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/*

 * 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 device           *hwmon_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);

        long 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->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, &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->hwmon_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);