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

/*
    matorb.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.
*/


#define DEBUG 1

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/i2c-proc.h>
#include <linux/init.h>
#include "version.h"

MODULE_LICENSE("GPL");

/* Addresses to scan */
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(matorb);

/* Many MATORB constants specified below */


/* Each client has this additional data */
struct matorb_data {
        struct i2c_client client;
        int sysctl_id;

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

};

static int matorb_attach_adapter(struct i2c_adapter *adapter);
static int matorb_detect(struct i2c_adapter *adapter, int address,
                         unsigned short flags, int kind);
static void matorb_init_client(struct i2c_client *client);
static int matorb_detach_client(struct i2c_client *client);

static int matorb_write_value(struct i2c_client *client, u8 reg,
                              u16 value);
static void matorb_disp(struct i2c_client *client, int operation,
                        int ctl_name, int *nrels_mag, long *results);
static void matorb_update_client(struct i2c_client *client);


/* This is the driver that will be inserted */
static struct i2c_driver matorb_driver = {
        .name           = "Matrix Orbital LCD driver",
        .id             = I2C_DRIVERID_MATORB,
        .flags          = I2C_DF_NOTIFY,
        .attach_adapter = matorb_attach_adapter,
        .detach_client  = matorb_detach_client,
};

/* -- SENSORS SYSCTL START -- */
#define MATORB_SYSCTL_DISP 1000
/* -- SENSORS SYSCTL END -- */

/* These files are created for each detected MATORB. 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 matorb_dir_table_template[] = {
        {MATORB_SYSCTL_DISP, "disp", NULL, 0, 0644, NULL, &i2c_proc_real,
         &i2c_sysctl_real, NULL, &matorb_disp},
        {0}
};

static int matorb_id = 0;

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

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

        /* 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
                    ("matorb.o: matorb_detect called for an ISA bus adapter?!?\n");
                return 0;
        }
#endif

        if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WRITE_BYTE |
                                     I2C_FUNC_SMBUS_WRITE_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 matorb_{read,write}_value. */
        if (!(data = kmalloc(sizeof(struct matorb_data), GFP_KERNEL))) {
                err = -ENOMEM;
                goto ERROR0;
        }

        new_client = &data->client;
        new_client->addr = address;
        new_client->data = data;
        new_client->adapter = adapter;
        new_client->driver = &matorb_driver;
        new_client->flags = 0;

        /* Now, we do the remaining detection. It is lousy. */
        cur = i2c_smbus_write_byte_data(new_client, 0x0FE, 0x58);       /* clear screen */

        printk("matorb.o: debug detect 0x%X\n", cur);

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

        new_client->id = matorb_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,
                                        matorb_dir_table_template)) < 0) {
                err = i;
                goto ERROR4;
        }
        data->sysctl_id = i;

        matorb_init_client(new_client);
        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:
        kfree(data);
      ERROR0:
        return err;
}

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

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

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

        kfree(client->data);

        return 0;
}


#if 0
/* All registers are word-sized, except for the configuration register.
   MATORB uses a high-byte first convention, which is exactly opposite to
   the usual practice. */
static int matorb_read_value(struct i2c_client *client, u8 reg)
{
        return -1;              /* Doesn't support reads */
}
#endif

/* All registers are word-sized, except for the configuration register.
   MATORB uses a high-byte first convention, which is exactly opposite to
   the usual practice. */
static int matorb_write_value(struct i2c_client *client, u8 reg, u16 value)
{
        if (reg == 0) {
                return i2c_smbus_write_byte(client, value);
        } else {
                return i2c_smbus_write_byte_data(client, reg, value);
        }
}

static void matorb_init_client(struct i2c_client *client)
{
        /* Initialize the MATORB chip */
}

static void matorb_update_client(struct i2c_client *client)
{
        struct matorb_data *data = client->data;

        down(&data->update_lock);

        if ((jiffies - data->last_updated > HZ + HZ / 2) ||
            (jiffies < data->last_updated) || !data->valid) {

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

/* nothing yet */
                data->last_updated = jiffies;
                data->valid = 1;
        }

        up(&data->update_lock);
}


void matorb_disp(struct i2c_client *client, int operation, int ctl_name,
                 int *nrels_mag, long *results)
{
        int i;

        if (operation == SENSORS_PROC_REAL_INFO)
                *nrels_mag = 0;
        else if (operation == SENSORS_PROC_REAL_READ) {
                matorb_update_client(client);
                results[0] = 0;
                *nrels_mag = 3;
        } else if (operation == SENSORS_PROC_REAL_WRITE) {
                for (i = 1; i <= *nrels_mag; i++) {
                        matorb_write_value(client, 0, results[i - 1]);
                }
        }
}

static int __init sm_matorb_init(void)
{
        printk("matorb.o version %s (%s)\n", LM_VERSION, LM_DATE);
        return i2c_add_driver(&matorb_driver);
}

static void __exit sm_matorb_exit(void)
{
        i2c_del_driver(&matorb_driver);
}



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

module_init(sm_matorb_init);
module_exit(sm_matorb_exit);