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Diffstat (limited to 'drivers/i2c/chips/pca9539.c')
-rw-r--r--drivers/i2c/chips/pca9539.c192
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 @@
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#include <linux/i2c-sensor.h>
17
18/* Addresses to scan */
19static unsigned short normal_i2c[] = {0x74, 0x75, 0x76, 0x77, I2C_CLIENT_END};
20static unsigned int normal_isa[] = {I2C_CLIENT_ISA_END};
21
22/* Insmod parameters */
23SENSORS_INSMOD_1(pca9539);
24
25enum pca9539_cmd
26{
27 PCA9539_INPUT_0 = 0,
28 PCA9539_INPUT_1 = 1,
29 PCA9539_OUTPUT_0 = 2,
30 PCA9539_OUTPUT_1 = 3,
31 PCA9539_INVERT_0 = 4,
32 PCA9539_INVERT_1 = 5,
33 PCA9539_DIRECTION_0 = 6,
34 PCA9539_DIRECTION_1 = 7,
35};
36
37static int pca9539_attach_adapter(struct i2c_adapter *adapter);
38static int pca9539_detect(struct i2c_adapter *adapter, int address, int kind);
39static int pca9539_detach_client(struct i2c_client *client);
40
41/* This is the driver that will be inserted */
42static struct i2c_driver pca9539_driver = {
43 .owner = THIS_MODULE,
44 .name = "pca9539",
45 .flags = I2C_DF_NOTIFY,
46 .attach_adapter = pca9539_attach_adapter,
47 .detach_client = pca9539_detach_client,
48};
49
50struct pca9539_data {
51 struct i2c_client client;
52};
53
54/* following are the sysfs callback functions */
55static ssize_t pca9539_show(struct device *dev, struct device_attribute *attr,
56 char *buf)
57{
58 struct sensor_device_attribute *psa = to_sensor_dev_attr(attr);
59 struct i2c_client *client = to_i2c_client(dev);
60 return sprintf(buf, "%d\n", i2c_smbus_read_byte_data(client,
61 psa->index));
62}
63
64static ssize_t pca9539_store(struct device *dev, struct device_attribute *attr,
65 const char *buf, size_t count)
66{
67 struct sensor_device_attribute *psa = to_sensor_dev_attr(attr);
68 struct i2c_client *client = to_i2c_client(dev);
69 unsigned long val = simple_strtoul(buf, NULL, 0);
70 if (val > 0xff)
71 return -EINVAL;
72 i2c_smbus_write_byte_data(client, psa->index, val);
73 return count;
74}
75
76/* Define the device attributes */
77
78#define PCA9539_ENTRY_RO(name, cmd_idx) \
79 static SENSOR_DEVICE_ATTR(name, S_IRUGO, pca9539_show, NULL, cmd_idx)
80
81#define PCA9539_ENTRY_RW(name, cmd_idx) \
82 static SENSOR_DEVICE_ATTR(name, S_IRUGO | S_IWUSR, pca9539_show, \
83 pca9539_store, cmd_idx)
84
85PCA9539_ENTRY_RO(input0, PCA9539_INPUT_0);
86PCA9539_ENTRY_RO(input1, PCA9539_INPUT_1);
87PCA9539_ENTRY_RW(output0, PCA9539_OUTPUT_0);
88PCA9539_ENTRY_RW(output1, PCA9539_OUTPUT_1);
89PCA9539_ENTRY_RW(invert0, PCA9539_INVERT_0);
90PCA9539_ENTRY_RW(invert1, PCA9539_INVERT_1);
91PCA9539_ENTRY_RW(direction0, PCA9539_DIRECTION_0);
92PCA9539_ENTRY_RW(direction1, PCA9539_DIRECTION_1);
93
94static struct attribute *pca9539_attributes[] = {
95 &sensor_dev_attr_input0.dev_attr.attr,
96 &sensor_dev_attr_input1.dev_attr.attr,
97 &sensor_dev_attr_output0.dev_attr.attr,
98 &sensor_dev_attr_output1.dev_attr.attr,
99 &sensor_dev_attr_invert0.dev_attr.attr,
100 &sensor_dev_attr_invert1.dev_attr.attr,
101 &sensor_dev_attr_direction0.dev_attr.attr,
102 &sensor_dev_attr_direction1.dev_attr.attr,
103 NULL
104};
105
106static struct attribute_group pca9539_defattr_group = {
107 .attrs = pca9539_attributes,
108};
109
110static int pca9539_attach_adapter(struct i2c_adapter *adapter)
111{
112 return i2c_detect(adapter, &addr_data, pca9539_detect);
113}
114
115/* This function is called by i2c_detect */
116static int pca9539_detect(struct i2c_adapter *adapter, int address, int kind)
117{
118 struct i2c_client *new_client;
119 struct pca9539_data *data;
120 int err = 0;
121
122 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
123 goto exit;
124
125 /* OK. For now, we presume we have a valid client. We now create the
126 client structure, even though we cannot fill it completely yet. */
127 if (!(data = kmalloc(sizeof(struct pca9539_data), GFP_KERNEL))) {
128 err = -ENOMEM;
129 goto exit;
130 }
131 memset(data, 0, sizeof(struct pca9539_data));
132
133 new_client = &data->client;
134 i2c_set_clientdata(new_client, data);
135 new_client->addr = address;
136 new_client->adapter = adapter;
137 new_client->driver = &pca9539_driver;
138 new_client->flags = 0;
139
140 /* Detection: the pca9539 only has 8 registers (0-7).
141 A read of 7 should succeed, but a read of 8 should fail. */
142 if ((i2c_smbus_read_byte_data(new_client, 7) < 0) ||
143 (i2c_smbus_read_byte_data(new_client, 8) >= 0))
144 goto exit_kfree;
145
146 strlcpy(new_client->name, "pca9539", I2C_NAME_SIZE);
147
148 /* Tell the I2C layer a new client has arrived */
149 if ((err = i2c_attach_client(new_client)))
150 goto exit_kfree;
151
152 /* Register sysfs hooks (don't care about failure) */
153 sysfs_create_group(&new_client->dev.kobj, &pca9539_defattr_group);
154
155 return 0;
156
157exit_kfree:
158 kfree(data);
159exit:
160 return err;
161}
162
163static int pca9539_detach_client(struct i2c_client *client)
164{
165 int err;
166
167 if ((err = i2c_detach_client(client))) {
168 dev_err(&client->dev, "Client deregistration failed.\n");
169 return err;
170 }
171
172 kfree(i2c_get_clientdata(client));
173 return 0;
174}
175
176static int __init pca9539_init(void)
177{
178 return i2c_add_driver(&pca9539_driver);
179}
180
181static void __exit pca9539_exit(void)
182{
183 i2c_del_driver(&pca9539_driver);
184}
185
186MODULE_AUTHOR("Ben Gardner <bgardner@wabtec.com>");
187MODULE_DESCRIPTION("PCA9539 driver");
188MODULE_LICENSE("GPL");
189
190module_init(pca9539_init);
191module_exit(pca9539_exit);
192
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-29 19:20:18 -0500