LM75 driver finished

Well, it should work. But until we have implemented the remaining parts of
piix4.o, we won't be able to test it. Anybody?


git-svn-id: http://lm-sensors.org/svn/lm-sensors/trunk@29 7894878c-1315-0410-8ee3-d5d059ff63e0

TODO

@@ -12,10 +12,11 @@ Many, many things. Most notably:
 * Write piix4_* in piix4.c
 * Make lm78.c detect 'double hits', (same chip connected to both SMBus and
   ISA).
-* Better lm78 detection; insmod-time paramters to set addresses (difficult,
-  because of all i2c busses!).
+* Better lm78/lm75 detection; insmod-time paramters to set addresses 
+  (difficult, because of all i2c busses!).
 * Check whether some lm78 functionality is chip-generic and can be moved to
   sensors.c.
+* 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.
 * Write all other drivers

kernel/Module.mk

@@ -24,7 +24,7 @@ MODULE_DIR := src
 # defined value verbatim into the command-list of rules...
 SRCTARGETS := $(MODULE_DIR)/smbus.o $(MODULE_DIR)/piix4.o $(MODULE_DIR)/isa.o \
               $(MODULE_DIR)/lm78.o $(MODULE_DIR)/sensors.o  \
-              $(MODULE_DIR)/i2c-proc.o
+              $(MODULE_DIR)/i2c-proc.o $(MODULE_DIR)/lm75.o
 
