/*
 * adm1025.c
 *
 * Copyright (C) 2000       Chen-Yuan Wu <gwu@esoft.com>
 * Copyright (C) 2003-2004  Jean Delvare <khali@linux-fr.org>
 *
 * The ADM1025 is a sensor chip made by Analog Devices. It reports up to 6
 * voltages (including its own power source) and up to two temperatures
 * (its own plus up to one external one). Voltages are scaled internally
 * (which is not the common way) with ratios such that the nominal value
 * of each voltage correspond to a register value of 192 (which means a
 * resolution of about 0.5% of the nominal value). Temperature values are
 * reported with a 1 deg resolution and a 3 deg accuracy. Complete
 * datasheet can be obtained from Analog's website at:
 *   http://www.analog.com/Analog_Root/productPage/productHome/0,2121,ADM1025,00.html
 *
 * This driver also supports the ADM1025A, which differs from the ADM1025
 * only in that it has "open-drain VID inputs while the ADM1025 has
 * on-chip 100k pull-ups on the VID inputs". It doesn't make any
 * difference for us.
 *
 * This driver also supports the NE1619, a sensor chip made by Philips.
 * That chip is similar to the ADM1025A, with a few differences. The only
 * difference that matters to us is that the NE1619 has only two possible
 * addresses while the ADM1025A has a third one. Complete datasheet can be
 * obtained from Philips's website at:
 *   http://www.semiconductors.philips.com/pip/NE1619DS.html
 *
 * Since the ADM1025 was the first chipset supported by this driver, most
 * comments will refer to this chipset, but are actually general and
 * concern all supported chipsets, unless mentioned otherwise.
 *
 * 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-vid.h>
#include <linux/err.h>
#include <linux/mutex.h>

/*
 * Addresses to scan
 * ADM1025 and ADM1025A have three possible addresses: 0x2c, 0x2d and 0x2e.
 * NE1619 has two possible addresses: 0x2c and 0x2d.
 */

static unsigned short normal_i2c[] = { 0x2c, 0x2d, 0x2e, I2C_CLIENT_END };

/*
 * Insmod parameters
 */

I2C_CLIENT_INSMOD_2(adm1025, ne1619);

/*
 * The ADM1025 registers
 */

#define ADM1025_REG_MAN_ID              0x3E
#define ADM1025_REG_CHIP_ID             0x3F
#define ADM1025_REG_CONFIG              0x40
#define ADM1025_REG_STATUS1             0x41
#define ADM1025_REG_STATUS2             0x42
#define ADM1025_REG_IN(nr)              (0x20 + (nr))
#define ADM1025_REG_IN_MAX(nr)          (0x2B + (nr) * 2)
#define ADM1025_REG_IN_MIN(nr)          (0x2C + (nr) * 2)
#define ADM1025_REG_TEMP(nr)            (0x26 + (nr))
#define ADM1025_REG_TEMP_HIGH(nr)       (0x37 + (nr) * 2)
#define ADM1025_REG_TEMP_LOW(nr)        (0x38 + (nr) * 2)
#define ADM1025_REG_VID                 0x47
#define ADM1025_REG_VID4                0x49

/*
 * Conversions and various macros
 * The ADM1025 uses signed 8-bit values for temperatures.
 */

static int in_scale[6] = { 2500, 2250, 3300, 5000, 12000, 3300 };

#define IN_FROM_REG(reg,scale)  (((reg) * (scale) + 96) / 192)
#define IN_TO_REG(val,scale)    ((val) <= 0 ? 0 : \
                                 (val) * 192 >= (scale) * 255 ? 255 : \
                                 ((val) * 192 + (scale)/2) / (scale))

#define TEMP_FROM_REG(reg)      ((reg) * 1000)
#define TEMP_TO_REG(val)        ((val) <= -127500 ? -128 : \
                                 (val) >= 126500 ? 127 : \
                                 (((val) < 0 ? (val)-500 : (val)+500) / 1000))

/*
 * Functions declaration
 */

static int adm1025_attach_adapter(struct i2c_adapter *adapter);
static int adm1025_detect(struct i2c_adapter *adapter, int address, int kind);
static void adm1025_init_client(struct i2c_client *client);
static int adm1025_detach_client(struct i2c_client *client);
static struct adm1025_data *adm1025_update_device(struct device *dev);

