xref: /linux/drivers/input/touchscreen/cyttsp_i2c.c (revision b889fcf63cb62e7fdb7816565e28f44dbe4a76a5)
1 /*
2  * Source for:
3  * Cypress TrueTouch(TM) Standard Product (TTSP) I2C touchscreen driver.
4  * For use with Cypress Txx3xx parts.
5  * Supported parts include:
6  * CY8CTST341
7  * CY8CTMA340
8  *
9  * Copyright (C) 2009, 2010, 2011 Cypress Semiconductor, Inc.
10  * Copyright (C) 2012 Javier Martinez Canillas <javier@dowhile0.org>
11  *
12  * This program is free software; you can redistribute it and/or
13  * modify it under the terms of the GNU General Public License
14  * version 2, and only version 2, as published by the
15  * Free Software Foundation.
16  *
17  * This program is distributed in the hope that it will be useful,
18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  * GNU General Public License for more details.
21  *
22  * You should have received a copy of the GNU General Public License along
23  * with this program; if not, write to the Free Software Foundation, Inc.,
24  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
25  *
26  * Contact Cypress Semiconductor at www.cypress.com <kev@cypress.com>
27  *
28  */
29 
30 #include "cyttsp_core.h"
31 
32 #include <linux/i2c.h>
33 #include <linux/input.h>
34 
35 #define CY_I2C_DATA_SIZE	128
36 
37 static int cyttsp_i2c_read_block_data(struct cyttsp *ts,
38 				      u8 addr, u8 length, void *values)
39 {
40 	struct i2c_client *client = to_i2c_client(ts->dev);
41 	struct i2c_msg msgs[] = {
42 		{
43 			.addr = client->addr,
44 			.flags = 0,
45 			.len = 1,
46 			.buf = &addr,
47 		},
48 		{
49 			.addr = client->addr,
50 			.flags = I2C_M_RD,
51 			.len = length,
52 			.buf = values,
53 		},
54 	};
55 	int retval;
56 
57 	retval = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
58 	if (retval < 0)
59 		return retval;
60 
61 	return retval != ARRAY_SIZE(msgs) ? -EIO : 0;
62 }
63 
64 static int cyttsp_i2c_write_block_data(struct cyttsp *ts,
65 				       u8 addr, u8 length, const void *values)
66 {
67 	struct i2c_client *client = to_i2c_client(ts->dev);
68 	int retval;
69 
70 	ts->xfer_buf[0] = addr;
71 	memcpy(&ts->xfer_buf[1], values, length);
72 
73 	retval = i2c_master_send(client, ts->xfer_buf, length + 1);
74 
75 	return retval < 0 ? retval : 0;
76 }
77 
78 static const struct cyttsp_bus_ops cyttsp_i2c_bus_ops = {
79 	.bustype	= BUS_I2C,
80 	.write		= cyttsp_i2c_write_block_data,
81 	.read           = cyttsp_i2c_read_block_data,
82 };
83 
84 static int cyttsp_i2c_probe(struct i2c_client *client,
85 				      const struct i2c_device_id *id)
86 {
87 	struct cyttsp *ts;
88 
89 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
90 		dev_err(&client->dev, "I2C functionality not Supported\n");
91 		return -EIO;
92 	}
93 
94 	ts = cyttsp_probe(&cyttsp_i2c_bus_ops, &client->dev, client->irq,
95 			  CY_I2C_DATA_SIZE);
96 
97 	if (IS_ERR(ts))
98 		return PTR_ERR(ts);
99 
100 	i2c_set_clientdata(client, ts);
101 
102 	return 0;
103 }
104 
105 static int cyttsp_i2c_remove(struct i2c_client *client)
106 {
107 	struct cyttsp *ts = i2c_get_clientdata(client);
108 
109 	cyttsp_remove(ts);
110 
111 	return 0;
112 }
113 
114 static const struct i2c_device_id cyttsp_i2c_id[] = {
115 	{ CY_I2C_NAME, 0 },
116 	{ }
117 };
118 MODULE_DEVICE_TABLE(i2c, cyttsp_i2c_id);
119 
120 static struct i2c_driver cyttsp_i2c_driver = {
121 	.driver = {
122 		.name	= CY_I2C_NAME,
123 		.owner	= THIS_MODULE,
124 		.pm	= &cyttsp_pm_ops,
125 	},
126 	.probe		= cyttsp_i2c_probe,
127 	.remove		= cyttsp_i2c_remove,
128 	.id_table	= cyttsp_i2c_id,
129 };
130 
131 module_i2c_driver(cyttsp_i2c_driver);
132 
133 MODULE_LICENSE("GPL");
134 MODULE_DESCRIPTION("Cypress TrueTouch(R) Standard Product (TTSP) I2C driver");
135 MODULE_AUTHOR("Cypress");
136 MODULE_ALIAS("i2c:cyttsp");
137