1 /*
2  * AD7879-1/AD7889-1 touchscreen (I2C bus)
3  *
4  * Copyright (C) 2008-2010 Michael Hennerich, Analog Devices Inc.
5  *
6  * Licensed under the GPL-2 or later.
7  */
8 
9 #include <linux/input.h>	/* BUS_I2C */
10 #include <linux/i2c.h>
11 #include <linux/module.h>
12 #include <linux/types.h>
13 
14 #include "ad7879.h"
15 
16 #define AD7879_DEVID		0x79	/* AD7879-1/AD7889-1 */
17 
18 #ifdef CONFIG_PM
19 static int ad7879_i2c_suspend(struct i2c_client *client, pm_message_t message)
20 {
21 	struct ad7879 *ts = i2c_get_clientdata(client);
22 
23 	ad7879_suspend(ts);
24 
25 	return 0;
26 }
27 
28 static int ad7879_i2c_resume(struct i2c_client *client)
29 {
30 	struct ad7879 *ts = i2c_get_clientdata(client);
31 
32 	ad7879_resume(ts);
33 
34 	return 0;
35 }
36 #else
37 # define ad7879_i2c_suspend NULL
38 # define ad7879_i2c_resume  NULL
39 #endif
40 
41 /* All registers are word-sized.
42  * AD7879 uses a high-byte first convention.
43  */
44 static int ad7879_i2c_read(struct device *dev, u8 reg)
45 {
46 	struct i2c_client *client = to_i2c_client(dev);
47 
48 	return swab16(i2c_smbus_read_word_data(client, reg));
49 }
50 
51 static int ad7879_i2c_multi_read(struct device *dev,
52 				 u8 first_reg, u8 count, u16 *buf)
53 {
54 	u8 idx;
55 
56 	for (idx = 0; idx < count; ++idx)
57 		buf[idx] = ad7879_i2c_read(dev, first_reg + idx);
58 
59 	return 0;
60 }
61 
62 static int ad7879_i2c_write(struct device *dev, u8 reg, u16 val)
63 {
64 	struct i2c_client *client = to_i2c_client(dev);
65 
66 	return i2c_smbus_write_word_data(client, reg, swab16(val));
67 }
68 
69 static const struct ad7879_bus_ops ad7879_i2c_bus_ops = {
70 	.bustype	= BUS_I2C,
71 	.read		= ad7879_i2c_read,
72 	.multi_read	= ad7879_i2c_multi_read,
73 	.write		= ad7879_i2c_write,
74 };
75 
76 static int __devinit ad7879_i2c_probe(struct i2c_client *client,
77 				      const struct i2c_device_id *id)
78 {
79 	struct ad7879 *ts;
80 
81 	if (!i2c_check_functionality(client->adapter,
82 				     I2C_FUNC_SMBUS_WORD_DATA)) {
83 		dev_err(&client->dev, "SMBUS Word Data not Supported\n");
84 		return -EIO;
85 	}
86 
87 	ts = ad7879_probe(&client->dev, AD7879_DEVID, client->irq,
88 			  &ad7879_i2c_bus_ops);
89 	if (IS_ERR(ts))
90 		return PTR_ERR(ts);
91 
92 	i2c_set_clientdata(client, ts);
93 
94 	return 0;
95 }
96 
97 static int __devexit ad7879_i2c_remove(struct i2c_client *client)
98 {
99 	struct ad7879 *ts = i2c_get_clientdata(client);
100 
101 	ad7879_remove(ts);
102 
103 	return 0;
104 }
105 
106 static const struct i2c_device_id ad7879_id[] = {
107 	{ "ad7879", 0 },
108 	{ "ad7889", 0 },
109 	{ }
110 };
111 MODULE_DEVICE_TABLE(i2c, ad7879_id);
112 
113 static struct i2c_driver ad7879_i2c_driver = {
114 	.driver = {
115 		.name	= "ad7879",
116 		.owner	= THIS_MODULE,
117 	},
118 	.probe		= ad7879_i2c_probe,
119 	.remove		= __devexit_p(ad7879_i2c_remove),
120 	.suspend	= ad7879_i2c_suspend,
121 	.resume		= ad7879_i2c_resume,
122 	.id_table	= ad7879_id,
123 };
124 
125 static int __init ad7879_i2c_init(void)
126 {
127 	return i2c_add_driver(&ad7879_i2c_driver);
128 }
129 module_init(ad7879_i2c_init);
130 
131 static void __exit ad7879_i2c_exit(void)
132 {
133 	i2c_del_driver(&ad7879_i2c_driver);
134 }
135 module_exit(ad7879_i2c_exit);
136 
137 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
138 MODULE_DESCRIPTION("AD7879(-1) touchscreen I2C bus driver");
139 MODULE_LICENSE("GPL");
140 MODULE_ALIAS("i2c:ad7879");
141