isa module added, some bugfixes

'isa.o' is roughly what was called 'sensor.o' in doc/design.


git-svn-id: http://lm-sensors.org/svn/lm-sensors/trunk@12 7894878c-1315-0410-8ee3-d5d059ff63e0

kernel/busses/i2c-isa.c

@@ -0,0 +1,191 @@
+/*
+    isa.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.
+*/
+
+/* 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/module.h>
+#include <linux/kernel.h>
+
+#include "i2c.h"
+#ifdef SPINLOCK
+#include <asm/spinlock.h>
+#else
+#include <asm/semaphore.h>
+#endif
+
+#include "version.h"
+#include "isa.h"
+
+static int isa_master_xfer (struct isa_adapter *adap,
+                            struct i2c_msg msgs[], int num);
+static int isa_slave_send (struct isa_adapter *adap, char *data, int len);
+static int isa_slave_recv (struct isa_adapter *adap, char *data, int len);
+static int isa_algo_control (struct isa_adapter *adap, unsigned int cmd,
+                             unsigned long arg);
+static int isa_client_register (struct isa_client *client);
+static int isa_client_unregister (struct isa_client *client);
+
+static int isa_init(void);
+static int isa_cleanup(void);
+
+#ifdef MODULE
+extern int init_module(void);
+extern int cleanup_module(void);
+#endif /* MODULE */
+
+/* This is the actual algorithm we define */
+static struct isa_algorithm isa_algorithm = {
+  /* name */            "ISA bus adapter",
+  /* id */              ALGO_ISA,
+  /* master_xfer */     &isa_master_xfer,
+  /* slave_send */      &isa_slave_send,
+  /* slave_rcv */       &isa_slave_recv,
+  /* algo_control */    &isa_algo_control,
+  /* client_register */ &isa_client_register,
+  /* client_unregister*/&isa_client_unregister
+};
+
+/* There can only be one... */
+static struct isa_adapter isa_adapter;
+
+/* Used in isa_init/cleanup */
+static int isa_initialized;
+
+/* Algorithm master_xfer call-back implementation. Can't do that... */
+int isa_master_xfer (struct isa_adapter *adap, struct i2c_msg msgs[],
+                     int num)
+{
+  printk("isa_master_xfer called for adapter `%s' "
+         "(no i2c level access possible!)\n",
+         adap->name);
+  return 0;
+}
+
+/* Algorithm slave_send call-back implementation. Can't do that... */
+int isa_slave_send (struct isa_adapter *adap, char *data, int len)
+{
+  printk("isa_slave_send called for adapter `%s' "
+         "(no i2c level access possible!)\n",
+         adap->name);
+  return 0;
+}
+
+/* Algorithm slave_recv call-back implementation. Can't do that... */
+int isa_slave_recv (struct isa_adapter *adap, char *data, int len)
+{
+  printk("isa_slave_recv called for adapter `%s' "
+         "(no i2c level access possible!)\n",
+         adap->name);
+  return 0;
+}
+
+/* Here we can put additional calls to modify the workings of the algorithm.
+   But right now, there is no need for that. */
+int isa_algo_control (struct isa_adapter *adap, unsigned int cmd,
+                       unsigned long arg)
+{
+  return 0;
+}
+
+/* Ehm... This is called when a client is registered to an adapter. We could
+   do all kinds of neat stuff here like, ehm - returning success? */
+int isa_client_register (struct isa_client *client)
+{
+  return 0;
+}
+
+int isa_client_unregister (struct isa_client *client)
+{
+  return 0;
+}
+
+int isa_init(void)
+{
+  int res;
+  printk("isa.o version %s (%s)\n",LM_VERSION,LM_DATE);
+#ifdef DEBUG
+  if (isa_initialized) {
+    printk("isa.o: Oops, isa_init called a second time!\n");
+    return -EBUSY;
+  }
+#endif
+  isa_initialized = 0;
+  if ((res = isa_add_algorithm(&isa_algorithm))) {
+    printk("isa.o: Algorithm registration failed, module isa.o not inserted\n");
+    isa_cleanup();
+    return res;
+  }
+  isa_initialized++;
+  strcpy(isa_adapter.name,"ISA main adapter");
+  isa_adapter.id = ALGO_ISA | ISA_MAIN;
+  isa_adapter.algo = &isa_algorithm;
+  if ((res = isa_add_adapter(&isa_adapter))) {
+    printk("isa.o: Adapter registration failed, "
+           "module isa.o is not inserted\n");
+    isa_cleanup();
+    return res;
+  }
+  isa_initialized++;
+  printk("isa.o: ISA bus access for i2c modules initialized\n");
+  return 0;
+}
+
+int isa_cleanup(void)
+{
+  int res;
+  if (isa_initialized >= 2)
+  {
+    if ((res = isa_del_adapter(&isa_adapter))) {
+      printk("isa.o: isa_del_adapter failed, module not removed\n");
+      return res;
+    } else
+      isa_initialized--;
+  }
+  if (isa_initialized >= 1)
+  {
+    if ((res = isa_del_algorithm(&isa_algorithm))) {
+      printk("isa.o: isa_del_algorithm failed, module not removed\n");
+      return res;
+    } else
+      isa_initialized--;
+  }
+  return 0;
+}
+
+#ifdef MODULE
+
+MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>");
+MODULE_DESCRIPTION("ISA bus access through i2c");
+
+int init_module(void)
+{
+  return isa_init();
+}
+
+int cleanup_module(void)
+{
+  return isa_cleanup();
+}
+
+#endif /* MODULE */
+