i2c/chips: Remove deprecated pcf8574 driver
The pcf8574 driver in drivers/i2c/chips which just exports its register to sysfs is superseded by drivers/gpio/pcf857x.c which properly uses the gpiolib. As this driver has been deprecated for more than a year, finally remove it. Signed-off-by: Wolfram Sang <w.sang@pengutronix.de> Cc: Aurelien Jarno <aurelien@aurel32.net> Signed-off-by: Jean Delvare <khali@linux-fr.org>
This commit is contained in:
parent
732d481127
commit
e7c5c49ecd
4 changed files with 0 additions and 298 deletions
|
@ -1,65 +0,0 @@
|
|||
Kernel driver pcf8574
|
||||
=====================
|
||||
|
||||
Supported chips:
|
||||
* Philips PCF8574
|
||||
Prefix: 'pcf8574'
|
||||
Addresses scanned: none
|
||||
Datasheet: Publicly available at the Philips Semiconductors website
|
||||
http://www.semiconductors.philips.com/pip/PCF8574P.html
|
||||
|
||||
* Philips PCF8574A
|
||||
Prefix: 'pcf8574a'
|
||||
Addresses scanned: none
|
||||
Datasheet: Publicly available at the Philips Semiconductors website
|
||||
http://www.semiconductors.philips.com/pip/PCF8574P.html
|
||||
|
||||
Authors:
|
||||
Frodo Looijaard <frodol@dds.nl>,
|
||||
Philip Edelbrock <phil@netroedge.com>,
|
||||
Dan Eaton <dan.eaton@rocketlogix.com>,
|
||||
Aurelien Jarno <aurelien@aurel32.net>,
|
||||
Jean Delvare <khali@linux-fr.org>,
|
||||
|
||||
|
||||
Description
|
||||
-----------
|
||||
The PCF8574(A) 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 16
|
||||
separate devices (8 x PCF8574 and 8 x PCF8574A).
|
||||
|
||||
This device consists of a quasi-bidirectional port. Each of the eight I/Os
|
||||
can be independently used as an input or output. To setup an I/O as an
|
||||
input, you have to write a 1 to the corresponding output.
|
||||
|
||||
For more informations see the datasheet.
|
||||
|
||||
|
||||
Accessing PCF8574(A) via /sys interface
|
||||
-------------------------------------
|
||||
|
||||
The PCF8574(A) is plainly impossible to detect ! Stupid chip.
|
||||
So, you have to pass the I2C bus and address of the installed PCF857A
|
||||
and PCF8574A devices explicitly to the driver at load time via the
|
||||
force=... parameter.
|
||||
|
||||
On detection (i.e. insmod, modprobe et al.), directories are being
|
||||
created for each detected PCF8574(A):
|
||||
|
||||
/sys/bus/i2c/devices/<0>-<1>/
|
||||
where <0> is the bus the chip was detected on (e. g. i2c-0)
|
||||
and <1> the chip address ([20..27] or [38..3f]):
|
||||
|
||||
(example: /sys/bus/i2c/devices/1-0020/)
|
||||
|
||||
Inside these directories, there are two files each:
|
||||
read and write (and one file with chip name).
|
||||
|
||||
The read file is read-only. Reading gives you the current I/O input
|
||||
if the corresponding output is set as 1, otherwise the current output
|
||||
value, that is to say 0.
|
||||
|
||||
The write file is read/write. Writing a value outputs it on the I/O
|
||||
port. Reading returns the last written value. As it is not possible
|
||||
to read this value from the chip, you need to write at least once to
|
||||
this file before you can read back from it.
|
|
@ -16,23 +16,6 @@ config DS1682
|
|||
This driver can also be built as a module. If so, the module
|
||||
will be called ds1682.
|
||||
|
||||
config SENSORS_PCF8574
|
||||
tristate "Philips PCF8574 and PCF8574A (DEPRECATED)"
|
||||
depends on EXPERIMENTAL && GPIO_PCF857X = "n"
|
||||
default n
|
||||
help
|
||||
If you say yes here you get support for Philips PCF8574 and
|
||||
PCF8574A chips. These chips are 8-bit I/O expanders for the I2C bus.
|
||||
|
||||
This driver can also be built as a module. If so, the module
|
||||
will be called pcf8574.
|
||||
|
||||
This driver is deprecated and will be dropped soon. Use
|
||||
drivers/gpio/pcf857x.c instead.
|
||||
|
||||
These devices are hard to detect and rarely found on mainstream
|
||||
hardware. If unsure, say N.
