/*
    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/malloc.h>
#include <linux/i2c.h>
#include "sensors.h"
#include "i2c-isa.h"
#include "version.h"
#include "compat.h"

/* Addresses to scan */
static unsigned short normal_i2c[] = {SENSORS_I2C_END};
static unsigned short normal_i2c_range[] = {0x18,0x1a,0x29,0x2b,
                                            0x4c,0x4e,SENSORS_I2C_END};
static unsigned int normal_isa[] = {SENSORS_ISA_END};
static unsigned int normal_isa_range[] = {SENSORS_ISA_END};

/* Insmod parameters */
SENSORS_INSMOD_3(adm1021,max1617,max1617a);

/* 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  /* should always read 0x41 */
#define ADM1021_REG_DEV_ID 0x0FF /* ADM1021 */
#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
#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 : val)
#define TEMP_TO_REG(val)   (SENSORS_LIMIT((val < 0 ? val+256 : val),0,255))

/* Initial values */

/* Note: Eventhough 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 actuall triggers an alarm instead of 
clearing it.  Weird, ey?   --Phil  */
#define adm1021_INIT_TOS 60
#define adm1021_INIT_THYST 20
#define adm1021_INIT_REMOTE_TOS 60
#define adm1021_INIT_REMOTE_THYST 20

/* Each client has this additional data */
struct adm1021_data {
         int sysctl_id;
	 enum chips type;

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

         u8 temp,temp_os,temp_hyst; /* Register values */
         u8 remote_temp,remote_temp_os,remote_temp_hyst,alarms,die_code; 
};

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

static int adm1021_init(void);
static int adm1021_cleanup(void);
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_command(struct i2c_client *client, unsigned int cmd,
                        void *arg);
static void adm1021_inc_use (struct i2c_client *client);
static void adm1021_dec_use (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 void adm1021_temp(struct i2c_client *client, int operation, int ctl_name,
                      int *nrels_mag, long *results);
static void adm1021_remote_temp(struct i2c_client *client, int operation, int ctl_name,
                      int *nrels_mag, long *results);
static void adm1021_alarms(struct i2c_client *client, int operation, int ctl_name,
                      int *nrels_mag, long *results);
static void adm1021_die_code(struct i2c_client *client, int operation, int ctl_name,
                      int *nrels_mag, long *results);
static void adm1021_update_client(struct i2c_client *client);


/* This is the driver that will be inserted */
static struct i2c_driver adm1021_driver = {
  /* name */            "adm1021, MAX1617 sensor driver",
  /* id */              I2C_DRIVERID_ADM1021,
  /* flags */           I2C_DF_NOTIFY,
  /* attach_adapter */  &adm1021_attach_adapter,
  /* detach_client */   &adm1021_detach_client,
  /* command */         &adm1021_command,
  /* inc_use */         &adm1021_inc_use,
  /* dec_use */         &adm1021_dec_use
};

/* These files are created for each detected adm1021. 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 adm1021_dir_table_template[] = {
  { ADM1021_SYSCTL_TEMP, "temp", NULL, 0, 0644, NULL, &sensors_proc_real,
    &sensors_sysctl_real, NULL, &adm1021_temp },
    {ADM1021_SYSCTL_REMOTE_TEMP, "remote_temp", NULL, 0, 0644, NULL, &sensors_proc_real,
    &sensors_sysctl_real, NULL, &adm1021_remote_temp },
    {ADM1021_SYSCTL_DIE_CODE, "die_code", NULL, 0, 0444, NULL, &sensors_proc_real,
    &sensors_sysctl_real, NULL, &adm1021_die_code },
    {ADM1021_SYSCTL_ALARMS, "alarms", NULL, 0, 0444, NULL, &sensors_proc_real,
    &sensors_sysctl_real, NULL, &adm1021_alarms },
  { 0 }
};

static ctl_table adm1021_max_dir_table_template[] = {
  { ADM1021_SYSCTL_TEMP, "temp", NULL, 0, 0644, NULL, &sensors_proc_real,
    &sensors_sysctl_real, NULL, &adm1021_temp },
    {ADM1021_SYSCTL_REMOTE_TEMP, "remote_temp", NULL, 0, 0644, NULL, &sensors_proc_real,
    &sensors_sysctl_real, NULL, &adm1021_remote_temp },
    {ADM1021_SYSCTL_ALARMS, "alarms", NULL, 0, 0444, NULL, &sensors_proc_real,
    &sensors_sysctl_real, NULL, &adm1021_alarms },
  { 0 }
};


/* Used by init/cleanup */
static int adm1021_initialized = 0;

/* I choose here for semi-static allocation. Complete dynamic
   allocation could also be used; the code needed for this would probably
   take more memory than the datastructure takes now. */
#define MAX_ADM1021_NR 9
static struct i2c_client *adm1021_list[MAX_ADM1021_NR];

int adm1021_attach_adapter(struct i2c_adapter *adapter)
{
  return sensors_detect(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 = "";
  const char *client_name = "";

