[PATCH 2/2] [I2C] add PCA9543 chip driver

[Bryan Wu <cooloney-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>]

From: Michael Hennerich <michael.hennerich-OyLXuOCK7orQT0dZR+AlfA@public.gmane.org>

Signed-off-by: Michael Hennerich <michael.hennerich-OyLXuOCK7orQT0dZR+AlfA@public.gmane.org>
Signed-off-by: Bryan Wu <cooloney-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
---
 drivers/i2c/chips/Kconfig   |   13 +++
 drivers/i2c/chips/Makefile  |    1 +
 drivers/i2c/chips/pca9543.c |  212 +++++++++++++++++++++++++++++++++++++++++++
 include/linux/i2c-id.h      |    1 +
 4 files changed, 227 insertions(+), 0 deletions(-)
 create mode 100644 drivers/i2c/chips/pca9543.c

diff --git a/drivers/i2c/chips/Kconfig b/drivers/i2c/chips/Kconfig
index 1222e36..908fe9a 100644
--- a/drivers/i2c/chips/Kconfig
+++ b/drivers/i2c/chips/Kconfig
@@ -60,6 +60,19 @@ config PCF8575
 	  This device is hard to detect and is rarely found on mainstream
 	  hardware.  If unsure, say N.
 
+config SENSORS_PCA9543
+	tristate "Philips PCA9543 bi-directional translating switch"
+	depends on I2C && EXPERIMENTAL
+	default n
+	help
+	  If you say yes here you get support for Philips PCA9543.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called pca9543.
+
+	  These devices are hard to detect and rarely found on mainstream
+	  hardware.  If unsure, say N.
+
 config SENSORS_PCA9539
 	tristate "Philips PCA9539 16-bit I/O port (DEPRECATED)"
 	depends on EXPERIMENTAL && GPIO_PCA9539 = "n"
diff --git a/drivers/i2c/chips/Makefile b/drivers/i2c/chips/Makefile
index 866def2..7b292e6 100644
--- a/drivers/i2c/chips/Makefile
+++ b/drivers/i2c/chips/Makefile
@@ -14,6 +14,7 @@ obj-$(CONFIG_DS1682)		+= ds1682.o
 obj-$(CONFIG_SENSORS_EEPROM)	+= eeprom.o
 obj-$(CONFIG_SENSORS_MAX6875)	+= max6875.o
 obj-$(CONFIG_SENSORS_PCA9539)	+= pca9539.o
+obj-$(CONFIG_SENSORS_PCA9543)	+= pca9543.o
 obj-$(CONFIG_SENSORS_PCF8574)	+= pcf8574.o
 obj-$(CONFIG_PCF8575)		+= pcf8575.o
 obj-$(CONFIG_SENSORS_PCF8591)	+= pcf8591.o
diff --git a/drivers/i2c/chips/pca9543.c b/drivers/i2c/chips/pca9543.c
new file mode 100644
index 0000000..dc19638
--- /dev/null
+++ b/drivers/i2c/chips/pca9543.c
@@ -0,0 +1,212 @@
+/*
+    pca9543.c - Part of lm_sensors, Linux kernel modules for hardware
+             monitoring
+    Copyright (c) 2000  Frodo Looijaard <frodol-B0qZmFHriGg@public.gmane.org>,
+                        Philip Edelbrock <phil-KXOFo5pg7o1l57MIdRCFDg@public.gmane.org>,
+                        Dan Eaton <dan.eaton-RtyX3GHucphnQYSypqKXDg@public.gmane.org>
+    Ported to Linux 2.6 by Aurelien Jarno <aurel32-8fiUuRrzOP0dnm+yROfE0A@public.gmane.org> with
+    the help of Jean Delvare <khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org>
+
+    Copyright (C) 2007 Michael Hennerich, Analog Devices Inc.
+    			<hennerich-ZG0+EudsQA8dtHy/vicBwGD2FQJk+8+b@public.gmane.org>
+	based on the pcf8574.c
+
+    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.
+*/
+
+/* A few notes about the PCA9543:
+
+*   The PCA9543 is a bi-directional translating switch, controlled by the
+    I2C bus. The SCL/SDA upstream pair fans out to two downstream
+    pairs, or channels. Any individual SCx/SDx channels or combination
+    of channels can be selected, determined by the contents of the
+    programmable control register. Two interrupt inputs, INT0 to INT3,
+    one for each of the downstream pairs, are provided. One interrupt
+    output INT, which acts as an AND of the two interrupt inputs, is
+    provided.
+
+*/
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+
+/* Addresses to scan */
+static unsigned short normal_i2c[] = { 0x70,0x71, 0x72, 0x73, I2C_CLIENT_END };
+
+/* Insmod parameters */
+I2C_CLIENT_INSMOD_1(pca9543);
+
+
+/* Each client has this additional data */
+struct pca9543_data {
+	struct i2c_client client;
+
+	u8 write;			/* Remember last written value */
+};
+
+static int pca9543_attach_adapter(struct i2c_adapter *adapter);
+static int pca9543_detect(struct i2c_adapter *adapter, int address, int kind);
+static int pca9543_detach_client(struct i2c_client *client);
+
+
+/* This is the driver that will be inserted */
+static struct i2c_driver pca9543_driver = {
+	.driver = {
