xref: /openbmc/linux/drivers/input/misc/ad714x-i2c.c (revision e3b9f1e8)
1 /*
2  * AD714X CapTouch Programmable Controller driver (I2C bus)
3  *
4  * Copyright 2009-2011 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 #include "ad714x.h"
15 
16 static int __maybe_unused ad714x_i2c_suspend(struct device *dev)
17 {
18 	return ad714x_disable(i2c_get_clientdata(to_i2c_client(dev)));
19 }
20 
21 static int __maybe_unused ad714x_i2c_resume(struct device *dev)
22 {
23 	return ad714x_enable(i2c_get_clientdata(to_i2c_client(dev)));
24 }
25 
26 static SIMPLE_DEV_PM_OPS(ad714x_i2c_pm, ad714x_i2c_suspend, ad714x_i2c_resume);
27 
28 static int ad714x_i2c_write(struct ad714x_chip *chip,
29 			    unsigned short reg, unsigned short data)
30 {
31 	struct i2c_client *client = to_i2c_client(chip->dev);
32 	int error;
33 
34 	chip->xfer_buf[0] = cpu_to_be16(reg);
35 	chip->xfer_buf[1] = cpu_to_be16(data);
36 
37 	error = i2c_master_send(client, (u8 *)chip->xfer_buf,
38 				2 * sizeof(*chip->xfer_buf));
39 	if (unlikely(error < 0)) {
40 		dev_err(&client->dev, "I2C write error: %d\n", error);
41 		return error;
42 	}
43 
44 	return 0;
45 }
46 
47 static int ad714x_i2c_read(struct ad714x_chip *chip,
48 			   unsigned short reg, unsigned short *data, size_t len)
49 {
50 	struct i2c_client *client = to_i2c_client(chip->dev);
51 	int i;
52 	int error;
53 
54 	chip->xfer_buf[0] = cpu_to_be16(reg);
55 
56 	error = i2c_master_send(client, (u8 *)chip->xfer_buf,
57 				sizeof(*chip->xfer_buf));
58 	if (error >= 0)
59 		error = i2c_master_recv(client, (u8 *)chip->xfer_buf,
60 					len * sizeof(*chip->xfer_buf));
61 
62 	if (unlikely(error < 0)) {
63 		dev_err(&client->dev, "I2C read error: %d\n", error);
64 		return error;
65 	}
66 
67 	for (i = 0; i < len; i++)
68 		data[i] = be16_to_cpu(chip->xfer_buf[i]);
69 
70 	return 0;
71 }
72 
73 static int ad714x_i2c_probe(struct i2c_client *client,
74 					const struct i2c_device_id *id)
75 {
76 	struct ad714x_chip *chip;
77 
78 	chip = ad714x_probe(&client->dev, BUS_I2C, client->irq,
79 			    ad714x_i2c_read, ad714x_i2c_write);
80 	if (IS_ERR(chip))
81 		return PTR_ERR(chip);
82 
83 	i2c_set_clientdata(client, chip);
84 
85 	return 0;
86 }
87 
88 static const struct i2c_device_id ad714x_id[] = {
89 	{ "ad7142_captouch", 0 },
90 	{ "ad7143_captouch", 0 },
91 	{ "ad7147_captouch", 0 },
92 	{ "ad7147a_captouch", 0 },
93 	{ "ad7148_captouch", 0 },
94 	{ }
95 };
96 MODULE_DEVICE_TABLE(i2c, ad714x_id);
97 
98 static struct i2c_driver ad714x_i2c_driver = {
99 	.driver = {
100 		.name = "ad714x_captouch",
101 		.pm   = &ad714x_i2c_pm,
102 	},
103 	.probe    = ad714x_i2c_probe,
104 	.id_table = ad714x_id,
105 };
106 
107 module_i2c_driver(ad714x_i2c_driver);
108 
109 MODULE_DESCRIPTION("Analog Devices AD714X Capacitance Touch Sensor I2C Bus Driver");
110 MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
111 MODULE_LICENSE("GPL");
112