[PATCH 2.6.12-rc5-mm2] pca9539: new i2c drvier (retry)

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Please ignore the previous patch -- I had left out the Makefile and
Kconfig changes.

This is a driver for the PCA9539, a 16 bit digital I/O chip.
It uses the new i2c-sysfs interfaces.

Signed-off-by: Ben Gardner <bgardner at wabtec.com>

--- linux-2.6.12-rc5-mm2-clean/drivers/i2c/chips/pca9539.c
1969-12-31 18:00:00.000000000 -0600
+++ linux-2.6.12-rc5-mm2-pca9539/drivers/i2c/chips/pca9539.c
2005-06-03 15:15:02.000000000 -0500
@@ -0,0 +1,188 @@
+/*
+    pca9539.c - 16 port digital I/O with interrupt and reset
+    
+    Copyright (C) 2005 Ben Gardner <bgardner at wabtec.com>
+
+    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.
+*/
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/i2c-sysfs.h>
+#include <linux/i2c-sensor.h>
+
+/* Addresses to scan */
+static unsigned short normal_i2c[] = { 0x74, 0x75, 0x76, 0x77,
I2C_CLIENT_END };
+static unsigned int normal_isa[] = { I2C_CLIENT_ISA_END };
+
+/* Insmod parameters */
+SENSORS_INSMOD_1(pca9539);
+
+enum pca9539_cmd
+{
+	PCA9539_INPUT_0 = 0,
+	PCA9539_INPUT_1 = 1,
+	PCA9539_OUTPUT_0 = 2,
+	PCA9539_OUTPUT_1 = 3,
+	PCA9539_INVERT_0 = 4,
+	PCA9539_INVERT_1 = 5,
+	PCA9539_CONFIG_0 = 6,
+	PCA9539_CONFIG_1 = 7
+};
+
+static int pca9539_attach_adapter(struct i2c_adapter *adapter);
+static int pca9539_detect(struct i2c_adapter *adapter, int address, int
kind);
+static int pca9539_detach_client(struct i2c_client *client);
+
+/* This is the driver that will be inserted */
+static struct i2c_driver pca9539_driver = {
+	.owner		= THIS_MODULE,
+	.name		= "pca9539",
+	.flags		= I2C_DF_NOTIFY,
+	.attach_adapter	= pca9539_attach_adapter,
+	.detach_client	= pca9539_detach_client,
+};
+
+struct pca9539_data {
+	struct i2c_client client;
+};
+
+/* following are the sysfs callback functions */
+static ssize_t pca9539_show(struct device *dev, struct device_attribute
*attr,
+			    char *buf)
+{
+	struct sensor_device_attribute *psa = to_sensor_dev_attr(attr);
+	struct pca9539_data *data =
i2c_get_clientdata(to_i2c_client(dev));
+	return sprintf(buf, "%d\n",
i2c_smbus_read_byte_data(&data->client, (u8)psa->index));
+}
+
+static ssize_t pca9539_store(struct device *dev, struct
device_attribute *attr,
+			     const char *buf, size_t count)
+{
+	struct sensor_device_attribute *psa = to_sensor_dev_attr(attr);
+	struct pca9539_data *data =
i2c_get_clientdata(to_i2c_client(dev));
+	u8 val = simple_strtoul(buf, NULL, 0);
+	i2c_smbus_write_byte_data(&data->client, (u8)psa->index, val);
+	return count;
+}
+
+/* Define the device attributes */
+
+#define PCA9539_ENTRY_RO(name,enum_name)	\
+	static
SENSOR_DEVICE_ATTR(name,S_IRUGO,pca9539_show,NULL,enum_name)
+
+#define PCA9539_ENTRY_RW(name,enum_name)	\
+	static
SENSOR_DEVICE_ATTR(name,S_IRUGO|S_IWUSR,pca9539_show,pca9539_store,enum_
name)
+
+PCA9539_ENTRY_RO(input0,  PCA9539_INPUT_0);
+PCA9539_ENTRY_RO(input1,  PCA9539_INPUT_1);
+PCA9539_ENTRY_RW(output0, PCA9539_OUTPUT_0);
+PCA9539_ENTRY_RW(output1, PCA9539_OUTPUT_1);
+PCA9539_ENTRY_RW(invert0, PCA9539_INVERT_0);
+PCA9539_ENTRY_RW(invert1, PCA9539_INVERT_1);
+PCA9539_ENTRY_RW(config0, PCA9539_CONFIG_0);
+PCA9539_ENTRY_RW(config1, PCA9539_CONFIG_1);
+
+static struct attribute *pca9539_attributes[] = {
+	&sensor_dev_attr_input0.dev_attr.attr,
+	&sensor_dev_attr_input1.dev_attr.attr,
+	&sensor_dev_attr_output0.dev_attr.attr,
