The beginnings of i2c-dev

Everything is in, except the IOCTL hook (which will be pretty simple to add).
It compiles cleanly. It is not tested at all.

Also a very small fix for i2c-proc, and Makefile.


git-svn-id: http://lm-sensors.org/svn/lm-sensors/trunk@158 7894878c-1315-0410-8ee3-d5d059ff63e0

Makefile

@@ -24,7 +24,7 @@
 # Uncomment the third line on SMP systems if the magic invocation fails. It
 # is a bit complicated because SMP configuration changed around kernel 2.1.130
 SMP := $(shell if grep -q '^SMP[[:space:]]*=' /usr/src/linux/Makefile || \
-                  grep -q '^CONFIG_SMP=y' /usr/src/linux/.config ;  \
+                  grep -q '^[[:space:]]*\#define[[::space:]]*CONFIG_SMP[[:space:]]*1' /usr/include/linux/autoconf.h ; \
                then echo 1; else echo 0; fi)
 #SMP := 0
 #SMP := 1

TODO

@@ -1,5 +1,6 @@
 Many, many things. Most notably:
 
+* Fans give overflow if small values are written to them.
 * At least the bit-lp and bit-velle modules do no detection on loading;
   ask Simon whether this is possible to add.
 * kmalloc with GFP_KERNEL can cause a context switch! Check whether this is
@@ -12,10 +13,13 @@ Many, many things. Most notably:
 * Make it SMP-safe: there are no spinlocks yet. They are needed at many
   places, probably (everywhere where global vars are accessed). This must be
   done for the i2c modules, too.
+* Better general locking, or at least a once-over to check no race-conditions
+  remain.
 * Make lm78.c detect 'double hits', (same chip connected to both SMBus and
   ISA).
 * Better chip detection; insmod-time paramters to set addresses 
   (difficult, because of all i2c busses!).
+* At least one case report that unused port addresses do not return 0xff
 * Registrate which i2c addresses are used (a la ISA) for each adapter.
 * Rename i2c-proc.c to i2c-user.c, and extend it with /dev entries;
   or, create a better i2c-dev.c, that understands SMBus commands.

kernel/Module.mk

@@ -28,7 +28,8 @@ SRCTARGETS := $(MODULE_DIR)/smbus.o $(MODULE_DIR)/piix4.o $(MODULE_DIR)/isa.o \
               $(MODULE_DIR)/i2c-proc.o $(MODULE_DIR)/gl518sm.o \
               $(MODULE_DIR)/eeprom.o $(MODULE_DIR)/w83781d.o \
               $(MODULE_DIR)/lm80.o $(MODULE_DIR)/adm1021.o \
-              $(MODULE_DIR)/adm9240.o $(MODULE_DIR)/ltc1710.o
+              $(MODULE_DIR)/adm9240.o $(MODULE_DIR)/ltc1710.o \
+              $(MODULE_DIR)/i2c-dev.o
 
 SRCHEADERFILES := $(MODULE_DIR)/sensors.h $(MODULE_DIR)/isa.h \
                $(MODULE_DIR)/smbus.h

