diff options
Diffstat (limited to 'drivers/i2c/chips/pca9539.c')
| -rw-r--r-- | drivers/i2c/chips/pca9539.c | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/drivers/i2c/chips/pca9539.c b/drivers/i2c/chips/pca9539.c new file mode 100644 index 000000000000..9f3ad45daae2 --- /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); + |
