hwmon: New AD7416, AD7417 and AD7418 driver

A driver for the Analog Devices AD7416, AD7417 and AD7418 chips.

Signed-off-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

3 files changed, 384 insertions, 0 deletions

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index e488d691da4a..1691c6c7bbca 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -39,6 +39,16 @@ config SENSORS_ABITUGURU
           This driver can also be built as a module.  If so, the module
           will be called abituguru.
 
+config SENSORS_AD7418
+        tristate "Analog Devices AD7416, AD7417 and AD7418"
+        depends on HWMON && I2C && EXPERIMENTAL
+        help
+          If you say yes here you get support for the Analog Devices
+          AD7416, AD7417 and AD7418 temperature monitoring chips.
+
+          This driver can also be built as a module. If so, the module
+          will be called ad7418.
+
 config SENSORS_ADM1021
         tristate "Analog Devices ADM1021 and compatibles"
         depends on HWMON && I2C
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 33780678bd4b..d83f2380e089 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -14,6 +14,7 @@ obj-$(CONFIG_SENSORS_W83781D)	+= w83781d.o
 obj-$(CONFIG_SENSORS_W83791D)   += w83791d.o
 
 obj-$(CONFIG_SENSORS_ABITUGURU) += abituguru.o
+obj-$(CONFIG_SENSORS_AD7418)    += ad7418.o
 obj-$(CONFIG_SENSORS_ADM1021)   += adm1021.o
 obj-$(CONFIG_SENSORS_ADM1025)   += adm1025.o
 obj-$(CONFIG_SENSORS_ADM1026)   += adm1026.o
diff --git a/drivers/hwmon/ad7418.c b/drivers/hwmon/ad7418.c
new file mode 100644
index 000000000000..cc8b624a1e51
--- /dev/null
+++ b/drivers/hwmon/ad7418.c
@@ -0,0 +1,373 @@
+/*
+ * An hwmon driver for the Analog Devices AD7416/17/18
+ * Copyright (C) 2006-07 Tower Technologies
+ *
+ * Author: Alessandro Zummo <a.zummo@towertech.it>
+ *
+ * Based on lm75.c
+ * Copyright (C) 1998-99 Frodo Looijaard <frodol@dds.nl>
+ *
+ * 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 - version 2.
+ */
+
+#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/delay.h>
+
+#include "lm75.h"
+
+#define DRV_VERSION "0.3"
+
+/* Addresses to scan */
+static unsigned short normal_i2c[] = { 0x28, I2C_CLIENT_END };
+/* Insmod parameters */
+I2C_CLIENT_INSMOD_3(ad7416, ad7417, ad7418);
+
+/* AD7418 registers */
+#define AD7418_REG_TEMP_IN      0x00
+#define AD7418_REG_CONF         0x01
+#define AD7418_REG_TEMP_HYST    0x02
+#define AD7418_REG_TEMP_OS      0x03
+#define AD7418_REG_ADC          0x04
+#define AD7418_REG_CONF2        0x05
+
+#define AD7418_REG_ADC_CH(x)    ((x) << 5)
+#define AD7418_CH_TEMP          AD7418_REG_ADC_CH(0)
+
+static const u8 AD7418_REG_TEMP[] = { AD7418_REG_TEMP_IN,
+                                        AD7418_REG_TEMP_HYST,
+                                        AD7418_REG_TEMP_OS };
+
+struct ad7418_data {
+        struct i2c_client       client;
+        struct class_device     *class_dev;
+        struct attribute_group  attrs;
+        enum chips              type;
+        struct mutex            lock;
+        int                     adc_max;        /* number of ADC channels */
+        char                    valid;
+        unsigned long           last_updated;   /* In jiffies */
+        s16                     temp[3];        /* Register values */
+        u16                     in[4];
+};
+
+static int ad7418_attach_adapter(struct i2c_adapter *adapter);
+static int ad7418_detect(struct i2c_adapter *adapter, int address, int kind);
+static int ad7418_detach_client(struct i2c_client *client);
+
+static struct i2c_driver ad7418_driver = {
+        .driver = {
+                .name   = "ad7418",
+        },
+        .attach_adapter = ad7418_attach_adapter,
+        .detach_client  = ad7418_detach_client,
+};
+
+/* All registers are word-sized, except for the configuration registers.
+ * AD7418 uses a high-byte first convention. Do NOT use those functions to
+ * access the configuration registers CONF and CONF2, as they are byte-sized.
+ */
+static inline int ad7418_read(struct i2c_client *client, u8 reg)
+{
+        return swab16(i2c_smbus_read_word_data(client, reg));
+}
+
+static inline int ad7418_write(struct i2c_client *client, u8 reg, u16 value)
+{
+        return i2c_smbus_write_word_data(client, reg, swab16(value));
+}
+
+static void ad7418_init_client(struct i2c_client *client)
+{
+        struct ad7418_data *data = i2c_get_clientdata(client);
+
+        int reg = i2c_smbus_read_byte_data(client, AD7418_REG_CONF);
+        if (reg < 0) {
+                dev_err(&client->dev, "cannot read configuration register\n");
+        } else {
+                dev_info(&client->dev, "configuring for mode 1\n");
+                i2c_smbus_write_byte_data(client, AD7418_REG_CONF, reg & 0xfe);
+
