2 pca9539.c - 16-bit I/O port with interrupt and reset
4 Copyright (C) 2005 Ben Gardner <bgardner@wabtec.com>
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.
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>
17 /* Addresses to scan */
18 static unsigned short normal_i2c
[] = {0x74, 0x75, 0x76, 0x77, I2C_CLIENT_END
};
20 /* Insmod parameters */
21 I2C_CLIENT_INSMOD_1(pca9539
);
31 PCA9539_DIRECTION_0
= 6,
32 PCA9539_DIRECTION_1
= 7,
35 static int pca9539_attach_adapter(struct i2c_adapter
*adapter
);
36 static int pca9539_detect(struct i2c_adapter
*adapter
, int address
, int kind
);
37 static int pca9539_detach_client(struct i2c_client
*client
);
39 /* This is the driver that will be inserted */
40 static struct i2c_driver pca9539_driver
= {
43 .attach_adapter
= pca9539_attach_adapter
,
44 .detach_client
= pca9539_detach_client
,
48 struct i2c_client client
;
51 /* following are the sysfs callback functions */
52 static ssize_t
pca9539_show(struct device
*dev
, struct device_attribute
*attr
,
55 struct sensor_device_attribute
*psa
= to_sensor_dev_attr(attr
);
56 struct i2c_client
*client
= to_i2c_client(dev
);
57 return sprintf(buf
, "%d\n", i2c_smbus_read_byte_data(client
,
61 static ssize_t
pca9539_store(struct device
*dev
, struct device_attribute
*attr
,
62 const char *buf
, size_t count
)
64 struct sensor_device_attribute
*psa
= to_sensor_dev_attr(attr
);
65 struct i2c_client
*client
= to_i2c_client(dev
);
66 unsigned long val
= simple_strtoul(buf
, NULL
, 0);
69 i2c_smbus_write_byte_data(client
, psa
->index
, val
);
73 /* Define the device attributes */
75 #define PCA9539_ENTRY_RO(name, cmd_idx) \
76 static SENSOR_DEVICE_ATTR(name, S_IRUGO, pca9539_show, NULL, cmd_idx)
78 #define PCA9539_ENTRY_RW(name, cmd_idx) \
79 static SENSOR_DEVICE_ATTR(name, S_IRUGO | S_IWUSR, pca9539_show, \
80 pca9539_store, cmd_idx)
82 PCA9539_ENTRY_RO(input0
, PCA9539_INPUT_0
);
83 PCA9539_ENTRY_RO(input1
, PCA9539_INPUT_1
);
84 PCA9539_ENTRY_RW(output0
, PCA9539_OUTPUT_0
);
85 PCA9539_ENTRY_RW(output1
, PCA9539_OUTPUT_1
);
86 PCA9539_ENTRY_RW(invert0
, PCA9539_INVERT_0
);
87 PCA9539_ENTRY_RW(invert1
, PCA9539_INVERT_1
);
88 PCA9539_ENTRY_RW(direction0
, PCA9539_DIRECTION_0
);
89 PCA9539_ENTRY_RW(direction1
, PCA9539_DIRECTION_1
);
91 static struct attribute
*pca9539_attributes
[] = {
92 &sensor_dev_attr_input0
.dev_attr
.attr
,
93 &sensor_dev_attr_input1
.dev_attr
.attr
,
94 &sensor_dev_attr_output0
.dev_attr
.attr
,
95 &sensor_dev_attr_output1
.dev_attr
.attr
,
96 &sensor_dev_attr_invert0
.dev_attr
.attr
,
97 &sensor_dev_attr_invert1
.dev_attr
.attr
,
98 &sensor_dev_attr_direction0
.dev_attr
.attr
,
99 &sensor_dev_attr_direction1
.dev_attr
.attr
,
103 static struct attribute_group pca9539_defattr_group
= {
104 .attrs
= pca9539_attributes
,
107 static int pca9539_attach_adapter(struct i2c_adapter
*adapter
)
109 return i2c_probe(adapter
, &addr_data
, pca9539_detect
);
112 /* This function is called by i2c_probe */
113 static int pca9539_detect(struct i2c_adapter
*adapter
, int address
, int kind
)
115 struct i2c_client
*new_client
;
116 struct pca9539_data
*data
;
119 if (!i2c_check_functionality(adapter
, I2C_FUNC_SMBUS_BYTE_DATA
))
122 /* OK. For now, we presume we have a valid client. We now create the
123 client structure, even though we cannot fill it completely yet. */
124 if (!(data
= kzalloc(sizeof(struct pca9539_data
), GFP_KERNEL
))) {
129 new_client
= &data
->client
;
130 i2c_set_clientdata(new_client
, data
);
131 new_client
->addr
= address
;
132 new_client
->adapter
= adapter
;
133 new_client
->driver
= &pca9539_driver
;
134 new_client
->flags
= 0;
136 /* Detection: the pca9539 only has 8 registers (0-7).
137 A read of 7 should succeed, but a read of 8 should fail. */
138 if ((i2c_smbus_read_byte_data(new_client
, 7) < 0) ||
139 (i2c_smbus_read_byte_data(new_client
, 8) >= 0))
142 strlcpy(new_client
->name
, "pca9539", I2C_NAME_SIZE
);
144 /* Tell the I2C layer a new client has arrived */
145 if ((err
= i2c_attach_client(new_client
)))
148 /* Register sysfs hooks (don't care about failure) */
149 sysfs_create_group(&new_client
->dev
.kobj
, &pca9539_defattr_group
);
159 static int pca9539_detach_client(struct i2c_client
*client
)
163 if ((err
= i2c_detach_client(client
)))
166 kfree(i2c_get_clientdata(client
));
170 static int __init
pca9539_init(void)
172 return i2c_add_driver(&pca9539_driver
);
175 static void __exit
pca9539_exit(void)
177 i2c_del_driver(&pca9539_driver
);
180 MODULE_AUTHOR("Ben Gardner <bgardner@wabtec.com>");
181 MODULE_DESCRIPTION("PCA9539 driver");
182 MODULE_LICENSE("GPL");
184 module_init(pca9539_init
);
185 module_exit(pca9539_exit
);