Loadable module support for bt-ALPHA-0.0.1
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

To install this patch: cd to the directory where you have extracted
bt-ALPHA-0.0.1 and pipe this file into "patch -p".

Then cd to bt-ALPHA-0.0.1 and read README.module.

     Marc
--
Marc Huber (huber@fzi.de)

diff -u --recursive --new-file bt-ALPHA-0.0.1.original/Makefile bt-ALPHA-0.0.1/Makefile
--- bt-ALPHA-0.0.1.original/Makefile	Thu Oct 27 20:52:47 1994
+++ bt-ALPHA-0.0.1/Makefile	Mon Sep 25 09:11:36 1995
@@ -41,6 +41,10 @@
 #	Initial revision
 #
 ###############################################################################
+#
+# Loadable module support by Marc Huber (huber@fzi.de) 1995/09/21
+#
+###############################################################################
 
 # management information
 VERSION	= $(shell sed -n '/bt_version/s/[^"]*"\([^"]*\).*/\1/p' < bt_version.h)
@@ -78,7 +82,13 @@
 FILES	= $(INFOFILES) $(PATCHFILE) $(SRCS) $(HDRS) $(MAN) $(TSTPRGS) $(SETUPPRG)
 ANNOUNCE=ANNOUNCE
 
-default: zdisk
+DEFINES = -D__KERNEL__ -DMODULE
+
+CFLAGS = -O2 -m486 -Wall -Wstrict-prototypes -fomit-frame-pointer $(DEFINES)
+
+default: bt.o
+
+bt.o: *.c *.h $(KINCDIR)/version.h
 
 dist $(TARFILE): $(FILES)
 	rm -f -r $(TMPDIR)
@@ -98,7 +108,10 @@
 ##############################################################################
 # Software installation by copying
 # (choose between soft- or hard installation)
-install:	install.full
+install:	install.module
+
+install.module: bt.o
+	install -m 644 bt.o /lib/modules/`uname -r`/misc/
 
 install.full:	install.src apply.patch install.doc
 
@@ -142,6 +155,9 @@
 
 ##############################################################################
 clean:
+	rm bt.o
+
+clean.dist:
 	rm -f $(PATCHFILE) $(TARFILE) $(DOSTARF)
 	rm -f -r $(TMPDIR)
 
diff -u --recursive --new-file bt-ALPHA-0.0.1.original/README.module bt-ALPHA-0.0.1/README.module
--- bt-ALPHA-0.0.1.original/README.module	Thu Jan  1 01:00:00 1970
+++ bt-ALPHA-0.0.1/README.module	Mon Sep 25 10:30:41 1995
@@ -0,0 +1,72 @@
+Loadable module support for Thomas Weidenfeller's BiTronics device driver
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Warranty & Copyright
+~~~~~~~~~~~~~~~~~~~~
+Please understand that there's no warranty of any kind. The modifications
+I've made to Thomas Weidenfeller`s bt driver are in the public domain. The
+usual disclaimers apply.
+
+
+Why a loadable module?
+~~~~~~~~~~~~~~~~~~~~~~
+There's no need to modify anything in the /usr/src/linux hierarchy. The
+"bt" driver is one of the non-standard drivers -- installing it into the
+kernel could break Linus' patches.
+
+
+Changes to the original bt distribution
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
++ Loadable module support with auto-creation of necessary devices.
++ Minor fix for BT_COOPERATE_WITH_LP
+
+
+Installation
+~~~~~~~~~~~~
+Have a look at bt_config.h and at the Makefile and make changes where
+appropriate. Uncomment BT_COOPERATE_WITH_LP in bt_config.h if you want to
+have both the bt and lp device drivers installed. This is not recommended,
+but it worked for me. It's saver, however, to remove the lp driver from the
+kernel. If you #define BT_COOPERATE_WITH_LP: make shure that the relevant
+devices don't use conflicting parameters.
+
+Become root, then type
+
+	make install.module install.man
+
+That's it. You may load the module with
+
+	depmod -a; modprobe bt
+
+The kernel will write a few lines similar to
+
+	bt: Experimental BiTronics device driver vALPHA-0.0.1 at major # 63
+	bt: parallel port at 0x378 is minor device # 1 (bt1)
+
+to /var/adm/messages, hopefully indicating that everything went fine.
+
+The module will automatically create the necessary /dev/bt* devices, so
+make shure you have "/" mounted read-write. The default ownership/permissions
+for the /dev/bt* devices are:
+
+	uid=0 gid=7 perm=0660
+
+You can change these defaults in bt_config.h, or simply use the insmod
+"symbol=<value>" mechanism. Example: "insmod bt.o uid=1999 gid=0 perm=0644"
+
+If you have more than one parallel port and don't want to run bt on every
+port, you may add "ports=<bitfield>", where <bitfield> is an integer with
+only those bits set whose positions match the interface numbers which bt may
+use. E.g., "ports=3" will tell the module to use the parallel ports 0 and 1,
+and to leave port 2 alone.
+
+At the time of writing, the loadable module support was tested with the
+1.3.25 kernel only. It may or may not work with other kernel releases.
+
+Have fun!
+
+	Marc
+
+---
+Marc Huber (huber@fzi.de)
+
diff -u --recursive --new-file bt-ALPHA-0.0.1.original/bt.c bt-ALPHA-0.0.1/bt.c
--- bt-ALPHA-0.0.1.original/bt.c	Thu Oct 27 20:52:47 1994
+++ bt-ALPHA-0.0.1/bt.c	Mon Sep 25 10:27:38 1995
@@ -78,6 +78,12 @@
  *	Initial revision
  *****************************************************************************/
 