+                if (data->type == ad7417 || data->type == ad7418)
+                        i2c_smbus_write_byte_data(client,
+                                                AD7418_REG_CONF2, 0x00);
+        }
+}
+
+static struct ad7418_data *ad7418_update_device(struct device *dev)
+{
+        struct i2c_client *client = to_i2c_client(dev);
+        struct ad7418_data *data = i2c_get_clientdata(client);
+
+        mutex_lock(&data->lock);
+
+        if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
+                || !data->valid) {
+                u8 cfg;
+                int i, ch;
+
+                /* read config register and clear channel bits */
+                cfg = i2c_smbus_read_byte_data(client, AD7418_REG_CONF);
+                cfg &= 0x1F;
+
+                i2c_smbus_write_byte_data(client, AD7418_REG_CONF,
+                                                cfg | AD7418_CH_TEMP);
+                udelay(30);
+
+                for (i = 0; i < 3; i++) {
+                        data->temp[i] = ad7418_read(client, AD7418_REG_TEMP[i]);
+                }
+
+                for (i = 0, ch = 4; i < data->adc_max; i++, ch--) {
+                        i2c_smbus_write_byte_data(client,
+                                        AD7418_REG_CONF,
+                                        cfg | AD7418_REG_ADC_CH(ch));
+
+                        udelay(15);
+                        data->in[data->adc_max - 1 - i] =
+                                ad7418_read(client, AD7418_REG_ADC);
+                }
+
+                /* restore old configuration value */
+                ad7418_write(client, AD7418_REG_CONF, cfg);
+
+                data->last_updated = jiffies;
+                data->valid = 1;
+        }
+
+        mutex_unlock(&data->lock);
+
+        return data;
+}
+
+static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
+                        char *buf)
+{
+        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+        struct ad7418_data *data = ad7418_update_device(dev);
+        return sprintf(buf, "%d\n",
+                LM75_TEMP_FROM_REG(data->temp[attr->index]));
+}
+
+static ssize_t show_adc(struct device *dev, struct device_attribute *devattr,
+                        char *buf)
+{
+        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+        struct ad7418_data *data = ad7418_update_device(dev);
+
+        return sprintf(buf, "%d\n",
+                ((data->in[attr->index] >> 6) * 2500 + 512) / 1024);
+}
+
+static ssize_t set_temp(struct device *dev, struct device_attribute *devattr,
+                        const char *buf, size_t count)
+{
+        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+        struct i2c_client *client = to_i2c_client(dev);
+        struct ad7418_data *data = i2c_get_clientdata(client);
+        int temp = simple_strtol(buf, NULL, 10);
+
+        mutex_lock(&data->lock);
+        data->temp[attr->index] = LM75_TEMP_TO_REG(temp);
+        ad7418_write(client, AD7418_REG_TEMP[attr->index], data->temp[attr->index]);
+        mutex_unlock(&data->lock);
+        return count;
+}
+
+static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
+static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO,
+                                show_temp, set_temp, 1);
+static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
+                                show_temp, set_temp, 2);
+
+static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, show_adc, NULL, 0);
+static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, show_adc, NULL, 1);
+static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, show_adc, NULL, 2);
+static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, show_adc, NULL, 3);
+
+static int ad7418_attach_adapter(struct i2c_adapter *adapter)
+{
+        if (!(adapter->class & I2C_CLASS_HWMON))
+                return 0;
+        return i2c_probe(adapter, &addr_data, ad7418_detect);
+}
+
+static struct attribute *ad7416_attributes[] = {
+        &sensor_dev_attr_temp1_max.dev_attr.attr,
+        &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
+        &sensor_dev_attr_temp1_input.dev_attr.attr,
+        NULL
+};
+
+static struct attribute *ad7417_attributes[] = {
+        &sensor_dev_attr_temp1_max.dev_attr.attr,
+        &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
+        &sensor_dev_attr_temp1_input.dev_attr.attr,
+        &sensor_dev_attr_in1_input.dev_attr.attr,
+        &sensor_dev_attr_in2_input.dev_attr.attr,
+        &sensor_dev_attr_in3_input.dev_attr.attr,
+        &sensor_dev_attr_in4_input.dev_attr.attr,
+        NULL
+};
+
+static struct attribute *ad7418_attributes[] = {
+        &sensor_dev_attr_temp1_max.dev_attr.attr,
+        &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
