root/lm-sensors/trunk/kernel/chips/eeprom.c @ 1201

/*
    eeprom.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/version.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include "sensors.h"
#include "version.h"
#include <linux/init.h>

#ifdef MODULE_LICENSE
MODULE_LICENSE("GPL");
#endif

#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,2,18)) || \
    (LINUX_VERSION_CODE == KERNEL_VERSION(2,3,0))
#define init_MUTEX(s) do { *(s) = MUTEX; } while(0)
#endif

#ifndef THIS_MODULE
#define THIS_MODULE NULL
#endif

/* Addresses to scan */
static unsigned short normal_i2c[] = { SENSORS_I2C_END };
static unsigned short normal_i2c_range[] = { 0x50, 0x57, 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(eeprom);

static int checksum = 0;
MODULE_PARM(checksum, "i");
MODULE_PARM_DESC(checksum,
                 "Only accept eeproms whose checksum is correct");


/* Many constants specified below */

/* EEPROM registers */
#define EEPROM_REG_CHECKSUM 0x3f

/* EEPROM memory types: */
#define ONE_K           1
#define TWO_K           2
#define FOUR_K          3
#define EIGHT_K         4
#define SIXTEEN_K       5

/* Conversions */
/* Size of EEPROM in bytes */
#define EEPROM_SIZE 128

/* Each client has this additional data */
struct eeprom_data {
        int sysctl_id;

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

        u8 data[EEPROM_SIZE];   /* Register values */
        int memtype;
};

#ifdef MODULE
extern int init_module(void);
extern int cleanup_module(void);
#endif                          /* MODULE */

#ifdef MODULE
static
#else
extern
#endif
int __init sensors_eeprom_init(void);
static int __init eeprom_cleanup(void);

static int eeprom_attach_adapter(struct i2c_adapter *adapter);
static int eeprom_detect(struct i2c_adapter *adapter, int address,
                         unsigned short flags, int kind);
static int eeprom_detach_client(struct i2c_client *client);
static int eeprom_command(struct i2c_client *client, unsigned int cmd,
                          void *arg);

static void eeprom_inc_use(struct i2c_client *client);
static void eeprom_dec_use(struct i2c_client *client);

#if 0
static int eeprom_write_value(struct i2c_client *client, u8 reg,
                              u16 value);
#endif

static void eeprom_contents(struct i2c_client *client, int operation,
                            int ctl_name, int *nrels_mag, long *results);
static void eeprom_update_client(struct i2c_client *client);


/* This is the driver that will be inserted */
static struct i2c_driver eeprom_driver = {
        /* name */ "EEPROM READER",
        /* id */ I2C_DRIVERID_EEPROM,
        /* flags */ I2C_DF_NOTIFY,
        /* attach_adapter */ &eeprom_attach_adapter,
        /* detach_client */ &eeprom_detach_client,
        /* command */ &eeprom_command,
        /* inc_use */ &eeprom_inc_use,
        /* dec_use */ &eeprom_dec_use
};

/* These files are created for each detected EEPROM. This is just a template;
   though at first sight, you might think we could use a statically
   allocated list, we need some way to get back to the parent - which
   is done through one of the 'extra' fields which are initialized
   when a new copy is allocated. */
static ctl_table eeprom_dir_table_template[] = {
        {EEPROM_SYSCTL1, "data0-15", NULL, 0, 0444, NULL, &i2c_proc_real,
         &i2c_sysctl_real, NULL, &eeprom_contents},
        {EEPROM_SYSCTL2, "data16-31", NULL, 0, 0444, NULL, &i2c_proc_real,
         &i2c_sysctl_real, NULL, &eeprom_contents},
        {EEPROM_SYSCTL3, "data32-47", NULL, 0, 0444, NULL, &i2c_proc_real,
         &i2c_sysctl_real, NULL, &eeprom_contents},
        {EEPROM_SYSCTL4, "data48-63", NULL, 0, 0444, NULL, &i2c_proc_real,
         &i2c_sysctl_real, NULL, &eeprom_contents},
        {EEPROM_SYSCTL5, "data64-79", NULL, 0, 0444, NULL, &i2c_proc_real,
         &i2c_sysctl_real, NULL, &eeprom_contents},
        {EEPROM_SYSCTL6, "data80-95", NULL, 0, 0444, NULL, &i2c_proc_real,
         &i2c_sysctl_real, NULL, &eeprom_contents},
        {EEPROM_SYSCTL7, "data96-111", NULL, 0, 0444, NULL, &i2c_proc_real,
         &i2c_sysctl_real, NULL, &eeprom_contents},
        {EEPROM_SYSCTL8, "data112-127", NULL, 0, 0444, NULL, &i2c_proc_real,
         &i2c_sysctl_real, NULL, &eeprom_contents},
        {0}
};

