piix4.c basic skeleton

The real PIIX4 access code must still be written; perhaps somebody else could
do this? Most of it could be copied from the old piix4.c. But check carefully
what you are doing, as some things *have* changed (like the SMBUS_{BYTE,...}
variables!).


git-svn-id: http://lm-sensors.org/svn/lm-sensors/trunk@9 7894878c-1315-0410-8ee3-d5d059ff63e0

kernel/Module.mk

@@ -22,7 +22,7 @@ MODULE_DIR := src
 
 # Regrettably, even 'simply expanded variables' will not put their currently
 # defined value verbatim into the command-list of rules...
-SRCTARGETS := $(MODULE_DIR)/smbus.o 
+SRCTARGETS := $(MODULE_DIR)/smbus.o $(MODULE_DIR)/piix4.o
 
 # Include all dependency files
 include $(SRCTARGETS:.o=.d)

kernel/busses/i2c-piix4.c

@@ -0,0 +1,118 @@
+/*
+    smbus.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/kernel.h>
+#include "smbus.h"
+
+static int piix4_init(void);
+static int piix4_cleanup(void);
+static int piix4_setup(void);
+static s32 piix4_access(u8 addr, char read_write,
+                        u8 command, int size, union smbus_data * data);
+
+#ifdef MODULE
+extern int init_module(void);
+extern int cleanup_module(void);
+#endif /* MODULE */
+
+static struct smbus_adapter piix4_adapter;
+static int piix4_initialized;
+
+/* Detect whether a PIIX4 can be found, and initialize it, where necessary. 
+   Return -ENODEV if not found. */
+int piix4_setup(void)
+{
+  /* TO BE WRITTEN! */
+}
+
+/* Return -1 on error. See smbus.h for more information */
+s32 piix4_access(u8 addr, char read_write,
+                 u8 command, int size, union smbus_data * data)
+{
+  /* TO BE WRITTEN! */
+}
+
+
+int piix4_init(void)
+{
+  int res;
+#ifdef DEBUG
+  if (piix4_initialized) {
+    printk("piix4.o: Oops, piix4_init called a second time!");
+    return -EBUSY;
+  }
+#endif
+  piix4_initialized = 0;
+  if ((res = piix4_setup())) {
+    printk("piix4.o: PIIX4 not detected, module not inserted");
+    piix4_cleanup();
+    return res;
+  }
+  piix4_initialized ++;
+  strcpy(piix4_adapter.name,"SMBus PIIX4 adapter");
+  piix4_adapter.id = ALGO_SMBUS | SMBUS_PIIX4;
+  piix4_adapter.algo = &smbus_algorithm;
+  piix4_adapter.smbus_access = &piix4_access;
+  if ((res = smbus_add_adapter(&piix4_adapter))) {
+    printk("piix4.o: smbus_add_adapter failed, module not inserted");
+    piix4_cleanup();
+    return res;
+  }
+  piix4_initialized++;
+  printk("piix4.o: PIIX4 bus detected and initialized");
+  return 0;
+}
+
+int piix4_cleanup(void)
+{
+  int res;
+  if (piix4_initialized >= 2)
+  {
+    if ((res = smbus_del_adapter(&piix4_adapter))) {
+      printk("piix4.o: smbus_del_adapter failed, module not removed");
+      return res;
+    }
+    else
+      piix4_initialized--;
+  }
+  if (piix4_initialized >= 1) {
+    /* Undo anything piix4_setup did */
+    piix4_initialized--;
+  }
+  return 0;
+}
+
+#ifdef MODULE
+
+MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>");
+MODULE_DESCRIPTION("PIIX4 SMBus driver");
+
+int init_module(void)
+{
+  return piix4_init();
+}
+
+int cleanup_module(void)
+{
+  return piix4_cleanup();
+}
+
+#endif /* MODULE */
+

kernel/include/smbus.h

@@ -109,9 +109,9 @@ struct smbus_adapter {
   int timeout;
   int retries;
 
-  /* Here ended i2c_algorithm */
-  s32 (* smbus_access) (__u8 addr, char read_write,
-                        __u8 command, int size, union smbus_data * data);
+  /* Here ended i2c_adapter */
+  s32 (* smbus_access) (u8 addr, char read_write,
+                        u8 command, int size, union smbus_data * data);
 };
 