kernel/i2c-dev.c

@@ -0,0 +1,407 @@
+/*
+    i2c-dev.c - Part of lm_sensors, Linux kernel modules for hardware
+                 monitoring
+    Copyright (c) 1995-1997, 1999 by Frodo Looijaard <frodol@dds.nl> and
+    Simon Vogl
+
+    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.
+*/
+
+/* Note that this is a complete rewrite of Simon Vogl's i2c-dev module.
+   But I have used so much of his original code and ideas that it seems
+   only fair to recognize him as co-author -- Frodo */
+
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/malloc.h>
+#include "compat.h"
+#include "i2c.h"
+#include "isa.h"
+#include "sensors.h"
+#include "version.h"
+
+#ifdef MODULE
+extern int init_module(void);
+extern int cleanup_module(void);
+#endif /* def MODULE */
+
+/* struct file_operations changed too often in the 2.1 series for nice code */
+
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,1,70))
+static loff_t i2cdev_lseek (struct file *file, loff_t offset, int origin);
+#elif (LINUX_VERSION_CODE >= KERNEL_VERSION(2,1,56))
+static long long i2cdev_lseek (struct file *file, long long offset, int origin);
+#elif (LINUX_VERSION_CODE >= KERNEL_VERSION(2,1,0))
+static long long i2cdev_llseek (struct inode *inode, struct file *file, 
+                                long long offset, int origin);
+#else
+static int i2cdev_lseek (struct inode *inode, struct file *file, off_t offset, 
+                         int origin);
+#endif
+
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,1,70))
+static ssize_t i2cdev_read (struct file *file, char *buf, size_t count, 
+                            loff_t *offset);
+static ssize_t i2cdev_write (struct file *file, const char *buf, size_t count, 
+                             loff_t *offset);
+#elif (LINUX_VERSION_CODE >= KERNEL_VERSION(2,1,0))
+static long i2cdev_read (struct inode *inode, struct file *file, char *buf, 
+                         unsigned long count);
+static long i2cdev_write (struct inode *inode, struct file *file, 
+                          const char *buf, unsigned long offset);
+#else
+static int i2cdev_read(struct inode *inode, struct file *file, char *buf, 
+                       int count);
+static int i2cdev_write(struct inode *inode, struct file *file, 
+                        const char *buf, int count);
+#endif
+
+static int i2cdev_ioctl (struct inode *inode, struct file *file, 
+                         unsigned int cmd, unsigned long arg);
+static int i2cdev_open (struct inode *inode, struct file *file);
+
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,1,31))
+static int i2cdev_release (struct inode *inode, struct file *file);
+#else
+static void i2cdev_release (struct inode *inode, struct file *file);
+#endif
+
+
+static int i2cdev_attach_adapter(struct i2c_adapter *adap);
+static int i2cdev_detach_client(struct i2c_client *client);
+static int i2cdev_command(struct i2c_client *client, unsigned int cmd,
+                           void *arg);
+static void i2cdev_inc_use(struct i2c_client *client);
+static void i2cdev_dec_use(struct i2c_client *client);
+
+static int i2cdev_init(void);
+static int i2cdev_cleanup(void);
+
+static struct file_operations i2cdev_fops = {
+    i2cdev_lseek,
+    i2cdev_read,
+    i2cdev_write,
+    NULL,                   /* i2cdev_readdir  */
+    NULL,                   /* i2cdev_select   */
+    i2cdev_ioctl,
+    NULL,                   /* i2cdev_mmap     */
+    i2cdev_open,
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,1,118)
+    NULL,                   /* i2cdev_flush    */
+#endif
+    i2cdev_release,
+};
+
+#define I2CDEV_CLIENTS_MAX I2C_ADAP_MAX
+static struct i2c_client *i2cdev_clients[I2CDEV_CLIENTS_MAX];
+
+static struct i2c_driver i2cdev_driver = {
+  /* name */            "i2c-dev dummy driver",
+  /* id */              I2C_DRIVERID_I2CDEV,
+  /* flags */           DF_NOTIFY,
+  /* attach_adapter */  &i2cdev_attach_adapter,
+  /* detach_client */   &i2cdev_detach_client,
