hwmon: ad7414 driver

Driver for the Analog Devices AD7414 temperature monitoring chip.

Signed-off-by: Sean MacLennan <smaclennan@pikatech.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

3 files changed, 279 insertions, 0 deletions

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 7fe392899908..bf4ebfb86fa5 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -57,6 +57,16 @@ config SENSORS_ABITUGURU3
           This driver can also be built as a module.  If so, the module
           will be called abituguru3.
 
+config SENSORS_AD7414
+        tristate "Analog Devices AD7414"
+        depends on I2C && EXPERIMENTAL
+        help
+          If you say yes here you get support for the Analog Devices
+          AD7414 temperature monitoring chip.
+
+          This driver can also be built as a module. If so, the module
+          will be called ad7414.
+
 config SENSORS_AD7418
         tristate "Analog Devices AD7416, AD7417 and AD7418"
         depends on I2C && EXPERIMENTAL
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index d098677e08de..7943e5cefb06 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -15,6 +15,7 @@ obj-$(CONFIG_SENSORS_W83791D)	+= w83791d.o
 
 obj-$(CONFIG_SENSORS_ABITUGURU) += abituguru.o
 obj-$(CONFIG_SENSORS_ABITUGURU3)+= abituguru3.o
+obj-$(CONFIG_SENSORS_AD7414)    += ad7414.o
 obj-$(CONFIG_SENSORS_AD7418)    += ad7418.o
 obj-$(CONFIG_SENSORS_ADM1021)   += adm1021.o
 obj-$(CONFIG_SENSORS_ADM1025)   += adm1025.o
diff --git a/drivers/hwmon/ad7414.c b/drivers/hwmon/ad7414.c
new file mode 100644
index 000000000000..ce8d94fbfd7e
--- /dev/null
+++ b/drivers/hwmon/ad7414.c
@@ -0,0 +1,268 @@
+/*
+ * An hwmon driver for the Analog Devices AD7414
+ *
+ * Copyright 2006 Stefan Roese <sr at denx.de>, DENX Software Engineering
+ *
+ * Copyright (c) 2008 PIKA Technologies
+ *   Sean MacLennan <smaclennan@pikatech.com>
+ *
+ * Copyright (c) 2008 Spansion Inc.
+ *   Frank Edelhaeuser <frank.edelhaeuser at spansion.com>
+ *   (converted to "new style" I2C driver model, removed checkpatch.pl warnings)
+ *
+ * Based on ad7418.c
+ * Copyright 2006 Tower Technologies, Alessandro Zummo <a.zummo at towertech.it>
+ *
+ * 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.
+ */
+
+#include <linux/module.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>
+
+
+/* AD7414 registers */
+#define AD7414_REG_TEMP         0x00
+#define AD7414_REG_CONF         0x01
+#define AD7414_REG_T_HIGH       0x02
+#define AD7414_REG_T_LOW        0x03
+
+static u8 AD7414_REG_LIMIT[] = { AD7414_REG_T_HIGH, AD7414_REG_T_LOW };
+
+struct ad7414_data {
+        struct device           *hwmon_dev;
+        struct mutex            lock;   /* atomic read data updates */
+        char                    valid;  /* !=0 if following fields are valid */
+        unsigned long           next_update;    /* In jiffies */
+        s16                     temp_input;     /* Register values */
+        s8                      temps[ARRAY_SIZE(AD7414_REG_LIMIT)];
+};
+
+/* REG: (0.25C/bit, two's complement) << 6 */
+static inline int ad7414_temp_from_reg(s16 reg)
+{
+        /* use integer division instead of equivalent right shift to
+         * guarantee arithmetic shift and preserve the sign
+         */
+        return ((int)reg / 64) * 250;
+}
+
+static inline int ad7414_read(struct i2c_client *client, u8 reg)
+{
+        if (reg == AD7414_REG_TEMP) {
+                int value = i2c_smbus_read_word_data(client, reg);
+                return (value < 0) ? value : swab16(value);
+        } else
+                return i2c_smbus_read_byte_data(client, reg);
+}
+
+static inline int ad7414_write(struct i2c_client *client, u8 reg, u8 value)
+{
+        return i2c_smbus_write_byte_data(client, reg, value);
+}
+
+struct ad7414_data *ad7414_update_device(struct device *dev)
+{
+        struct i2c_client *client = to_i2c_client(dev);
+        struct ad7414_data *data = i2c_get_clientdata(client);
+
+        mutex_lock(&data->lock);
+
+        if (time_after(jiffies, data->next_update) || !data->valid) {
+                int value, i;
+
+                dev_dbg(&client->dev, "starting ad7414 update\n");
+
+                value = ad7414_read(client, AD7414_REG_TEMP);
+                if (value < 0)
+                        dev_dbg(&client->dev, "AD7414_REG_TEMP err %d\n",
+                                value);
+                else
+                        data->temp_input = value;
+
+                for (i = 0; i < ARRAY_SIZE(AD7414_REG_LIMIT); ++i) {
+                        value = ad7414_read(client, AD7414_REG_LIMIT[i]);
+                        if (value < 0)
+                                dev_dbg(&client->dev, "AD7414 reg %d err %d\n",
+                                        AD7414_REG_LIMIT[i], value);
+                        else
+                                data->temps[i] = value;
+                }
+
+                data->next_update = jiffies + HZ + HZ / 2;
+                data->valid = 1;
+        }
+
+        mutex_unlock(&data->lock);
+
+        return data;