 /* We need to mark SMBus algorithms in the algorithm structure. 
@@ -121,11 +121,14 @@ struct smbus_adapter {
    this flag is set! */
 #define ALGO_SMBUS 0x40000
 
+/* SMBus Adapter ids */
+#define SMBUS_PIIX4 1
+
 /* This union is used within smbus_access routines */
 union smbus_data { 
-        __u8 byte;
-        __u16 word;
-        __u8 block[32];
+        u8 byte;
+        u16 word;
+        u8 block[32];
 };
 
 /* smbus_access read or write markers */

kernel/smbus.c

@@ -19,6 +19,13 @@
 
 #include <linux/module.h>
 #include <linux/kernel.h>
+
+#ifdef SPINLOCK
+#include <asm/spinlock.h>
+#else
+#include <asm/semaphore.h>
+#endif
+
 #include "smbus.h"
 
 static s32 smbus_access_i2c (struct smbus_adapter * adapter, u8 addr,
@@ -57,14 +64,28 @@ struct smbus_algorithm smbus_algorithm = {
 
 /* OK, so you want to access a bus using the SMBus protocols. Well, it either
    is registered as a SMBus-only adapter (like the PIIX4), or we need to
-   simulate the SMBus commands using the i2c access routines. */
+   simulate the SMBus commands using the i2c access routines. 
+   We do all locking here, so you can ignore that in the adapter-specific
+   smbus_accesss routine. */
 s32 smbus_access (struct smbus_adapter * adapter, u8 addr, char read_write,
                   u8 command, int size, union smbus_data * data)
 {
+  int res;
+#ifdef SPINLOCK
+  spin_lock_irqsave(&adapter->lock,adapter->lockflags);
+#else
+  down(&adapter->lock);
+#endif
   if (adapter->id & ALGO_SMBUS) 
-    return adapter->smbus_access(addr,read_write,command,size,data);
+    res = adapter->smbus_access(addr,read_write,command,size,data);
   else
-    return smbus_access_i2c(adapter,addr,read_write,command,size,data);
+    res = smbus_access_i2c(adapter,addr,read_write,command,size,data);
+#ifdef SPINLOCK
+  spin_unlock_irqrestore(&adapter->lock,adapter->lockflags);
+#else
+  up(&adapter->lock);
+#endif
+  return res;
 }
   
 /* Simulate a SMBus command using the i2c protocol 

src/Module.mk

@@ -22,7 +22,7 @@ MODULE_DIR := src
 
 # Regrettably, even 'simply expanded variables' will not put their currently
 # defined value verbatim into the command-list of rules...
-SRCTARGETS := $(MODULE_DIR)/smbus.o 
+SRCTARGETS := $(MODULE_DIR)/smbus.o $(MODULE_DIR)/piix4.o
 
