--- /dev/null
+/*
+ pca9539.c - 16-bit I/O port with interrupt and reset
+
+ Copyright (C) 2005 Ben Gardner <bgardner@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/hwmon-sysfs.h>
+
+/* Addresses to scan */
+static unsigned short normal_i2c[] = {0x74, 0x75, 0x76, 0x77, I2C_CLIENT_END};
+
+/* Insmod parameters */
+I2C_CLIENT_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_DIRECTION_0 = 6,
+ PCA9539_DIRECTION_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 = {
+ .driver = {
+ .name = "pca9539",
+ },
+ .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 i2c_client *client = to_i2c_client(dev);
+ return sprintf(buf, "%d\n", i2c_smbus_read_byte_data(client,
+ 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 i2c_client *client = to_i2c_client(dev);
+ unsigned long val = simple_strtoul(buf, NULL, 0);
+ if (val > 0xff)
+ return -EINVAL;
+ i2c_smbus_write_byte_data(client, psa->index, val);
+ return count;
+}
+
+/* Define the device attributes */
+
+#define PCA9539_ENTRY_RO(name, cmd_idx) \
+ static SENSOR_DEVICE_ATTR(name, S_IRUGO, pca9539_show, NULL, cmd_idx)
+
+#define PCA9539_ENTRY_RW(name, cmd_idx) \
+ static SENSOR_DEVICE_ATTR(name, S_IRUGO | S_IWUSR, pca9539_show, \
+ pca9539_store, cmd_idx)
+
+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(direction0, PCA9539_DIRECTION_0);
+PCA9539_ENTRY_RW(direction1, PCA9539_DIRECTION_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_direction0.dev_attr.attr,
+ &sensor_dev_attr_direction1.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_probe(adapter, &addr_data, pca9539_detect);
+}
+
+/* This function is called by i2c_probe */
+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_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 = kzalloc(sizeof(struct pca9539_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 = &pca9539_driver;
+ 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))
+ 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);
+
+ return 0;
+
+exit_kfree:
+ kfree(data);
+exit:
+ return err;
+}
+
+static int pca9539_detach_client(struct i2c_client *client)
+{
+ int err;
+
+ if ((err = i2c_detach_client(client)))
+ 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@wabtec.com>");
+MODULE_DESCRIPTION("PCA9539 driver");
+MODULE_LICENSE("GPL");
+
+module_init(pca9539_init);
+module_exit(pca9539_exit);
+
git://git.onelab.eu / linux-2.6.git / blobdiff