+}
+
+static ssize_t show_temp_input(struct device *dev,
+                               struct device_attribute *attr, char *buf)
+{
+        struct ad7414_data *data = ad7414_update_device(dev);
+        return sprintf(buf, "%d\n", ad7414_temp_from_reg(data->temp_input));
+}
+static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_input, NULL, 0);
+
+static ssize_t show_max_min(struct device *dev, struct device_attribute *attr,
+                          char *buf)
+{
+        int index = to_sensor_dev_attr(attr)->index;
+        struct ad7414_data *data = ad7414_update_device(dev);
+        return sprintf(buf, "%d\n", data->temps[index] * 1000);
+}
+
+static ssize_t set_max_min(struct device *dev,
+                           struct device_attribute *attr,
+                           const char *buf, size_t count)
+{
+        struct i2c_client *client = to_i2c_client(dev);
+        struct ad7414_data *data = i2c_get_clientdata(client);
+        int index = to_sensor_dev_attr(attr)->index;
+        u8 reg = AD7414_REG_LIMIT[index];
+        long temp = simple_strtol(buf, NULL, 10);
+
+        temp = SENSORS_LIMIT(temp, -40000, 85000);
+        temp = (temp + (temp < 0 ? -500 : 500)) / 1000;
+
+        mutex_lock(&data->lock);
+        data->temps[index] = temp;
+        ad7414_write(client, reg, temp);
+        mutex_unlock(&data->lock);
+        return count;
+}
+
+static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
+                          show_max_min, set_max_min, 0);
+static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO,
+                          show_max_min, set_max_min, 1);
+
+static ssize_t show_alarm(struct device *dev, struct device_attribute *attr,
+                          char *buf)
+{
+        int bitnr = to_sensor_dev_attr(attr)->index;
+        struct ad7414_data *data = ad7414_update_device(dev);
+        int value = (data->temp_input >> bitnr) & 1;
+        return sprintf(buf, "%d\n", value);
+}
+
+static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 3);
+static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 4);
+
+static struct attribute *ad7414_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,
+        &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
+        &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
+        NULL
+};
+
+static const struct attribute_group ad7414_group = {
+        .attrs = ad7414_attributes,
+};
+
+static int ad7414_probe(struct i2c_client *client,
+                        const struct i2c_device_id *dev_id)
+{
+        struct ad7414_data *data;
+        int conf;
+        int err = 0;
+
+        if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA |
+                                     I2C_FUNC_SMBUS_READ_WORD_DATA))
+                goto exit;
+
+        data = kzalloc(sizeof(struct ad7414_data), GFP_KERNEL);
+        if (!data) {
+                err = -ENOMEM;
+                goto exit;
+        }
+
+        i2c_set_clientdata(client, data);
+        mutex_init(&data->lock);
+
+        dev_info(&client->dev, "chip found\n");
+
+        /* Make sure the chip is powered up. */
+        conf = i2c_smbus_read_byte_data(client, AD7414_REG_CONF);
+        if (conf < 0)
+                dev_warn(&client->dev,
+                         "ad7414_probe unable to read config register.\n");
+        else {
+                conf &= ~(1 << 7);
+                i2c_smbus_write_byte_data(client, AD7414_REG_CONF, conf);
+        }
+
+        /* Register sysfs hooks */
+        err = sysfs_create_group(&client->dev.kobj, &ad7414_group);
+        if (err)
+                goto exit_free;
+
+        data->hwmon_dev = hwmon_device_register(&client->dev);
+        if (IS_ERR(data->hwmon_dev)) {
+                err = PTR_ERR(data->hwmon_dev);
+                goto exit_remove;
+        }
+
+        return 0;
+
+exit_remove:
+        sysfs_remove_group(&client->dev.kobj, &ad7414_group);
+exit_free:
+        kfree(data);
+exit:
+        return err;
+}
+
+static int __devexit ad7414_remove(struct i2c_client *client)
+{
+        struct ad7414_data *data = i2c_get_clientdata(client);
+
+        hwmon_device_unregister(data->hwmon_dev);
+        sysfs_remove_group(&client->dev.kobj, &ad7414_group);
+        kfree(data);
+        return 0;
+}
+
+static const struct i2c_device_id ad7414_id[] = {
+        { "ad7414", 0 },
+        {}
+};
+
+static struct i2c_driver ad7414_driver = {
+        .driver = {
+                .name   = "ad7414",
+        },
+        .probe  = ad7414_probe,
+        .remove = __devexit_p(ad7414_remove),
+        .id_table = ad7414_id,
+};
+
+static int __init ad7414_init(void)
+{
+        return i2c_add_driver(&ad7414_driver);
+}
+module_init(ad7414_init);
+
+static void __exit ad7414_exit(void)
+{
+        i2c_del_driver(&ad7414_driver);
+}
+module_exit(ad7414_exit);
+
+MODULE_AUTHOR("Stefan Roese <sr at denx.de>, "
+              "Frank Edelhaeuser <frank.edelhaeuser at spansion.com>");
+
+MODULE_DESCRIPTION("AD7414 driver");
+MODULE_LICENSE("GPL");