1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
|
/*
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>
/* Addresses to scan */
static unsigned short normal_i2c[] = {0x74, 0x75, 0x76, 0x77, I2C_CLIENT_END};
/* Insmod parameters */
I2C_CLIENT_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_probe(adapter, &addr_data, pca9539_detect);
}
/* This function is called by i2c_probe */
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)))
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);
|