+  /* command */         &i2cdev_command,
+  /* inc_use */         &i2cdev_inc_use,
+  /* dec_use */         &i2cdev_dec_use
+};
+
+static struct i2c_client i2cdev_client_template = {
+  /* name */          "I2C /dev entry",
+  /* id */            1,
+  /* flags */         0,
+  /* addr */          -1,
+  /* adapter */       NULL,
+  /* driver */        &i2cdev_driver,
+  /* data */          NULL
+};
+
+static int i2cdev_initialized;
+
+/* Note that the lseek function is called llseek in 2.1 kernels. But things
+   are complicated enough as is. */
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,1,70))
+loff_t i2cdev_lseek (struct file *file, loff_t offset, int origin)
+#elif (LINUX_VERSION_CODE >= KERNEL_VERSION(2,1,56))
+long long i2cdev_lseek (struct file *file, long long offset, int origin)
+#elif (LINUX_VERSION_CODE >= KERNEL_VERSION(2,1,0))
+long long i2cdev_llseek (struct inode *inode, struct file *file, 
+                         long long offset, int origin)
+#else
+int i2cdev_lseek (struct inode *inode, struct file *file, off_t offset, 
+                  int origin)
+#endif
+{
+  return -ESPIPE;
+}
+
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,1,70))
+static ssize_t i2cdev_read (struct file *file, char *buf, size_t count,
+                            loff_t *offset)
+#elif (LINUX_VERSION_CODE >= KERNEL_VERSION(2,1,0))
+static long i2cdev_read (struct inode *inode, struct file *file, char *buf,
+                         unsigned long count)
+#else
+static int i2cdev_read(struct inode *inode, struct file *file, char *buf,
+                       int count)
+#endif
+{
+  char *tmp;
+  int ret;
+
+  struct i2c_client *client = (struct i2c_client *)file->private_data;
+
+#ifdef  DEBUG
+  printk("i2cdev_read: i2c%d reading %d bytes from %d.\n",minor,count,
+         client->addr);
+#endif
+
+  /* copy user space data to kernel space. */
+  tmp = kmalloc(count,GFP_KERNEL);
+  if (tmp==NULL)
+     return -ENOMEM;
+  ret = i2c_master_recv(client,tmp,count);
+  copy_to_user(buf,tmp,count);
+  kfree(tmp);
+  return ret;
+}
+
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,1,70))
+static ssize_t i2cdev_write (struct file *file, const char *buf, size_t count,
+                             loff_t *offset)
+#elif (LINUX_VERSION_CODE >= KERNEL_VERSION(2,1,0))
+static long i2cdev_write (struct inode *inode, struct file *file,
+                          const char *buf, unsigned long offset)
+#else
+static int i2cdev_write(struct inode *inode, struct file *file,
+                        const char *buf, int count)
+#endif
+{
+  int ret;
+  char *tmp;
+  struct i2c_client *client = (struct i2c_client *)file->private_data;
+
+  /* copy user space data to kernel space. */
+  tmp = kmalloc(count,GFP_KERNEL);
+  if (tmp==NULL)
+    return -ENOMEM;
+  copy_from_user(tmp,buf,count);
+
+#ifdef DEBUG
+  printk("i2c_write: i2c%d writing %d bytes.\n",minor,count);
+#endif
+  ret = i2c_master_send(client,tmp,count);
+  kfree(tmp);
+  return ret;
+}
+
+  
+int i2cdev_open (struct inode *inode, struct file *file)
+{
+  unsigned int minor = MINOR(inode->i_rdev);
+  struct i2c_client *client;
+
+  if (! i2cdev_clients[minor]) {
+#ifdef DEBUG
+    printk("i2cdev: trying to open unattached adapter i2c-%d\n",minor);
+#endif
+    return -ENODEV;
+  }
+
+  /* Note that we here allocate a client for later use, but we will *not*
+     register this client! Yes, this is safe. No, it is not very clean. */
+  if(! (client = kmalloc(sizeof(struct i2c_client),GFP_KERNEL)))
+    return -ENOMEM;
+  memcpy(client,&i2cdev_client_template,sizeof(struct i2c_client));
+  client->adapter = i2cdev_clients[minor]->adapter;
+  file->private_data = client;
+
+  MOD_INC_USE_COUNT;
+
+#ifdef DEBUG
+  printk("i2cdev_open: i2c-%d\n",minor);
+#endif
+  return 0;
+}
+
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,1,31))
+static int i2cdev_release (struct inode *inode, struct file *file)
+#else
