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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> |
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16 | |
17 | /* Addresses to scan */ |
18 | static unsigned short normal_i2c[] = {0x74, 0x75, 0x76, 0x77, I2C_CLIENT_END}; |
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19 | |
20 | /* Insmod parameters */ |
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21 | I2C_CLIENT_INSMOD_1(pca9539); |
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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", |
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43 | .attach_adapter = pca9539_attach_adapter, |
44 | .detach_client = pca9539_detach_client, |
45 | }; |
46 | |
47 | struct pca9539_data { |
48 | struct i2c_client client; |
49 | }; |
50 | |
51 | /* following are the sysfs callback functions */ |
52 | static ssize_t pca9539_show(struct device *dev, struct device_attribute *attr, |
53 | char *buf) |
54 | { |
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, |
58 | psa->index)); |
59 | } |
60 | |
61 | static ssize_t pca9539_store(struct device *dev, struct device_attribute *attr, |
62 | const char *buf, size_t count) |
63 | { |
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); |
67 | if (val > 0xff) |
68 | return -EINVAL; |
69 | i2c_smbus_write_byte_data(client, psa->index, val); |
70 | return count; |
71 | } |
72 | |
73 | /* Define the device attributes */ |
74 | |
75 | #define PCA9539_ENTRY_RO(name, cmd_idx) \ |
76 | static SENSOR_DEVICE_ATTR(name, S_IRUGO, pca9539_show, NULL, cmd_idx) |
77 | |
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) |
81 | |
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); |
90 | |
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, |
100 | NULL |
101 | }; |
102 | |
103 | static struct attribute_group pca9539_defattr_group = { |
104 | .attrs = pca9539_attributes, |
105 | }; |
106 | |
107 | static int pca9539_attach_adapter(struct i2c_adapter *adapter) |
108 | { |
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109 | return i2c_probe(adapter, &addr_data, pca9539_detect); |
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110 | } |
111 | |
2ed2dc3c |
112 | /* This function is called by i2c_probe */ |
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113 | static int pca9539_detect(struct i2c_adapter *adapter, int address, int kind) |
114 | { |
115 | struct i2c_client *new_client; |
116 | struct pca9539_data *data; |
117 | int err = 0; |
118 | |
119 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) |
120 | goto exit; |
121 | |
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. */ |
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124 | if (!(data = kzalloc(sizeof(struct pca9539_data), GFP_KERNEL))) { |
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125 | err = -ENOMEM; |
126 | goto exit; |
127 | } |
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128 | |
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; |
135 | |
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)) |
140 | goto exit_kfree; |
141 | |
142 | strlcpy(new_client->name, "pca9539", I2C_NAME_SIZE); |
143 | |
144 | /* Tell the I2C layer a new client has arrived */ |
145 | if ((err = i2c_attach_client(new_client))) |
146 | goto exit_kfree; |
147 | |
148 | /* Register sysfs hooks (don't care about failure) */ |
149 | sysfs_create_group(&new_client->dev.kobj, &pca9539_defattr_group); |
150 | |
151 | return 0; |
152 | |
153 | exit_kfree: |
154 | kfree(data); |
155 | exit: |
156 | return err; |
157 | } |
158 | |
159 | static int pca9539_detach_client(struct i2c_client *client) |
160 | { |
161 | int err; |
162 | |
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163 | if ((err = i2c_detach_client(client))) |
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164 | return err; |
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165 | |
166 | kfree(i2c_get_clientdata(client)); |
167 | return 0; |
168 | } |
169 | |
170 | static int __init pca9539_init(void) |
171 | { |
172 | return i2c_add_driver(&pca9539_driver); |
173 | } |
174 | |
175 | static void __exit pca9539_exit(void) |
176 | { |
177 | i2c_del_driver(&pca9539_driver); |
178 | } |
179 | |
180 | MODULE_AUTHOR("Ben Gardner <bgardner@wabtec.com>"); |
181 | MODULE_DESCRIPTION("PCA9539 driver"); |
182 | MODULE_LICENSE("GPL"); |
183 | |
184 | module_init(pca9539_init); |
185 | module_exit(pca9539_exit); |
186 | |