firmware/drivers/synaptics-rmi.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2011 by Amaury Pouly
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version 2
  15  * of the License, or (at your option) any later version.
  16  *
  17  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  18  * KIND, either express or implied.
  19  *
  20  ****************************************************************************/
  21 #include "system.h"
  22 #include "synaptics-rmi.h"
  23 #include "i2c.h"
  24
  25 static int rmi_cur_page;
  26 static int rmi_i2c_addr;
  27
  28 /* NOTE:
  29  * RMI over i2c supports some special aliases on page 0x2 but this driver don't
  30  * use them */
  31
  32 int rmi_init(int i2c_dev_addr)
  33 {
  34     rmi_i2c_addr = i2c_dev_addr;
  35     rmi_cur_page = 0x4;
  36     return 0;
  37 }
  38
  39 static int rmi_select_page(unsigned char page)
  40 {
  41     /* Lazy page select */
  42     if(page != rmi_cur_page)
  43     {
  44         rmi_cur_page = page;
  45         return i2c_writemem(rmi_i2c_addr, RMI_PAGE_SELECT, &page, 1);
  46     }
  47     else
  48         return 0;
  49 }
  50
  51 int rmi_read(int address, int byte_count, unsigned char *buffer)
  52 {
  53     int ret;
  54     if((ret = rmi_select_page(address >> 8)) < 0)
  55         return ret;
  56     return i2c_readmem(rmi_i2c_addr, address & 0xff, buffer, byte_count);
  57 }
  58
  59 int rmi_read_single(int address)
  60 {
  61     unsigned char c;
  62     int ret = rmi_read(address, 1, &c);
  63     return ret < 0 ? ret : c;
  64 }
  65
  66 int rmi_write(int address, int byte_count, const unsigned char *buffer)
  67 {
  68     int ret;
  69     if((ret = rmi_select_page(address >> 8)) < 0)
  70         return ret;
  71     return i2c_writemem(rmi_i2c_addr, address & 0xff, buffer, byte_count);
  72 }
  73
  74 int rmi_write_single(int address, unsigned char byte)
  75 {
  76     return rmi_write(address, 1, &byte);
  77 }