![Jean Delvare](/assets/img/avatar_default.png)
The only thing left in i2c-sensor.h are module parameter definition macros. It's only an extension of what i2c.h offers, and this extension is not sensors-specific. As a matter of fact, a few non-sensors drivers use them. So we better merge them in i2c.h, and get rid of i2c-sensor.h altogether. Signed-off-by: Jean Delvare <khali@linux-fr> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
223 lines
6.2 KiB
C
223 lines
6.2 KiB
C
/*
|
|
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>
|
|
Ported to Linux 2.6 by Aurelien Jarno <aurel32@debian.org> with
|
|
the help of Jean Delvare <khali@linux-fr.org>
|
|
|
|
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 PCF8574:
|
|
|
|
* The PCF8574 is an 8-bit I/O expander for the I2C bus produced by
|
|
Philips Semiconductors. It is designed to provide a byte I2C
|
|
interface to up to 8 separate devices.
|
|
|
|
* The PCF8574 appears as a very simple SMBus device which can be
|
|
read from or written to with SMBUS byte read/write accesses.
|
|
|
|
--Dan
|
|
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/init.h>
|
|
#include <linux/slab.h>
|
|
#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 };
|
|
|
|
/* 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 */
|
|
};
|
|
|
|
static int pcf8574_attach_adapter(struct i2c_adapter *adapter);
|
|
static int pcf8574_detect(struct i2c_adapter *adapter, int address, int kind);
|
|
static int pcf8574_detach_client(struct i2c_client *client);
|
|
static void pcf8574_init_client(struct i2c_client *client);
|
|
|
|
/* This is the driver that will be inserted */
|
|
static struct i2c_driver pcf8574_driver = {
|
|
.owner = THIS_MODULE,
|
|
.name = "pcf8574",
|
|
.id = I2C_DRIVERID_PCF8574,
|
|
.flags = I2C_DF_NOTIFY,
|
|
.attach_adapter = pcf8574_attach_adapter,
|
|
.detach_client = pcf8574_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 pcf8574_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 pcf8574_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);
|
|
|
|
/*
|
|
* Real code
|
|
*/
|
|
|
|
static int pcf8574_attach_adapter(struct i2c_adapter *adapter)
|
|
{
|
|
return i2c_probe(adapter, &addr_data, pcf8574_detect);
|
|
}
|
|
|
|
/* This function is called by i2c_probe */
|
|
int pcf8574_detect(struct i2c_adapter *adapter, int address, int kind)
|
|
{
|
|
struct i2c_client *new_client;
|
|
struct pcf8574_data *data;
|
|
int err = 0;
|
|
const char *client_name = "";
|
|
|
|
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 = kmalloc(sizeof(struct pcf8574_data), GFP_KERNEL))) {
|
|
err = -ENOMEM;
|
|
goto exit;
|
|
}
|
|
memset(data, 0, sizeof(struct pcf8574_data));
|
|
|
|
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;
|
|
|
|
/* Now, we would do the remaining detection. But the PCF8574 is plainly
|
|
impossible to detect! Stupid chip. */
|
|
|
|
/* Determine the chip type */
|
|
if (kind <= 0) {
|
|
if (address >= 0x38 && address <= 0x3f)
|
|
kind = pcf8574a;
|
|
else
|
|
kind = pcf8574;
|
|
}
|
|
|
|
if (kind == pcf8574a)
|
|
client_name = "pcf8574a";
|
|
else
|
|
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);
|
|
|
|
/* Tell the I2C layer a new client has arrived */
|
|
if ((err = i2c_attach_client(new_client)))
|
|
goto exit_free;
|
|
|
|
/* Initialize the PCF8574 chip */
|
|
pcf8574_init_client(new_client);
|
|
|
|
/* Register sysfs hooks */
|
|
device_create_file(&new_client->dev, &dev_attr_read);
|
|
device_create_file(&new_client->dev, &dev_attr_write);
|
|
return 0;
|
|
|
|
/* OK, this is not exactly good programming practice, usually. But it is
|
|
very code-efficient in this case. */
|
|
|
|
exit_free:
|
|
kfree(data);
|
|
exit:
|
|
return err;
|
|
}
|
|
|
|
static int pcf8574_detach_client(struct i2c_client *client)
|
|
{
|
|
int err;
|
|
|
|
if ((err = i2c_detach_client(client)))
|
|
return err;
|
|
|
|
kfree(i2c_get_clientdata(client));
|
|
return 0;
|
|
}
|
|
|
|
/* Called when we have found a new PCF8574. */
|
|
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);
|
|
}
|
|
|
|
static int __init pcf8574_init(void)
|
|
{
|
|
return i2c_add_driver(&pcf8574_driver);
|
|
}
|
|
|
|
static void __exit pcf8574_exit(void)
|
|
{
|
|
i2c_del_driver(&pcf8574_driver);
|
|
}
|
|
|
|
|
|
MODULE_AUTHOR
|
|
("Frodo Looijaard <frodol@dds.nl>, "
|
|
"Philip Edelbrock <phil@netroedge.com>, "
|
|
"Dan Eaton <dan.eaton@rocketlogix.com> "
|
|
"and Aurelien Jarno <aurelien@aurel32.net>");
|
|
MODULE_DESCRIPTION("PCF8574 driver");
|
|
MODULE_LICENSE("GPL");
|
|
|
|
module_init(pcf8574_init);
|
|
module_exit(pcf8574_exit);
|