/*
 * Driver data (common to all clients)
 */

static struct i2c_driver adm1025_driver = {
        .driver = {
                .name   = "adm1025",
        },
        .id             = I2C_DRIVERID_ADM1025,
        .attach_adapter = adm1025_attach_adapter,
        .detach_client  = adm1025_detach_client,
};

/*
 * Client data (each client gets its own)
 */

struct adm1025_data {
        struct i2c_client client;
        struct device *hwmon_dev;
        struct mutex update_lock;
        char valid; /* zero until following fields are valid */
        unsigned long last_updated; /* in jiffies */

        u8 in[6];               /* register value */
        u8 in_max[6];           /* register value */
        u8 in_min[6];           /* register value */
        s8 temp[2];             /* register value */
        s8 temp_min[2];         /* register value */
        s8 temp_max[2];         /* register value */
        u16 alarms;             /* register values, combined */
        u8 vid;                 /* register values, combined */
        u8 vrm;
};

/*
 * Sysfs stuff
 */

#define show_in(offset) \
static ssize_t show_in##offset(struct device *dev, struct device_attribute *attr, char *buf) \
{ \
        struct adm1025_data *data = adm1025_update_device(dev); \
        return sprintf(buf, "%u\n", IN_FROM_REG(data->in[offset], \
                       in_scale[offset])); \
} \
static ssize_t show_in##offset##_min(struct device *dev, struct device_attribute *attr, char *buf) \
{ \
        struct adm1025_data *data = adm1025_update_device(dev); \
        return sprintf(buf, "%u\n", IN_FROM_REG(data->in_min[offset], \
                       in_scale[offset])); \
} \
static ssize_t show_in##offset##_max(struct device *dev, struct device_attribute *attr, char *buf) \
{ \
        struct adm1025_data *data = adm1025_update_device(dev); \
        return sprintf(buf, "%u\n", IN_FROM_REG(data->in_max[offset], \
                       in_scale[offset])); \
} \
static DEVICE_ATTR(in##offset##_input, S_IRUGO, show_in##offset, NULL);
show_in(0);
show_in(1);
show_in(2);
show_in(3);
show_in(4);
show_in(5);

#define show_temp(offset) \
static ssize_t show_temp##offset(struct device *dev, struct device_attribute *attr, char *buf) \
{ \
        struct adm1025_data *data = adm1025_update_device(dev); \
        return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[offset-1])); \
} \
static ssize_t show_temp##offset##_min(struct device *dev, struct device_attribute *attr, char *buf) \
{ \
        struct adm1025_data *data = adm1025_update_device(dev); \
        return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp_min[offset-1])); \
} \
static ssize_t show_temp##offset##_max(struct device *dev, struct device_attribute *attr, char *buf) \
{ \
        struct adm1025_data *data = adm1025_update_device(dev); \
        return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp_max[offset-1])); \
}\
static DEVICE_ATTR(temp##offset##_input, S_IRUGO, show_temp##offset, NULL);
show_temp(1);
show_temp(2);

#define set_in(offset) \
static ssize_t set_in##offset##_min(struct device *dev, struct device_attribute *attr, const char *buf, \
        size_t count) \
{ \
        struct i2c_client *client = to_i2c_client(dev); \
        struct adm1025_data *data = i2c_get_clientdata(client); \
        long val = simple_strtol(buf, NULL, 10); \
 \
        mutex_lock(&data->update_lock); \
        data->in_min[offset] = IN_TO_REG(val, in_scale[offset]); \
        i2c_smbus_write_byte_data(client, ADM1025_REG_IN_MIN(offset), \
                                  data->in_min[offset]); \
        mutex_unlock(&data->update_lock); \
        return count; \
} \
static ssize_t set_in##offset##_max(struct device *dev, struct device_attribute *attr, const char *buf, \
        size_t count) \
{ \
        struct i2c_client *client = to_i2c_client(dev); \
        struct adm1025_data *data = i2c_get_clientdata(client); \
        long val = simple_strtol(buf, NULL, 10); \
 \
        mutex_lock(&data->update_lock); \
        data->in_max[offset] = IN_TO_REG(val, in_scale[offset]); \
        i2c_smbus_write_byte_data(client, ADM1025_REG_IN_MAX(offset), \
                                  data->in_max[offset]); \
        mutex_unlock(&data->update_lock); \
        return count; \
} \
static DEVICE_ATTR(in##offset##_min, S_IWUSR | S_IRUGO, \
        show_in##offset##_min, set_in##offset##_min); \
static DEVICE_ATTR(in##offset##_max, S_IWUSR | S_IRUGO, \
        show_in##offset##_max, set_in##offset##_max);
set_in(0);
set_in(1);
set_in(2);
set_in(3);
set_in(4);
set_in(5);

