--- linux/drivers/i2c/chips/pca9539.c	2005-10-01 00:17:35.000000000 +0300
+++ se95/drivers/i2c/chips/pca9539.c	2005-12-31 19:18:15.000000000 +0200
@@ -3,6 +3,13 @@
 
     Copyright (C) 2005 Ben Gardner <bgardner@wabtec.com>
 
+    Similar chips added:
+    pca9538 -  8-bit I/O port 
+    pca9554(a) - 8-bit I/O port 
+    pca9555(a) - 16-bit I/O port - FIXME
+    pcf8574(a) - 8-bit I/O port - FIXME
+    Copyright (C) 2005 Tonu Samuel <tonu@spam.ee>
+    
     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; version 2 of the License.
@@ -15,11 +22,28 @@
 #include <linux/hwmon-sysfs.h>
 
 /* Addresses to scan */
-static unsigned short normal_i2c[] = {0x74, 0x75, 0x76, 0x77, I2C_CLIENT_END};
+static unsigned short normal_i2c[] = { 
+	/* pca9554 (without A) addresses */
+	0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
+	/* pca9554A addresses */
+	0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,
+	/* pca9538 addresses */
+	0x70, 0x71, 0x72, 0x73,
+	/* pca9539 addresses*/
+	0x74, 0x75, 0x76, 0x77, I2C_CLIENT_END};
 
 /* Insmod parameters */
 I2C_CLIENT_INSMOD_1(pca9539);
 
+enum pca9538_cmd
+{
+	PCA9538_INPUT		= 0,
+	PCA9538_OUTPUT		= 1,
+	PCA9538_INVERT		= 2,
+	PCA9538_DIRECTION	= 3,
+};
+
+
 enum pca9539_cmd
 {
 	PCA9539_INPUT_0		= 0,
@@ -47,6 +71,7 @@
 
 struct pca9539_data {
 	struct i2c_client client;
+	int is_pca9538;
 };
 
 /* following are the sysfs callback functions */
@@ -80,15 +105,30 @@
 	static SENSOR_DEVICE_ATTR(name, S_IRUGO | S_IWUSR, pca9539_show, \
 				  pca9539_store, cmd_idx)
 
+PCA9539_ENTRY_RO(input, PCA9538_INPUT);
 PCA9539_ENTRY_RO(input0, PCA9539_INPUT_0);
 PCA9539_ENTRY_RO(input1, PCA9539_INPUT_1);
+
+PCA9539_ENTRY_RW(output, PCA9538_OUTPUT);
 PCA9539_ENTRY_RW(output0, PCA9539_OUTPUT_0);
 PCA9539_ENTRY_RW(output1, PCA9539_OUTPUT_1);
+
+PCA9539_ENTRY_RW(invert, PCA9538_INVERT);
 PCA9539_ENTRY_RW(invert0, PCA9539_INVERT_0);
 PCA9539_ENTRY_RW(invert1, PCA9539_INVERT_1);
+
+PCA9539_ENTRY_RW(direction, PCA9538_DIRECTION);
 PCA9539_ENTRY_RW(direction0, PCA9539_DIRECTION_0);
 PCA9539_ENTRY_RW(direction1, PCA9539_DIRECTION_1);
 
+static struct attribute *pca9538_attributes[] = {
+	&sensor_dev_attr_input.dev_attr.attr,
+	&sensor_dev_attr_output.dev_attr.attr,
+	&sensor_dev_attr_invert.dev_attr.attr,
+	&sensor_dev_attr_direction.dev_attr.attr,
+	NULL
+};
+
 static struct attribute *pca9539_attributes[] = {
 	&sensor_dev_attr_input0.dev_attr.attr,
 	&sensor_dev_attr_input1.dev_attr.attr,
@@ -101,6 +141,10 @@
 	NULL
 };
 
+static struct attribute_group pca9538_defattr_group = {
+	.attrs = pca9538_attributes,
+};
+
 static struct attribute_group pca9539_defattr_group = {
 	.attrs = pca9539_attributes,
 };
@@ -136,19 +180,36 @@
 	new_client->flags = 0;
 
 	/* Detection: the pca9539 only has 8 registers (0-7).
-	   A read of 7 should succeed, but a read of 8 should fail. */
-	if ((i2c_smbus_read_byte_data(new_client, 7) < 0) ||
-	    (i2c_smbus_read_byte_data(new_client, 8) >= 0))
+	   A read of 7 should succeed, but a read of 8 should fail. 
+           If reading 4 fails but 0..3 works, it should be pca9538,
+	   8-bit younger brother of pca9539 */
+
+	/* Trying for pca9539 */
+	if ((i2c_smbus_read_byte_data(new_client, 7) >= 0) &&
+	    (i2c_smbus_read_byte_data(new_client, 8) < 0))
+		strlcpy(new_client->name, "pca9539", I2C_NAME_SIZE);
+	/* Trying for pca9538, pca9554(a) */
+	else if ((i2c_smbus_read_byte_data(new_client, 3) >= 0) && 
+	    (i2c_smbus_read_byte_data(new_client, 4) < 0)) {
+		if(address<=0x27) 
+		        strlcpy(new_client->name, "pca9554", I2C_NAME_SIZE);
+		else if(address>=0x48 && address<=0x4f)
+		        strlcpy(new_client->name, "pca9554A", I2C_NAME_SIZE);
+		else
+		        strlcpy(new_client->name, "pca9538", I2C_NAME_SIZE);
+		data->is_pca9538=1;
+        } else
 		goto exit_kfree;
 
-	strlcpy(new_client->name, "pca9539", I2C_NAME_SIZE);
-
 	/* Tell the I2C layer a new client has arrived */
 	if ((err = i2c_attach_client(new_client)))
 		goto exit_kfree;
 
 	/* Register sysfs hooks (don't care about failure) */
-	sysfs_create_group(&new_client->dev.kobj, &pca9539_defattr_group);
+	if(data->is_pca9538)
+		sysfs_create_group(&new_client->dev.kobj, &pca9538_defattr_group);
+	else
+		sysfs_create_group(&new_client->dev.kobj, &pca9539_defattr_group);
 
 	return 0;