 HEADERFILES := $(MODULE_DIR)/sensors.h 
 

kernel/chips/lm75.c

@@ -0,0 +1,353 @@
+/*
+    lm75.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 "smbus.h"
+#include "sensors.h"
+#include "i2c.h"
+#include "version.h"
+
+/* Many LM75 constants specified below */
+
+/* The LM75 registers */
+#define LM75_REG_TEMP 0x00
+#define LM75_REG_CONF 0x01
+#define LM75_REG_TEMP_HYST 0x02
+#define LM75_REG_TEMP_OS 0x03
+
+/* Conversions */
+#define TEMP_FROM_REG(val) (((val) >> 7) * 5)
+#define TEMP_TO_REG(val)   (((((val) + 2) / 5) << 7) & 0xff80)
+
+/* Initial values */
+#define LM75_INIT_TEMP_OS 50
+#define LM75_INIT_TEMP_HYST 60
+
+/* Each client has this additional data */
+struct lm75_data {
+         int sysctl_id;
+
+         struct semaphore update_lock;
+         char valid;                 /* !=0 if following fields are valid */
+         unsigned long last_updated; /* In jiffies */
+
+         u16 temp,temp_os,temp_hyst; /* Register values */
+};
+
+#ifdef MODULE
+extern int init_module(void);
+extern int cleanup_module(void);
+#endif /* MODULE */
+
+static int lm75_init(void);
+static int lm75_cleanup(void);
+static int lm75_attach_adapter(struct i2c_adapter *adapter);
+int lm75_detach_client(struct i2c_client *client);
+static int lm75_command(struct i2c_client *client, unsigned int cmd,
+                        void *arg);
+static void lm75_inc_use (struct i2c_client *client);
+static void lm75_dec_use (struct i2c_client *client);
+static u16 swap_bytes(u16 val);
+static int lm75_read_value(struct i2c_client *client, u8 reg);
+static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value);
+static void lm75_temp(struct i2c_client *client, int operation, int ctl_name,
+                      int *nrels_mag, long *results);
+
+
+/* This is the driver that will be inserted */
+static struct i2c_driver lm75_driver = {
+  /* name */            "LM75 sensor chip driver",
+  /* id */              I2C_DRIVERID_LM75,
+  /* flags */           DF_NOTIFY,
+  /* attach_adapter */  &lm75_attach_adapter,
+  /* detach_client */   &lm75_detach_client,
+  /* command */         &lm75_command,
+  /* inc_use */         &lm75_inc_use,
+  /* dec_use */         &lm75_dec_use
+};
+
+/* These files are created for each detected LM75. 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 lm75_dir_table_template[] = {
+  { LM75_SYSCTL_TEMP, "temp", NULL, 0, 0644, NULL, &sensors_proc_real,
+    &sensors_sysctl_real, NULL, &lm75_temp },
+  { 0 }
+};
+
+/* Used by init/cleanup */
+static int lm75_initialized = 0;
+
+/* I choose here for semi-static LM78 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_LM75_NR 8
+static struct i2c_client *lm75_list[MAX_LM75_NR];
+
+
+int lm75_attach_adapter(struct i2c_adapter *adapter)
+{
+  int address,err,i;
+  struct i2c_client *new_client;
+  struct lm75_data *data;
+
+  err = 0;
+
+  /* OK, this is no detection. I know. It will do for now, though.  */
+
+  /* Set err only if a global error would make registering other clients
+     impossible too (like out-of-memory). */
+  for (address = 0x48; (! err) && (address <= 0x4f); address ++) {
+
+    /* Later on, we will keep a list of registered addresses for each
+       adapter, and check whether they are used here */
+    
+    if (smbus_read_byte_data(adapter,address,LM75_REG_CONF) == 0xff)
+      continue;
+
+    /* Real detection code goes here */
+
+    /* Allocate space for a new client structure */
+    if (! (new_client =  kmalloc(sizeof(struct i2c_client) +
+                                sizeof(struct lm75_data),
+                               GFP_KERNEL))) {
+      err = -ENOMEM;
+      continue;
+    }
+
+    /* Find a place in our global list */
+    for (i = 0; i < MAX_LM75_NR; i++)
+      if (! lm75_list[i])
+         break;
+    if (i == MAX_LM75_NR) {
+      err = -ENOMEM;
+      printk("lm75.o: No empty slots left, recompile and heighten "
+             "MAX_LM75_NR!\n");
+      goto ERROR1;
+    }
+    lm75_list[i] = new_client;
+    
+    /* Fill the new client structure with data */
+    data = (struct lm75_data *) (new_client + 1);
+    new_client->data = data;
+    new_client->id = i;
+    new_client->addr = address;
+    new_client->adapter = adapter;
+    new_client->driver = &lm75_driver;
+    strcpy(new_client->name,"LM75 chip");
+    data->valid = 0;
+    data->update_lock = MUTEX;
+    
+    /* Tell i2c-core a new client has arrived */
+    if ((err = i2c_attach_client(new_client)))
+      goto ERROR2;
+    
+    /* Register a new directory entry with module sensors */
+    if ((err = sensors_register_entry(new_client,"lm75",
+                                      lm75_dir_table_template)) < 0)
+      goto ERROR3;
+    data->sysctl_id = err;
+
+    /* Initialize the LM75 chip */
+    lm75_write_value(new_client,LM75_REG_TEMP_OS,LM75_INIT_TEMP_OS);
+    lm75_write_value(new_client,LM75_REG_TEMP_HYST,LM75_INIT_TEMP_HYST);
+    lm75_write_value(new_client,LM75_REG_CONF,0);
+
+    continue;
+
+/* OK, this is not exactly good programming practice, usually. But it is
+   very code-efficient in this case. */
+
+ERROR3:
+    i2c_detach_client(new_client);
+ERROR2:
+    lm75_list[i] = NULL;
+ERROR1:
+    kfree(new_client);
+  }
+  return err;
+}
+
+int lm75_detach_client(struct i2c_client *client)
+{
+  int err,i;
+  for (i = 0; i < MAX_LM75_NR; i++)
+    if (client == lm75_list[i])
+      break;
+  if ((i == MAX_LM75_NR)) {
+    printk("lm75.o: Client to detach not found.\n");
+    return -ENOENT;
+  }
+
+  sensors_deregister_entry(((struct lm75_data *)(client->data))->sysctl_id);
+
+  if ((err = i2c_detach_client(client))) {
+    printk("lm75.o: Client deregistration failed, client not detached.\n");
+    return err;
+  }
+
+  lm75_list[i] = NULL;
+  kfree(client);
+  return 0;
+}
+
+
+/* No commands defined yet */
+int lm75_command(struct i2c_client *client, unsigned int cmd, void *arg)
+{
+  return 0;
+}
+
+/* Nothing here yet */
+void lm75_inc_use (struct i2c_client *client)
+{
+}
+
+/* Nothing here yet */
+void lm75_dec_use (struct i2c_client *client)
+{
+}
+
+u16 swap_bytes(u16 val)
+{
+  return (val >> 8) | (val << 8);
+}
+
+/* All registers are word-sized, except for the configuration register.
+   For some reason, we must swap the low and high byte, but only on 
+   reading words?!? */
+int lm75_read_value(struct i2c_client *client, u8 reg)
+{
+  if (reg == LM75_REG_CONF)
+    return smbus_read_byte_data(client->adapter,client->addr,reg);
+  else
+    return swap_bytes(smbus_read_word_data(client->adapter,client->addr,reg));
+}
+
+/* No swapping needed here! */
+int lm75_write_value(struct i2c_client *client, u8 reg, u16 value)
+{
+  if (reg == LM75_REG_CONF)
+    return smbus_write_byte_data(client->adapter,client->addr,reg,value);
+  else
+    return smbus_write_word_data(client->adapter,client->addr,reg,value);
+}
+
+void lm75_update_client(struct i2c_client *client)
+{
+  struct lm75_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 lm75 update\n");
+#endif
+
+    data->temp = lm75_read_value(client,LM75_REG_TEMP);
+    data->temp_os = lm75_read_value(client,LM75_REG_TEMP_OS);
+    data->temp_hyst = lm75_read_value(client,LM75_REG_TEMP_HYST);
+    data->last_updated = jiffies;
+    data->valid = 1;
+  }
+
+  up(&data->update_lock);
+}
+
+
+void lm75_temp(struct i2c_client *client, int operation, int ctl_name,
+               int *nrels_mag, long *results)
+{
+  struct lm75_data *data = client->data;
+  if (operation == SENSORS_PROC_REAL_INFO)
+    *nrels_mag = 1;
+  else if (operation == SENSORS_PROC_REAL_READ) {
+    lm75_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]);
+      lm75_write_value(client,LM75_REG_TEMP_OS,data->temp_os);
+    }
+    if (*nrels_mag >= 2) {
+      data->temp_os = TEMP_TO_REG(results[1]);
+      lm75_write_value(client,LM75_REG_TEMP_HYST,data->temp_os);
+    }
+  }
+}
+
+
+
+
+int lm75_init(void)
+{
+  int res;
+
+  printk("lm75.o version %s (%s)\n",LM_VERSION,LM_DATE);
+  lm75_initialized = 0;
+  if ((res = i2c_add_driver(&lm75_driver))) {
+    printk("lm75.o: Driver registration failed, module not inserted.\n");
+    lm75_cleanup();
+    return res;
+  }
+  lm75_initialized ++;
+  return 0;
+}
+
+int lm75_cleanup(void)
+{
+  int res;
+
+  if (lm75_initialized >= 1) {
+    if ((res = i2c_del_driver(&lm75_driver))) {
+      printk("lm75.o: Driver deregistration failed, module not removed.\n");
+      return res;
+    }
+  } else
+    lm75_initialized --;
+
+  return 0;
+}
+
+
+#ifdef MODULE
+
+MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>");
+MODULE_DESCRIPTION("LM75 driver");
+
+int init_module(void)
+{
+  return lm75_init();
+}
+
+int cleanup_module(void)
+{
+  return lm75_cleanup();
+}
+
+#endif /* MODULE */
+