#define set_temp(offset) \
static ssize_t set_temp##offset##_min(struct device *dev, struct device_attribute *attr, const char *buf, \
        size_t count) \
{ \
        struct i2c_client *client = to_i2c_client(dev); \
        struct adm1025_data *data = i2c_get_clientdata(client); \
        long val = simple_strtol(buf, NULL, 10); \
 \
        mutex_lock(&data->update_lock); \
        data->temp_min[offset-1] = TEMP_TO_REG(val); \
        i2c_smbus_write_byte_data(client, ADM1025_REG_TEMP_LOW(offset-1), \
                                  data->temp_min[offset-1]); \
        mutex_unlock(&data->update_lock); \
        return count; \
} \
static ssize_t set_temp##offset##_max(struct device *dev, struct device_attribute *attr, const char *buf, \
        size_t count) \
{ \
        struct i2c_client *client = to_i2c_client(dev); \
        struct adm1025_data *data = i2c_get_clientdata(client); \
        long val = simple_strtol(buf, NULL, 10); \
 \
        mutex_lock(&data->update_lock); \
        data->temp_max[offset-1] = TEMP_TO_REG(val); \
        i2c_smbus_write_byte_data(client, ADM1025_REG_TEMP_HIGH(offset-1), \
                                  data->temp_max[offset-1]); \
        mutex_unlock(&data->update_lock); \
        return count; \
} \
static DEVICE_ATTR(temp##offset##_min, S_IWUSR | S_IRUGO, \
        show_temp##offset##_min, set_temp##offset##_min); \
static DEVICE_ATTR(temp##offset##_max, S_IWUSR | S_IRUGO, \
        show_temp##offset##_max, set_temp##offset##_max);
set_temp(1);
set_temp(2);

static ssize_t show_alarms(struct device *dev, struct device_attribute *attr, char *buf)
{
        struct adm1025_data *data = adm1025_update_device(dev);
        return sprintf(buf, "%u\n", data->alarms);
}
static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);

static ssize_t show_vid(struct device *dev, struct device_attribute *attr, char *buf)
{
        struct adm1025_data *data = adm1025_update_device(dev);
        return sprintf(buf, "%u\n", vid_from_reg(data->vid, data->vrm));
}
static DEVICE_ATTR(cpu0_vid, S_IRUGO, show_vid, NULL);

static ssize_t show_vrm(struct device *dev, struct device_attribute *attr, char *buf)
{
        struct adm1025_data *data = dev_get_drvdata(dev);
        return sprintf(buf, "%u\n", data->vrm);
}
static ssize_t set_vrm(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
        struct i2c_client *client = to_i2c_client(dev);
        struct adm1025_data *data = i2c_get_clientdata(client);
        data->vrm = simple_strtoul(buf, NULL, 10);
        return count;
}
static DEVICE_ATTR(vrm, S_IRUGO | S_IWUSR, show_vrm, set_vrm);

/*
 * Real code
 */

static int adm1025_attach_adapter(struct i2c_adapter *adapter)
{
        if (!(adapter->class & I2C_CLASS_HWMON))
                return 0;
        return i2c_probe(adapter, &addr_data, adm1025_detect);
}

static struct attribute *adm1025_attributes[] = {
        &dev_attr_in0_input.attr,
        &dev_attr_in1_input.attr,
        &dev_attr_in2_input.attr,
        &dev_attr_in3_input.attr,
        &dev_attr_in5_input.attr,
        &dev_attr_in0_min.attr,
        &dev_attr_in1_min.attr,
        &dev_attr_in2_min.attr,
        &dev_attr_in3_min.attr,
        &dev_attr_in5_min.attr,
        &dev_attr_in0_max.attr,
        &dev_attr_in1_max.attr,
        &dev_attr_in2_max.attr,
        &dev_attr_in3_max.attr,
        &dev_attr_in5_max.attr,
        &dev_attr_temp1_input.attr,
        &dev_attr_temp2_input.attr,
        &dev_attr_temp1_min.attr,
        &dev_attr_temp2_min.attr,
        &dev_attr_temp1_max.attr,
        &dev_attr_temp2_max.attr,
        &dev_attr_alarms.attr,
        &dev_attr_cpu0_vid.attr,
        &dev_attr_vrm.attr,
        NULL
};

static const struct attribute_group adm1025_group = {
        .attrs = adm1025_attributes,
};

static struct attribute *adm1025_attributes_opt[] = {
        &dev_attr_in4_input.attr,
        &dev_attr_in4_min.attr,
        &dev_attr_in4_max.attr,
        NULL
};

static const struct attribute_group adm1025_group_opt = {
        .attrs = adm1025_attributes_opt,
};

