Greg KH
2005-06-22T07:27:48Z

[PATCH] I2C: add new pca9539 driver

This is an i2c driver for the Philips PCA9539 (16 bit I/O port).
It uses the new i2c-sysfs interfaces.
The patch includes documentation.
It depends on the patch that renames "i2c-sysfs.h" to "hwmon-sysfs.h"

Signed-off-by: Ben Gardner <bgardner@wabtec.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
commit 69dd204b6b45987dbf9ce7058cd238d355865281
tree e033f9697109d4a411e5c6707b0e6991e00ede7f
parent 10c08f8100ee2c4d27b862635574cdf4ef439e67
author bgardner@wabtec.com <bgardner@wabtec.com> Tue, 07 Jun 2005 08:55:38 -0500
committer Greg Kroah-Hartman <gregkh@suse.de> Tue, 21 Jun 2005 21:52:05 -0700

Documentation/i2c/chips/pca9539 | 47 ++++++++++
drivers/i2c/chips/Kconfig | 10 ++
drivers/i2c/chips/Makefile | 1
drivers/i2c/chips/pca9539.c | 192 +++++++++++++++++++++++++++++++++++++++
4 files changed, 250 insertions(+), 0 deletions(-)

diff --git a/Documentation/i2c/chips/pca9539 b/Documentation/i2c/chips/pca9539
new file mode 100644
--- /dev/null
+++ b/Documentation/i2c/chips/pca9539
@@ -0,0 +1,47 @@
+Kernel driver pca9539
+=====================
+
+Supported chips:
+ * Philips PCA9539
+ Prefix: 'pca9539'
+ Addresses scanned: 0x74 - 0x77
+ Datasheet:
+ http://www.semiconductors.philips.com/acrobat/datasheets/PCA9539_2.pdf
+
+Author: Ben Gardner <bgardner@wabtec.com>
+
+
+Description
+-----------
+
+The Philips PCA9539 is a 16 bit low power I/O device.
+All 16 lines can be individually configured as an input or output.
+The input sense can also be inverted.
+The 16 lines are split between two bytes.
+
+
+Sysfs entries
+-------------
+
+Each is a byte that maps to the 8 I/O bits.
+A '0' suffix is for bits 0-7, while '1' is for bits 8-15.
+
+input[01] - read the current value
+output[01] - sets the output value
+direction[01] - direction of each bit: 1=input, 0=output
+invert[01] - toggle the input bit sense
+
+input reads the actual state of the line and is always available.
+The direction defaults to input for all channels.
+
+
+General Remarks
+---------------
+
+Note that each output, direction, and invert entry controls 8 lines.
+You should use the read, modify, write sequence.
+For example. to set output bit 0 of 1.
+ val=$(cat output0)
+ val=$(( $val | 1 ))
+ echo $val > output0
+
diff --git a/drivers/i2c/chips/Kconfig b/drivers/i2c/chips/Kconfig
--- a/drivers/i2c/chips/Kconfig
+++ b/drivers/i2c/chips/Kconfig
@@ -440,6 +440,16 @@ config SENSORS_PCF8574
This driver can also be built as a module. If so, the module
will be called pcf8574.

+config SENSORS_PCA9539
+ tristate "Philips PCA9539 16-bit I/O port"
+ depends on I2C && EXPERIMENTAL
+ help
+ If you say yes here you get support for the Philips PCA9539
+ 16-bit I/O port.
+
+ This driver can also be built as a module. If so, the module
+ will be called pca9539.
+
config SENSORS_PCF8591
tristate "Philips PCF8591"
depends on I2C && EXPERIMENTAL
diff --git a/drivers/i2c/chips/Makefile b/drivers/i2c/chips/Makefile
--- a/drivers/i2c/chips/Makefile
+++ b/drivers/i2c/chips/Makefile
@@ -35,6 +35,7 @@ obj-$(CONFIG_SENSORS_MAX1619) += max1619
obj-$(CONFIG_SENSORS_MAX6875) += max6875.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
diff --git a/drivers/i2c/chips/pca9539.c b/drivers/i2c/chips/pca9539.c
new file mode 100644
--- /dev/null
+++ b/drivers/i2c/chips/pca9539.c
@@ -0,0 +1,192 @@
+/*
+ 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>
+#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_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 = {
+ .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 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_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_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: 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))) {
+ dev_err(&client->dev, "Client deregistration failed.\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@wabtec.com>");
+MODULE_DESCRIPTION("PCA9539 driver");
+MODULE_LICENSE("GPL");
+
+module_init(pca9539_init);
+module_exit(pca9539_exit);
+