hwmon: Driver for ADT7410

This patch brings basic support for the Analog Devices ADT7410 temperature
sensor. The following functionality has been implemented:

  * get current temperature
  * get/set minimum, maximum and critical temperature
  * get/set hysteresis
  * get alarm events for minimum, maximum and critical temperature

All implemented sysfs attributes have been sucessfully tested at temperatures
of 15°C to 40°C.

Signed-off-by: Hartmut Knaack <knaack.h@gmx.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

1 files changed, 459 insertions, 0 deletions

diff --git a/drivers/hwmon/adt7410.c b/drivers/hwmon/adt7410.c
new file mode 100644
index 000000000000..f8606dff3d1c
--- /dev/null
+++ b/drivers/hwmon/adt7410.c
@@ -0,0 +1,459 @@
+/*
+ * adt7410.c - Part of lm_sensors, Linux kernel modules for hardware
+ *       monitoring
+ * This driver handles the ADT7410 and compatible digital temperature sensors.
+ * Hartmut Knaack <knaack.h@gmx.de> 2012-07-22
+ * based on lm75.c by Frodo Looijaard <frodol@dds.nl>
+ * and adt7410.c from iio-staging by Sonic Zhang <sonic.zhang@analog.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.
+ *
+ * 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.
+ */
+
+#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/delay.h>
+
+/*
+ * ADT7410 registers definition
+ */
+
+#define ADT7410_TEMPERATURE             0
+#define ADT7410_STATUS                  2
+#define ADT7410_CONFIG                  3
+#define ADT7410_T_ALARM_HIGH            4
+#define ADT7410_T_ALARM_LOW             6
+#define ADT7410_T_CRIT                  8
+#define ADT7410_T_HYST                  0xA
+
+/*
+ * ADT7410 status
+ */
+#define ADT7410_STAT_T_LOW              (1 << 4)
+#define ADT7410_STAT_T_HIGH             (1 << 5)
+#define ADT7410_STAT_T_CRIT             (1 << 6)
+#define ADT7410_STAT_NOT_RDY            (1 << 7)
+
+/*
+ * ADT7410 config
+ */
+#define ADT7410_FAULT_QUEUE_MASK        (1 << 0 | 1 << 1)
+#define ADT7410_CT_POLARITY             (1 << 2)
+#define ADT7410_INT_POLARITY            (1 << 3)
+#define ADT7410_EVENT_MODE              (1 << 4)
+#define ADT7410_MODE_MASK               (1 << 5 | 1 << 6)
+#define ADT7410_FULL                    (0 << 5 | 0 << 6)
+#define ADT7410_PD                      (1 << 5 | 1 << 6)
+#define ADT7410_RESOLUTION              (1 << 7)
+
+/*
+ * ADT7410 masks
+ */
+#define ADT7410_T13_VALUE_MASK                  0xFFF8
+#define ADT7410_T_HYST_MASK                     0xF
+
+/* straight from the datasheet */
+#define ADT7410_TEMP_MIN (-55000)
+#define ADT7410_TEMP_MAX 150000
+
+enum adt7410_type {             /* keep sorted in alphabetical order */
+        adt7410,
+};
+
+/* Addresses scanned */
+static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b,
+                                        I2C_CLIENT_END };
+
+static const u8 ADT7410_REG_TEMP[4] = {
+        ADT7410_TEMPERATURE,            /* input */
+        ADT7410_T_ALARM_HIGH,           /* high */
+        ADT7410_T_ALARM_LOW,            /* low */
+        ADT7410_T_CRIT,                 /* critical */
+};
+
+/* Each client has this additional data */
+struct adt7410_data {
+        struct device           *hwmon_dev;
+        struct mutex            update_lock;
+        u8                      config;
+        u8                      oldconfig;
+        bool                    valid;          /* true if registers valid */
+        unsigned long           last_updated;   /* In jiffies */
+        s16                     temp[4];        /* Register values,
+                                                   0 = input
+                                                   1 = high
+                                                   2 = low
+                                                   3 = critical */
+        u8                      hyst;           /* hysteresis offset */
+};
+
+/*
+ * adt7410 register access by I2C
+ */
+static int adt7410_temp_ready(struct i2c_client *client)
+{
+        int i, status;
+
+        for (i = 0; i < 6; i++) {
+                status = i2c_smbus_read_byte_data(client, ADT7410_STATUS);
+                if (status < 0)
+                        return status;
+                if (!(status & ADT7410_STAT_NOT_RDY))
+                        return 0;
+                msleep(60);
+        }
+        return -ETIMEDOUT;
+}
+
+static struct adt7410_data *adt7410_update_device(struct device *dev)
+{