+static void i2cdev_release (struct inode *inode, struct file *file)
+#endif
+{
+   kfree(file->private_data);
+   file->private_data=NULL;
+#ifdef DEBUG
+   printk("i2c_close: i2c-%d\n", MINOR(inode->i_rdev));
+#endif
+  MOD_DEC_USE_COUNT;
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,1,31))
+   return 0;
+#endif
+}
+
+int i2cdev_attach_adapter(struct i2c_adapter *adap)
+{
+  int i,res;
+  struct i2c_client *client;
+
+  if ((i = i2c_adapter_id(adap)) < 0) {
+    printk("i2cdev_attach_adapter: unknown adapter?!?\n");
+    return -ENODEV;
+  }
+  if (i >= I2CDEV_CLIENTS_MAX) {
+    printk("i2cdev_attach_adapter: adapter number too large?!? (%d)\n",i);
+    return -ENODEV;
+  }
+  if (i2cdev_clients[i]) {
+    printk("i2cdev_attach_adapter: adapter already in use?!? (%d)\n",i);
+    return -EBUSY;
+  }
+  if (i2c_is_isa_adapter(adap)) {
+    printk("i2cdev_attach_adapter: Can't open ISA adapter!\n");
+    return -ENODEV;
+  }
+
+  if (! (client = (struct i2c_client *)kmalloc(sizeof(struct i2c_client), 
+                                               GFP_KERNEL)))
+    return -ENOMEM;
+  memcpy(client,&i2cdev_client_template,sizeof(struct i2c_client));
+  client->adapter = adap;
+  if ((res =  i2c_attach_client(client))) {
+    printk("i2cdev_attach_adapter: attaching client failed.\n");
+    kfree(client);
+    return res;
+  }
+  i2cdev_clients[i] = client;
+  printk("i2cdev: registered '%s' as minor %d\n",adap->name,i);
+  return 0;
+}
+
+int i2cdev_detach_client(struct i2c_client *client)
+{
+  struct i2c_adapter *adap = client->adapter;
+  int i,res;
+
+  if ((i = i2c_adapter_id(adap)) < 0) {
+    printk("i2cdev_detach_adapter: unknown adapter?!?\n");
+    return -ENODEV;
+  }
+  if (i >= I2CDEV_CLIENTS_MAX) {
+    printk("i2cdev_detach_adapter: adapter number too large?!? (%d)\n",i);
+    return -ENODEV;
+  }
+  if (!i2cdev_clients[i]) {
+    printk("i2cdev_detach_adapter: adapter not in use?!? (%d)\n",i);
+    return -ENODEV;
+  }
+
+  if ((res =  i2c_detach_client(client))) {
+    printk("i2cdev_detach_adapter: detaching client failed.\n");
+    return res;
+  }
+
+  kfree(i2cdev_clients[i]);
+  i2cdev_clients[i] = NULL;
+
+#ifdef DEBUG
+  printk("i2c(char): adapter unregistered: %s\n",adap->name);
+#endif
+  return 0;
+}
+
+static int i2cdev_command(struct i2c_client *client, unsigned int cmd,
+                           void *arg)
+{
+  return -1;
+}
+
+
+static void i2cdev_inc_use(struct i2c_client *client)
+{
+#ifdef MODULE
+  MOD_INC_USE_COUNT;
+#endif
+}
+
+static void i2cdev_dec_use(struct i2c_client *client)
+{
+#ifdef MODULE
+  MOD_DEC_USE_COUNT;
+#endif
+}
+
+int i2cdev_init(void)
+{
+  int res;
+
+  printk("i2c-dev.o version %s (%s)\n",LM_VERSION,LM_DATE);
+  i2cdev_initialized = 0;
+  if (register_chrdev(I2C_MAJOR,"i2c",&i2cdev_fops)) {
+    printk("i2c-dev.o: unable to get major %d for i2c bus\n",I2C_MAJOR);
+    return -EIO;
+  }
+  i2cdev_initialized ++;
+
+  if ((res = i2c_add_driver(&i2cdev_driver))) {
+    printk("i2c-dev.o: Driver registration failed, module not inserted.\n");
+    i2cdev_cleanup();
+    return res;
+  }
+  i2cdev_initialized ++;
+  return 0;
+}
+
+int i2cdev_cleanup(void)
+{
+  int res;
+
+  if (i2cdev_initialized >= 2) {
+    if ((res = i2c_del_driver(&i2cdev_driver))) {
+      printk("i2c-dev.o: Driver deregistration failed, "
+             "module not removed.\n");
+      return res;
+    }
+    i2cdev_initialized ++;
+  }
+
+  if (i2cdev_initialized >= 1) {
+    if ((res = unregister_chrdev(I2C_MAJOR,"i2c"))) {
+      printk("i2c-dev.o: unable to release major %d for i2c bus\n",I2C_MAJOR);
+      return res;
+    }
+    i2cdev_initialized --;
+  }
+  return 0;
+}
+
+
+#ifdef MODULE
+
+MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and Simon G. Vogl <simon@tk.uni-linz.ac.at>");
+MODULE_DESCRIPTION("I2C /dev entries driver");
+
+int init_module(void)
+{
+  return i2cdev_init();
+}
+
+int cleanup_module(void)
+{
+  return i2cdev_cleanup();
+}
+
+#endif /* def MODULE */
+