kernel/chips/lm78.c

@@ -442,7 +442,7 @@ int lm78_detect_smbus(struct i2c_adapter *adapter)
     /* Later on, we will keep a list of registered addresses for each
        adapter, and check whether they are used here */
 
-    if (smbus_read_byte_data(adapter,address,1) == 0xff) 
+    if (smbus_read_byte_data(adapter,address,LM78_REG_CONFIG) == 0xff) 
       continue;
 
     /* Real detection code goes here */
@@ -465,7 +465,8 @@ int lm78_detect_smbus(struct i2c_adapter *adapter)
       continue;
 
 
-    /* Allocate space for a new client structure */
+    /* Allocate space for a new client structure. To counter memory
+       ragmentation somewhat, we only do one kmalloc. */
     if (! (new_client = kmalloc(sizeof(struct i2c_client) + 
                                 sizeof(struct lm78_data),
                                GFP_KERNEL))) {

kernel/include/sensors.h

@@ -20,6 +20,9 @@
 #ifndef SENSORS_SENSORS_H
 #define SENSORS_SENSORS_H
 
+/* Next two must be included before sysctl.h can be included, in 2.0 kernels */
+#include <linux/types.h>
+#include <linux/fs.h>
 #include <linux/sysctl.h>
 
 #ifdef __KERNEL__
@@ -77,6 +80,7 @@ extern void sensors_deregister_entry(int id);
 /* Driver IDs */
 #define I2C_DRIVERID_I2CPROC 1001
 #define I2C_DRIVERID_LM78 1002
+#define I2C_DRIVERID_LM75 1003
 