/* Used by init/cleanup */
static int __initdata eeprom_initialized = 0;

static int eeprom_id = 0;

int eeprom_attach_adapter(struct i2c_adapter *adapter)
{
        return i2c_detect(adapter, &addr_data, eeprom_detect);
}

/* This function is called by i2c_detect */
int eeprom_detect(struct i2c_adapter *adapter, int address,
                  unsigned short flags, int kind)
{
        int i, cs;
        struct i2c_client *new_client;
        struct eeprom_data *data;
        int err = 0;
        const char *type_name, *client_name;

        /* Make sure we aren't probing the ISA bus!! This is just a safety check
           at this moment; i2c_detect really won't call us. */
#ifdef DEBUG
        if (i2c_is_isa_adapter(adapter)) {
                printk
                    ("eeprom.o: eeprom_detect called for an ISA bus adapter?!?\n");
                return 0;
        }
#endif

        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 eeprom_{read,write}_value. */
        if (!(new_client = kmalloc(sizeof(struct i2c_client) +
                                   sizeof(struct eeprom_data),
                                   GFP_KERNEL))) {
                err = -ENOMEM;
                goto ERROR0;
        }

        data = (struct eeprom_data *) (new_client + 1);
        new_client->addr = address;
        new_client->data = data;
        new_client->adapter = adapter;
        new_client->driver = &eeprom_driver;
        new_client->flags = 0;

        /* Now, we do the remaining detection. It is not there, unless you force
           the checksum to work out. */
        if (checksum) {
                cs = 0;
                for (i = 0; i <= 0x3e; i++)
                        cs += i2c_smbus_read_byte_data(new_client, i);
                cs &= 0xff;
                if (i2c_smbus_read_byte_data
                    (new_client, EEPROM_REG_CHECKSUM) != cs)
                        goto ERROR1;
        }

        /* Determine the chip type - only one kind supported! */
        if (kind <= 0)
                kind = eeprom;

        if (kind == eeprom) {
                type_name = "eeprom";
                client_name = "EEPROM chip";
        } else {
#ifdef DEBUG
                printk("eeprom.o: Internal error: unknown kind (%d)?!?",
                       kind);
#endif
                goto ERROR1;
        }

        /* Fill in the remaining client fields and put it into the global list */
        strcpy(new_client->name, client_name);

        new_client->id = eeprom_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)))
                goto ERROR3;

        /* Register a new directory entry with module sensors */
        if ((i = i2c_register_entry(new_client, type_name,
                                        eeprom_dir_table_template,
                                        THIS_MODULE)) < 0) {
                err = i;
                goto ERROR4;
        }
        data->sysctl_id = i;

        return 0;

/* OK, this is not exactly good programming practice, usually. But it is
   very code-efficient in this case. */

      ERROR4:
        i2c_detach_client(new_client);
      ERROR3:
      ERROR1:
        kfree(new_client);
      ERROR0:
        return err;
}

int eeprom_detach_client(struct i2c_client *client)
{
        int err;

        i2c_deregister_entry(((struct eeprom_data *) (client->data))->
                                 sysctl_id);

        if ((err = i2c_detach_client(client))) {
                printk
                    ("eeprom.o: Client deregistration failed, client not detached.\n");
                return err;
        }

        kfree(client);

        return 0;
}


/* No commands defined yet */
int eeprom_command(struct i2c_client *client, unsigned int cmd, void *arg)
{
        return 0;
}

void eeprom_inc_use(struct i2c_client *client)
{
#ifdef MODULE
        MOD_INC_USE_COUNT;
#endif
}

void eeprom_dec_use(struct i2c_client *client)
{
#ifdef MODULE
        MOD_DEC_USE_COUNT;
#endif
}

