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 	struct i2c_client *client = to_i2c_client(dev);
55 	u8 idx;
56 
57 	i2c_smbus_read_i2c_block_data(client, first_reg, count * 2, (u8 *)buf);
58 
59 	for (idx = 0; idx < count; ++idx)
60 		buf[idx] = swab16(buf[idx]);
61 
62 	return 0;
63 }
64 
65 static int ad7879_i2c_write(struct device *dev, u8 reg, u16 val)
66 {
67 	struct i2c_client *client = to_i2c_client(dev);
68 
69 	return i2c_smbus_write_word_data(client, reg, swab16(val));
70 }
71 
72 static const struct ad7879_bus_ops ad7879_i2c_bus_ops = {
73 	.bustype	= BUS_I2C,
74 	.read		= ad7879_i2c_read,
75 	.multi_read	= ad7879_i2c_multi_read,
76 	.write		= ad7879_i2c_write,
77 };
78 
79 static int __devinit ad7879_i2c_probe(struct i2c_client *client,
80 				      const struct i2c_device_id *id)
81 {
82 	struct ad7879 *ts;
83 
84 	if (!i2c_check_functionality(client->adapter,
85 				     I2C_FUNC_SMBUS_WORD_DATA)) {
86 		dev_err(&client->dev, "SMBUS Word Data not Supported\n");
87 		return -EIO;
88 	}
89 
90 	ts = ad7879_probe(&client->dev, AD7879_DEVID, client->irq,
91 			  &ad7879_i2c_bus_ops);
92 	if (IS_ERR(ts))
93 		return PTR_ERR(ts);
94 
95 	i2c_set_clientdata(client, ts);
96 
97 	return 0;
98 }
99 
100 static int __devexit ad7879_i2c_remove(struct i2c_client *client)
101 {
102 	struct ad7879 *ts = i2c_get_clientdata(client);
103 
104 	ad7879_remove(ts);
105 
106 	return 0;
107 }
108 
109 static const struct i2c_device_id ad7879_id[] = {
110 	{ "ad7879", 0 },
111 	{ "ad7889", 0 },
112 	{ }
113 };
114 MODULE_DEVICE_TABLE(i2c, ad7879_id);
115 
116 static struct i2c_driver ad7879_i2c_driver = {
117 	.driver = {
118 		.name	= "ad7879",
119 		.owner	= THIS_MODULE,
120 	},
121 	.probe		= ad7879_i2c_probe,
122 	.remove		= __devexit_p(ad7879_i2c_remove),
123 	.suspend	= ad7879_i2c_suspend,
124 	.resume		= ad7879_i2c_resume,
125 	.id_table	= ad7879_id,
126 };
127 
128 static int __init ad7879_i2c_init(void)
129 {
130 	return i2c_add_driver(&ad7879_i2c_driver);
131 }
132 module_init(ad7879_i2c_init);
133 
134 static void __exit ad7879_i2c_exit(void)
135 {
136 	i2c_del_driver(&ad7879_i2c_driver);
137 }
138 module_exit(ad7879_i2c_exit);
139 
140 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
141 MODULE_DESCRIPTION("AD7879(-1) touchscreen I2C bus driver");
142 MODULE_LICENSE("GPL");
143 MODULE_ALIAS("i2c:ad7879");
144