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[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>
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47
Documentation/i2c/chips/pca9539
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47
Documentation/i2c/chips/pca9539
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Kernel driver pca9539
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=====================
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Supported chips:
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* Philips PCA9539
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Prefix: 'pca9539'
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Addresses scanned: 0x74 - 0x77
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Datasheet:
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http://www.semiconductors.philips.com/acrobat/datasheets/PCA9539_2.pdf
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Author: Ben Gardner <bgardner@wabtec.com>
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Description
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-----------
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The Philips PCA9539 is a 16 bit low power I/O device.
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All 16 lines can be individually configured as an input or output.
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The input sense can also be inverted.
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The 16 lines are split between two bytes.
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Sysfs entries
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-------------
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Each is a byte that maps to the 8 I/O bits.
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A '0' suffix is for bits 0-7, while '1' is for bits 8-15.
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input[01] - read the current value
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output[01] - sets the output value
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direction[01] - direction of each bit: 1=input, 0=output
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invert[01] - toggle the input bit sense
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input reads the actual state of the line and is always available.
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The direction defaults to input for all channels.
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General Remarks
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---------------
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Note that each output, direction, and invert entry controls 8 lines.
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You should use the read, modify, write sequence.
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For example. to set output bit 0 of 1.
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val=$(cat output0)
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val=$(( $val | 1 ))
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echo $val > output0
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@ -440,6 +440,16 @@ config SENSORS_PCF8574
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This driver can also be built as a module. If so, the module
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This driver can also be built as a module. If so, the module
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will be called pcf8574.
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will be called pcf8574.
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config SENSORS_PCA9539
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tristate "Philips PCA9539 16-bit I/O port"
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depends on I2C && EXPERIMENTAL
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help
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If you say yes here you get support for the Philips PCA9539
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16-bit I/O port.
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This driver can also be built as a module. If so, the module
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will be called pca9539.
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config SENSORS_PCF8591
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config SENSORS_PCF8591
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tristate "Philips PCF8591"
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tristate "Philips PCF8591"
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depends on I2C && EXPERIMENTAL
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depends on I2C && EXPERIMENTAL
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@ -35,6 +35,7 @@ obj-$(CONFIG_SENSORS_MAX1619) += max1619.o
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obj-$(CONFIG_SENSORS_MAX6875) += max6875.o
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obj-$(CONFIG_SENSORS_MAX6875) += max6875.o
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obj-$(CONFIG_SENSORS_M41T00) += m41t00.o
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obj-$(CONFIG_SENSORS_M41T00) += m41t00.o
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obj-$(CONFIG_SENSORS_PC87360) += pc87360.o
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obj-$(CONFIG_SENSORS_PC87360) += pc87360.o
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obj-$(CONFIG_SENSORS_PCA9539) += pca9539.o
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obj-$(CONFIG_SENSORS_PCF8574) += pcf8574.o
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obj-$(CONFIG_SENSORS_PCF8574) += pcf8574.o
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obj-$(CONFIG_SENSORS_PCF8591) += pcf8591.o
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obj-$(CONFIG_SENSORS_PCF8591) += pcf8591.o
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obj-$(CONFIG_SENSORS_RTC8564) += rtc8564.o
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obj-$(CONFIG_SENSORS_RTC8564) += rtc8564.o
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192
drivers/i2c/chips/pca9539.c
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drivers/i2c/chips/pca9539.c
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/*
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pca9539.c - 16-bit I/O port with interrupt and reset
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Copyright (C) 2005 Ben Gardner <bgardner@wabtec.com>
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; version 2 of the License.
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*/
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <linux/i2c.h>
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#include <linux/hwmon-sysfs.h>
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#include <linux/i2c-sensor.h>
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/* Addresses to scan */
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static unsigned short normal_i2c[] = {0x74, 0x75, 0x76, 0x77, I2C_CLIENT_END};
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static unsigned int normal_isa[] = {I2C_CLIENT_ISA_END};
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/* Insmod parameters */
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SENSORS_INSMOD_1(pca9539);
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enum pca9539_cmd
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{
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PCA9539_INPUT_0 = 0,
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PCA9539_INPUT_1 = 1,
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PCA9539_OUTPUT_0 = 2,
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PCA9539_OUTPUT_1 = 3,
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PCA9539_INVERT_0 = 4,
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PCA9539_INVERT_1 = 5,
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PCA9539_DIRECTION_0 = 6,
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PCA9539_DIRECTION_1 = 7,
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};
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static int pca9539_attach_adapter(struct i2c_adapter *adapter);
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static int pca9539_detect(struct i2c_adapter *adapter, int address, int kind);
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static int pca9539_detach_client(struct i2c_client *client);
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/* This is the driver that will be inserted */
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static struct i2c_driver pca9539_driver = {
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.owner = THIS_MODULE,
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.name = "pca9539",
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.flags = I2C_DF_NOTIFY,
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.attach_adapter = pca9539_attach_adapter,
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.detach_client = pca9539_detach_client,
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};
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struct pca9539_data {
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struct i2c_client client;
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};
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/* following are the sysfs callback functions */
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static ssize_t pca9539_show(struct device *dev, struct device_attribute *attr,