+#ifdef MODULE
+/******************************************************************************
+ * Loadable module support by Marc Huber (huber@fzi.de) 1995/09/21
+ *****************************************************************************/
+#endif 
+
 /*
 .EOC
 .P
@@ -89,7 +95,6 @@
 
 #include <linux/errno.h>
 #include <linux/kernel.h>
-#include <linux/major.h>
 #include <linux/sched.h>
 #include <linux/malloc.h>
 #include <linux/delay.h>
@@ -98,9 +103,20 @@
 
 #ifdef BT_COOPERATE_WITH_LP
 	#include <linux/lp.h>
+	extern struct lp_struct lp_table[];
 #endif
 
+#ifndef MODULE
 #include <linux/bt.h>
+#include <linux/major.h>
+#else
+#include <linux/unistd.h>
+#include <linux/stat.h>
+#include <linux/fs.h>
+#include <linux/module.h>
+#include <linux/version.h>
+#include "bt.h"
+#endif
 
 /******************************************************************************
  * driver internal definitions
@@ -109,15 +125,30 @@
 static char bt_RCS_ID[] = "@(#)$Id: bt.c,v 1.7 1994/10/26 18:23:46 root Exp $";
 #define BT_USE(x)	((void)(x))	/* null macro to hide warning	*/
 
+#ifdef MODULE
+/*******************************************************************************
+ * Global variables needed for auto-creation of devices. You may override the
+ * BT_* defaults when loading the module -- insmod(1) is your friend ;-)
+ *******************************************************************************/
+
+static int major   = 0;
+static int uid     = BT_UID;
+static int gid     = BT_GID;
+static int perm    = BT_PERM;
+static int ports   = BT_PORTS;
+static char name[] = BT_DEVICE_NAME;
+#endif
+
 
 /*
 .P
 */
+
 /*******************************************************************************
  * Create the status lookup tables
  *******************************************************************************/
 
-BT_PRN_STAT bt_prn_stat_norm[] = {
+static BT_PRN_STAT bt_prn_stat_norm[] = {
 	BT_PRN_STE(READY),
 	BT_PRN_STE(NO_PRN),
 	BT_PRN_STE(PE),	  
@@ -127,7 +158,7 @@
 	{ 0, 0, NULL }
 };
 
