LXR linux/drivers/input/touchscreen/cyttsp_i2c

   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");
  86