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 "generic_i2c.h"
  23 #include "synaptics-rmi.h"
  24
  25 static int rmi_cur_page;
  26 static int rmi_i2c_addr;
  27 static int rmi_i2c_bus;
  28
  29 /* NOTE:
  30  * RMI over i2c supports some special aliases on page 0x2 but this driver don't
  31  * use them */
  32
  33 int rmi_init(int i2c_bus_index, int i2c_dev_addr)
  34 {
  35     rmi_i2c_bus = i2c_bus_index;
  36     rmi_i2c_addr = i2c_dev_addr;
  37     rmi_cur_page = 0x4;
  38     return 0;
  39 }
  40
  41 static int rmi_select_page(unsigned char page)
  42 {
  43     /* Lazy page select */
  44     if(page != rmi_cur_page)
  45     {
  46         rmi_cur_page = page;
  47         return i2c_write_data(rmi_i2c_bus, rmi_i2c_addr, RMI_PAGE_SELECT, &page, 1);
  48     }
  49     else
  50         return 0;
  51 }
  52
  53 int rmi_read(int address, int byte_count, unsigned char *buffer)
  54 {
  55     if(rmi_select_page(address >> 8) < 0)
  56         return -1;
  57     return i2c_read_data(rmi_i2c_bus, rmi_i2c_addr, address & 0xff, buffer, byte_count);
  58 }
  59
  60 int rmi_read_single(int address)
  61 {
  62     unsigned char c;
  63     int ret = rmi_read(address, 1, &c);
  64     return ret < 0 ? ret : c;
  65 }
  66
  67 int rmi_write(int address, int byte_count, const unsigned char *buffer)
  68 {
  69     if(rmi_select_page(address >> 8) < 0)
  70         return -1;
  71     return i2c_write_data(rmi_i2c_bus, 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 }