 /* Sysctl IDs */
 #ifdef DEV_HWMON
@@ -101,4 +105,6 @@ extern void sensors_deregister_entry(int id);
 #define LM78_SYSCTL_FAN_DIV 2000 /* 1, 2, 4 or 8 */
 #define LM78_SYSCTL_ALARMS 2001 /* bitvector */
 
+#define LM75_SYSCTL_TEMP 1200 /* Degrees Celcius * 10 */
+
 #endif /* def SENSORS_SENSORS_H */

src/Module.mk

@@ -24,7 +24,7 @@ MODULE_DIR := src
 # defined value verbatim into the command-list of rules...
 SRCTARGETS := $(MODULE_DIR)/smbus.o $(MODULE_DIR)/piix4.o $(MODULE_DIR)/isa.o \
               $(MODULE_DIR)/lm78.o $(MODULE_DIR)/sensors.o  \
-              $(MODULE_DIR)/i2c-proc.o
+              $(MODULE_DIR)/i2c-proc.o $(MODULE_DIR)/lm75.o
 
 HEADERFILES := $(MODULE_DIR)/sensors.h 
 

src/lm75.c

@@ -0,0 +1,353 @@
+/*
+    lm75.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 "smbus.h"
+#include "sensors.h"
+#include "i2c.h"
+#include "version.h"
+
+/* Many LM75 constants specified below */
+
+/* The LM75 registers */
+#define LM75_REG_TEMP 0x00
+#define LM75_REG_CONF 0x01
+#define LM75_REG_TEMP_HYST 0x02
+#define LM75_REG_TEMP_OS 0x03
+
+/* Conversions */
+#define TEMP_FROM_REG(val) (((val) >> 7) * 5)
+#define TEMP_TO_REG(val)   (((((val) + 2) / 5) << 7) & 0xff80)
+
+/* Initial values */
+#define LM75_INIT_TEMP_OS 50
+#define LM75_INIT_TEMP_HYST 60
+
+/* Each client has this additional data */
+struct lm75_data {
+         int sysctl_id;
+
+         struct semaphore update_lock;
+         char valid;                 /* !=0 if following fields are valid */
+         unsigned long last_updated; /* In jiffies */
+
+         u16 temp,temp_os,temp_hyst; /* Register values */
+};
+
+#ifdef MODULE
+extern int init_module(void);
+extern int cleanup_module(void);
+#endif /* MODULE */
+
+static int lm75_init(void);
+static int lm75_cleanup(void);
+static int lm75_attach_adapter(struct i2c_adapter *adapter);
+int lm75_detach_client(struct i2c_client *client);
+static int lm75_command(struct i2c_client *client, unsigned int cmd,
+                        void *arg);
+static void lm75_inc_use (struct i2c_client *client);
+static void lm75_dec_use (struct i2c_client *client);
+static u16 swap_bytes(u16 val);
+static int lm75_read_value(struct i2c_client *client, u8 reg);
+static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value);
+static void lm75_temp(struct i2c_client *client, int operation, int ctl_name,
+                      int *nrels_mag, long *results);
+
+
+/* This is the driver that will be inserted */
+static struct i2c_driver lm75_driver = {
+  /* name */            "LM75 sensor chip driver",
+  /* id */              I2C_DRIVERID_LM75,
+  /* flags */           DF_NOTIFY,
+  /* attach_adapter */  &lm75_attach_adapter,
+  /* detach_client */   &lm75_detach_client,
+  /* command */         &lm75_command,
+  /* inc_use */         &lm75_inc_use,
+  /* dec_use */         &lm75_dec_use
+};
+
+/* These files are created for each detected LM75. 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 lm75_dir_table_template[] = {
+  { LM75_SYSCTL_TEMP, "temp", NULL, 0, 0644, NULL, &sensors_proc_real,
+    &sensors_sysctl_real, NULL, &lm75_temp },
+  { 0 }
+};
+
+/* Used by init/cleanup */
+static int lm75_initialized = 0;
+
+/* I choose here for semi-static LM78 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_LM75_NR 8
+static struct i2c_client *lm75_list[MAX_LM75_NR];
+
+
+int lm75_attach_adapter(struct i2c_adapter *adapter)
+{
+  int address,err,i;
+  struct i2c_client *new_client;
+  struct lm75_data *data;
+
+  err = 0;
+
+  /* OK, this is no detection. I know. It will do for now, though.  */
+
+  /* Set err only if a global error would make registering other clients
+     impossible too (like out-of-memory). */
+  for (address = 0x48; (! err) && (address <= 0x4f); address ++) {
+
+    /* Later on, we will keep a list of registered addresses for each
+       adapter, and check whether they are used here */
+    
+    if (smbus_read_byte_data(adapter,address,LM75_REG_CONF) == 0xff)
+      continue;
+
+    /* Real detection code goes here */
+
+    /* Allocate space for a new client structure */
+    if (! (new_client =  kmalloc(sizeof(struct i2c_client) +
+                                sizeof(struct lm75_data),
+                               GFP_KERNEL))) {
+      err = -ENOMEM;
+      continue;
+    }
+
+    /* Find a place in our global list */
+    for (i = 0; i < MAX_LM75_NR; i++)
+      if (! lm75_list[i])
+         break;
+    if (i == MAX_LM75_NR) {
+      err = -ENOMEM;
+      printk("lm75.o: No empty slots left, recompile and heighten "
+             "MAX_LM75_NR!\n");
+      goto ERROR1;
+    }
+    lm75_list[i] = new_client;
+    
+    /* Fill the new client structure with data */