+	&sensor_dev_attr_output1.dev_attr.attr,
+	&sensor_dev_attr_invert0.dev_attr.attr,
+	&sensor_dev_attr_invert1.dev_attr.attr,
+	&sensor_dev_attr_config0.dev_attr.attr,
+	&sensor_dev_attr_config1.dev_attr.attr,
+	NULL
+};
+
+static struct attribute_group pca9539_defattr_group = {
+	.attrs = pca9539_attributes,
+};
+
+static int pca9539_attach_adapter(struct i2c_adapter *adapter)
+{
+	return i2c_detect(adapter, &addr_data, pca9539_detect);
+}
+
+/* This function is called by i2c_detect */
+static int pca9539_detect(struct i2c_adapter *adapter, int address, int
kind)
+{
+	struct i2c_client *new_client;
+	struct pca9539_data *data;
+	int err = 0;
+
+	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE
+				     | I2C_FUNC_SMBUS_WRITE_BYTE_DATA
+				     | I2C_FUNC_SMBUS_READ_BYTE_DATA))
+		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 = kmalloc(sizeof(struct pca9539_data), GFP_KERNEL)))
{
+		err = -ENOMEM;
+		goto exit;
+	}
+	memset(data, 0, sizeof(struct pca9539_data));
+	
+	new_client = &data->client;
+	i2c_set_clientdata(new_client, data);
+	new_client->addr = address;
+	new_client->adapter = adapter;
+	new_client->driver = &pca9539_driver;
+	new_client->flags = 0;
+
+	/* Detection: not sure how to do that... 
+	 * possibility: toggle the value read from invert0 and see if
input0
+	 * changes polarity. 
+	 * However, if the inputs are changing, this won't work.
+	 */
+	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 */
+	return sysfs_create_group(&new_client->dev.kobj,
&pca9539_defattr_group);
+
+exit_kfree:
+	kfree(data);
+exit:
+	return err;
+}
+
+static int pca9539_detach_client(struct i2c_client *client)
+{
+	int err;
+
+	if ((err = i2c_detach_client(client))) {
+		dev_err(&client->dev,
+			"Client deregistration failed, client not
detached.\n");
+		return err;
+	}
+
+	kfree(i2c_get_clientdata(client));
+	return 0;
+}
+
+static int __init pca9539_init(void)
+{
+	return i2c_add_driver(&pca9539_driver);
+}
+
+static void __exit pca9539_exit(void)
+{
+	i2c_del_driver(&pca9539_driver);
+}
+
+MODULE_AUTHOR("Ben Gardner <bgardner at wabtec.com>");
+MODULE_DESCRIPTION("PCA9539 driver");
+MODULE_LICENSE("GPL");
+
+module_init(pca9539_init);
+module_exit(pca9539_exit);
+
--- linux-2.6.12-rc5-mm2-clean/drivers/i2c/chips/Makefile
2005-06-01 14:29:17.000000000 -0500
+++ linux-2.6.12-rc5-mm2-pca9539/drivers/i2c/chips/Makefile
2005-06-03 12:09:41.000000000 -0500
@@ -34,6 +34,7 @@
 obj-$(CONFIG_SENSORS_MAX1619)	+= max1619.o
 obj-$(CONFIG_SENSORS_M41T00)	+= m41t00.o
 obj-$(CONFIG_SENSORS_PC87360)	+= pc87360.o
+obj-$(CONFIG_SENSORS_PCA9539)	+= pca9539.o
 obj-$(CONFIG_SENSORS_PCF8574)	+= pcf8574.o
 obj-$(CONFIG_SENSORS_PCF8591)	+= pcf8591.o
 obj-$(CONFIG_SENSORS_RTC8564)	+= rtc8564.o
--- linux-2.6.12-rc5-mm2-clean/drivers/i2c/chips/Kconfig
2005-06-01 14:29:17.000000000 -0500
+++ linux-2.6.12-rc5-mm2-pca9539/drivers/i2c/chips/Kconfig
2005-06-03 12:09:22.000000000 -0500
@@ -498,4 +498,14 @@
 	  This driver can also be built as a module.  If so, the module
 	  will be called m41t00.
 
+config SENSORS_PCA9539
+	tristate "PCA9539 16-bit digital IO"
+	depends on I2C && EXPERIMENTAL
+	help
+	  If you say yes here you get support for the PCA9539
+	  low power digital I/O with 16 bit.
+          
+	  This driver can also be built as a module.  If so, the module
+	  will be called pca9539.
+
 endmenu





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