-BT_PRN_STAT bt_prn_stat_bt[] = {
+static BT_PRN_STAT bt_prn_stat_bt[] = {
 	BT_PRN_STE(ACK),  
 	BT_PRN_STE(ADR),    
 	BT_PRN_STE(CLK_H),
@@ -226,7 +257,7 @@
  ******************************************************************************/
 static void bt_release(struct inode *inode, struct file *file);
 static int  bt_open(   struct inode *inode, struct file *file);
-static int  bt_write(  struct inode* inode, struct file *file, char *buf, int count);
+static int  bt_write(  struct inode* inode, struct file *file, const char *buf, int count);
 static int  bt_read(   struct inode* inode, struct file *file, char *buf, int count);
 
 /*
@@ -594,7 +625,7 @@
 
 
 
-static int bt_write(struct inode* inode, struct file *file, char *buf,
+static int bt_write(struct inode* inode, struct file *file, const char *buf,
 	int count)
 /******************************************************************************
  * Performes the writing of data to the printer
@@ -664,7 +695,7 @@
  * READ operation
  ******************************************************************************/
 
-int bt_read_char(int minor, char *c)
+static int bt_read_char(int minor, char *c)
 /******************************************************************************
  * Reads one byte (two nibbles) from the printer
  * IN:  minor           Minor device to use
@@ -905,6 +936,7 @@
  * Open/Release & Initialisation/Deinitialisation
  ******************************************************************************/
 
+
 static int bt_open(struct inode *inode, struct file *file)
 /******************************************************************************
  * Probes if a minor device exists and - if yes - brings it into service
@@ -951,6 +983,9 @@
 	bt_data[minor].last_error = BT_NO_ERROR;
 
 	BTEXIT(BTTF_ALL,"OK\n");
+#ifdef MODULE
+	MOD_INC_USE_COUNT;
+#endif
 	return 0;
 }
 
@@ -980,6 +1015,9 @@
 	LP_F(minor) &= ~LP_BUSY;
 #endif
 	bt_data[minor].busy = 0;
+#ifdef MODULE
+	MOD_DEC_USE_COUNT;
+#endif
 }
 
 
@@ -1009,7 +1047,30 @@
 	}
 }
 
+#ifdef MODULE
+void cleanup_module(void);
+
+char kernel_version[]= UTS_RELEASE;
+
+/*
+ * Syscalls needed for creating/removing the special files
+ */
+
+typedef int (*syscall_ptr)(const char *, ...);
+extern syscall_ptr sys_call_table[];
 
+#define unlink sys_call_table[__NR_unlink]
+#define mknod  sys_call_table[__NR_mknod]
+#define chown  sys_call_table[__NR_chown]
+#define chmod  sys_call_table[__NR_chmod]
+
+long init_module(long kmem_start)
+/******************************************************************************
+ * Initialize the driver, create devices
+ * IN:	kmem_start	First kernel mem addr. which could be used
+ * OUT: 0: module loaded, any other for failure
+ *****************************************************************************/
+#else
 long bt_init(long kmem_start)
 /******************************************************************************
  * Initialize the driver (really strange that this is called by mem.c, but
@@ -1017,33 +1078,108 @@
  * IN:	kmem_start	First kernel mem addr. which could be used
  * OUT:	bt_init		New first unused kernel mem addr.
  *****************************************************************************/
+#endif
 {
 	int	minor;
 	int	n_existing = 0;	/* nbr of existing ports	*/
+#ifdef MODULE
+	int	len, oldfs, res;
+#endif
 
 	BT_USE(bt_RCS_ID);	/* get rid of "defined but not used" warning */
 
 	/*
 	 * use the chance to make ourselfe known
 	 */
+#ifndef MODULE
 	if (register_chrdev(BT_MAJOR, BT_DRIVER_NAME, &bt_fops)) {
-		printk(BT_DRIVER_NAME ": unable to get major # %d for driver\ndriver not usable!\n", BT_MAJOR);
+#else
+	if ((major = register_chrdev(0, BT_DRIVER_NAME, &bt_fops)) < 1) {
+#endif
+		printk(BT_DRIVER_NAME ": no major device id available\ndriver not usable!\n");
+#ifndef MODULE
 		return kmem_start;
-			/* XXX perhaps a loop to get first unused major # ???*/
-			/* XXX perhaps auto creation of /dev/bt? entries???  */
 	}
 