+    data = (struct lm75_data *) (new_client + 1);
+    new_client->data = data;
+    new_client->id = i;
+    new_client->addr = address;
+    new_client->adapter = adapter;
+    new_client->driver = &lm75_driver;
+    strcpy(new_client->name,"LM75 chip");
+    data->valid = 0;
+    data->update_lock = MUTEX;
+    
+    /* Tell i2c-core a new client has arrived */
+    if ((err = i2c_attach_client(new_client)))
+      goto ERROR2;
+    
+    /* Register a new directory entry with module sensors */
+    if ((err = sensors_register_entry(new_client,"lm75",
+                                      lm75_dir_table_template)) < 0)
+      goto ERROR3;
+    data->sysctl_id = err;
+
+    /* Initialize the LM75 chip */
+    lm75_write_value(new_client,LM75_REG_TEMP_OS,LM75_INIT_TEMP_OS);
+    lm75_write_value(new_client,LM75_REG_TEMP_HYST,LM75_INIT_TEMP_HYST);
+    lm75_write_value(new_client,LM75_REG_CONF,0);
+
+    continue;
+
+/* OK, this is not exactly good programming practice, usually. But it is
+   very code-efficient in this case. */
+
+ERROR3:
+    i2c_detach_client(new_client);
+ERROR2:
+    lm75_list[i] = NULL;
+ERROR1:
+    kfree(new_client);
+  }
+  return err;
+}
+
+int lm75_detach_client(struct i2c_client *client)
+{
+  int err,i;
+  for (i = 0; i < MAX_LM75_NR; i++)
+    if (client == lm75_list[i])
+      break;
+  if ((i == MAX_LM75_NR)) {
+    printk("lm75.o: Client to detach not found.\n");
+    return -ENOENT;
+  }
+
+  sensors_deregister_entry(((struct lm75_data *)(client->data))->sysctl_id);
+
+  if ((err = i2c_detach_client(client))) {
+    printk("lm75.o: Client deregistration failed, client not detached.\n");
+    return err;
+  }
+
+  lm75_list[i] = NULL;
+  kfree(client);
+  return 0;
+}
+
+
+/* No commands defined yet */
+int lm75_command(struct i2c_client *client, unsigned int cmd, void *arg)
+{
+  return 0;
+}
+
+/* Nothing here yet */
+void lm75_inc_use (struct i2c_client *client)
+{
+}
+
+/* Nothing here yet */
+void lm75_dec_use (struct i2c_client *client)
+{
+}
+
+u16 swap_bytes(u16 val)
+{
+  return (val >> 8) | (val << 8);
+}
+
+/* All registers are word-sized, except for the configuration register.
+   For some reason, we must swap the low and high byte, but only on 
+   reading words?!? */
+int lm75_read_value(struct i2c_client *client, u8 reg)
+{
+  if (reg == LM75_REG_CONF)
+    return smbus_read_byte_data(client->adapter,client->addr,reg);
+  else
+    return swap_bytes(smbus_read_word_data(client->adapter,client->addr,reg));
+}
+
+/* No swapping needed here! */
+int lm75_write_value(struct i2c_client *client, u8 reg, u16 value)
+{
+  if (reg == LM75_REG_CONF)
+    return smbus_write_byte_data(client->adapter,client->addr,reg,value);
+  else
+    return smbus_write_word_data(client->adapter,client->addr,reg,value);
+}
+
+void lm75_update_client(struct i2c_client *client)
+{
+  struct lm75_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 lm75 update\n");
+#endif
+
+    data->temp = lm75_read_value(client,LM75_REG_TEMP);
+    data->temp_os = lm75_read_value(client,LM75_REG_TEMP_OS);
+    data->temp_hyst = lm75_read_value(client,LM75_REG_TEMP_HYST);
+    data->last_updated = jiffies;
+    data->valid = 1;
+  }
+
+  up(&data->update_lock);
+}
+
+
+void lm75_temp(struct i2c_client *client, int operation, int ctl_name,
+               int *nrels_mag, long *results)
+{
+  struct lm75_data *data = client->data;
+  if (operation == SENSORS_PROC_REAL_INFO)
+    *nrels_mag = 1;
+  else if (operation == SENSORS_PROC_REAL_READ) {
+    lm75_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]);
+      lm75_write_value(client,LM75_REG_TEMP_OS,data->temp_os);
+    }
+    if (*nrels_mag >= 2) {
+      data->temp_os = TEMP_TO_REG(results[1]);
+      lm75_write_value(client,LM75_REG_TEMP_HYST,data->temp_os);
+    }
+  }
+}
+
+
+
+
+int lm75_init(void)
+{
+  int res;
+
+  printk("lm75.o version %s (%s)\n",LM_VERSION,LM_DATE);
+  lm75_initialized = 0;
+  if ((res = i2c_add_driver(&lm75_driver))) {
+    printk("lm75.o: Driver registration failed, module not inserted.\n");
+    lm75_cleanup();
+    return res;
+  }
+  lm75_initialized ++;
+  return 0;
+}
+
+int lm75_cleanup(void)
+{
+  int res;
+
+  if (lm75_initialized >= 1) {
+    if ((res = i2c_del_driver(&lm75_driver))) {
+      printk("lm75.o: Driver deregistration failed, module not removed.\n");
+      return res;
+    }
+  } else
+    lm75_initialized --;
+
+  return 0;
+}
+
+
+#ifdef MODULE
+
+MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>");
+MODULE_DESCRIPTION("LM75 driver");
+
+int init_module(void)
+{
+  return lm75_init();
+}
+
+int cleanup_module(void)
+{
+  return lm75_cleanup();
+}
+
+#endif /* MODULE */
+

