hwmon: New driver for the National Semiconductor LM73

The National Semiconductor LM73 is a single temperature sensor, much
like the famous LM75.

Signed-off-by: Adrien Demarez <adrien.demarez@bolloretelecom.eu>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

1 files changed, 205 insertions, 0 deletions

diff --git a/drivers/hwmon/lm73.c b/drivers/hwmon/lm73.c
new file mode 100644
index 000000000000..0bf8b2a8e9f0
--- /dev/null
+++ b/drivers/hwmon/lm73.c
@@ -0,0 +1,205 @@
+/*
+ * LM73 Sensor driver
+ * Based on LM75
+ *
+ * Copyright (C) 2007, CenoSYS (www.cenosys.com).
+ * Copyright (C) 2009, Bollore telecom (www.bolloretelecom.eu).
+ *
+ * Guillaume Ligneul <guillaume.ligneul@gmail.com>
+ * Adrien Demarez <adrien.demarez@bolloretelecom.eu>
+ * Jeremy Laine <jeremy.laine@bolloretelecom.eu>
+ *
+ * This software program is licensed subject to the GNU General Public License
+ * (GPL).Version 2,June 1991, available at
+ * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/err.h>
+
+
+/* Addresses scanned */
+static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4c,
+					0x4d, 0x4e, I2C_CLIENT_END };
+
+/* Insmod parameters */
+I2C_CLIENT_INSMOD_1(lm73);
+
+/* LM73 registers */
+#define LM73_REG_INPUT		0x00
+#define LM73_REG_CONF		0x01
+#define LM73_REG_MAX		0x02
+#define LM73_REG_MIN		0x03
+#define LM73_REG_CTRL		0x04
+#define LM73_REG_ID		0x07
+
+#define LM73_ID			0x9001 /* or 0x190 after a swab16() */
+#define DRVNAME			"lm73"
+#define LM73_TEMP_MIN		(-40)
+#define LM73_TEMP_MAX		150
+
+/*-----------------------------------------------------------------------*/
+
+
+static ssize_t set_temp(struct device *dev, struct device_attribute *da,
+			const char *buf, size_t count)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
+	struct i2c_client *client = to_i2c_client(dev);
+	long temp;
+	short value;
+
+	int status = strict_strtol(buf, 10, &temp);
+	if (status < 0)
+		return status;
+
+	/* Write value */
+	value = (short) SENSORS_LIMIT(temp/250, (LM73_TEMP_MIN*4),
+		(LM73_TEMP_MAX*4)) << 5;
+	i2c_smbus_write_word_data(client, attr->index, swab16(value));
+	return count;
+}
+
+static ssize_t show_temp(struct device *dev, struct device_attribute *da,
+			 char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
+	struct i2c_client *client = to_i2c_client(dev);
+	/* use integer division instead of equivalent right shift to
+	   guarantee arithmetic shift and preserve the sign */
+	int temp = ((s16) (swab16(i2c_smbus_read_word_data(client,
+		attr->index)))*250) / 32;
+	return sprintf(buf, "%d\n", temp);
+}
+
+
+/*-----------------------------------------------------------------------*/
+
+/* sysfs attributes for hwmon */
+
+static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
+			show_temp, set_temp, LM73_REG_MAX);
+static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO,
+			show_temp, set_temp, LM73_REG_MIN);
+static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO,
+			show_temp, NULL, LM73_REG_INPUT);
+
+
+static struct attribute *lm73_attributes[] = {
+	&sensor_dev_attr_temp1_input.dev_attr.attr,
+	&sensor_dev_attr_temp1_max.dev_attr.attr,
+	&sensor_dev_attr_temp1_min.dev_attr.attr,
+
+	NULL
+};
+
+static const struct attribute_group lm73_group = {
+	.attrs = lm73_attributes,
+};
+
+/*-----------------------------------------------------------------------*/
+
+/* device probe and removal */
+
+static int
+lm73_probe(struct i2c_client *client, const struct i2c_device_id *id)
+{
+	struct device *hwmon_dev;
+	int status;
+
+	/* Register sysfs hooks */
+	status = sysfs_create_group(&client->dev.kobj, &lm73_group);
+	if (status)
+		return status;
+
+	hwmon_dev = hwmon_device_register(&client->dev);
+	if (IS_ERR(hwmon_dev)) {
+		status = PTR_ERR(hwmon_dev);
+		goto exit_remove;
+	}
+	i2c_set_clientdata(client, hwmon_dev);
+
+	dev_info(&client->dev, "%s: sensor '%s'\n",
+		 dev_name(hwmon_dev), client->name);
+
+	return 0;
+
+exit_remove:
+	sysfs_remove_group(&client->dev.kobj, &lm73_group);
+	return status;
+}
+
+static int lm73_remove(struct i2c_client *client)
+{
+	struct device *hwmon_dev = i2c_get_clientdata(client);
+
+	hwmon_device_unregister(hwmon_dev);
+	sysfs_remove_group(&client->dev.kobj, &lm73_group);
+	i2c_set_clientdata(client, NULL);
+	return 0;
+}
+
+static const struct i2c_device_id lm73_ids[] = {
+	{ "lm73", lm73 },
+	{ /* LIST END */ }
+};
+MODULE_DEVICE_TABLE(i2c, lm73_ids);
+
+/* Return 0 if detection is successful, -ENODEV otherwise */
+static int lm73_detect(struct i2c_client *new_client, int kind,
+			struct i2c_board_info *info)
+{
+	struct i2c_adapter *adapter = new_client->adapter;
+	u16 id;
+	u8 ctrl;
+
+	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
+					I2C_FUNC_SMBUS_WORD_DATA))
+		return -ENODEV;
+
+	/* Check device ID */
+	id = i2c_smbus_read_word_data(new_client, LM73_REG_ID);
+	ctrl = i2c_smbus_read_byte_data(new_client, LM73_REG_CTRL);
+	if ((id != LM73_ID) || (ctrl & 0x10))
+		return -ENODEV;
+
+	strlcpy(info->type, "lm73", I2C_NAME_SIZE);
+
+	return 0;
+}
+
+static struct i2c_driver lm73_driver = {
+	.class		= I2C_CLASS_HWMON,
+	.driver = {
+		.name	= "lm73",
+	},
+	.probe		= lm73_probe,
+	.remove		= lm73_remove,
+	.id_table	= lm73_ids,
+	.detect		= lm73_detect,
+	.address_data	= &addr_data,
+};
+
+/* module glue */
+
+static int __init sensors_lm73_init(void)
+{
+	return i2c_add_driver(&lm73_driver);
+}
+
+static void __exit sensors_lm73_exit(void)
+{
+	i2c_del_driver(&lm73_driver);
+}
+
+MODULE_AUTHOR("Guillaume Ligneul <guillaume.ligneul@gmail.com>");
+MODULE_DESCRIPTION("LM73 driver");
+MODULE_LICENSE("GPL");
+
+module_init(sensors_lm73_init);
+module_exit(sensors_lm73_exit);