patch-2.3.34 linux/drivers/i2c/i2c-philips-par.c

• Lines: 233
• Date: Thu Dec 16 13:59:38 1999
• Orig file: v2.3.33/linux/drivers/i2c/i2c-philips-par.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.33/linux/drivers/i2c/i2c-philips-par.c linux/drivers/i2c/i2c-philips-par.c
@@ -0,0 +1,232 @@
+/* ------------------------------------------------------------------------- */
+/* i2c-philips-par.c i2c-hw access for philips style parallel port adapters  */
+/* ------------------------------------------------------------------------- */
+/*   Copyright (C) 1995-99 Simon G. Vogl
+
+    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.		     */
+/* ------------------------------------------------------------------------- 
+static char rcsid[] = "$Id: i2c-philips-par.c,v 1.11 1999/10/08 14:25:11 frodo Exp $";
+   ------------------------------------------------------------------------- */
+
+/* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and even
+   Frodo Looijaard <frodol@dds.nl> */
+
+#include <linux/kernel.h>
+#include <linux/ioport.h>
+#include <linux/module.h>
+#if LINUX_VERSION_CODE >= 0x020135
+#include <linux/init.h>
+#else
+#define __init 
+#endif
+#include <asm/io.h>
+#include <linux/stddef.h>
+
+/* 2.0.0 kernel compatibility */
+#if LINUX_VERSION_CODE < 0x020100
+#define MODULE_AUTHOR(noone)
+#define MODULE_DESCRIPTION(none)
+#define MODULE_PARM(no,param)
+#define MODULE_PARM_DESC(no,description)
+#define EXPORT_SYMBOL(noexport)
+#define EXPORT_NO_SYMBOLS
+#endif
+
+#include <linux/i2c.h>
+#include <linux/i2c-algo-bit.h>
+
+#define DEFAULT_BASE 0x378
+static int base=0;
+
+/* Note: all we need to know is the base address of the parallel port, so
+ * instead of having a dedicated struct to store this value, we store this
+ * int in the pointer field (=bit_lp_ops.data) itself.
+ */
+
+/* Note2: as the hw that implements the i2c bus on the parallel port is 
+ * incompatible with other epp stuff etc., we access the port exclusively
+ * and don't cooperate with parport functions.
+ */
+
+/* ----- global defines -----------------------------------------------	*/
+#define DEB(x)		/* should be reasonable open, close &c. 	*/
+#define DEB2(x) 	/* low level debugging - very slow 		*/
+#define DEBE(x)	x	/* error messages 				*/
+
+/* ----- printer port defines ------------------------------------------*/
+					/* Pin Port  Inverted	name	*/
+#define I2C_ON		0x20		/* 12 status N	paper		*/
+					/* ... only for phil. not used  */
+#define I2C_SDA		0x80		/*  9 data   N	data7		*/
+#define I2C_SCL		0x08		/* 17 ctrl   N	dsel		*/
+
+#define I2C_SDAIN	0x80		/* 11 stat   Y	busy		*/
+#define I2C_SCLIN	0x08		/* 15 stat   Y	enable		*/
+
+#define I2C_DMASK	0x7f
+#define I2C_CMASK	0xf7
+
+/* --- Convenience defines for the parallel port:			*/
+#define BASE	(unsigned int)(data)
+#define DATA	BASE			/* Centronics data port		*/
+#define STAT	(BASE+1)		/* Centronics status port	*/
+#define CTRL	(BASE+2)		/* Centronics control port	*/
+
+/* ----- local functions ----------------------------------------------	*/
+
+static void bit_lp_setscl(void *data, int state)
+{
+	/*be cautious about state of the control register - 
+		touch only the one bit needed*/
+	if (state) {
+		outb(inb(CTRL)|I2C_SCL,   CTRL);
+	} else {
+		outb(inb(CTRL)&I2C_CMASK, CTRL);
+	}
+}
+
+static void bit_lp_setsda(void *data, int state)
+{
+	if (state) {
+		outb(I2C_DMASK , DATA);
+	} else {
+		outb(I2C_SDA , DATA);
+	}
+}
+
+static int bit_lp_getscl(void *data)
+{
+	return ( 0 != ( (inb(STAT)) & I2C_SCLIN ) );
+}
+
+static int bit_lp_getsda(void *data)
+{
+	return ( 0 != ( (inb(STAT)) & I2C_SDAIN ) );
+}
+
+static int bit_lp_init(void)
+{
+	if (check_region(base,(base == 0x3bc)? 3 : 8) < 0 ) {
+		return -ENODEV;
+	} else {
+		request_region(base,(base == 0x3bc)? 3 : 8,
+			"i2c (parallel port adapter)");
+		/* reset hardware to sane state */
+		bit_lp_setsda((void*)base,1);
+		bit_lp_setscl((void*)base,1);
+	}
+	return 0;
+}
+
+static void bit_lp_exit(void)
+{
+	release_region( base , (base == 0x3bc)? 3 : 8 );
+}
+
+static int bit_lp_reg(struct i2c_client *client)
+{
+	return 0;
+}
+
+static int bit_lp_unreg(struct i2c_client *client)
+{
+	return 0;
+}
+
+static void bit_lp_inc_use(struct i2c_adapter *adap)
+{
+  MOD_INC_USE_COUNT;
+}
+
+static void bit_lp_dec_use(struct i2c_adapter *adap)
+{
+  MOD_DEC_USE_COUNT;
+}
+
+/* ------------------------------------------------------------------------
+ * Encapsulate the above functions in the correct operations structure.
+ * This is only done when more than one hardware adapter is supported.
+ */
+ 
+static struct i2c_algo_bit_data bit_lp_data = {
+	NULL,
+	bit_lp_setsda,
+	bit_lp_setscl,
+	bit_lp_getsda,
+	bit_lp_getscl,
+	80, 80, 100,		/*	waits, timeout */
+}; 
+
+static struct i2c_adapter bit_lp_ops = {
+	"Philips Parallel port adapter",
+	I2C_HW_B_LP,
+	NULL,
+	&bit_lp_data,
+	bit_lp_inc_use,
+	bit_lp_dec_use,
+	bit_lp_reg,
+	bit_lp_unreg,
+};
+
+
+int __init i2c_bitlp_init(void)
+{
+        printk("i2c-philips-par.o: i2c Philips parallel port adapter module\n");
+	if (base==0) {
+		/* probe some values */
+		base=DEFAULT_BASE;
+		bit_lp_data.data=(void*)DEFAULT_BASE;
+		if (bit_lp_init()==0) {
+			if (i2c_bit_add_bus(&bit_lp_ops) < 0)
+				return -ENODEV;
+		} else {
+			return -ENODEV;
+		}
+	} else {
+		bit_lp_data.data=(void*)base;
+		if (bit_lp_init()==0) {
+			if (i2c_bit_add_bus(&bit_lp_ops) < 0)
+				return -ENODEV;
+		} else {
+			return -ENODEV;
+		}
+	}
+	printk("i2c-philips-par.o: found device at %#x.\n",base);
+	return 0;
+}
+
+EXPORT_NO_SYMBOLS;
+
+#ifdef MODULE
+MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>");
+MODULE_DESCRIPTION("I2C-Bus adapter routines for Philips parallel port adapter");
+
+MODULE_PARM(base, "i");
+
+int init_module(void) 
+{
+	return i2c_bitlp_init();
+}
+
+void cleanup_module(void) 
+{
+	i2c_bit_del_bus(&bit_lp_ops);
+	bit_lp_exit();
+}
+
+#endif
+
+
+