root/lm-sensors/trunk/kernel/chips/w83l785ts.c @ 2781

/*
 * w83l785ts.c - Part of lm_sensors, Linux kernel modules for hardware
 *               monitoring
 * Copyright (C) 2003-2004  Jean Delvare <khali@linux-fr.org>
 *
 * Inspired from the lm83 driver. The W83L785TS-S is a sensor chip made
 * by Winbond. It reports a single external temperature with a 1 deg
 * resolution and a 3 deg accuracy. Data sheet can be obtained from
 * Winbond's website at:
 *   http://www.winbond-usa.com/products/winbond_products/pdfs/PCIC/W83L785TS-S.pdf
 *
 * Thanks to James Bolt <james@evilpenguin.com> for benchmarking the read
 * error handling mechanism.
 *
 * 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/slab.h>
#include <linux/i2c.h>
#include <linux/i2c-proc.h>
#include <linux/init.h>
#include <linux/delay.h>
#include "version.h"

#ifndef I2C_DRIVERID_W83L785TS
#define I2C_DRIVERID_W83L785TS  1047
#endif

/* How many retries on register read error */
#define MAX_RETRIES     5

/*
 * Address to scan
 * Address is fully defined internally and cannot be changed.
 */

static unsigned short normal_i2c[] = { 0x2e, SENSORS_I2C_END };
static unsigned short normal_i2c_range[] = { SENSORS_I2C_END };
static unsigned int normal_isa[] = { SENSORS_ISA_END };
static unsigned int normal_isa_range[] = { SENSORS_ISA_END };

/*
 * Insmod parameters
 */

SENSORS_INSMOD_1(w83l785ts);

/*
 * The W83L785TS-S registers
 * Manufacturer ID is 0x5CA3 for Winbond.
 */

#define W83L785TS_REG_MAN_ID1           0x4D
#define W83L785TS_REG_MAN_ID2           0x4C
#define W83L785TS_REG_CHIP_ID           0x4E
#define W83L785TS_REG_CONFIG            0x40
#define W83L785TS_REG_TYPE              0x52
#define W83L785TS_REG_TEMP              0x27
#define W83L785TS_REG_TEMP_OVER         0x53 /* not sure about this one */

/*
 * Conversions
 * The W83L785TS-S uses signed 8-bit values.
 */

#define TEMP_FROM_REG(val)      (val & 0x80 ? val-0x100 : val)

/*
 * Functions declaration
 */

static int w83l785ts_attach_adapter(struct i2c_adapter *adapter);
static int w83l785ts_detect(struct i2c_adapter *adapter, int address, unsigned
        short flags, int kind);
static int w83l785ts_detach_client(struct i2c_client *client);
static u8 w83l785ts_read_value(struct i2c_client *client, u8 reg, u8 defval);
static void w83l785ts_update_client(struct i2c_client *client);
static void w83l785ts_temp(struct i2c_client *client, int operation, int
        ctl_name, int *nrels_mag, long *results);

/*
 * Driver data (common to all clients)
 */
 
static struct i2c_driver w83l785ts_driver = {
        .name           = "W83L785S-S sensor driver",
        .id             = I2C_DRIVERID_W83L785TS,
        .flags          = I2C_DF_NOTIFY,
        .attach_adapter = w83l785ts_attach_adapter,
        .detach_client  = w83l785ts_detach_client,
};

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

struct w83l785ts_data {
        struct i2c_client client;
        int sysctl_id;

        struct semaphore update_lock;
        char valid; /* zero until following fields are valid */
        unsigned long last_updated; /* in jiffies */

        /* registers values */
        u8 temp, temp_over;
};

/*
 * Proc entries
 * These files are created for each detected W83L785TS-S.
 */

/* -- SENSORS SYSCTL START -- */

#define W83L785TS_SYSCTL_TEMP   1200

/* -- SENSORS SYSCTL END -- */


static ctl_table w83l785ts_dir_table_template[] =
{
        {W83L785TS_SYSCTL_TEMP, "temp", NULL, 0, 0444, NULL,
         &i2c_proc_real, &i2c_sysctl_real, NULL, &w83l785ts_temp},
        {0}
};

/*
 * Internal variables
 */

static int w83l785ts_id = 0;

/*
 * Real code
 */

static int w83l785ts_attach_adapter(struct i2c_adapter *adapter)
{
        return i2c_detect(adapter, &addr_data, w83l785ts_detect);
}

/*
 * The following function does more than just detection. If detection
 * succeeds, it also registers the new chip.
 */
static int w83l785ts_detect(struct i2c_adapter *adapter, int address,
        unsigned short flags, int kind)
{
        struct i2c_client *new_client;
        struct w83l785ts_data *data;
        int err = 0;
        const char *type_name = "";
        const char *client_name = "";

        if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) {
#ifdef DEBUG
                printk(KERN_DEBUG "w83l785ts.o: I2C bus doesn't support "
                        "byte read mode, skipping.\n");
#endif
                return 0;
        }

        if (!(data = kmalloc(sizeof(struct w83l785ts_data), GFP_KERNEL))) {
                printk(KERN_ERR "w83l785ts.o: Out of memory in w83l785ts_detect "
                        "(new_client).\n");
                return -ENOMEM;
        }

