/home/lenb/linux-2.6 branch 'acpi-2.6.12'
[linux-2.6] / drivers / i2c / chips / pca9539.c
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 */
19 static unsigned short normal_i2c[] = {0x74, 0x75, 0x76, 0x77, I2C_CLIENT_END};
20 static unsigned int normal_isa[] = {I2C_CLIENT_ISA_END};
21
22 /* Insmod parameters */
23 SENSORS_INSMOD_1(pca9539);
24
25 enum 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
37 static int pca9539_attach_adapter(struct i2c_adapter *adapter);
38 static int pca9539_detect(struct i2c_adapter *adapter, int address, int kind);
39 static int pca9539_detach_client(struct i2c_client *client);
40
41 /* This is the driver that will be inserted */
42 static 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
50 struct pca9539_data {
51         struct i2c_client client;
52 };
53
54 /* following are the sysfs callback functions */
55 static 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
64 static 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
85 PCA9539_ENTRY_RO(input0, PCA9539_INPUT_0);
86 PCA9539_ENTRY_RO(input1, PCA9539_INPUT_1);
87 PCA9539_ENTRY_RW(output0, PCA9539_OUTPUT_0);
88 PCA9539_ENTRY_RW(output1, PCA9539_OUTPUT_1);
89 PCA9539_ENTRY_RW(invert0, PCA9539_INVERT_0);
90 PCA9539_ENTRY_RW(invert1, PCA9539_INVERT_1);
91 PCA9539_ENTRY_RW(direction0, PCA9539_DIRECTION_0);
92 PCA9539_ENTRY_RW(direction1, PCA9539_DIRECTION_1);
93
94 static 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
106 static struct attribute_group pca9539_defattr_group = {
107         .attrs = pca9539_attributes,
108 };
109
110 static 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 */
116 static 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
157 exit_kfree:
158         kfree(data);
159 exit:
160         return err;
161 }
162
163 static 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
176 static int __init pca9539_init(void)
177 {
178         return i2c_add_driver(&pca9539_driver);
179 }
180
181 static void __exit pca9539_exit(void)
182 {
183         i2c_del_driver(&pca9539_driver);
184 }
185
186 MODULE_AUTHOR("Ben Gardner <bgardner@wabtec.com>");
187 MODULE_DESCRIPTION("PCA9539 driver");
188 MODULE_LICENSE("GPL");
189
190 module_init(pca9539_init);
191 module_exit(pca9539_exit);
192