kbuild: document howto build external modules using several directories

[linux-2.6/verdex.git] / drivers / hwmon / adm1021.c

/*
    adm1021.c - Part of lm_sensors, Linux kernel modules for hardware
             monitoring
    Copyright (c) 1998, 1999  Frodo Looijaard <frodol@dds.nl> and
    Philip Edelbrock <phil@netroedge.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/err.h>


/* Addresses to scan */
static unsigned short normal_i2c[] = { 0x18, 0x19, 0x1a,
                                        0x29, 0x2a, 0x2b,
                                        0x4c, 0x4d, 0x4e, 
                                        I2C_CLIENT_END };

/* Insmod parameters */
I2C_CLIENT_INSMOD_8(adm1021, adm1023, max1617, max1617a, thmc10, lm84, gl523sm, mc1066);

/* adm1021 constants specified below */

/* The adm1021 registers */
/* Read-only */
#define ADM1021_REG_TEMP                0x00
#define ADM1021_REG_REMOTE_TEMP         0x01
#define ADM1021_REG_STATUS              0x02
#define ADM1021_REG_MAN_ID              0x0FE   /* 0x41 = AMD, 0x49 = TI, 0x4D = Maxim, 0x23 = Genesys , 0x54 = Onsemi*/
#define ADM1021_REG_DEV_ID              0x0FF   /* ADM1021 = 0x0X, ADM1023 = 0x3X */
#define ADM1021_REG_DIE_CODE            0x0FF   /* MAX1617A */
/* These use different addresses for reading/writing */
#define ADM1021_REG_CONFIG_R            0x03
#define ADM1021_REG_CONFIG_W            0x09
#define ADM1021_REG_CONV_RATE_R         0x04
#define ADM1021_REG_CONV_RATE_W         0x0A
/* These are for the ADM1023's additional precision on the remote temp sensor */
#define ADM1021_REG_REM_TEMP_PREC       0x010
#define ADM1021_REG_REM_OFFSET          0x011
#define ADM1021_REG_REM_OFFSET_PREC     0x012
#define ADM1021_REG_REM_TOS_PREC        0x013
#define ADM1021_REG_REM_THYST_PREC      0x014
/* limits */
#define ADM1021_REG_TOS_R               0x05
#define ADM1021_REG_TOS_W               0x0B
#define ADM1021_REG_REMOTE_TOS_R        0x07
#define ADM1021_REG_REMOTE_TOS_W        0x0D
#define ADM1021_REG_THYST_R             0x06
#define ADM1021_REG_THYST_W             0x0C
#define ADM1021_REG_REMOTE_THYST_R      0x08
#define ADM1021_REG_REMOTE_THYST_W      0x0E
/* write-only */
#define ADM1021_REG_ONESHOT             0x0F


/* Conversions. Rounding and limit checking is only done on the TO_REG
   variants. Note that you should be a bit careful with which arguments
   these macros are called: arguments may be evaluated more than once.
   Fixing this is just not worth it. */
/* Conversions  note: 1021 uses normal integer signed-byte format*/
#define TEMP_FROM_REG(val)      (val > 127 ? (val-256)*1000 : val*1000)
#define TEMP_TO_REG(val)        (SENSORS_LIMIT((val < 0 ? (val/1000)+256 : val/1000),0,255))

/* Initial values */

/* Note: Even though I left the low and high limits named os and hyst, 
they don't quite work like a thermostat the way the LM75 does.  I.e., 
a lower temp than THYST actually triggers an alarm instead of 
clearing it.  Weird, ey?   --Phil  */

/* Each client has this additional data */
struct adm1021_data {
        struct i2c_client client;
        struct class_device *class_dev;
        enum chips type;

        struct semaphore update_lock;
        char valid;             /* !=0 if following fields are valid */
        unsigned long last_updated;     /* In jiffies */

        u8      temp_max;       /* Register values */
        u8      temp_hyst;
        u8      temp_input;
        u8      remote_temp_max;
        u8      remote_temp_hyst;
        u8      remote_temp_input;
        u8      alarms;
        /* Special values for ADM1023 only */
        u8      remote_temp_prec;
        u8      remote_temp_os_prec;
        u8      remote_temp_hyst_prec;
        u8      remote_temp_offset;
        u8      remote_temp_offset_prec;
};

static int adm1021_attach_adapter(struct i2c_adapter *adapter);
static int adm1021_detect(struct i2c_adapter *adapter, int address, int kind);
static void adm1021_init_client(struct i2c_client *client);
static int adm1021_detach_client(struct i2c_client *client);
static int adm1021_read_value(struct i2c_client *client, u8 reg);
static int adm1021_write_value(struct i2c_client *client, u8 reg,
                               u16 value);
static struct adm1021_data *adm1021_update_device(struct device *dev);

/* (amalysh) read only mode, otherwise any limit's writing confuse BIOS */
static int read_only;


