+
+static struct tmp401_data *tmp401_update_device(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct tmp401_data *data = i2c_get_clientdata(client);
+	int i;
+
+	mutex_lock(&data->update_lock);
+
+	if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
+		data->status = i2c_smbus_read_byte_data(client, TMP401_STATUS);
+		data->config = i2c_smbus_read_byte_data(client,
+						TMP401_CONFIG_READ);
+		for (i = 0; i < 2; i++) {
+			/* High byte must be read first immediately followed
+			   by the low byte */
+			data->temp[i] = i2c_smbus_read_byte_data(client,
+						TMP401_TEMP_MSB[i]) << 8;
+			data->temp[i] |= i2c_smbus_read_byte_data(client,
+						TMP401_TEMP_LSB[i]);
+			data->temp_low[i] = i2c_smbus_read_byte_data(client,
+				TMP401_TEMP_LOW_LIMIT_MSB_READ[i]) << 8;
+			data->temp_low[i] |= i2c_smbus_read_byte_data(client,
+						TMP401_TEMP_LOW_LIMIT_LSB[i]);
+			data->temp_high[i] = i2c_smbus_read_byte_data(client,
+				TMP401_TEMP_HIGH_LIMIT_MSB_READ[i]) << 8;
+			data->temp_high[i] |= i2c_smbus_read_byte_data(client,
+						TMP401_TEMP_HIGH_LIMIT_LSB[i]);
+			data->temp_crit[i] = i2c_smbus_read_byte_data(client,
+						TMP401_TEMP_CRIT_LIMIT[i]);
+		}
+
+		data->temp_crit_hyst = i2c_smbus_read_byte_data(client,
+						TMP401_TEMP_CRIT_HYST);
+
+		data->last_updated = jiffies;
+		data->valid = 1;
+	}
+
+	mutex_unlock(&data->update_lock);
+
+	return data;
+}
+
+static int __init tmp401_init(void)
+{
+	return i2c_add_driver(&tmp401_driver);
+}
+
+static void __exit tmp401_exit(void)
+{
+	i2c_del_driver(&tmp401_driver);
+}
+
+MODULE_AUTHOR("Hans de Goede <[e-mail]>");
+MODULE_DESCRIPTION("Texas Instruments TMP401 temperature sensor driver");
+MODULE_LICENSE("GPL");
+
+module_init(tmp401_init);
+module_exit(tmp401_exit);