i2c: added i2c-isa bus controller driver.

Based on the i2c cvs version of this driver.

drivers/i2c/busses/Kconfig

@@ -76,6 +76,24 @@ config I2C_I801
 	  in the lm_sensors package, which you can download at 
 	  http://www.lm-sensors.nu
 
+config I2C_ISA
+	tristate "  ISA Bus support"
+	depends on I2C && I2C_PROC && ISA && EXPERIMENTAL
+	help
+	  If you say yes to this option, support will be included for i2c
+	  interfaces that are on the ISA bus.
+
+	  This can also be built as a module which can be inserted and removed 
+	  while the kernel is running.  If you want to compile it as a module,
+	  say M here and read <file:Documentation/modules.txt>.
+
+	  The module will be called i2c-isa.
+
+	  You will also need the latest user-space utilties: you can find them
+	  in the lm_sensors package, which you can download at 
+	  http://www.lm-sensors.nu
+
+
 config I2C_PIIX4
 	tristate "  Intel PIIX4"
 	depends on I2C && I2C_PROC && PCI && EXPERIMENTAL

drivers/i2c/busses/Makefile

@@ -6,4 +6,5 @@ obj-$(CONFIG_I2C_ALI15X3)	+= i2c-ali15x3.o
 obj-$(CONFIG_I2C_AMD756)	+= i2c-amd756.o
 obj-$(CONFIG_I2C_AMD8111)	+= i2c-amd8111.o
 obj-$(CONFIG_I2C_I801)		+= i2c-i801.o
+obj-$(CONFIG_I2C_ISA)		+= i2c-isa.o
 obj-$(CONFIG_I2C_PIIX4)		+= i2c-piix4.o

drivers/i2c/busses/i2c-isa.c

+/*
+    i2c-isa.c - Part of lm_sensors, Linux kernel modules for hardware
+            monitoring
+    Copyright (c) 1998, 1999  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.
+*/
+
+/* This implements an i2c algorithm/adapter for ISA bus. Not that this is
+   on first sight very useful; almost no functionality is preserved.
+   Except that it makes writing drivers for chips which can be on both
+   the SMBus and the ISA bus very much easier. See lm78.c for an example
+   of this. */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/i2c.h>
+
+/* This is the actual algorithm we define */
+static struct i2c_algorithm isa_algorithm = {
+	.name		= "ISA bus algorithm",
+	.id		= I2C_ALGO_ISA,
+};
+
+/* There can only be one... */
+static struct i2c_adapter isa_adapter = {
+	.owner		= THIS_MODULE,
+	.name		= "ISA main adapter",
+	.id		= I2C_ALGO_ISA | I2C_HW_ISA,
+	.algo		= &isa_algorithm,
+};
+
+static int __init i2c_isa_init(void)
+{
+	return i2c_add_adapter(&isa_adapter);
+}
+
+static void __exit i2c_isa_exit(void)
+{
+	i2c_del_adapter(&isa_adapter);
+}
+
+MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>");
+MODULE_DESCRIPTION("ISA bus access through i2c");
+MODULE_LICENSE("GPL");
+
+module_init(i2c_isa_init);
+module_exit(i2c_isa_exit);