xref: /linux/drivers/input/touchscreen/cyttsp_i2c_common.c (revision a13d7201d7deedcbb6ac6efa94a1a7d34d3d79ec)
1 /*
2  * cyttsp_i2c_common.c
3  * Cypress TrueTouch(TM) Standard Product (TTSP) I2C touchscreen driver.
4  * For use with Cypress Txx3xx and Txx4xx parts.
5  * Supported parts include:
6  * CY8CTST341
7  * CY8CTMA340
8  * TMA4XX
9  * TMA1036
10  *
11  * Copyright (C) 2009, 2010, 2011 Cypress Semiconductor, Inc.
12  * Copyright (C) 2012 Javier Martinez Canillas <javier@dowhile0.org>
13  *
14  * This program is free software; you can redistribute it and/or
15  * modify it under the terms of the GNU General Public License
16  * version 2, and only version 2, as published by the
17  * Free Software Foundation.
18  *
19  * This program is distributed in the hope that it will be useful,
20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
22  * GNU General Public License for more details.
23  *
24  * Contact Cypress Semiconductor at www.cypress.com <ttdrivers@cypress.com>
25  *
26  */
27 
28 #include <linux/device.h>
29 #include <linux/export.h>
30 #include <linux/i2c.h>
31 #include <linux/module.h>
32 #include <linux/types.h>
33 
34 #include "cyttsp4_core.h"
35 
36 int cyttsp_i2c_read_block_data(struct device *dev, u8 *xfer_buf,
37 				      u16 addr, u8 length, void *values)
38 {
39 	struct i2c_client *client = to_i2c_client(dev);
40 	u8 client_addr = client->addr | ((addr >> 8) & 0x1);
41 	u8 addr_lo = addr & 0xFF;
42 	struct i2c_msg msgs[] = {
43 		{
44 			.addr = client_addr,
45 			.flags = 0,
46 			.len = 1,
47 			.buf = &addr_lo,
48 		},
49 		{
50 			.addr = client_addr,
51 			.flags = I2C_M_RD,
52 			.len = length,
53 			.buf = values,
54 		},
55 	};
56 	int retval;
57 
58 	retval = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
59 	if (retval < 0)
60 		return retval;
61 
62 	return retval != ARRAY_SIZE(msgs) ? -EIO : 0;
63 }
64 EXPORT_SYMBOL_GPL(cyttsp_i2c_read_block_data);
65 
66 int cyttsp_i2c_write_block_data(struct device *dev, u8 *xfer_buf,
67 				       u16 addr, u8 length, const void *values)
68 {
69 	struct i2c_client *client = to_i2c_client(dev);
70 	u8 client_addr = client->addr | ((addr >> 8) & 0x1);
71 	u8 addr_lo = addr & 0xFF;
72 	struct i2c_msg msgs[] = {
73 		{
74 			.addr = client_addr,
75 			.flags = 0,
76 			.len = length + 1,
77 			.buf = xfer_buf,
78 		},
79 	};
80 	int retval;
81 
82 	xfer_buf[0] = addr_lo;
83 	memcpy(&xfer_buf[1], values, length);
84 
85 	retval = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
86 	if (retval < 0)
87 		return retval;
88 
89 	return retval != ARRAY_SIZE(msgs) ? -EIO : 0;
90 }
91 EXPORT_SYMBOL_GPL(cyttsp_i2c_write_block_data);
92 
93 
94 MODULE_LICENSE("GPL");
95 MODULE_AUTHOR("Cypress");
96