/*
 * The following function does more than just detection. If detection
 * succeeds, it also registers the new chip.
 */
static int adm1025_detect(struct i2c_adapter *adapter, int address, int kind)
{
        struct i2c_client *new_client;
        struct adm1025_data *data;
        int err = 0;
        const char *name = "";
        u8 config;

        if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
                goto exit;

        if (!(data = kzalloc(sizeof(struct adm1025_data), GFP_KERNEL))) {
                err = -ENOMEM;
                goto exit;
        }

        /* The common I2C client data is placed right before the
           ADM1025-specific data. */
        new_client = &data->client;
        i2c_set_clientdata(new_client, data);
        new_client->addr = address;
        new_client->adapter = adapter;
        new_client->driver = &adm1025_driver;
        new_client->flags = 0;

        /*
         * Now we do the remaining detection. A negative kind means that
         * the driver was loaded with no force parameter (default), so we
         * must both detect and identify the chip. A zero kind means that
         * the driver was loaded with the force parameter, the detection
         * step shall be skipped. A positive kind means that the driver
         * was loaded with the force parameter and a given kind of chip is
         * requested, so both the detection and the identification steps
         * are skipped.
         */
        config = i2c_smbus_read_byte_data(new_client, ADM1025_REG_CONFIG);
        if (kind < 0) { /* detection */
                if ((config & 0x80) != 0x00
                 || (i2c_smbus_read_byte_data(new_client,
                     ADM1025_REG_STATUS1) & 0xC0) != 0x00
                 || (i2c_smbus_read_byte_data(new_client,
                     ADM1025_REG_STATUS2) & 0xBC) != 0x00) {
                        dev_dbg(&adapter->dev,
                                "ADM1025 detection failed at 0x%02x.\n",
                                address);
                        goto exit_free;
                }
        }

        if (kind <= 0) { /* identification */
                u8 man_id, chip_id;

                man_id = i2c_smbus_read_byte_data(new_client,
                         ADM1025_REG_MAN_ID);
                chip_id = i2c_smbus_read_byte_data(new_client,
                          ADM1025_REG_CHIP_ID);
                
                if (man_id == 0x41) { /* Analog Devices */
                        if ((chip_id & 0xF0) == 0x20) { /* ADM1025/ADM1025A */
                                kind = adm1025;
                        }
                } else
                if (man_id == 0xA1) { /* Philips */
                        if (address != 0x2E
                         && (chip_id & 0xF0) == 0x20) { /* NE1619 */
                                kind = ne1619;
                        }
                }

                if (kind <= 0) { /* identification failed */
                        dev_info(&adapter->dev,
                            "Unsupported chip (man_id=0x%02X, "
                            "chip_id=0x%02X).\n", man_id, chip_id);
                        goto exit_free;
                }
        }

        if (kind == adm1025) {
                name = "adm1025";
        } else if (kind == ne1619) {
                name = "ne1619";
        }

        /* We can fill in the remaining client fields */
        strlcpy(new_client->name, name, I2C_NAME_SIZE);
        data->valid = 0;
        mutex_init(&data->update_lock);

        /* Tell the I2C layer a new client has arrived */
        if ((err = i2c_attach_client(new_client)))
                goto exit_free;

        /* Initialize the ADM1025 chip */
        adm1025_init_client(new_client);

        /* Register sysfs hooks */
        if ((err = sysfs_create_group(&new_client->dev.kobj, &adm1025_group)))
                goto exit_detach;

        /* Pin 11 is either in4 (+12V) or VID4 */
        if (!(config & 0x20)) {
                if ((err = device_create_file(&new_client->dev,
                                        &dev_attr_in4_input))
                 || (err = device_create_file(&new_client->dev,
                                        &dev_attr_in4_min))
                 || (err = device_create_file(&new_client->dev,
                                        &dev_attr_in4_max)))
                        goto exit_remove;
        }

        data->hwmon_dev = hwmon_device_register(&new_client->dev);
        if (IS_ERR(data->hwmon_dev)) {
                err = PTR_ERR(data->hwmon_dev);
                goto exit_remove;
        }

        return 0;

exit_remove:
        sysfs_remove_group(&new_client->dev.kobj, &adm1025_group);
        sysfs_remove_group(&new_client->dev.kobj, &adm1025_group_opt);
exit_detach:
        i2c_detach_client(new_client);
exit_free:
        kfree(data);
exit:
        return err;
}

static void adm1025_init_client(struct i2c_client *client)
{
        u8 reg;
        struct adm1025_data *data = i2c_get_clientdata(client);
        int i;

        data->vrm = vid_which_vrm();