+		.name	= "pca9543",
+	},
+	.id		= I2C_DRIVERID_PCF8574,
+	.attach_adapter	= pca9543_attach_adapter,
+	.detach_client	= pca9543_detach_client,
+};
+
+/* following are the sysfs callback functions */
+static ssize_t show_read(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	return sprintf(buf, "%u\n", i2c_smbus_read_byte(client));
+}
+
+static DEVICE_ATTR(read, S_IRUGO, show_read, NULL);
+
+static ssize_t show_write(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct pca9543_data *data = i2c_get_clientdata(to_i2c_client(dev));
+	return sprintf(buf, "%u\n", data->write);
+}
+
+static ssize_t set_write(struct device *dev, struct device_attribute *attr, const char *buf,
+			 size_t count)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct pca9543_data *data = i2c_get_clientdata(client);
+	unsigned long val = simple_strtoul(buf, NULL, 10);
+
+	if (val > 0xff)
+		return -EINVAL;
+
+	data->write = val;
+	i2c_smbus_write_byte(client, data->write);
+	return count;
+}
+
+static DEVICE_ATTR(write, S_IWUSR | S_IRUGO, show_write, set_write);
+
+static struct attribute *pca9543_attributes[] = {
+	&dev_attr_read.attr,
+	&dev_attr_write.attr,
+	NULL
+};
+
+static const struct attribute_group pca9543_attr_group = {
+	.attrs = pca9543_attributes,
+};
+
+/*
+ * Real code
+ */
+
+static int pca9543_attach_adapter(struct i2c_adapter *adapter)
+{
+	return i2c_probe(adapter, &addr_data, pca9543_detect);
+}
+
+/* This function is called by i2c_probe */
+static int pca9543_detect(struct i2c_adapter *adapter, int address, int kind)
+{
+	struct i2c_client *new_client;
+	struct pca9543_data *data;
+	int err = 0;
+	const char *client_name = "pca9543";
+
+	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
+		goto exit;
+
+	/* OK. For now, we presume we have a valid client. We now create the
+	   client structure, even though we cannot fill it completely yet. */
+	if (!(data = kzalloc(sizeof(struct pca9543_data), GFP_KERNEL))) {
+		err = -ENOMEM;
+		goto exit;
+	}
+
+	new_client = &data->client;
+	i2c_set_clientdata(new_client, data);
+	new_client->addr = address;
+	new_client->adapter = adapter;
+	new_client->driver = &pca9543_driver;
+	new_client->flags = 0;
+
+	/* Now, we would do the remaining detection. But the PCF8574 is plainly
+	   impossible to detect! Stupid chip. */
+
+	/* Fill in the remaining client fields and put it into the global list */
+	strlcpy(new_client->name, client_name, I2C_NAME_SIZE);
+
+	/* Tell the I2C layer a new client has arrived */
+	if ((err = i2c_attach_client(new_client)))
+		goto exit_free;
+
+
+	/* Register sysfs hooks */
+	err = sysfs_create_group(&new_client->dev.kobj, &pca9543_attr_group);
+	if (err)
+		goto exit_detach;
+	return 0;
+
+      exit_detach:
+	i2c_detach_client(new_client);
+      exit_free:
+	kfree(data);
+      exit:
+	return err;
+}
+
+static int pca9543_detach_client(struct i2c_client *client)
+{
+	int err;
+
+	sysfs_remove_group(&client->dev.kobj, &pca9543_attr_group);
+
+	if ((err = i2c_detach_client(client)))
+		return err;
+
+	kfree(i2c_get_clientdata(client));
+	return 0;
+}
+
+
+static int __init pca9543_init(void)
+{
+	return i2c_add_driver(&pca9543_driver);
+}
+
+static void __exit pca9543_exit(void)
+{
+	i2c_del_driver(&pca9543_driver);
+}
+
+
+MODULE_AUTHOR
+    ("Frodo Looijaard <frodol-B0qZmFHriGg@public.gmane.org>, "
+     "Philip Edelbrock <phil-KXOFo5pg7o1l57MIdRCFDg@public.gmane.org>, "
+     "Dan Eaton <dan.eaton-RtyX3GHucphnQYSypqKXDg@public.gmane.org> "
+     "and Aurelien Jarno <aurelien-rXXEIb44qovR7s880joybQ@public.gmane.org>"
+     "Michael Hennerich <hennerich-ZG0+EudsQA8dtHy/vicBwGD2FQJk+8+b@public.gmane.org>");
+MODULE_DESCRIPTION("PCA9543 driver");
+MODULE_LICENSE("GPL");
+
+module_init(pca9543_init);
+module_exit(pca9543_exit);
diff --git a/include/linux/i2c-id.h b/include/linux/i2c-id.h
index adfcf71..72c246a 100644
--- a/include/linux/i2c-id.h
+++ b/include/linux/i2c-id.h
@@ -95,6 +95,7 @@
 
 #define I2C_DRIVERID_OV7670 1048	/* Omnivision 7670 camera */
 #define I2C_DRIVERID_AD5252 1049
+#define I2C_DRIVERID_PCF8575 1050
 
 /*
  * ---- Adapter types ----------------------------------------------------
-- 
1.5.5


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