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69dd204b BG |
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> | |
69dd204b BG |
16 | |
17 | /* Addresses to scan */ | |
18 | static unsigned short normal_i2c[] = {0x74, 0x75, 0x76, 0x77, I2C_CLIENT_END}; | |
69dd204b BG |
19 | |
20 | /* Insmod parameters */ | |
f4b50261 | 21 | I2C_CLIENT_INSMOD_1(pca9539); |
69dd204b BG |
22 | |
23 | enum 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 | ||
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); | |
38 | ||
39 | /* This is the driver that will be inserted */ | |
40 | static struct i2c_driver pca9539_driver = { | |
41 | .owner = THIS_MODULE, | |
42 | .name = "pca9539", | |
43 | .flags = I2C_DF_NOTIFY, | |
44 | .attach_adapter = pca9539_attach_adapter, | |
45 | .detach_client = pca9539_detach_client, | |
46 | }; | |
47 | ||
48 | struct pca9539_data { | |
49 | struct i2c_client client; | |
50 | }; | |
51 | ||
52 | /* following are the sysfs callback functions */ | |
53 | static 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 | ||
62 | static 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 | ||
83 | PCA9539_ENTRY_RO(input0, PCA9539_INPUT_0); | |
84 | PCA9539_ENTRY_RO(input1, PCA9539_INPUT_1); | |
85 | PCA9539_ENTRY_RW(output0, PCA9539_OUTPUT_0); | |
86 | PCA9539_ENTRY_RW(output1, PCA9539_OUTPUT_1); | |
87 | PCA9539_ENTRY_RW(invert0, PCA9539_INVERT_0); | |
88 | PCA9539_ENTRY_RW(invert1, PCA9539_INVERT_1); | |
89 | PCA9539_ENTRY_RW(direction0, PCA9539_DIRECTION_0); | |
90 | PCA9539_ENTRY_RW(direction1, PCA9539_DIRECTION_1); | |
91 | ||
92 | static 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 | ||
104 | static struct attribute_group pca9539_defattr_group = { | |
105 | .attrs = pca9539_attributes, | |
106 | }; | |
107 | ||
108 | static int pca9539_attach_adapter(struct i2c_adapter *adapter) | |
109 | { | |
2ed2dc3c | 110 | return i2c_probe(adapter, &addr_data, pca9539_detect); |
69dd204b BG |
111 | } |
112 | ||
2ed2dc3c | 113 | /* This function is called by i2c_probe */ |
69dd204b BG |
114 | static 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 = kmalloc(sizeof(struct pca9539_data), GFP_KERNEL))) { | |
126 | err = -ENOMEM; | |
127 | goto exit; | |
128 | } | |
129 | memset(data, 0, sizeof(struct pca9539_data)); | |
130 | ||
131 | new_client = &data->client; | |
132 | i2c_set_clientdata(new_client, data); | |
133 | new_client->addr = address; | |
134 | new_client->adapter = adapter; | |
135 | new_client->driver = &pca9539_driver; | |
136 | new_client->flags = 0; | |
137 | ||
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 | strlcpy(new_client->name, "pca9539", I2C_NAME_SIZE); | |
145 | ||
146 | /* Tell the I2C layer a new client has arrived */ | |
147 | if ((err = i2c_attach_client(new_client))) | |
148 | goto exit_kfree; | |
149 | ||
150 | /* Register sysfs hooks (don't care about failure) */ | |
151 | sysfs_create_group(&new_client->dev.kobj, &pca9539_defattr_group); | |
152 | ||
153 | return 0; | |
154 | ||
155 | exit_kfree: | |
156 | kfree(data); | |
157 | exit: | |
158 | return err; | |
159 | } | |
160 | ||
161 | static int pca9539_detach_client(struct i2c_client *client) | |
162 | { | |
163 | int err; | |
164 | ||
7bef5594 | 165 | if ((err = i2c_detach_client(client))) |
69dd204b | 166 | return err; |
69dd204b BG |
167 | |
168 | kfree(i2c_get_clientdata(client)); | |
169 | return 0; | |
170 | } | |
171 | ||
172 | static int __init pca9539_init(void) | |
173 | { | |
174 | return i2c_add_driver(&pca9539_driver); | |
175 | } | |
176 | ||
177 | static void __exit pca9539_exit(void) | |
178 | { | |
179 | i2c_del_driver(&pca9539_driver); | |
180 | } | |
181 | ||
182 | MODULE_AUTHOR("Ben Gardner <bgardner@wabtec.com>"); | |
183 | MODULE_DESCRIPTION("PCA9539 driver"); | |
184 | MODULE_LICENSE("GPL"); | |
185 | ||
186 | module_init(pca9539_init); | |
187 | module_exit(pca9539_exit); | |
188 |