kernel/i2c-proc.c

@@ -459,11 +459,17 @@ int i2cproc_command(struct i2c_client *client, unsigned int cmd,
 /* Nothing here yet */
 void i2cproc_inc_use(struct i2c_client *client)
 {
+#ifdef MODULE
+  MOD_INC_USE_COUNT;
+#endif
 }
 
 /* Nothing here yet */
 void i2cproc_dec_use(struct i2c_client *client)
 {
+#ifdef MODULE
+  MOD_DEC_USE_COUNT;
+#endif
 }
 
 #ifdef MODULE

kernel/include/sensors.h

@@ -81,6 +81,7 @@ extern void sensors_deregister_entry(int id);
 #define SENSORS_PREFIX_MAX 20
 
 /* Driver IDs */
+#define I2C_DRIVERID_I2CDEV 1000
 #define I2C_DRIVERID_I2CPROC 1001
 #define I2C_DRIVERID_LM78 1002
 #define I2C_DRIVERID_LM75 1003

src/Module.mk

@@ -28,7 +28,8 @@ SRCTARGETS := $(MODULE_DIR)/smbus.o $(MODULE_DIR)/piix4.o $(MODULE_DIR)/isa.o \
               $(MODULE_DIR)/i2c-proc.o $(MODULE_DIR)/gl518sm.o \
               $(MODULE_DIR)/eeprom.o $(MODULE_DIR)/w83781d.o \
               $(MODULE_DIR)/lm80.o $(MODULE_DIR)/adm1021.o \
-              $(MODULE_DIR)/adm9240.o $(MODULE_DIR)/ltc1710.o
+              $(MODULE_DIR)/adm9240.o $(MODULE_DIR)/ltc1710.o \
+              $(MODULE_DIR)/i2c-dev.o
 
 SRCHEADERFILES := $(MODULE_DIR)/sensors.h $(MODULE_DIR)/isa.h \
                $(MODULE_DIR)/smbus.h