        /*
         * The common I2C client data is placed right after the
         * W83L785TS-specific. The W83L785TS-specific data is pointed to by the
         * data field from the I2C client data.
         */

        new_client = &data->client;
        new_client->addr = address;
        new_client->data = data;
        new_client->adapter = adapter;
        new_client->driver = &w83l785ts_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 (actually there is only
         * one possible kind of chip for now, W83L785TS-S). 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.
         */

        if (kind < 0) { /* detection */
                if (((w83l785ts_read_value(new_client, W83L785TS_REG_CONFIG, 0)
                        & 0x80) != 0x00)
                 || ((w83l785ts_read_value(new_client, W83L785TS_REG_TYPE, 0)
                        & 0xFC) != 0x00)) {
#ifdef DEBUG
                        printk(KERN_DEBUG "w83l785ts.o: Detection failed at "
                                "0x%02x.\n", address);
#endif
                        goto ERROR1;
                }
        }

        if (kind <= 0) { /* identification */
                u16 man_id;
                u8 chip_id;

                man_id = (w83l785ts_read_value(new_client, W83L785TS_REG_MAN_ID1, 0) << 8)
                       +  w83l785ts_read_value(new_client, W83L785TS_REG_MAN_ID2, 0);
                chip_id = w83l785ts_read_value(new_client, W83L785TS_REG_CHIP_ID, 0);
                if (man_id == 0x5CA3) { /* Winbond */
                        if (chip_id == 0x70)
                                kind = w83l785ts;
                }
        }

        if (kind <= 0) { /* identification failed */
                printk(KERN_INFO "w83l785ts.o: Unsupported chip.\n");
                goto ERROR1;
        }

        if (kind == w83l785ts) {
                type_name = "w83l785ts";
                client_name = "W83L785TS-S chip";
        } else {
                printk(KERN_ERR "w83l785ts.o: Unknown kind %d.\n", kind);
                goto ERROR1;
        }
        
        /*
         * OK, we got a valid chip so we can fill in the remaining client
         * fields.
         */

        strcpy(new_client->name, client_name);
        new_client->id = w83l785ts_id++;
        data->valid = 0;
        init_MUTEX(&data->update_lock);

        /*
         * Tell the I2C layer a new client has arrived.
         */

        if ((err = i2c_attach_client(new_client))) {
#ifdef DEBUG
                printk(KERN_ERR "w83l785ts.o: Failed attaching client.\n");
#endif
                goto ERROR1;
        }

        /*
         * Register a new directory entry.
         */

        if ((err = i2c_register_entry(new_client, type_name,
            w83l785ts_dir_table_template)) < 0) {
#ifdef DEBUG
                printk(KERN_ERR "w83l785ts.o: Failed registering directory "
                        "entry.\n");
#endif
                goto ERROR2;
        }
        data->sysctl_id = err;

        /*
         * Initialize the W83L785TS chip
         * Nothing yet, assume it is already started.
         */

        return 0;

        ERROR2:
        i2c_detach_client(new_client);
        ERROR1:
        kfree(data);
        return err;
}

static int w83l785ts_detach_client(struct i2c_client *client)
{
        int err;

        i2c_deregister_entry(((struct w83l785ts_data *) (client->data))->sysctl_id);
        if ((err = i2c_detach_client(client))) {
                printk(KERN_ERR "w83l785ts.o: Client deregistration failed, "
                        "client not detached.\n");
                return err;
        }

        kfree(client->data);
        return 0;
}

static u8 w83l785ts_read_value(struct i2c_client *client, u8 reg, u8 defval)
{
        int value, i;

        /* Frequent read errors have been reported on Asus boards, so we
         * retry on read errors. If it still fails (unlikely), return the
         * default value requested by the caller. */
        for (i = 1; i <= MAX_RETRIES; i++) {
                value = i2c_smbus_read_byte_data(client, reg);
                if (value >= 0)
                        return value;
                printk(KERN_WARNING "w83l785ts.o: Read failed, will retry "
                        "in %d.\n", i);
                mdelay(i);
        }

        printk(KERN_ERR "w83l785ts.o: Couldn't read value from register. "
                "Please report.\n");
        return defval;
}

static void w83l785ts_update_client(struct i2c_client *client)
{
        struct w83l785ts_data *data = client->data;

        down(&data->update_lock);

        if ((jiffies - data->last_updated > HZ * 2)
         || (jiffies < data->last_updated)
         || !data->valid) {
#ifdef DEBUG
                printk(KERN_DEBUG "w83l785ts.o: Updating data.\n");
#endif
                data->temp = w83l785ts_read_value(client, W83L785TS_REG_TEMP,
                        data->temp);
                data->temp_over = w83l785ts_read_value(client,
                        W83L785TS_REG_TEMP_OVER, data->temp_over);
                data->last_updated = jiffies;
                data->valid = 1;
        }

        up(&data->update_lock);
}

static void w83l785ts_temp(struct i2c_client *client, int operation,
        int ctl_name, int *nrels_mag, long *results)
{
        struct w83l785ts_data *data = client->data;

        if (operation == SENSORS_PROC_REAL_INFO) {
                *nrels_mag = 0; /* magnitude */
        } else if (operation == SENSORS_PROC_REAL_READ) {
                w83l785ts_update_client(client);
                results[0] = TEMP_FROM_REG(data->temp_over);
                results[1] = TEMP_FROM_REG(data->temp);
                *nrels_mag = 2;
        }
}

static int __init sm_w83l785ts_init(void)
{
        printk(KERN_INFO "w83l785ts.o version %s (%s)\n", LM_VERSION, LM_DATE);
        return i2c_add_driver(&w83l785ts_driver);
}

static void __exit sm_w83l785ts_exit(void)
{
        i2c_del_driver(&w83l785ts_driver);
}

MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
MODULE_DESCRIPTION("W83L785TS-S sensor driver");
MODULE_LICENSE("GPL");

module_init(sm_w83l785ts_init);
module_exit(sm_w83l785ts_exit);