+        struct i2c_client *client = to_i2c_client(dev);
+        struct adt7410_data *data = i2c_get_clientdata(client);
+        struct adt7410_data *ret = data;
+        mutex_lock(&data->update_lock);
+
+        if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
+            || !data->valid) {
+                int i, status;
+
+                dev_dbg(&client->dev, "Starting update\n");
+
+                status = adt7410_temp_ready(client); /* check for new value */
+                if (unlikely(status)) {
+                        ret = ERR_PTR(status);
+                        goto abort;
+                }
+                for (i = 0; i < ARRAY_SIZE(data->temp); i++) {
+                        status = i2c_smbus_read_word_swapped(client,
+                                                        ADT7410_REG_TEMP[i]);
+                        if (unlikely(status < 0)) {
+                                dev_dbg(dev,
+                                        "Failed to read value: reg %d, error %d\n",
+                                        ADT7410_REG_TEMP[i], status);
+                                ret = ERR_PTR(status);
+                                goto abort;
+                        }
+                        data->temp[i] = status;
+                }
+                status = i2c_smbus_read_byte_data(client, ADT7410_T_HYST);
+                if (unlikely(status < 0)) {
+                        dev_dbg(dev,
+                                "Failed to read value: reg %d, error %d\n",
+                                ADT7410_T_HYST, status);
+                        ret = ERR_PTR(status);
+                        goto abort;
+                }
+                data->hyst = status;
+                data->last_updated = jiffies;
+                data->valid = true;
+        }
+
+abort:
+        mutex_unlock(&data->update_lock);
+        return ret;
+}
+
+static s16 ADT7410_TEMP_TO_REG(long temp)
+{
+        return DIV_ROUND_CLOSEST(SENSORS_LIMIT(temp, ADT7410_TEMP_MIN,
+                                               ADT7410_TEMP_MAX) * 128, 1000);
+}
+
+static int ADT7410_REG_TO_TEMP(struct adt7410_data *data, s16 reg)
+{
+        /* in 13 bit mode, bits 0-2 are status flags - mask them out */
+        if (!(data->config & ADT7410_RESOLUTION))
+                reg &= ADT7410_T13_VALUE_MASK;
+        /*
+         * temperature is stored in twos complement format, in steps of
+         * 1/128°C
+         */
+        return DIV_ROUND_CLOSEST(reg * 1000, 128);
+}
+
+/*-----------------------------------------------------------------------*/
+
+/* sysfs attributes for hwmon */
+
+static ssize_t adt7410_show_temp(struct device *dev,
+                                 struct device_attribute *da, char *buf)
+{
+        struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
+        struct adt7410_data *data = adt7410_update_device(dev);
+
+        if (IS_ERR(data))
+                return PTR_ERR(data);
+
+        return sprintf(buf, "%d\n", ADT7410_REG_TO_TEMP(data,
+                       data->temp[attr->index]));
+}
+
+static ssize_t adt7410_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);
+        struct adt7410_data *data = i2c_get_clientdata(client);
+        int nr = attr->index;
+        long temp;
+        int ret;
+
+        ret = kstrtol(buf, 10, &temp);
+        if (ret)
+                return ret;
+
+        mutex_lock(&data->update_lock);
+        data->temp[nr] = ADT7410_TEMP_TO_REG(temp);
+        ret = i2c_smbus_write_word_swapped(client, ADT7410_REG_TEMP[nr],
+                                           data->temp[nr]);
+        if (ret)
+                count = ret;
+        mutex_unlock(&data->update_lock);
+        return count;
+}
+
+static ssize_t adt7410_show_t_hyst(struct device *dev,
+                                   struct device_attribute *da,
+                                   char *buf)
+{
+        struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
+        struct adt7410_data *data = adt7410_update_device(dev);
+        int nr = attr->index;
+        int hyst = (data->hyst & ADT7410_T_HYST_MASK) * 1000;
+
+        /*
+         * hysteresis is stored as a 4 bit offset in the device, convert it
+         * to an absolute value
+         */
+        if (nr == 2)    /* min has positive offset, others have negative */
+                hyst = -hyst;
+        return sprintf(buf, "%d\n",