        /*
         * Set high limits
         * Usually we avoid setting limits on driver init, but it happens
         * that the ADM1025 comes with stupid default limits (all registers
         * set to 0). In case the chip has not gone through any limit
         * setting yet, we better set the high limits to the max so that
         * no alarm triggers.
         */
        for (i=0; i<6; i++) {
                reg = i2c_smbus_read_byte_data(client,
                                               ADM1025_REG_IN_MAX(i));
                if (reg == 0)
                        i2c_smbus_write_byte_data(client,
                                                  ADM1025_REG_IN_MAX(i),
                                                  0xFF);
        }
        for (i=0; i<2; i++) {
                reg = i2c_smbus_read_byte_data(client,
                                               ADM1025_REG_TEMP_HIGH(i));
                if (reg == 0)
                        i2c_smbus_write_byte_data(client,
                                                  ADM1025_REG_TEMP_HIGH(i),
                                                  0x7F);
        }

        /*
         * Start the conversions
         */
        reg = i2c_smbus_read_byte_data(client, ADM1025_REG_CONFIG);
        if (!(reg & 0x01))
                i2c_smbus_write_byte_data(client, ADM1025_REG_CONFIG,
                                          (reg&0x7E)|0x01);
}

static int adm1025_detach_client(struct i2c_client *client)
{
        struct adm1025_data *data = i2c_get_clientdata(client);
        int err;

        hwmon_device_unregister(data->hwmon_dev);
        sysfs_remove_group(&client->dev.kobj, &adm1025_group);
        sysfs_remove_group(&client->dev.kobj, &adm1025_group_opt);

        if ((err = i2c_detach_client(client)))
                return err;

        kfree(data);
        return 0;
}

static struct adm1025_data *adm1025_update_device(struct device *dev)
{
        struct i2c_client *client = to_i2c_client(dev);
        struct adm1025_data *data = i2c_get_clientdata(client);

        mutex_lock(&data->update_lock);

        if (time_after(jiffies, data->last_updated + HZ * 2) || !data->valid) {
                int i;

                dev_dbg(&client->dev, "Updating data.\n");
                for (i=0; i<6; i++) {
                        data->in[i] = i2c_smbus_read_byte_data(client,
                                      ADM1025_REG_IN(i));
                        data->in_min[i] = i2c_smbus_read_byte_data(client,
                                          ADM1025_REG_IN_MIN(i));
                        data->in_max[i] = i2c_smbus_read_byte_data(client,
                                          ADM1025_REG_IN_MAX(i));
                }
                for (i=0; i<2; i++) {
                        data->temp[i] = i2c_smbus_read_byte_data(client,
                                        ADM1025_REG_TEMP(i));
                        data->temp_min[i] = i2c_smbus_read_byte_data(client,
                                            ADM1025_REG_TEMP_LOW(i));
                        data->temp_max[i] = i2c_smbus_read_byte_data(client,
                                            ADM1025_REG_TEMP_HIGH(i));
                }
                data->alarms = i2c_smbus_read_byte_data(client,
                               ADM1025_REG_STATUS1)
                             | (i2c_smbus_read_byte_data(client,
                                ADM1025_REG_STATUS2) << 8);
                data->vid = (i2c_smbus_read_byte_data(client,
                             ADM1025_REG_VID) & 0x0f)
                          | ((i2c_smbus_read_byte_data(client,
                              ADM1025_REG_VID4) & 0x01) << 4);

                data->last_updated = jiffies;
                data->valid = 1;
        }

        mutex_unlock(&data->update_lock);

        return data;
}

static int __init sensors_adm1025_init(void)
{
        return i2c_add_driver(&adm1025_driver);
}

static void __exit sensors_adm1025_exit(void)
{
        i2c_del_driver(&adm1025_driver);
}

MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
MODULE_DESCRIPTION("ADM1025 driver");
MODULE_LICENSE("GPL");

module_init(sensors_adm1025_init);
module_exit(sensors_adm1025_exit);