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/of.h>
14 #include <linux/pm.h>
15 
16 #include "ad7879.h"
17 
18 #define AD7879_DEVID		0x79	/* AD7879-1/AD7889-1 */
19 
20 /* All registers are word-sized.
21  * AD7879 uses a high-byte first convention.
22  */
23 static int ad7879_i2c_read(struct device *dev, u8 reg)
24 {
25 	struct i2c_client *client = to_i2c_client(dev);
26 
27 	return i2c_smbus_read_word_swapped(client, reg);
28 }
29 
30 static int ad7879_i2c_multi_read(struct device *dev,
31 				 u8 first_reg, u8 count, u16 *buf)
32 {
33 	struct i2c_client *client = to_i2c_client(dev);
34 	u8 idx;
35 
36 	i2c_smbus_read_i2c_block_data(client, first_reg, count * 2, (u8 *)buf);
37 
38 	for (idx = 0; idx < count; ++idx)
39 		buf[idx] = swab16(buf[idx]);
40 
41 	return 0;
42 }
43 
44 static int ad7879_i2c_write(struct device *dev, u8 reg, u16 val)
45 {
46 	struct i2c_client *client = to_i2c_client(dev);
47 
48 	return i2c_smbus_write_word_swapped(client, reg, val);
49 }
50 
51 static const struct ad7879_bus_ops ad7879_i2c_bus_ops = {
52 	.bustype	= BUS_I2C,
53 	.read		= ad7879_i2c_read,
54 	.multi_read	= ad7879_i2c_multi_read,
55 	.write		= ad7879_i2c_write,
56 };
57 
58 static int ad7879_i2c_probe(struct i2c_client *client,
59 				      const struct i2c_device_id *id)
60 {
61 	struct ad7879 *ts;
62 
63 	if (!i2c_check_functionality(client->adapter,
64 				     I2C_FUNC_SMBUS_WORD_DATA)) {
65 		dev_err(&client->dev, "SMBUS Word Data not Supported\n");
66 		return -EIO;
67 	}
68 
69 	ts = ad7879_probe(&client->dev, AD7879_DEVID, client->irq,
70 			  &ad7879_i2c_bus_ops);
71 	if (IS_ERR(ts))
72 		return PTR_ERR(ts);
73 
74 	i2c_set_clientdata(client, ts);
75 
76 	return 0;
77 }
78 
79 static int ad7879_i2c_remove(struct i2c_client *client)
80 {
81 	struct ad7879 *ts = i2c_get_clientdata(client);
82 
83 	ad7879_remove(ts);
84 
85 	return 0;
86 }
87 
88 static const struct i2c_device_id ad7879_id[] = {
89 	{ "ad7879", 0 },
90 	{ "ad7889", 0 },
91 	{ }
92 };
93 MODULE_DEVICE_TABLE(i2c, ad7879_id);
94 
95 #ifdef CONFIG_OF
96 static const struct of_device_id ad7879_i2c_dt_ids[] = {
97 	{ .compatible = "adi,ad7879-1", },
98 	{ }
99 };
100 MODULE_DEVICE_TABLE(of, ad7879_i2c_dt_ids);
101 #endif
102 
103 static struct i2c_driver ad7879_i2c_driver = {
104 	.driver = {
105 		.name	= "ad7879",
106 		.pm	= &ad7879_pm_ops,
107 		.of_match_table = of_match_ptr(ad7879_i2c_dt_ids),
108 	},
109 	.probe		= ad7879_i2c_probe,
110 	.remove		= ad7879_i2c_remove,
111 	.id_table	= ad7879_id,
112 };
113 
114 module_i2c_driver(ad7879_i2c_driver);
115 
116 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
117 MODULE_DESCRIPTION("AD7879(-1) touchscreen I2C bus driver");
118 MODULE_LICENSE("GPL");
119