1/* 2 pca9539.c - 16-bit I/O port with interrupt and reset 3 4 Copyright (C) 2005 Ben Gardner <bgardner@wabtec.com> 5 6 This program is free software; you can redistribute it and/or modify 7 it under the terms of the GNU General Public License as published by 8 the Free Software Foundation; version 2 of the License. 9*/ 10 11#include <linux/module.h> 12#include <linux/init.h> 13#include <linux/slab.h> 14#include <linux/i2c.h> 15#include <linux/hwmon-sysfs.h> 16 17/* Addresses to scan */ 18static unsigned short normal_i2c[] = {0x74, 0x75, 0x76, 0x77, I2C_CLIENT_END}; 19 20/* Insmod parameters */ 21I2C_CLIENT_INSMOD_1(pca9539); 22 23enum pca9539_cmd 24{ 25 PCA9539_INPUT_0 = 0, 26 PCA9539_INPUT_1 = 1, 27 PCA9539_OUTPUT_0 = 2, 28 PCA9539_OUTPUT_1 = 3, 29 PCA9539_INVERT_0 = 4, 30 PCA9539_INVERT_1 = 5, 31 PCA9539_DIRECTION_0 = 6, 32 PCA9539_DIRECTION_1 = 7, 33}; 34 35static int pca9539_attach_adapter(struct i2c_adapter *adapter); 36static int pca9539_detect(struct i2c_adapter *adapter, int address, int kind); 37static int pca9539_detach_client(struct i2c_client *client); 38 39/* This is the driver that will be inserted */ 40static struct i2c_driver pca9539_driver = { 41 .driver = { 42 .name = "pca9539", 43 }, 44 .attach_adapter = pca9539_attach_adapter, 45 .detach_client = pca9539_detach_client, 46}; 47 48struct pca9539_data { 49 struct i2c_client client; 50}; 51 52/* following are the sysfs callback functions */ 53static ssize_t pca9539_show(struct device *dev, struct device_attribute *attr, 54 char *buf) 55{ 56 struct sensor_device_attribute *psa = to_sensor_dev_attr(attr); 57 struct i2c_client *client = to_i2c_client(dev); 58 return sprintf(buf, "%d\n", i2c_smbus_read_byte_data(client, 59 psa->index)); 60} 61 62static ssize_t pca9539_store(struct device *dev, struct device_attribute *attr, 63 const char *buf, size_t count) 64{ 65 struct sensor_device_attribute *psa = to_sensor_dev_attr(attr); 66 struct i2c_client *client = to_i2c_client(dev); 67 unsigned long val = simple_strtoul(buf, NULL, 0); 68 if (val > 0xff) 69 return -EINVAL; 70 i2c_smbus_write_byte_data(client, psa->index, val); 71 return count; 72} 73 74/* Define the device attributes */ 75 76#define PCA9539_ENTRY_RO(name, cmd_idx) \ 77 static SENSOR_DEVICE_ATTR(name, S_IRUGO, pca9539_show, NULL, cmd_idx) 78 79#define PCA9539_ENTRY_RW(name, cmd_idx) \ 80 static SENSOR_DEVICE_ATTR(name, S_IRUGO | S_IWUSR, pca9539_show, \ 81 pca9539_store, cmd_idx) 82 83PCA9539_ENTRY_RO(input0, PCA9539_INPUT_0); 84PCA9539_ENTRY_RO(input1, PCA9539_INPUT_1); 85PCA9539_ENTRY_RW(output0, PCA9539_OUTPUT_0); 86PCA9539_ENTRY_RW(output1, PCA9539_OUTPUT_1); 87PCA9539_ENTRY_RW(invert0, PCA9539_INVERT_0); 88PCA9539_ENTRY_RW(invert1, PCA9539_INVERT_1); 89PCA9539_ENTRY_RW(direction0, PCA9539_DIRECTION_0); 90PCA9539_ENTRY_RW(direction1, PCA9539_DIRECTION_1); 91 92static struct attribute *pca9539_attributes[] = { 93 &sensor_dev_attr_input0.dev_attr.attr, 94 &sensor_dev_attr_input1.dev_attr.attr, 95 &sensor_dev_attr_output0.dev_attr.attr, 96 &sensor_dev_attr_output1.dev_attr.attr, 97 &sensor_dev_attr_invert0.dev_attr.attr, 98 &sensor_dev_attr_invert1.dev_attr.attr, 99 &sensor_dev_attr_direction0.dev_attr.attr, 100 &sensor_dev_attr_direction1.dev_attr.attr, 101 NULL 102}; 103 104static struct attribute_group pca9539_defattr_group = { 105 .attrs = pca9539_attributes, 106}; 107 108static int pca9539_attach_adapter(struct i2c_adapter *adapter) 109{ 110 return i2c_probe(adapter, &addr_data, pca9539_detect); 111} 112 113/* This function is called by i2c_probe */ 114static int pca9539_detect(struct i2c_adapter *adapter, int address, int kind) 115{ 116 struct i2c_client *new_client; 117 struct pca9539_data *data; 118 int err = 0; 119 120 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) 121 goto exit; 122 123 /* OK. For now, we presume we have a valid client. We now create the 124 client structure, even though we cannot fill it completely yet. */ 125 if (!(data = kzalloc(sizeof(struct pca9539_data), GFP_KERNEL))) { 126 err = -ENOMEM; 127 goto exit; 128 } 129 130 new_client = &data->client; 131 i2c_set_clientdata(new_client, data); 132 new_client->addr = address; 133 new_client->adapter = adapter; 134 new_client->driver = &pca9539_driver; 135 new_client->flags = 0; 136 137 if (kind < 0) { 138 /* Detection: the pca9539 only has 8 registers (0-7). 139 A read of 7 should succeed, but a read of 8 should fail. */ 140 if ((i2c_smbus_read_byte_data(new_client, 7) < 0) || 141 (i2c_smbus_read_byte_data(new_client, 8) >= 0)) 142 goto exit_kfree; 143 } 144 145 strlcpy(new_client->name, "pca9539", I2C_NAME_SIZE); 146 147 /* Tell the I2C layer a new client has arrived */ 148 if ((err = i2c_attach_client(new_client))) 149 goto exit_kfree; 150 151 /* Register sysfs hooks */ 152 err = sysfs_create_group(&new_client->dev.kobj, 153 &pca9539_defattr_group); 154 if (err) 155 goto exit_detach; 156 157 return 0; 158 159exit_detach: 160 i2c_detach_client(new_client); 161exit_kfree: 162 kfree(data); 163exit: 164 return err; 165} 166 167static int pca9539_detach_client(struct i2c_client *client) 168{ 169 int err; 170 171 sysfs_remove_group(&client->dev.kobj, &pca9539_defattr_group); 172 173 if ((err = i2c_detach_client(client))) 174 return err; 175 176 kfree(i2c_get_clientdata(client)); 177 return 0; 178} 179 180static int __init pca9539_init(void) 181{ 182 return i2c_add_driver(&pca9539_driver); 183} 184 185static void __exit pca9539_exit(void) 186{ 187 i2c_del_driver(&pca9539_driver); 188} 189 190MODULE_AUTHOR("Ben Gardner <bgardner@wabtec.com>"); 191MODULE_DESCRIPTION("PCA9539 driver"); 192MODULE_LICENSE("GPL"); 193 194module_init(pca9539_init); 195module_exit(pca9539_exit); 196