/* This is the driver that will be inserted */
static struct i2c_driver adm1021_driver = {
        .owner          = THIS_MODULE,
        .name           = "adm1021",
        .id             = I2C_DRIVERID_ADM1021,
        .flags          = I2C_DF_NOTIFY,
        .attach_adapter = adm1021_attach_adapter,
        .detach_client  = adm1021_detach_client,
};

#define show(value)     \
static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf)               \
{                                                                       \
        struct adm1021_data *data = adm1021_update_device(dev);         \
        return sprintf(buf, "%d\n", TEMP_FROM_REG(data->value));        \
}
show(temp_max);
show(temp_hyst);
show(temp_input);
show(remote_temp_max);
show(remote_temp_hyst);
show(remote_temp_input);

#define show2(value)    \
static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf)               \
{                                                                       \
        struct adm1021_data *data = adm1021_update_device(dev);         \
        return sprintf(buf, "%d\n", data->value);                       \
}
show2(alarms);

#define set(value, reg) \
static ssize_t set_##value(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)    \
{                                                               \
        struct i2c_client *client = to_i2c_client(dev);         \
        struct adm1021_data *data = i2c_get_clientdata(client); \
        int temp = simple_strtoul(buf, NULL, 10);               \
                                                                \
        down(&data->update_lock);                               \
        data->value = TEMP_TO_REG(temp);                        \
        adm1021_write_value(client, reg, data->value);          \
        up(&data->update_lock);                                 \
        return count;                                           \
}
set(temp_max, ADM1021_REG_TOS_W);
set(temp_hyst, ADM1021_REG_THYST_W);
set(remote_temp_max, ADM1021_REG_REMOTE_TOS_W);
set(remote_temp_hyst, ADM1021_REG_REMOTE_THYST_W);

static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp_max, set_temp_max);
static DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp_hyst, set_temp_hyst);
static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_input, NULL);
static DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_remote_temp_max, set_remote_temp_max);
static DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_remote_temp_hyst, set_remote_temp_hyst);
static DEVICE_ATTR(temp2_input, S_IRUGO, show_remote_temp_input, NULL);
static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);


static int adm1021_attach_adapter(struct i2c_adapter *adapter)
{
        if (!(adapter->class & I2C_CLASS_HWMON))
                return 0;
        return i2c_probe(adapter, &addr_data, adm1021_detect);
}

static int adm1021_detect(struct i2c_adapter *adapter, int address, int kind)
{
        int i;
        struct i2c_client *new_client;
        struct adm1021_data *data;
        int err = 0;
        const char *type_name = "";

        if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
                goto error0;

        /* OK. For now, we presume we have a valid client. We now create the
           client structure, even though we cannot fill it completely yet.
           But it allows us to access adm1021_{read,write}_value. */

        if (!(data = kzalloc(sizeof(struct adm1021_data), GFP_KERNEL))) {
                err = -ENOMEM;
                goto error0;
        }

        new_client = &data->client;
        i2c_set_clientdata(new_client, data);
        new_client->addr = address;
        new_client->adapter = adapter;
        new_client->driver = &adm1021_driver;
        new_client->flags = 0;

        /* Now, we do the remaining detection. */
        if (kind < 0) {
                if ((adm1021_read_value(new_client, ADM1021_REG_STATUS) & 0x03) != 0x00
                 || (adm1021_read_value(new_client, ADM1021_REG_CONFIG_R) & 0x3F) != 0x00
                 || (adm1021_read_value(new_client, ADM1021_REG_CONV_RATE_R) & 0xF8) != 0x00) {
                        err = -ENODEV;
                        goto error1;
                }
        }

        /* Determine the chip type. */
        if (kind <= 0) {
                i = adm1021_read_value(new_client, ADM1021_REG_MAN_ID);
                if (i == 0x41)
                        if ((adm1021_read_value(new_client, ADM1021_REG_DEV_ID) & 0x0F0) == 0x030)
                                kind = adm1023;
                        else
                                kind = adm1021;
                else if (i == 0x49)
                        kind = thmc10;
                else if (i == 0x23)
                        kind = gl523sm;
                else if ((i == 0x4d) &&
                         (adm1021_read_value(new_client, ADM1021_REG_DEV_ID) == 0x01))
                        kind = max1617a;
                else if (i == 0x54)
                        kind = mc1066;
                /* LM84 Mfr ID in a different place, and it has more unused bits */
                else if (adm1021_read_value(new_client, ADM1021_REG_CONV_RATE_R) == 0x00
                      && (kind == 0 /* skip extra detection */
                       || ((adm1021_read_value(new_client, ADM1021_REG_CONFIG_R) & 0x7F) == 0x00
                        && (adm1021_read_value(new_client, ADM1021_REG_STATUS) & 0xAB) == 0x00)))
                        kind = lm84;
                else
                        kind = max1617;
        }

        if (kind == max1617) {
                type_name = "max1617";
        } else if (kind == max1617a) {
                type_name = "max1617a";
        } else if (kind == adm1021) {
                type_name = "adm1021";
        } else if (kind == adm1023) {
                type_name = "adm1023";
        } else if (kind == thmc10) {
                type_name = "thmc10";
        } else if (kind == lm84) {
                type_name = "lm84";
        } else if (kind == gl523sm) {
                type_name = "gl523sm";
        } else if (kind == mc1066) {
                type_name = "mc1066";
        }

