lm-sensors/kernel/sensors.c

/*
    sensors.c - A Linux module for reading sensor data.
    Copyright (c) 1998  Frodo Looijaard <frodol@dds.nl> 

    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/ctype.h>
#include <linux/sysctl.h>

#include "version.h"
#include "compat.h"
#include "i2c.h"
#include "isa.h"
#include "sensors.h"

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

int sensors_register_entry(struct i2c_client *client ,const char *prefix, 
                           ctl_table *ctl_template);
static int sensors_create_name(char **name, const char *prefix,
                               struct i2c_adapter * adapter, int addr);
static int sensors_init(void);
static int sensors_cleanup(void);

#define SENSORS_ENTRY_MAX 20
static struct ctl_table_header *sensors_entries[SENSORS_ENTRY_MAX];

static ctl_table sysctl_table[] = {
  { CTL_DEV, "dev", NULL, 0, 0555 },
  { 0 },
  { DEV_SENSORS, "sensors", NULL, 0, 0555 },
  { 0 },
  { 0, NULL, NULL, 0, 0555 },
  { 0 }
};

/* This returns a nice name for a new directory; for example lm78-isa-0310
   (for a LM78 chip on the ISA bus at port 0x310), or lm75-i2c-3-4e (for
   a LM75 chip on the third i2c bus at address 0x4e).  
   name is allocated first. */
int sensors_create_name(char **name, const char *prefix, 
                        struct i2c_adapter * adapter, int addr)
{
  char name_buffer[50]; 
  int id;
  if (i2c_is_isa_adapter(adapter)) 
    sprintf(name_buffer,"%s-isa-%d",prefix,addr);
  else {
    if ((id = i2c_adapter_id(adapter)) < 0);
      return -ENOENT;
    sprintf(name_buffer,"%s-i2c-%d-%d",prefix,id,addr);
  }
  *name = kmalloc(strlen(name_buffer)+1,GFP_KERNEL);
  strcpy(*name,name_buffer);
  return 0;
}

/* This rather complex function must be called when you want to add an entry
   to /proc/sys/dev/sensors/chips (not yet implemented). It also creates
   a new directory within /proc/sys/dev/sensors/.
   ctl_template should be a template of the newly created directory. It is
   copied in memory. The extra1 field of each file is set to point to client.
   If any driver wants subdirectories within the newly created directory,
   this function must be updated! */
int sensors_register_entry(struct i2c_client *client ,const char *prefix, 
                           ctl_table *ctl_template)
{
  int i,res,len,id;
  ctl_table *new_table;
  char *name;
  struct ctl_table_header *new_header;

  if ((res = sensors_create_name(&name,prefix,client->adapter,
                                 i2c_is_isa_client(client)?
                                 ((struct isa_client *) client)->isa_addr:
                                 client->addr)))
    return res;

  for (id = 0; id < SENSORS_ENTRY_MAX; i++)
    if (! sensors_entries[id]) {
      break;
    }
  if (id == SENSORS_ENTRY_MAX) {
    kfree(name);
    return -ENOMEM;
  }
  id += 256;

  len = 0;
  while (ctl_template[len].procname)
    len++;
  len += 7;
  if (! (new_table = kmalloc(sizeof(ctl_table) * len,GFP_KERNEL))) {
    kfree(name);
    return -ENOMEM;
  }
    
  memcpy(new_table,sysctl_table,6 * sizeof(ctl_table));
  new_table[0].child = &new_table[2];
  new_table[2].child = &new_table[4];
  new_table[4].child = &new_table[6];
  new_table[4].procname = name;
  new_table[4].ctl_name = id;
  memcpy(new_table+6,ctl_template,(len-6) * sizeof(ctl_table));
  for (i = 6; i < len; i++)
    new_table[i].extra1 = client;

  if (! (new_header = register_sysctl_table(new_table,0))) {
    kfree(new_table);
    kfree(name);
    return -ENOMEM;
  }

  sensors_entries[i] = new_header;

  return id;
}

void sensors_deregister_entry(int id)
{
  ctl_table *table;
  id -= 256;
  if (sensors_entries[id]) {
    table = sensors_entries[id]->ctl_table;
    unregister_sysctl_table(sensors_entries[id]);
    kfree((void *) (table->procname));
    kfree(table);
    sensors_entries[id] = 0;
  }
}

/* nrels contains initially the maximum number of elements which can be
   put in results, and finally the number of elements actually put there.
   A magnitude of 1 will multiply everything with 10; etc.
   buffer, bufsize is the character buffer we read from and its length.
   results will finally contain the parsed integers. 

   Buffer should contain several reals, separated by whitespace. A real
   has the following syntax:
     [ Minus ] Digit* [ Dot Digit* ] 
   (everything between [] is optional; * means zero or more).
   When the next character is unparsable, everything is skipped until the
   next whitespace.

