1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * cyttsp_i2c_common.c
4 * Cypress TrueTouch(TM) Standard Product (TTSP) I2C touchscreen driver.
5 * For use with Cypress Txx3xx and Txx4xx parts.
6 * Supported parts include:
7 * CY8CTST341
8 * CY8CTMA340
9 * TMA4XX
10 * TMA1036
11 *
12 * Copyright (C) 2009, 2010, 2011 Cypress Semiconductor, Inc.
13 * Copyright (C) 2012 Javier Martinez Canillas <javier@dowhile0.org>
14 *
15 * Contact Cypress Semiconductor at www.cypress.com <ttdrivers@cypress.com>
16 */
17
18#include <linux/device.h>
19#include <linux/export.h>
20#include <linux/i2c.h>
21#include <linux/module.h>
22#include <linux/types.h>
23
24#include "cyttsp4_core.h"
25
26int cyttsp_i2c_read_block_data(struct device *dev, u8 *xfer_buf,
27 u16 addr, u8 length, void *values)
28{
29 struct i2c_client *client = to_i2c_client(dev);
30 u8 client_addr = client->addr | ((addr >> 8) & 0x1);
31 u8 addr_lo = addr & 0xFF;
32 struct i2c_msg msgs[] = {
33 {
34 .addr = client_addr,
35 .flags = 0,
36 .len = 1,
37 .buf = &addr_lo,
38 },
39 {
40 .addr = client_addr,
41 .flags = I2C_M_RD,
42 .len = length,
43 .buf = values,
44 },
45 };
46 int retval;
47
48 retval = i2c_transfer(adap: client->adapter, msgs, ARRAY_SIZE(msgs));
49 if (retval < 0)
50 return retval;
51
52 return retval != ARRAY_SIZE(msgs) ? -EIO : 0;
53}
54EXPORT_SYMBOL_GPL(cyttsp_i2c_read_block_data);
55
56int cyttsp_i2c_write_block_data(struct device *dev, u8 *xfer_buf,
57 u16 addr, u8 length, const void *values)
58{
59 struct i2c_client *client = to_i2c_client(dev);
60 u8 client_addr = client->addr | ((addr >> 8) & 0x1);
61 u8 addr_lo = addr & 0xFF;
62 struct i2c_msg msgs[] = {
63 {
64 .addr = client_addr,
65 .flags = 0,
66 .len = length + 1,
67 .buf = xfer_buf,
68 },
69 };
70 int retval;
71
72 xfer_buf[0] = addr_lo;
73 memcpy(&xfer_buf[1], values, length);
74
75 retval = i2c_transfer(adap: client->adapter, msgs, ARRAY_SIZE(msgs));
76 if (retval < 0)
77 return retval;
78
79 return retval != ARRAY_SIZE(msgs) ? -EIO : 0;
80}
81EXPORT_SYMBOL_GPL(cyttsp_i2c_write_block_data);
82
83
84MODULE_LICENSE("GPL");
85MODULE_AUTHOR("Cypress");
86

source code of linux/drivers/input/touchscreen/cyttsp_i2c_common.c