  /* Make sure we aren't probing the ISA bus!! This is just a safety check
     at this moment; sensors_detect really won't call us. */
#ifdef DEBUG
  if (i2c_is_isa_adapter(adapter)) {
    printk("adm1021.o: adm1021_detect called for an ISA bus adapter?!?\n");
    return 0;
  }
#endif


  /* We need address registration for the I2C bus too. That is not yet
     implemented. */

  /* 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 (! (new_client = kmalloc(sizeof(struct i2c_client) +
                               sizeof(struct adm1021_data),
                               GFP_KERNEL))) {
    err = -ENOMEM;
    goto ERROR0;
  }

  data = (struct adm1021_data *) (new_client + 1);
  new_client->addr = address;
  new_client->data = data;
  new_client->adapter = adapter;
  new_client->driver = &adm1021_driver;

  /* Now, we do the remaining detection. */

  if (kind < 0) {
    if ((adm1021_read_value(new_client,ADM1021_REG_STATUS) & 0x03) != 0x00)
      goto ERROR1;
  }

  /* Determine the chip type. */
  
  if (kind <= 0) {
    i = adm1021_read_value(new_client,ADM1021_REG_MAN_ID);
    if (i == 0x41)
      kind = adm1021;
    else if ((i== 0x4d) && 
             (adm1021_read_value(new_client,ADM1021_REG_DEV_ID) == 0x01))
      kind = max1617a;
    else 
      kind = max1617;
  }

  if (kind == max1617) {
    type_name = "max1617";
    client_name = "MAX1617 chip";
  } else if (kind == max1617a) {
    type_name = "max1617a";
    client_name = "MAX1617A chip";
  } else if (kind == adm1021) {
    type_name = "adm1021";
    client_name = "ADM1021 chip";
  } else {
#ifdef DEBUG
    printk("adm1021.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);
  data->type = kind;

  for(i = 0; i < MAX_ADM1021_NR; i++)
    if (! adm1021_list[i])
      break;
  if (i == MAX_ADM1021_NR) {
    printk("adm1021.o: No empty slots left, recompile and heighten "
           "MAX_ADM1021_NR!\n");
    err = -ENOMEM;
    goto ERROR2;
  }
  adm1021_list[i] = new_client;
  new_client->id = i;
  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 = sensors_register_entry((struct i2c_client *) new_client,
                        type_name,
                        data->type==adm1021?adm1021_dir_table_template:
                                    adm1021_max_dir_table_template)) < 0) {
    err = i;
    goto ERROR4;
  }
  data->sysctl_id = i;

  /* Initialize the ADM1021 chip */
  adm1021_init_client((struct i2c_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:
  for (i = 0; i < MAX_ADM1021_NR; i++)
    if (new_client == adm1021_list[i])
      adm1021_list[i] = NULL;
ERROR2:
ERROR1:
  kfree(new_client);
ERROR0:
  return err;
}

void adm1021_init_client(struct i2c_client *client)
{
  /* Initialize the adm1021 chip */
  adm1021_write_value(client,ADM1021_REG_TOS_W,
                   TEMP_TO_REG(adm1021_INIT_TOS));
  adm1021_write_value(client,ADM1021_REG_THYST_W,
                   TEMP_TO_REG(adm1021_INIT_THYST));
  adm1021_write_value(client,ADM1021_REG_REMOTE_TOS_W,
                   TEMP_TO_REG(adm1021_INIT_REMOTE_TOS));
  adm1021_write_value(client,ADM1021_REG_REMOTE_THYST_W,
                   TEMP_TO_REG(adm1021_INIT_REMOTE_THYST));
  /* Enable ADC and disable suspend mode */
  adm1021_write_value(client,ADM1021_REG_CONFIG_W,0);  
  /* Set Conversion rate to 1/sec (this can be tinkered with) */
  adm1021_write_value(client,ADM1021_REG_CONV_RATE_W,0x04); 
}

int adm1021_detach_client(struct i2c_client *client)
{

  int err,i;

  sensors_deregister_entry(((struct adm1021_data *)(client->data))->sysctl_id);

  if ((err = i2c_detach_client(client))) {
    printk("adm1021.o: Client deregistration failed, client not detached.\n");
    return err;
  }

  for (i = 0; i < MAX_ADM1021_NR; i++)
    if (client == adm1021_list[i])
      break;
  if ((i == MAX_ADM1021_NR)) {
    printk("adm1021.o: Client to detach not found.\n");
    return -ENOENT;
  }
  adm1021_list[i] = NULL;

  kfree(client);

  return 0;

}


/* No commands defined yet */
int adm1021_command(struct i2c_client *client, unsigned int cmd, void *arg)
{
  return 0;
}

void adm1021_inc_use (struct i2c_client *client)
{
#ifdef MODULE
  MOD_INC_USE_COUNT;
#endif
}

void adm1021_dec_use (struct i2c_client *client)
{
#ifdef MODULE
  MOD_DEC_USE_COUNT;
#endif
}