#if 0
/* No writes yet (PAE) */
int eeprom_write_value(struct i2c_client *client, u8 reg, u16 value)
{
        if (reg == EEPROM_REG_CONF)
                return i2c_smbus_write_byte_data(client, reg, value);
        else
                return i2c_smbus_write_word_data(client, reg, value);
        */return 0;
}
#endif

void eeprom_update_client(struct i2c_client *client)
{
        struct eeprom_data *data = client->data;
        int i;

        down(&data->update_lock);

        if ((jiffies - data->last_updated > 300 * HZ) |
            (jiffies < data->last_updated) || !data->valid) {

#ifdef DEBUG
                printk("Starting eeprom update\n");
#endif

                if (i2c_smbus_write_byte(client, 0)) {
#ifdef DEBUG
                        printk("eeprom read start has failed!\n");
#endif
                }
                for (i = 0; i < EEPROM_SIZE; i++) {
                        data->data[i] = (u8) i2c_smbus_read_byte(client);
                }

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

        up(&data->update_lock);
}


void eeprom_contents(struct i2c_client *client, int operation,
                     int ctl_name, int *nrels_mag, long *results)
{
        int i;
        int base = 0;
        struct eeprom_data *data = client->data;

        if (ctl_name == EEPROM_SYSCTL2) {
                base = 16;
        }
        if (ctl_name == EEPROM_SYSCTL3) {
                base = 32;
        }
        if (ctl_name == EEPROM_SYSCTL4) {
                base = 48;
        }
        if (ctl_name == EEPROM_SYSCTL5) {
                base = 64;
        }
        if (ctl_name == EEPROM_SYSCTL6) {
                base = 80;
        }
        if (ctl_name == EEPROM_SYSCTL7) {
                base = 96;
        }
        if (ctl_name == EEPROM_SYSCTL8) {
                base = 112;
        }

        if (operation == SENSORS_PROC_REAL_INFO)
                *nrels_mag = 0;
        else if (operation == SENSORS_PROC_REAL_READ) {
                eeprom_update_client(client);
                for (i = 0; i < 16; i++) {
                        results[i] = data->data[i + base];
                }
#ifdef DEBUG
                printk("eeprom.o: 0x%X EEPROM Contents (base %d): ",
                       client->addr, base);
                for (i = 0; i < 16; i++) {
                        printk(" 0x%X", data->data[i + base]);
                }
                printk(" .\n");
#endif
                *nrels_mag = 16;
        } else if (operation == SENSORS_PROC_REAL_WRITE) {

/* No writes to the EEPROM (yet, anyway) (PAE) */
                printk("eeprom.o: No writes to EEPROMs supported!\n");
        }
}

int __init sensors_eeprom_init(void)
{
        int res;

        printk("eeprom.o version %s (%s)\n", LM_VERSION, LM_DATE);
        eeprom_initialized = 0;
        if ((res = i2c_add_driver(&eeprom_driver))) {
                printk
                    ("eeprom.o: Driver registration failed, module not inserted.\n");
                eeprom_cleanup();
                return res;
        }
        eeprom_initialized++;
        return 0;
}

int __init eeprom_cleanup(void)
{
        int res;

        if (eeprom_initialized >= 1) {
                if ((res = i2c_del_driver(&eeprom_driver))) {
                        printk
                            ("eeprom.o: Driver deregistration failed, module not removed.\n");
                        return res;
                }
        } else
                eeprom_initialized--;

        return 0;
}

EXPORT_NO_SYMBOLS;

#ifdef MODULE

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

int init_module(void)
{
        return sensors_eeprom_init();
}

int cleanup_module(void)
{
        return eeprom_cleanup();
}

#endif                          /* MODULE */