src/i2c-dev.c

@@ -0,0 +1,407 @@
+/*
+    i2c-dev.c - Part of lm_sensors, Linux kernel modules for hardware
+                 monitoring
+    Copyright (c) 1995-1997, 1999 by Frodo Looijaard <frodol@dds.nl> and
+    Simon Vogl
+
+    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.
+*/
+
+/* Note that this is a complete rewrite of Simon Vogl's i2c-dev module.
+   But I have used so much of his original code and ideas that it seems
+   only fair to recognize him as co-author -- Frodo */
+
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/malloc.h>
+#include "compat.h"
+#include "i2c.h"
+#include "isa.h"
+#include "sensors.h"
+#include "version.h"
+
+#ifdef MODULE
+extern int init_module(void);
+extern int cleanup_module(void);
+#endif /* def MODULE */
+
+/* struct file_operations changed too often in the 2.1 series for nice code */
+
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,1,70))
+static loff_t i2cdev_lseek (struct file *file, loff_t offset, int origin);
+#elif (LINUX_VERSION_CODE >= KERNEL_VERSION(2,1,56))
+static long long i2cdev_lseek (struct file *file, long long offset, int origin);
+#elif (LINUX_VERSION_CODE >= KERNEL_VERSION(2,1,0))
+static long long i2cdev_llseek (struct inode *inode, struct file *file, 
+                                long long offset, int origin);
+#else
+static int i2cdev_lseek (struct inode *inode, struct file *file, off_t offset, 
+                         int origin);
+#endif
+
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,1,70))
+static ssize_t i2cdev_read (struct file *file, char *buf, size_t count, 
+                            loff_t *offset);
+static ssize_t i2cdev_write (struct file *file, const char *buf, size_t count, 
+                             loff_t *offset);
+#elif (LINUX_VERSION_CODE >= KERNEL_VERSION(2,1,0))
+static long i2cdev_read (struct inode *inode, struct file *file, char *buf, 
+                         unsigned long count);
+static long i2cdev_write (struct inode *inode, struct file *file, 
+                          const char *buf, unsigned long offset);
+#else
+static int i2cdev_read(struct inode *inode, struct file *file, char *buf, 
+                       int count);
+static int i2cdev_write(struct inode *inode, struct file *file, 
+                        const char *buf, int count);
+#endif
+
+static int i2cdev_ioctl (struct inode *inode, struct file *file, 
+                         unsigned int cmd, unsigned long arg);
+static int i2cdev_open (struct inode *inode, struct file *file);
+
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,1,31))
+static int i2cdev_release (struct inode *inode, struct file *file);
+#else
+static void i2cdev_release (struct inode *inode, struct file *file);
+#endif
+
+
+static int i2cdev_attach_adapter(struct i2c_adapter *adap);
+static int i2cdev_detach_client(struct i2c_client *client);
+static int i2cdev_command(struct i2c_client *client, unsigned int cmd,
+                           void *arg);
+static void i2cdev_inc_use(struct i2c_client *client);
+static void i2cdev_dec_use(struct i2c_client *client);
+
+static int i2cdev_init(void);
+static int i2cdev_cleanup(void);
+
+static struct file_operations i2cdev_fops = {
+    i2cdev_lseek,
+    i2cdev_read,
+    i2cdev_write,
+    NULL,                   /* i2cdev_readdir  */
+    NULL,                   /* i2cdev_select   */
+    i2cdev_ioctl,
+    NULL,                   /* i2cdev_mmap     */
+    i2cdev_open,
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,1,118)
+    NULL,                   /* i2cdev_flush    */
+#endif
+    i2cdev_release,
+};
+
+#define I2CDEV_CLIENTS_MAX I2C_ADAP_MAX
+static struct i2c_client *i2cdev_clients[I2CDEV_CLIENTS_MAX];
+
+static struct i2c_driver i2cdev_driver = {
+  /* name */            "i2c-dev dummy driver",
+  /* id */              I2C_DRIVERID_I2CDEV,
+  /* flags */           DF_NOTIFY,
+  /* attach_adapter */  &i2cdev_attach_adapter,
+  /* detach_client */   &i2cdev_detach_client,
+  /* command */         &i2cdev_command,
+  /* inc_use */         &i2cdev_inc_use,
+  /* dec_use */         &i2cdev_dec_use
+};
+
+static struct i2c_client i2cdev_client_template = {
+  /* name */          "I2C /dev entry",