 # Include all dependency files
 include $(SRCTARGETS:.o=.d)

src/piix4.c

@@ -0,0 +1,118 @@
+/*
+    smbus.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/kernel.h>
+#include "smbus.h"
+
+static int piix4_init(void);
+static int piix4_cleanup(void);
+static int piix4_setup(void);
+static s32 piix4_access(u8 addr, char read_write,
+                        u8 command, int size, union smbus_data * data);
+
+#ifdef MODULE
+extern int init_module(void);
+extern int cleanup_module(void);
+#endif /* MODULE */
+
+static struct smbus_adapter piix4_adapter;
+static int piix4_initialized;
+
+/* Detect whether a PIIX4 can be found, and initialize it, where necessary. 
+   Return -ENODEV if not found. */
+int piix4_setup(void)
+{
+  /* TO BE WRITTEN! */
+}
+
+/* Return -1 on error. See smbus.h for more information */
+s32 piix4_access(u8 addr, char read_write,
+                 u8 command, int size, union smbus_data * data)
+{
+  /* TO BE WRITTEN! */
+}
+
+
+int piix4_init(void)
+{
+  int res;
+#ifdef DEBUG
+  if (piix4_initialized) {
+    printk("piix4.o: Oops, piix4_init called a second time!");
+    return -EBUSY;
+  }
+#endif
+  piix4_initialized = 0;
+  if ((res = piix4_setup())) {
+    printk("piix4.o: PIIX4 not detected, module not inserted");
+    piix4_cleanup();
+    return res;
+  }
+  piix4_initialized ++;
+  strcpy(piix4_adapter.name,"SMBus PIIX4 adapter");
+  piix4_adapter.id = ALGO_SMBUS | SMBUS_PIIX4;
+  piix4_adapter.algo = &smbus_algorithm;
+  piix4_adapter.smbus_access = &piix4_access;
+  if ((res = smbus_add_adapter(&piix4_adapter))) {
+    printk("piix4.o: smbus_add_adapter failed, module not inserted");
+    piix4_cleanup();
+    return res;
+  }
+  piix4_initialized++;
+  printk("piix4.o: PIIX4 bus detected and initialized");
+  return 0;
+}
+
+int piix4_cleanup(void)
+{
+  int res;
+  if (piix4_initialized >= 2)
+  {
+    if ((res = smbus_del_adapter(&piix4_adapter))) {
+      printk("piix4.o: smbus_del_adapter failed, module not removed");
+      return res;
+    }
+    else
+      piix4_initialized--;
+  }
+  if (piix4_initialized >= 1) {
+    /* Undo anything piix4_setup did */
+    piix4_initialized--;
+  }
+  return 0;
+}
+
+#ifdef MODULE
+
+MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>");
+MODULE_DESCRIPTION("PIIX4 SMBus driver");
+
+int init_module(void)
+{
+  return piix4_init();
+}
+
+int cleanup_module(void)
+{
+  return piix4_cleanup();
+}
+
+#endif /* MODULE */
+

src/smbus.c

@@ -19,6 +19,13 @@
 
 #include <linux/module.h>
 #include <linux/kernel.h>
+
+#ifdef SPINLOCK
+#include <asm/spinlock.h>
+#else
+#include <asm/semaphore.h>
+#endif
+
 #include "smbus.h"
 
 static s32 smbus_access_i2c (struct smbus_adapter * adapter, u8 addr,
@@ -57,14 +64,28 @@ struct smbus_algorithm smbus_algorithm = {
 
 /* OK, so you want to access a bus using the SMBus protocols. Well, it either
    is registered as a SMBus-only adapter (like the PIIX4), or we need to
-   simulate the SMBus commands using the i2c access routines. */
+   simulate the SMBus commands using the i2c access routines. 
+   We do all locking here, so you can ignore that in the adapter-specific
+   smbus_accesss routine. */
 s32 smbus_access (struct smbus_adapter * adapter, u8 addr, char read_write,
                   u8 command, int size, union smbus_data * data)
 {
+  int res;
+#ifdef SPINLOCK
+  spin_lock_irqsave(&adapter->lock,adapter->lockflags);
+#else
+  down(&adapter->lock);
+#endif
   if (adapter->id & ALGO_SMBUS) 
-    return adapter->smbus_access(addr,read_write,command,size,data);
+    res = adapter->smbus_access(addr,read_write,command,size,data);
   else
-    return smbus_access_i2c(adapter,addr,read_write,command,size,data);
+    res = smbus_access_i2c(adapter,addr,read_write,command,size,data);
+#ifdef SPINLOCK
+  spin_unlock_irqrestore(&adapter->lock,adapter->lockflags);
+#else
+  up(&adapter->lock);
+#endif
+  return res;
 }
   
 /* Simulate a SMBus command using the i2c protocol 

src/smbus.h

@@ -109,9 +109,9 @@ struct smbus_adapter {
   int timeout;
   int retries;
 
-  /* Here ended i2c_algorithm */
-  s32 (* smbus_access) (__u8 addr, char read_write,
-                        __u8 command, int size, union smbus_data * data);
+  /* Here ended i2c_adapter */
+  s32 (* smbus_access) (u8 addr, char read_write,
+                        u8 command, int size, union smbus_data * data);
 };
 
 /* We need to mark SMBus algorithms in the algorithm structure. 
@@ -121,11 +121,14 @@ struct smbus_adapter {
    this flag is set! */
 #define ALGO_SMBUS 0x40000
 
+/* SMBus Adapter ids */
+#define SMBUS_PIIX4 1
+
 /* This union is used within smbus_access routines */
 union smbus_data { 
-        __u8 byte;
-        __u16 word;
-        __u8 block[32];
+        u8 byte;
+        u16 word;
+        u8 block[32];
 };
 
 /* smbus_access read or write markers */