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char *buf)
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{
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struct sensor_device_attribute *psa = to_sensor_dev_attr(attr);
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struct i2c_client *client = to_i2c_client(dev);
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return sprintf(buf, "%d\n", i2c_smbus_read_byte_data(client,
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psa->index));
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}
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static ssize_t pca9539_store(struct device *dev, struct device_attribute *attr,
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const char *buf, size_t count)
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{
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struct sensor_device_attribute *psa = to_sensor_dev_attr(attr);
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struct i2c_client *client = to_i2c_client(dev);
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unsigned long val = simple_strtoul(buf, NULL, 0);
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if (val > 0xff)
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return -EINVAL;
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i2c_smbus_write_byte_data(client, psa->index, val);
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return count;
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}
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/* Define the device attributes */
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#define PCA9539_ENTRY_RO(name, cmd_idx) \
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static SENSOR_DEVICE_ATTR(name, S_IRUGO, pca9539_show, NULL, cmd_idx)
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#define PCA9539_ENTRY_RW(name, cmd_idx) \
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static SENSOR_DEVICE_ATTR(name, S_IRUGO | S_IWUSR, pca9539_show, \
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pca9539_store, cmd_idx)
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PCA9539_ENTRY_RO(input0, PCA9539_INPUT_0);
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PCA9539_ENTRY_RO(input1, PCA9539_INPUT_1);
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PCA9539_ENTRY_RW(output0, PCA9539_OUTPUT_0);
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PCA9539_ENTRY_RW(output1, PCA9539_OUTPUT_1);
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PCA9539_ENTRY_RW(invert0, PCA9539_INVERT_0);
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PCA9539_ENTRY_RW(invert1, PCA9539_INVERT_1);
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PCA9539_ENTRY_RW(direction0, PCA9539_DIRECTION_0);
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PCA9539_ENTRY_RW(direction1, PCA9539_DIRECTION_1);
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static struct attribute *pca9539_attributes[] = {
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&sensor_dev_attr_input0.dev_attr.attr,
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&sensor_dev_attr_input1.dev_attr.attr,
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&sensor_dev_attr_output0.dev_attr.attr,
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&sensor_dev_attr_output1.dev_attr.attr,
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&sensor_dev_attr_invert0.dev_attr.attr,
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&sensor_dev_attr_invert1.dev_attr.attr,
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&sensor_dev_attr_direction0.dev_attr.attr,
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&sensor_dev_attr_direction1.dev_attr.attr,
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NULL
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};
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static struct attribute_group pca9539_defattr_group = {
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.attrs = pca9539_attributes,
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};
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static int pca9539_attach_adapter(struct i2c_adapter *adapter)
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{
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return i2c_detect(adapter, &addr_data, pca9539_detect);
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}
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/* This function is called by i2c_detect */
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static int pca9539_detect(struct i2c_adapter *adapter, int address, int kind)
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{
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struct i2c_client *new_client;
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struct pca9539_data *data;
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int err = 0;
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if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
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goto exit;
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/* OK. For now, we presume we have a valid client. We now create the
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client structure, even though we cannot fill it completely yet. */
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if (!(data = kmalloc(sizeof(struct pca9539_data), GFP_KERNEL))) {
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err = -ENOMEM;
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goto exit;
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}
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memset(data, 0, sizeof(struct pca9539_data));
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new_client = &data->client;
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i2c_set_clientdata(new_client, data);
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new_client->addr = address;
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new_client->adapter = adapter;
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new_client->driver = &pca9539_driver;
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new_client->flags = 0;
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/* Detection: the pca9539 only has 8 registers (0-7).
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A read of 7 should succeed, but a read of 8 should fail. */
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if ((i2c_smbus_read_byte_data(new_client, 7) < 0) ||
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(i2c_smbus_read_byte_data(new_client, 8) >= 0))
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goto exit_kfree;
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strlcpy(new_client->name, "pca9539", I2C_NAME_SIZE);
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/* Tell the I2C layer a new client has arrived */
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if ((err = i2c_attach_client(new_client)))
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goto exit_kfree;
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/* Register sysfs hooks (don't care about failure) */
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sysfs_create_group(&new_client->dev.kobj, &pca9539_defattr_group);
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return 0;
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exit_kfree:
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kfree(data);
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exit:
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return err;
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}
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static int pca9539_detach_client(struct i2c_client *client)
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{
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int err;
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if ((err = i2c_detach_client(client))) {
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dev_err(&client->dev, "Client deregistration failed.\n");
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return err;
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}
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kfree(i2c_get_clientdata(client));
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return 0;
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}
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static int __init pca9539_init(void)
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{
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return i2c_add_driver(&pca9539_driver);
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}
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static void __exit pca9539_exit(void)
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{
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i2c_del_driver(&pca9539_driver);
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}
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MODULE_AUTHOR("Ben Gardner <bgardner@wabtec.com>");
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MODULE_DESCRIPTION("PCA9539 driver");
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MODULE_LICENSE("GPL");
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module_init(pca9539_init);
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module_exit(pca9539_exit);
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