drivers/input/touchscreen/cyttsp_i2c_common.c

   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
  26 int 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 }
  54 EXPORT_SYMBOL_GPL(cyttsp_i2c_read_block_data);
  55
  56 int 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 }
  81 EXPORT_SYMBOL_GPL(cyttsp_i2c_write_block_data);
  82
  83
  84 MODULE_LICENSE("GPL");
  85 MODULE_AUTHOR("Cypress");