+  /* id */            1,
+  /* flags */         0,
+  /* addr */          -1,
+  /* adapter */       NULL,
+  /* driver */        &i2cdev_driver,
+  /* data */          NULL
+};
+
+static int i2cdev_initialized;
+
+/* Note that the lseek function is called llseek in 2.1 kernels. But things
+   are complicated enough as is. */
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,1,70))
+loff_t i2cdev_lseek (struct file *file, loff_t offset, int origin)
+#elif (LINUX_VERSION_CODE >= KERNEL_VERSION(2,1,56))
+long long i2cdev_lseek (struct file *file, long long offset, int origin)
+#elif (LINUX_VERSION_CODE >= KERNEL_VERSION(2,1,0))
+long long i2cdev_llseek (struct inode *inode, struct file *file, 
+                         long long offset, int origin)
+#else
+int i2cdev_lseek (struct inode *inode, struct file *file, off_t offset, 
+                  int origin)
+#endif
+{
+  return -ESPIPE;
+}
+
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,1,70))
+static ssize_t i2cdev_read (struct file *file, char *buf, size_t count,
+                            loff_t *offset)
+#elif (LINUX_VERSION_CODE >= KERNEL_VERSION(2,1,0))
+static long i2cdev_read (struct inode *inode, struct file *file, char *buf,
+                         unsigned long count)
+#else
+static int i2cdev_read(struct inode *inode, struct file *file, char *buf,
+                       int count)
+#endif
+{
+  char *tmp;
+  int ret;
+
+  struct i2c_client *client = (struct i2c_client *)file->private_data;
+
+#ifdef  DEBUG
+  printk("i2cdev_read: i2c%d reading %d bytes from %d.\n",minor,count,
+         client->addr);
+#endif
+
+  /* copy user space data to kernel space. */
+  tmp = kmalloc(count,GFP_KERNEL);
+  if (tmp==NULL)
+     return -ENOMEM;
+  ret = i2c_master_recv(client,tmp,count);
+  copy_to_user(buf,tmp,count);
+  kfree(tmp);
+  return ret;
+}
+
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,1,70))
+static ssize_t i2cdev_write (struct file *file, const char *buf, size_t count,
+                             loff_t *offset)
+#elif (LINUX_VERSION_CODE >= KERNEL_VERSION(2,1,0))
+static long i2cdev_write (struct inode *inode, struct file *file,
+                          const char *buf, unsigned long offset)
+#else
+static int i2cdev_write(struct inode *inode, struct file *file,
+                        const char *buf, int count)
+#endif
+{
+  int ret;
+  char *tmp;
+  struct i2c_client *client = (struct i2c_client *)file->private_data;
+
+  /* copy user space data to kernel space. */
+  tmp = kmalloc(count,GFP_KERNEL);
+  if (tmp==NULL)
+    return -ENOMEM;
+  copy_from_user(tmp,buf,count);
+
+#ifdef DEBUG
+  printk("i2c_write: i2c%d writing %d bytes.\n",minor,count);
+#endif
+  ret = i2c_master_send(client,tmp,count);
+  kfree(tmp);
+  return ret;
+}
+
+  
+int i2cdev_open (struct inode *inode, struct file *file)
+{
+  unsigned int minor = MINOR(inode->i_rdev);
+  struct i2c_client *client;
+
+  if (! i2cdev_clients[minor]) {
+#ifdef DEBUG
+    printk("i2cdev: trying to open unattached adapter i2c-%d\n",minor);
+#endif
+    return -ENODEV;
+  }
+
+  /* Note that we here allocate a client for later use, but we will *not*
+     register this client! Yes, this is safe. No, it is not very clean. */
+  if(! (client = kmalloc(sizeof(struct i2c_client),GFP_KERNEL)))
+    return -ENOMEM;
+  memcpy(client,&i2cdev_client_template,sizeof(struct i2c_client));
+  client->adapter = i2cdev_clients[minor]->adapter;
+  file->private_data = client;
+
+  MOD_INC_USE_COUNT;
+
+#ifdef DEBUG
+  printk("i2cdev_open: i2c-%d\n",minor);
+#endif
+  return 0;
+}
+
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,1,31))
+static int i2cdev_release (struct inode *inode, struct file *file)
+#else
+static void i2cdev_release (struct inode *inode, struct file *file)
+#endif
+{
+   kfree(file->private_data);
+   file->private_data=NULL;
+#ifdef DEBUG
+   printk("i2c_close: i2c-%d\n", MINOR(inode->i_rdev));
+#endif
+  MOD_DEC_USE_COUNT;
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,1,31))
+   return 0;
+#endif
+}
+
+int i2cdev_attach_adapter(struct i2c_adapter *adap)
+{
+  int i,res;
+  struct i2c_client *client;
+