        /* Fill in the remaining client fields and put it into the global list */
        strlcpy(new_client->name, type_name, I2C_NAME_SIZE);
        data->type = kind;
        data->valid = 0;
        init_MUTEX(&data->update_lock);

        /* Tell the I2C layer a new client has arrived */
        if ((err = i2c_attach_client(new_client)))
                goto error1;

        /* Initialize the ADM1021 chip */
        if (kind != lm84)
                adm1021_init_client(new_client);

        /* Register sysfs hooks */
        data->class_dev = hwmon_device_register(&new_client->dev);
        if (IS_ERR(data->class_dev)) {
                err = PTR_ERR(data->class_dev);
                goto error2;
        }

        device_create_file(&new_client->dev, &dev_attr_temp1_max);
        device_create_file(&new_client->dev, &dev_attr_temp1_min);
        device_create_file(&new_client->dev, &dev_attr_temp1_input);
        device_create_file(&new_client->dev, &dev_attr_temp2_max);
        device_create_file(&new_client->dev, &dev_attr_temp2_min);
        device_create_file(&new_client->dev, &dev_attr_temp2_input);
        device_create_file(&new_client->dev, &dev_attr_alarms);

        return 0;

error2:
        i2c_detach_client(new_client);
error1:
        kfree(data);
error0:
        return err;
}

static void adm1021_init_client(struct i2c_client *client)
{
        /* Enable ADC and disable suspend mode */
        adm1021_write_value(client, ADM1021_REG_CONFIG_W,
                adm1021_read_value(client, ADM1021_REG_CONFIG_R) & 0xBF);
        /* Set Conversion rate to 1/sec (this can be tinkered with) */
        adm1021_write_value(client, ADM1021_REG_CONV_RATE_W, 0x04);
}

static int adm1021_detach_client(struct i2c_client *client)
{
        struct adm1021_data *data = i2c_get_clientdata(client);
        int err;

        hwmon_device_unregister(data->class_dev);

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

        kfree(data);
        return 0;
}

/* All registers are byte-sized */
static int adm1021_read_value(struct i2c_client *client, u8 reg)
{
        return i2c_smbus_read_byte_data(client, reg);
}

static int adm1021_write_value(struct i2c_client *client, u8 reg, u16 value)
{
        if (!read_only)
                return i2c_smbus_write_byte_data(client, reg, value);
        return 0;
}

static struct adm1021_data *adm1021_update_device(struct device *dev)
{
        struct i2c_client *client = to_i2c_client(dev);
        struct adm1021_data *data = i2c_get_clientdata(client);

        down(&data->update_lock);

        if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
            || !data->valid) {
                dev_dbg(&client->dev, "Starting adm1021 update\n");

                data->temp_input = adm1021_read_value(client, ADM1021_REG_TEMP);
                data->temp_max = adm1021_read_value(client, ADM1021_REG_TOS_R);
                data->temp_hyst = adm1021_read_value(client, ADM1021_REG_THYST_R);
                data->remote_temp_input = adm1021_read_value(client, ADM1021_REG_REMOTE_TEMP);
                data->remote_temp_max = adm1021_read_value(client, ADM1021_REG_REMOTE_TOS_R);
                data->remote_temp_hyst = adm1021_read_value(client, ADM1021_REG_REMOTE_THYST_R);
                data->alarms = adm1021_read_value(client, ADM1021_REG_STATUS) & 0x7c;
                if (data->type == adm1023) {
                        data->remote_temp_prec = adm1021_read_value(client, ADM1021_REG_REM_TEMP_PREC);
                        data->remote_temp_os_prec = adm1021_read_value(client, ADM1021_REG_REM_TOS_PREC);
                        data->remote_temp_hyst_prec = adm1021_read_value(client, ADM1021_REG_REM_THYST_PREC);
                        data->remote_temp_offset = adm1021_read_value(client, ADM1021_REG_REM_OFFSET);
                        data->remote_temp_offset_prec = adm1021_read_value(client, ADM1021_REG_REM_OFFSET_PREC);
                }
                data->last_updated = jiffies;
                data->valid = 1;
        }

        up(&data->update_lock);

        return data;
}

static int __init sensors_adm1021_init(void)
{
        return i2c_add_driver(&adm1021_driver);
}

static void __exit sensors_adm1021_exit(void)
{
        i2c_del_driver(&adm1021_driver);
}

MODULE_AUTHOR ("Frodo Looijaard <frodol@dds.nl> and "
                "Philip Edelbrock <phil@netroedge.com>");
MODULE_DESCRIPTION("adm1021 driver");
MODULE_LICENSE("GPL");

module_param(read_only, bool, 0);
MODULE_PARM_DESC(read_only, "Don't set any values, read only mode");

module_init(sensors_adm1021_init)
module_exit(sensors_adm1021_exit)