src/lm78.c

@@ -442,7 +442,7 @@ int lm78_detect_smbus(struct i2c_adapter *adapter)
     /* Later on, we will keep a list of registered addresses for each
        adapter, and check whether they are used here */
 
-    if (smbus_read_byte_data(adapter,address,1) == 0xff) 
+    if (smbus_read_byte_data(adapter,address,LM78_REG_CONFIG) == 0xff) 
       continue;
 
     /* Real detection code goes here */
@@ -465,7 +465,8 @@ int lm78_detect_smbus(struct i2c_adapter *adapter)
       continue;
 
 
-    /* Allocate space for a new client structure */
+    /* Allocate space for a new client structure. To counter memory
+       ragmentation somewhat, we only do one kmalloc. */
     if (! (new_client = kmalloc(sizeof(struct i2c_client) + 
                                 sizeof(struct lm78_data),
                                GFP_KERNEL))) {

src/sensors.h

@@ -20,6 +20,9 @@
 #ifndef SENSORS_SENSORS_H
 #define SENSORS_SENSORS_H
 
+/* Next two must be included before sysctl.h can be included, in 2.0 kernels */
+#include <linux/types.h>
+#include <linux/fs.h>
 #include <linux/sysctl.h>
 
 #ifdef __KERNEL__
@@ -77,6 +80,7 @@ extern void sensors_deregister_entry(int id);
 /* Driver IDs */
 #define I2C_DRIVERID_I2CPROC 1001
 #define I2C_DRIVERID_LM78 1002
+#define I2C_DRIVERID_LM75 1003
 
 /* Sysctl IDs */
 #ifdef DEV_HWMON
@@ -101,4 +105,6 @@ extern void sensors_deregister_entry(int id);
 #define LM78_SYSCTL_FAN_DIV 2000 /* 1, 2, 4 or 8 */
 #define LM78_SYSCTL_ALARMS 2001 /* bitvector */
 
+#define LM75_SYSCTL_TEMP 1200 /* Degrees Celcius * 10 */
+
 #endif /* def SENSORS_SENSORS_H */