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 #include <linux/pm.h>
14 
15 #include "ad7879.h"
16 
17 #define AD7879_DEVID		0x79	/* AD7879-1/AD7889-1 */
18 
19 /* All registers are word-sized.
20  * AD7879 uses a high-byte first convention.
21  */
22 static int ad7879_i2c_read(struct device *dev, u8 reg)
23 {
24 	struct i2c_client *client = to_i2c_client(dev);
25 
26 	return i2c_smbus_read_word_swapped(client, reg);
27 }
28 
29 static int ad7879_i2c_multi_read(struct device *dev,
30 				 u8 first_reg, u8 count, u16 *buf)
31 {
32 	struct i2c_client *client = to_i2c_client(dev);
33 	u8 idx;
34 
35 	i2c_smbus_read_i2c_block_data(client, first_reg, count * 2, (u8 *)buf);
36 
37 	for (idx = 0; idx < count; ++idx)
38 		buf[idx] = swab16(buf[idx]);
39 
40 	return 0;
41 }
42 
43 static int ad7879_i2c_write(struct device *dev, u8 reg, u16 val)
44 {
45 	struct i2c_client *client = to_i2c_client(dev);
46 
47 	return i2c_smbus_write_word_swapped(client, reg, val);
48 }
49 
50 static const struct ad7879_bus_ops ad7879_i2c_bus_ops = {
51 	.bustype	= BUS_I2C,
52 	.read		= ad7879_i2c_read,
53 	.multi_read	= ad7879_i2c_multi_read,
54 	.write		= ad7879_i2c_write,
55 };
56 
57 static int ad7879_i2c_probe(struct i2c_client *client,
58 				      const struct i2c_device_id *id)
59 {
60 	struct ad7879 *ts;
61 
62 	if (!i2c_check_functionality(client->adapter,
63 				     I2C_FUNC_SMBUS_WORD_DATA)) {
64 		dev_err(&client->dev, "SMBUS Word Data not Supported\n");
65 		return -EIO;
66 	}
67 
68 	ts = ad7879_probe(&client->dev, AD7879_DEVID, client->irq,
69 			  &ad7879_i2c_bus_ops);
70 	if (IS_ERR(ts))
71 		return PTR_ERR(ts);
72 
73 	i2c_set_clientdata(client, ts);
74 
75 	return 0;
76 }
77 
78 static int ad7879_i2c_remove(struct i2c_client *client)
79 {
80 	struct ad7879 *ts = i2c_get_clientdata(client);
81 
82 	ad7879_remove(ts);
83 
84 	return 0;
85 }
86 
87 static const struct i2c_device_id ad7879_id[] = {
88 	{ "ad7879", 0 },
89 	{ "ad7889", 0 },
90 	{ }
91 };
92 MODULE_DEVICE_TABLE(i2c, ad7879_id);
93 
94 static struct i2c_driver ad7879_i2c_driver = {
95 	.driver = {
96 		.name	= "ad7879",
97 		.owner	= THIS_MODULE,
98 		.pm	= &ad7879_pm_ops,
99 	},
100 	.probe		= ad7879_i2c_probe,
101 	.remove		= ad7879_i2c_remove,
102 	.id_table	= ad7879_id,
103 };
104 
105 module_i2c_driver(ad7879_i2c_driver);
106 
107 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
108 MODULE_DESCRIPTION("AD7879(-1) touchscreen I2C bus driver");
109 MODULE_LICENSE("GPL");
110