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 00000000000..0bf8b2a8e9f
--- /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);