cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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cyttsp_i2c_common.c (1991B)

      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(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(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");