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

int adm1021_write_value(struct i2c_client *client, u8 reg, u16 value)
{
    return i2c_smbus_write_byte_data(client->adapter,client->addr,reg,value);
}

void adm1021_update_client(struct i2c_client *client)
{
  struct adm1021_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 adm1021 update\n");
#endif

    data->temp = adm1021_read_value(client,ADM1021_REG_TEMP);
    data->temp_os = adm1021_read_value(client,ADM1021_REG_TOS_R);
    data->temp_hyst = adm1021_read_value(client,ADM1021_REG_THYST_R);
    data->remote_temp = adm1021_read_value(client,ADM1021_REG_REMOTE_TEMP);
    data->remote_temp_os = 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) & 0xec;
    if (data->type == adm1021)
      data->die_code = adm1021_read_value(client,ADM1021_REG_DIE_CODE);
    data->last_updated = jiffies;
    data->valid = 1;
  }

  up(&data->update_lock);
}


void adm1021_temp(struct i2c_client *client, int operation, int ctl_name,
               int *nrels_mag, long *results)
{
  struct adm1021_data *data = client->data;
  if (operation == SENSORS_PROC_REAL_INFO)
    *nrels_mag = 0;
  else if (operation == SENSORS_PROC_REAL_READ) {
    adm1021_update_client(client);
    results[0] = TEMP_FROM_REG(data->temp_os);
    results[1] = TEMP_FROM_REG(data->temp_hyst);
    results[2] = TEMP_FROM_REG(data->temp);
    *nrels_mag = 3;
  } else if (operation == SENSORS_PROC_REAL_WRITE) {
    if (*nrels_mag >= 1) {
      data->temp_os = TEMP_TO_REG(results[0]);
      adm1021_write_value(client,ADM1021_REG_TOS_W,data->temp_os);
    }
    if (*nrels_mag >= 2) {
      data->temp_hyst = TEMP_TO_REG(results[1]);
      adm1021_write_value(client,ADM1021_REG_THYST_W,data->temp_hyst);
    }
  }
}

void adm1021_remote_temp(struct i2c_client *client, int operation, int ctl_name,
               int *nrels_mag, long *results)
{
  struct adm1021_data *data = client->data;
  if (operation == SENSORS_PROC_REAL_INFO)
    *nrels_mag = 0;
  else if (operation == SENSORS_PROC_REAL_READ) {
    adm1021_update_client(client);
    results[0] = TEMP_FROM_REG(data->remote_temp_os);
    results[1] = TEMP_FROM_REG(data->remote_temp_hyst);
    results[2] = TEMP_FROM_REG(data->remote_temp);
    *nrels_mag = 3;
  } else if (operation == SENSORS_PROC_REAL_WRITE) {
    if (*nrels_mag >= 1) {
      data->remote_temp_os = TEMP_TO_REG(results[0]);
      adm1021_write_value(client,ADM1021_REG_REMOTE_TOS_W,data->remote_temp_os);
    }
    if (*nrels_mag >= 2) {
      data->remote_temp_hyst = TEMP_TO_REG(results[1]);
      adm1021_write_value(client,ADM1021_REG_REMOTE_THYST_W,data->remote_temp_hyst);
    }
  }
}

void adm1021_die_code(struct i2c_client *client, int operation, int ctl_name,
               int *nrels_mag, long *results)
{
  struct adm1021_data *data = client->data;
  if (operation == SENSORS_PROC_REAL_INFO)
    *nrels_mag = 0;
  else if (operation == SENSORS_PROC_REAL_READ) {
    adm1021_update_client(client);
    results[0] = data->die_code;
    *nrels_mag = 1;
  } else if (operation == SENSORS_PROC_REAL_WRITE) {
    /* Can't write to it */
  }
}

void adm1021_alarms(struct i2c_client *client, int operation, int ctl_name,
               int *nrels_mag, long *results)
{
  struct adm1021_data *data = client->data;
  if (operation == SENSORS_PROC_REAL_INFO)
    *nrels_mag = 0;
  else if (operation == SENSORS_PROC_REAL_READ) {
    adm1021_update_client(client);
    results[0] = data->alarms;
    *nrels_mag = 1;
  } else if (operation == SENSORS_PROC_REAL_WRITE) {
    /* Can't write to it */
  }
}

int adm1021_init(void)
{
  int res;

  printk("adm1021.o version %s (%s)\n",LM_VERSION,LM_DATE);
  adm1021_initialized = 0;
  if ((res = i2c_add_driver(&adm1021_driver))) {
    printk("adm1021.o: Driver registration failed, module not inserted.\n");
    adm1021_cleanup();
    return res;
  }
  adm1021_initialized ++;
  return 0;
}

int adm1021_cleanup(void)
{
  int res;

  if (adm1021_initialized >= 1) {
    if ((res = i2c_del_driver(&adm1021_driver))) {
      printk("adm1021.o: Driver deregistration failed, module not removed.\n");
      return res;
    }
    adm1021_initialized --;
  }

  return 0;
}


#ifdef MODULE

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

int init_module(void)
{
  return adm1021_init();
}

int cleanup_module(void)
{
  return adm1021_cleanup();
}

#endif /* MODULE */