/*
- pcf8574.c - Part of lm_sensors, Linux kernel modules for hardware
- monitoring
Copyright (c) 2000 Frodo Looijaard <frodol@dds.nl>,
Philip Edelbrock <phil@netroedge.com>,
Dan Eaton <dan.eaton@rocketlogix.com>
#include <linux/i2c.h>
/* Addresses to scan */
-static unsigned short normal_i2c[] = { 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
- 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
- I2C_CLIENT_END };
+static const unsigned short normal_i2c[] = {
+ 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
+ 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
+ I2C_CLIENT_END
+};
/* Insmod parameters */
I2C_CLIENT_INSMOD_2(pcf8574, pcf8574a);
-/* Initial values */
-#define PCF8574_INIT 255 /* All outputs on (input mode) */
-
/* Each client has this additional data */
struct pcf8574_data {
struct i2c_client client;
- u8 write; /* Remember last written value */
+ int write; /* Remember last written value */
};
static int pcf8574_attach_adapter(struct i2c_adapter *adapter);
.driver = {
.name = "pcf8574",
},
- .id = I2C_DRIVERID_PCF8574,
.attach_adapter = pcf8574_attach_adapter,
.detach_client = pcf8574_detach_client,
};
static ssize_t show_write(struct device *dev, struct device_attribute *attr, char *buf)
{
struct pcf8574_data *data = i2c_get_clientdata(to_i2c_client(dev));
- return sprintf(buf, "%u\n", data->write);
+
+ if (data->write < 0)
+ return data->write;
+
+ return sprintf(buf, "%d\n", data->write);
}
static ssize_t set_write(struct device *dev, struct device_attribute *attr, const char *buf,
/* This function is called by i2c_probe */
static int pcf8574_detect(struct i2c_adapter *adapter, int address, int kind)
{
- struct i2c_client *new_client;
+ struct i2c_client *client;
struct pcf8574_data *data;
int err = 0;
const char *client_name = "";
goto exit;
}
- new_client = &data->client;
- i2c_set_clientdata(new_client, data);
- new_client->addr = address;
- new_client->adapter = adapter;
- new_client->driver = &pcf8574_driver;
- new_client->flags = 0;
+ client = &data->client;
+ i2c_set_clientdata(client, data);
+ client->addr = address;
+ client->adapter = adapter;
+ client->driver = &pcf8574_driver;
/* Now, we would do the remaining detection. But the PCF8574 is plainly
impossible to detect! Stupid chip. */
client_name = "pcf8574";
/* Fill in the remaining client fields and put it into the global list */
- strlcpy(new_client->name, client_name, I2C_NAME_SIZE);
+ strlcpy(client->name, client_name, I2C_NAME_SIZE);
/* Tell the I2C layer a new client has arrived */
- if ((err = i2c_attach_client(new_client)))
+ if ((err = i2c_attach_client(client)))
goto exit_free;
/* Initialize the PCF8574 chip */
- pcf8574_init_client(new_client);
+ pcf8574_init_client(client);
/* Register sysfs hooks */
- err = sysfs_create_group(&new_client->dev.kobj, &pcf8574_attr_group);
+ err = sysfs_create_group(&client->dev.kobj, &pcf8574_attr_group);
if (err)
goto exit_detach;
return 0;
exit_detach:
- i2c_detach_client(new_client);
+ i2c_detach_client(client);
exit_free:
kfree(data);
exit:
static void pcf8574_init_client(struct i2c_client *client)
{
struct pcf8574_data *data = i2c_get_clientdata(client);
- data->write = PCF8574_INIT;
- i2c_smbus_write_byte(client, data->write);
+ data->write = -EAGAIN;
}
static int __init pcf8574_init(void)