|
||||
|
||||
config SENSORS_TSL2550
|
||||
tristate "Taos TSL2550 ambient light sensor"
|
||||
depends on EXPERIMENTAL
|
||||
|
|
|
@ -11,7 +11,6 @@
|
|||
#
|
||||
|
||||
obj-$(CONFIG_DS1682) += ds1682.o
|
||||
obj-$(CONFIG_SENSORS_PCF8574) += pcf8574.o
|
||||
obj-$(CONFIG_SENSORS_TSL2550) += tsl2550.o
|
||||
|
||||
ifeq ($(CONFIG_I2C_DEBUG_CHIP),y)
|
||||
|
|
|
@ -1,215 +0,0 @@
|
|||
/*
|
||||
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: none, device can't be detected */
|
||||
static const unsigned short normal_i2c[] = { I2C_CLIENT_END };
|
||||
|
||||
/* Insmod parameters */
|
||||
I2C_CLIENT_INSMOD_2(pcf8574, pcf8574a);
|
||||
|
||||
/* Each client has this additional data */
|
||||
struct pcf8574_data {
|
||||
int write; /* Remember last written value */
|
||||
};
|
||||
|
||||
static void pcf8574_init_client(struct i2c_client *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));
|
||||
|
||||
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,
|
||||
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);
|
||||
|
||||
static struct attribute *pcf8574_attributes[] = {
|
||||
&dev_attr_read.attr,
|
||||
&dev_attr_write.attr,
|
||||
NULL
|
||||
};
|
||||
|
||||
static const struct attribute_group pcf8574_attr_group = {
|
||||
.attrs = pcf8574_attributes,
|
||||
};
|
||||
|
||||
/*
|
||||
* Real code
|
||||
*/
|
||||
|
||||
/* Return 0 if detection is successful, -ENODEV otherwise */
|
||||
static int pcf8574_detect(struct i2c_client *client, int kind,
|
||||
struct i2c_board_info *info)
|
||||
{
|
||||
struct i2c_adapter *adapter = client->adapter;
|
||||
const char *client_name;
|
||||
|
||||
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
|
||||
return -ENODEV;
|
||||
|
||||
/* 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 (client->addr >= 0x38 && client->addr <= 0x3f)
|
||||
kind = pcf8574a;
|
||||
else
|
||||
kind = pcf8574;
|
||||
}
|
||||
|
||||
if (kind == pcf8574a)
|
||||
client_name = "pcf8574a";
|
||||
else
|
||||
client_name = "pcf8574";
|
||||
strlcpy(info->type, client_name, I2C_NAME_SIZE);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int pcf8574_probe(struct i2c_client *client,
|
||||
const struct i2c_device_id *id)
|
||||
{
|
||||
struct pcf8574_data *data;
|
||||
int err;
|
||||
|
||||
data = kzalloc(sizeof(struct pcf8574_data), GFP_KERNEL);
|
||||
if (!data) {
|
||||
err = -ENOMEM;
|
||||
goto exit;
|
||||
}
|
||||
|
||||
i2c_set_clientdata(client, data);
|
||||
|
||||
/* Initialize the PCF8574 chip */
|
||||
pcf8574_init_client(client);
|
||||
|
||||
/* Register sysfs hooks */
|
||||
err = sysfs_create_group(&client->dev.kobj, &pcf8574_attr_group);
|
||||
if (err)
|
||||
goto exit_free;
|
||||
return 0;
|
||||
|
||||
exit_free:
|
||||
kfree(data);
|
||||
exit:
|
||||
return err;
|
||||
}
|
||||
|
||||
static int pcf8574_remove(struct i2c_client *client)
|
||||
{
|
||||
sysfs_remove_group(&client->dev.kobj, &pcf8574_attr_group);
|
||||
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 = -EAGAIN;
|
||||
}
|
||||
|
||||
static const struct i2c_device_id pcf8574_id[] = {
|
||||
{ "pcf8574", 0 },
|
||||
{ "pcf8574a", 0 },
|
||||
{ }
|
||||
};
|
||||
|
||||
static struct i2c_driver pcf8574_driver = {
|
||||
.driver = {
|
||||
.name = "pcf8574",
|
||||
},
|
||||
.probe = pcf8574_probe,
|
||||
.remove = pcf8574_remove,
|
||||
.id_table = pcf8574_id,
|
||||
|
||||
.detect = pcf8574_detect,
|
||||
.address_data = &addr_data,
|
||||
};
|
||||
|
||||
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);
|
Loading…
Reference in a new issue