-
 	printk(BT_DRIVER_NAME ": Experimental BiTronics device driver v%s at major # %d\n", bt_version, BT_MAJOR);
 
+#else
+		return -EIO;
+	}
+
+	printk(BT_DRIVER_NAME ": Experimental BiTronics device driver v%s at major # %d\n", bt_version, major);
+
+	for(len = 0; name[len] ; len++);
+	len--;
+#endif
+
 	for(minor = 0; minor < BT_NBR; minor++) {
 		/*
 		 * iterate over all possible ports and note succesfull attempts
 		 */
+#ifndef MODULE
 		n_existing += bt_probe_port(minor);
+#else
+		if(bt_probe_port(minor) && ((ports >> minor) & 1)) {
+			n_existing++;
+			name[len] = '0' + minor;
+			oldfs=get_fs();
+			set_fs(KERNEL_DS);
+			unlink(name);
+			res = mknod(name, S_IFCHR, MKDEV(major, minor));
+			chown(name, uid, gid);
+			chmod(name, perm);
+			set_fs(oldfs);
+			if(res){
+				/*
+				 * Well, mknod failed, probably because "/" is
+				 * mounted read-only.
+				 */
+				printk(BT_DRIVER_NAME ": Creating %s (%d %d) failed!\n", name, major, minor);
+				cleanup_module();
+				return -EIO;
+			}
+		}
+#endif
 	}
+#ifndef MODULE
 	if(!n_existing)
 		printk(BT_DRIVER_NAME ": no printer ports found!\n");
+#else
+	if(!n_existing) {
+		printk(BT_DRIVER_NAME ": no printer ports found!\n");
+		cleanup_module();
+		return -EIO;
+	}
+#endif
 
+#ifndef MODULE
 	return kmem_start;
+#else
+	return 0;
+}
+
+void cleanup_module(void)
+/******************************************************************************
+ * Unregister the device, remove the devices created by bt_init()
+ *****************************************************************************/
+{
+	int len, minor, oldfs;
+	if(MOD_IN_USE)
+		printk("bt: busy - remove delayed\n");
+	else {
+		unregister_chrdev(major,"bt");
+		for(len = 0; name[len]; len++);
+		len--;
+		for(minor = 0; minor < BT_NBR; minor++){
+			if((ports >> minor) & 1) {
+				name[len] = '0' + minor;
+				oldfs=get_fs();
+				set_fs(KERNEL_DS);
+				unlink(name);
+				set_fs(oldfs);
+			}
+		}
+	}
 }
+#endif
diff -u --recursive --new-file bt-ALPHA-0.0.1.original/bt_config.h bt-ALPHA-0.0.1/bt_config.h
--- bt-ALPHA-0.0.1.original/bt_config.h	Thu Oct 27 20:52:47 1994
+++ bt-ALPHA-0.0.1/bt_config.h	Mon Sep 25 09:22:29 1995
@@ -47,10 +47,43 @@
 #ifndef BT_CONFIG_H_
 #define BT_CONFIG_H_
 
+
+#ifdef MODULE
+/******************************************************************************
+ * Loadable module support by Marc Huber (huber@fzi.de) 1995/09/21
+ *****************************************************************************/
+#endif 
+
+
 /*
  * how the driver identifies itselfe in printouts
  */
 #define BT_DRIVER_NAME	"bt"
+
+
+#ifdef MODULE
+
+/*
+ * Name template for auto-created devices
+ */
+#define BT_DEVICE_NAME	"/dev/bt?"
+
+
+/*
+ * Ownership and permissions of auto-created devices
+ */
+#define BT_UID		0 /* root */
+#define BT_GID		7 /* lp   */
+#define BT_PERM		0660
+
+
+/*
+ * The module will use only the ports with the corresponding bits in
+ * BT_PORTS set.
+ */
+#define BT_PORTS	1|2|4	/* ports 0, 1 and 2 */
+
+#endif
 
 
 /*