+        &sensor_dev_attr_temp1_input.dev_attr.attr,
+        &sensor_dev_attr_in1_input.dev_attr.attr,
+        NULL
+};
+
+static int ad7418_detect(struct i2c_adapter *adapter, int address, int kind)
+{
+        struct i2c_client *client;
+        struct ad7418_data *data;
+        int err = 0;
+
+        if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
+                                        I2C_FUNC_SMBUS_WORD_DATA))
+                goto exit;
+
+        if (!(data = kzalloc(sizeof(struct ad7418_data), GFP_KERNEL))) {
+                err = -ENOMEM;
+                goto exit;
+        }
+
+        client = &data->client;
+        client->addr = address;
+        client->adapter = adapter;
+        client->driver = &ad7418_driver;
+
+        i2c_set_clientdata(client, data);
+
+        mutex_init(&data->lock);
+
+        /* AD7418 has a curious behaviour on registers 6 and 7. They
+         * both always read 0xC071 and are not documented on the datasheet.
+         * We use them to detect the chip.
+         */
+        if (kind <= 0) {
+                int reg, reg6, reg7;
+
+                /* the AD7416 lies within this address range, but I have
+                 * no means to check.
+                 */
+                if (address >= 0x48 && address <= 0x4f) {
+                        /* XXX add tests for AD7416 here */
+                        /* data->type = ad7416; */
+                }
+                /* here we might have AD7417 or AD7418 */
+                else if (address >= 0x28 && address <= 0x2f) {
+                        reg6 = i2c_smbus_read_word_data(client, 0x06);
+                        reg7 = i2c_smbus_read_word_data(client, 0x07);
+
+                        if (address == 0x28 && reg6 == 0xC071 && reg7 == 0xC071)
+                                data->type = ad7418;
+
+                        /* XXX add tests for AD7417 here */
+
+
+                        /* both AD7417 and AD7418 have bits 0-5 of
+                         * the CONF2 register at 0
+                         */
+                        reg = i2c_smbus_read_byte_data(client,
+                                                        AD7418_REG_CONF2);
+                        if (reg & 0x3F)
+                                data->type = any_chip; /* detection failed */
+                }
+        } else {
+                dev_dbg(&adapter->dev, "detection forced\n");
+        }
+
+        if (kind > 0)
+                data->type = kind;
+        else if (kind < 0 && data->type == any_chip) {
+                err = -ENODEV;
+                goto exit_free;
+        }
+
+        switch (data->type) {
+        case any_chip:
+        case ad7416:
+                data->adc_max = 0;
+                data->attrs.attrs = ad7416_attributes;
+                strlcpy(client->name, "ad7416", I2C_NAME_SIZE);
+                break;
+
+        case ad7417:
+                data->adc_max = 4;
+                data->attrs.attrs = ad7417_attributes;
+                strlcpy(client->name, "ad7417", I2C_NAME_SIZE);
+                break;
+
+        case ad7418:
+                data->adc_max = 1;
+                data->attrs.attrs = ad7418_attributes;
+                strlcpy(client->name, "ad7418", I2C_NAME_SIZE);
+                break;
+        }
+
+        if ((err = i2c_attach_client(client)))
+                goto exit_free;
+
+        dev_info(&client->dev, "%s chip found\n", client->name);
+
+        /* Initialize the AD7418 chip */
+        ad7418_init_client(client);
+
+        /* Register sysfs hooks */
+        if ((err = sysfs_create_group(&client->dev.kobj, &data->attrs)))
+                goto exit_detach;
+
+        data->class_dev = hwmon_device_register(&client->dev);
+        if (IS_ERR(data->class_dev)) {
+                err = PTR_ERR(data->class_dev);
+                goto exit_remove;
+        }
+
+        return 0;
+
+exit_remove:
+        sysfs_remove_group(&client->dev.kobj, &data->attrs);
+exit_detach:
+        i2c_detach_client(client);
+exit_free:
+        kfree(data);
+exit:
+        return err;
+}
+
+static int ad7418_detach_client(struct i2c_client *client)
+{
+        struct ad7418_data *data = i2c_get_clientdata(client);
+        hwmon_device_unregister(data->class_dev);
+        sysfs_remove_group(&client->dev.kobj, &data->attrs);
+        i2c_detach_client(client);
+        kfree(data);
+        return 0;
+}
+
+static int __init ad7418_init(void)
+{
+        return i2c_add_driver(&ad7418_driver);
+}
+
+static void __exit ad7418_exit(void)
+{
+        i2c_del_driver(&ad7418_driver);
+}
+
+MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
+MODULE_DESCRIPTION("AD7416/17/18 driver");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(DRV_VERSION);
+
+module_init(ad7418_init);
+module_exit(ad7418_exit);