+                       ADT7410_REG_TO_TEMP(data, data->temp[nr]) - hyst);
+}
+
+static ssize_t adt7410_set_t_hyst(struct device *dev,
+                                  struct device_attribute *da,
+                                  const char *buf, size_t count)
+{
+        struct i2c_client *client = to_i2c_client(dev);
+        struct adt7410_data *data = i2c_get_clientdata(client);
+        int limit, ret;
+        long hyst;
+
+        ret = kstrtol(buf, 10, &hyst);
+        if (ret)
+                return ret;
+        /* convert absolute hysteresis value to a 4 bit delta value */
+        limit = ADT7410_REG_TO_TEMP(data, data->temp[1]);
+        hyst = SENSORS_LIMIT(hyst, ADT7410_TEMP_MIN, ADT7410_TEMP_MAX);
+        data->hyst = SENSORS_LIMIT(DIV_ROUND_CLOSEST(limit - hyst, 1000),
+                                   0, ADT7410_T_HYST_MASK);
+        ret = i2c_smbus_write_byte_data(client, ADT7410_T_HYST, data->hyst);
+        if (ret)
+                return ret;
+
+        return count;
+}
+
+static ssize_t adt7410_show_alarm(struct device *dev,
+                                  struct device_attribute *da,
+                                  char *buf)
+{
+        struct i2c_client *client = to_i2c_client(dev);
+        struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
+        int ret;
+
+        ret = i2c_smbus_read_byte_data(client, ADT7410_STATUS);
+        if (ret < 0)
+                return ret;
+
+        return sprintf(buf, "%d\n", !!(ret & attr->index));
+}
+
+static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, adt7410_show_temp, NULL, 0);
+static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
+                          adt7410_show_temp, adt7410_set_temp, 1);
+static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO,
+                          adt7410_show_temp, adt7410_set_temp, 2);
+static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO,
+                          adt7410_show_temp, adt7410_set_temp, 3);
+static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO,
+                          adt7410_show_t_hyst, adt7410_set_t_hyst, 1);
+static SENSOR_DEVICE_ATTR(temp1_min_hyst, S_IRUGO,
+                          adt7410_show_t_hyst, NULL, 2);
+static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IRUGO,
+                          adt7410_show_t_hyst, NULL, 3);
+static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, adt7410_show_alarm,
+                          NULL, ADT7410_STAT_T_LOW);
+static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, adt7410_show_alarm,
+                          NULL, ADT7410_STAT_T_HIGH);
+static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, adt7410_show_alarm,
+                          NULL, ADT7410_STAT_T_CRIT);
+
+static struct attribute *adt7410_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_crit.dev_attr.attr,
+        &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
+        &sensor_dev_attr_temp1_min_hyst.dev_attr.attr,
+        &sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
+        &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
+        &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
+        &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
+        NULL
+};
+
+static const struct attribute_group adt7410_group = {
+        .attrs = adt7410_attributes,
+};
+
+/*-----------------------------------------------------------------------*/
+
+/* device probe and removal */
+
+static int adt7410_probe(struct i2c_client *client,
+                         const struct i2c_device_id *id)
+{
+        struct adt7410_data *data;
+        int ret;
+
+        if (!i2c_check_functionality(client->adapter,
+                        I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA))
+                return -ENODEV;
+
+        data = devm_kzalloc(&client->dev, sizeof(struct adt7410_data),
+                            GFP_KERNEL);
+        if (!data)
+                return -ENOMEM;
+
+        i2c_set_clientdata(client, data);
+        mutex_init(&data->update_lock);
+
+        /* configure as specified */
+        ret = i2c_smbus_read_byte_data(client, ADT7410_CONFIG);
+        if (ret < 0) {
+                dev_dbg(&client->dev, "Can't read config? %d\n", ret);
+                return ret;
+        }
+        data->oldconfig = ret;
+        /*
+         * Set to 16 bit resolution, continous conversion and comparator mode.