   WARNING! This is tricky code. I have tested it, but there may still be
            hidden bugs in it, even leading to crashes and things!
*/
void sensors_parse_reals(int *nrels, void *buffer, int bufsize, 
                         long *results, int magnitude)
{
  int maxels,min,mag;
  long res;
  char nextchar=0;

  maxels = *nrels;
  *nrels = 0;

  while (bufsize && (*nrels < maxels)) {

    /* Skip spaces at the start */
    while (bufsize && ! get_user_data(nextchar,(char *) buffer) && 
           isspace((int) nextchar)) {
      bufsize --;
      ((char *) buffer)++;
    }

    /* Well, we may be done now */
    if (! bufsize)
      return;

    /* New defaults for our result */
    min = 0;
    res = 0;
    mag = magnitude;

    /* Check for a minus */
    if (! get_user_data(nextchar,(char *) buffer) && (nextchar == '-')) {
      min=1;
      bufsize--;
      ((char *) buffer)++;
    }

    /* Digits before a decimal dot */
    while (bufsize && !get_user_data(nextchar,(char *) buffer) && 
           isdigit((int) nextchar)) {
      res = res * 10 + nextchar - '0';
      bufsize--;
      ((char *) buffer)++;
    }

    /* If mag < 0, we must actually divide here! */
    while (mag < 0) {
      res = res / 10;
      mag++;
    }

    if (bufsize && (nextchar == '.')) {
      /* Skip the dot */
      bufsize--;
      ((char *) buffer)++;
  
      /* Read digits while they are significant */
      while(bufsize && (mag > 0) && 
            !get_user_data(nextchar,(char *) buffer) &&
            isdigit((int) nextchar)) {
        res = res * 10 + nextchar - '0';
        mag--;
        bufsize--;
        ((char *) buffer)++;
      }
    }
    /* If we are out of data, but mag > 0, we need to scale here */
    while (mag > 0) {
      res = res * 10;
      mag --;
    }

    /* Skip everything until we hit whitespace */
    while(bufsize && !get_user_data(nextchar,(char *) buffer) &&
          isspace ((int) nextchar)) {
      bufsize --;
      ((char *) buffer) ++;
    }

    /* Put res in results */
    results[*nrels] = (min?-1:1)*res;
    (*nrels)++;
  }    
  
  /* Well, there may be more in the buffer, but we need no more data. 
     Ignore anything that is left. */
  return;
}
    
void sensors_write_reals(int nrels,void *buffer,int *bufsize,long *results,
                         int magnitude)
{
  #define BUFLEN 20
  char BUF[BUFLEN+1]; /* An individual representation should fit in here! */
  char printfstr[10];
  int nr=0;
  int buflen,mag,times;
  int curbufsize=0;

  while ((nr < nrels) && (curbufsize < *bufsize)) {
    mag=magnitude;

    if (nr != 0) {
      put_user(' ', (char *) buffer);
      curbufsize ++;
      ((char *) buffer) ++;
    }

    /* Fill BUF with the representation of the next string */
    if (mag <= 0) {

      buflen=sprintf(BUF,"%ld",results[nr]);
      if (buflen < 0) { /* Oops, a sprintf error! */
        *bufsize=0;
        return;
      }
      while ((mag < 0) && (buflen < BUFLEN)) {
        BUF[buflen++]='0';
        mag++;
      }
      BUF[buflen]=0;
    } else {
      times=1;
      for (times=1; mag-- > 0; times *= 10);
      if (results[nr] < 0) {
        BUF[0] = '-';
        buflen = 1;
      } else
        buflen=0;
      strcpy(printfstr,"%ld.%0Xld");
      printfstr[6]=magnitude+'0';
      buflen+=sprintf(BUF+buflen,printfstr,abs(results[nr])/times,
                      abs(results[nr])%times);
      if (buflen < 0) { /* Oops, a sprintf error! */
        *bufsize=0;
        return;
      }
    }

    /* Now copy it to the user-space buffer */
    if (buflen + curbufsize > *bufsize)
      buflen=*bufsize-curbufsize;
    copy_to_user(buffer,BUF,buflen);
    curbufsize += buflen;
    (char *) buffer += buflen;

    nr ++;
  }
  if (curbufsize < *bufsize) {
    put_user('\n', (char *) buffer);
    curbufsize ++;
  }
  *bufsize=curbufsize;
}

int sensors_init(void) 
{
  printk("sensors.o version %s (%s)\n",LM_VERSION,LM_DATE);
  return 0;
}

int sensors_cleanup(void)
{
  return 0;
}

#ifdef MODULE

MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>");
MODULE_DESCRIPTION("LM78 driver");

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

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

#endif /* MODULE */