+  if ((i = i2c_adapter_id(adap)) < 0) {
+    printk("i2cdev_attach_adapter: unknown adapter?!?\n");
+    return -ENODEV;
+  }
+  if (i >= I2CDEV_CLIENTS_MAX) {
+    printk("i2cdev_attach_adapter: adapter number too large?!? (%d)\n",i);
+    return -ENODEV;
+  }
+  if (i2cdev_clients[i]) {
+    printk("i2cdev_attach_adapter: adapter already in use?!? (%d)\n",i);
+    return -EBUSY;
+  }
+  if (i2c_is_isa_adapter(adap)) {
+    printk("i2cdev_attach_adapter: Can't open ISA adapter!\n");
+    return -ENODEV;
+  }
+
+  if (! (client = (struct i2c_client *)kmalloc(sizeof(struct i2c_client), 
+                                               GFP_KERNEL)))
+    return -ENOMEM;
+  memcpy(client,&i2cdev_client_template,sizeof(struct i2c_client));
+  client->adapter = adap;
+  if ((res =  i2c_attach_client(client))) {
+    printk("i2cdev_attach_adapter: attaching client failed.\n");
+    kfree(client);
+    return res;
+  }
+  i2cdev_clients[i] = client;
+  printk("i2cdev: registered '%s' as minor %d\n",adap->name,i);
+  return 0;
+}
+
+int i2cdev_detach_client(struct i2c_client *client)
+{
+  struct i2c_adapter *adap = client->adapter;
+  int i,res;
+
+  if ((i = i2c_adapter_id(adap)) < 0) {
+    printk("i2cdev_detach_adapter: unknown adapter?!?\n");
+    return -ENODEV;
+  }
+  if (i >= I2CDEV_CLIENTS_MAX) {
+    printk("i2cdev_detach_adapter: adapter number too large?!? (%d)\n",i);
+    return -ENODEV;
+  }
+  if (!i2cdev_clients[i]) {
+    printk("i2cdev_detach_adapter: adapter not in use?!? (%d)\n",i);
+    return -ENODEV;
+  }
+
+  if ((res =  i2c_detach_client(client))) {
+    printk("i2cdev_detach_adapter: detaching client failed.\n");
+    return res;
+  }
+
+  kfree(i2cdev_clients[i]);
+  i2cdev_clients[i] = NULL;
+
+#ifdef DEBUG
+  printk("i2c(char): adapter unregistered: %s\n",adap->name);
+#endif
+  return 0;
+}
+
+static int i2cdev_command(struct i2c_client *client, unsigned int cmd,
+                           void *arg)
+{
+  return -1;
+}
+
+
+static void i2cdev_inc_use(struct i2c_client *client)
+{
+#ifdef MODULE
+  MOD_INC_USE_COUNT;
+#endif
+}
+
+static void i2cdev_dec_use(struct i2c_client *client)
+{
+#ifdef MODULE
+  MOD_DEC_USE_COUNT;
+#endif
+}
+
+int i2cdev_init(void)
+{
+  int res;
+
+  printk("i2c-dev.o version %s (%s)\n",LM_VERSION,LM_DATE);
+  i2cdev_initialized = 0;
+  if (register_chrdev(I2C_MAJOR,"i2c",&i2cdev_fops)) {
+    printk("i2c-dev.o: unable to get major %d for i2c bus\n",I2C_MAJOR);
+    return -EIO;
+  }
+  i2cdev_initialized ++;
+
+  if ((res = i2c_add_driver(&i2cdev_driver))) {
+    printk("i2c-dev.o: Driver registration failed, module not inserted.\n");
+    i2cdev_cleanup();
+    return res;
+  }
+  i2cdev_initialized ++;
+  return 0;
+}
+
+int i2cdev_cleanup(void)
+{
+  int res;
+
+  if (i2cdev_initialized >= 2) {
+    if ((res = i2c_del_driver(&i2cdev_driver))) {
+      printk("i2c-dev.o: Driver deregistration failed, "
+             "module not removed.\n");
+      return res;
+    }
+    i2cdev_initialized ++;
+  }
+
+  if (i2cdev_initialized >= 1) {
+    if ((res = unregister_chrdev(I2C_MAJOR,"i2c"))) {
+      printk("i2c-dev.o: unable to release major %d for i2c bus\n",I2C_MAJOR);
+      return res;
+    }
+    i2cdev_initialized --;
+  }
+  return 0;
+}
+
+
+#ifdef MODULE
+
+MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and Simon G. Vogl <simon@tk.uni-linz.ac.at>");
+MODULE_DESCRIPTION("I2C /dev entries driver");
+
+int init_module(void)
+{
+  return i2cdev_init();
+}
+
+int cleanup_module(void)
+{
+  return i2cdev_cleanup();
+}
+
+#endif /* def MODULE */
+

src/i2c-proc.c

@@ -459,11 +459,17 @@ int i2cproc_command(struct i2c_client *client, unsigned int cmd,
 /* Nothing here yet */
 void i2cproc_inc_use(struct i2c_client *client)
 {
+#ifdef MODULE
+  MOD_INC_USE_COUNT;
+#endif
 }
 
 /* Nothing here yet */
 void i2cproc_dec_use(struct i2c_client *client)
 {
+#ifdef MODULE
+  MOD_DEC_USE_COUNT;
+#endif
 }
 
 #ifdef MODULE

src/sensors.h

@@ -81,6 +81,7 @@ extern void sensors_deregister_entry(int id);
 #define SENSORS_PREFIX_MAX 20
 
 /* Driver IDs */
+#define I2C_DRIVERID_I2CDEV 1000
 #define I2C_DRIVERID_I2CPROC 1001
 #define I2C_DRIVERID_LM78 1002
 #define I2C_DRIVERID_LM75 1003