+         */
+        data->config = ret | ADT7410_FULL | ADT7410_RESOLUTION |
+                        ADT7410_EVENT_MODE;
+        if (data->config != data->oldconfig) {
+                ret = i2c_smbus_write_byte_data(client, ADT7410_CONFIG,
+                                                data->config);
+                if (ret)
+                        return ret;
+        }
+        dev_dbg(&client->dev, "Config %02x\n", data->config);
+
+        /* Register sysfs hooks */
+        ret = sysfs_create_group(&client->dev.kobj, &adt7410_group);
+        if (ret)
+                goto exit_restore;
+
+        data->hwmon_dev = hwmon_device_register(&client->dev);
+        if (IS_ERR(data->hwmon_dev)) {
+                ret = PTR_ERR(data->hwmon_dev);
+                goto exit_remove;
+        }
+
+        dev_info(&client->dev, "sensor '%s'\n", client->name);
+
+        return 0;
+
+exit_remove:
+        sysfs_remove_group(&client->dev.kobj, &adt7410_group);
+exit_restore:
+        i2c_smbus_write_byte_data(client, ADT7410_CONFIG, data->oldconfig);
+        return ret;
+}
+
+static int adt7410_remove(struct i2c_client *client)
+{
+        struct adt7410_data *data = i2c_get_clientdata(client);
+
+        hwmon_device_unregister(data->hwmon_dev);
+        sysfs_remove_group(&client->dev.kobj, &adt7410_group);
+        if (data->oldconfig != data->config)
+                i2c_smbus_write_byte_data(client, ADT7410_CONFIG,
+                                          data->oldconfig);
+        return 0;
+}
+
+static const struct i2c_device_id adt7410_ids[] = {
+        { "adt7410", adt7410, },
+        { /* LIST END */ }
+};
+MODULE_DEVICE_TABLE(i2c, adt7410_ids);
+
+#ifdef CONFIG_PM
+static int adt7410_suspend(struct device *dev)
+{
+        int ret;
+        struct i2c_client *client = to_i2c_client(dev);
+        struct adt7410_data *data = i2c_get_clientdata(client);
+
+        ret = i2c_smbus_write_byte_data(client, ADT7410_CONFIG,
+                                        data->config | ADT7410_PD);
+        return ret;
+}
+
+static int adt7410_resume(struct device *dev)
+{
+        int ret;
+        struct i2c_client *client = to_i2c_client(dev);
+        struct adt7410_data *data = i2c_get_clientdata(client);
+
+        ret = i2c_smbus_write_byte_data(client, ADT7410_CONFIG, data->config);
+        return ret;
+}
+
+static const struct dev_pm_ops adt7410_dev_pm_ops = {
+        .suspend        = adt7410_suspend,
+        .resume         = adt7410_resume,
+};
+#define ADT7410_DEV_PM_OPS (&adt7410_dev_pm_ops)
+#else
+#define ADT7410_DEV_PM_OPS NULL
+#endif /* CONFIG_PM */
+
+static struct i2c_driver adt7410_driver = {
+        .class          = I2C_CLASS_HWMON,
+        .driver = {
+                .name   = "adt7410",
+                .pm     = ADT7410_DEV_PM_OPS,
+        },
+        .probe          = adt7410_probe,
+        .remove         = adt7410_remove,
+        .id_table       = adt7410_ids,
+        .address_list   = normal_i2c,
+};
+
+module_i2c_driver(adt7410_driver);
+
+MODULE_AUTHOR("Hartmut Knaack");
+MODULE_DESCRIPTION("ADT7410 driver");
+MODULE_LICENSE("GPL");