firmware/drivers/qt1106.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2008 by Frank Gevaerts
  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
  22 #include "qt1106.h"
  23 #include "cpu.h"
  24 #include "system.h"
  25
  26
  27 #define SPIDELAY(_x) void(_x);
  28 #define SETMOSI() (PDAT1 |= (1 << 6))
  29 #define CLRMOSI() (PDAT1 &= ~(1 << 6))
  30
  31 #define MISO ((PDAT0 >> 3) & 1)
  32 #define RDY (PDAT1 & (1 << 5))
  33
  34 #define SETCLK() (PDAT0 |= (1 << 1))
  35 #define CLRCLK() (PDAT0 &= ~(1 << 1))
  36
  37 #define SETSS() (PDAT0 |= (1 << 0))
  38 #define CLRSS() (PDAT0 &= ~(1 << 0))
  39
  40 #define CHANGE (PDAT0 & (1 << 4))
  41
  42
  43 void init_qt1106(void)
  44 {
  45     int oldval;
  46
  47     oldval = PCON0;
  48     //Set P0.0 and P0.1 to output, set P0.3 and P0.4 to input
  49     PCON0 = ((oldval & ~(3 << 0 | 3 << 2 | 3 << 6 | 3 << 8)) | (1 << 0 | 1 << 2));
  50
  51     oldval = PCON1;
  52     //Set P1.5 to input, set P1.6 to output
  53     PCON1 = ((oldval & ~(0xf << 20 | 0xf << 24)) | (1 << 24));
  54
  55
  56     SETSS();
  57     SETCLK();
  58 }
  59
  60 static inline void delay(int duration)
  61 {
  62     volatile int i;
  63     for(i=0;i<duration;i++);
  64 }
  65
  66 void qt1106_wait(void)
  67 {
  68     while(!(PDAT0 & (1 << 4))) {}
  69 }
  70
  71 unsigned int qt1106_io(unsigned int output)
  72 {
  73     unsigned int input = 0;
  74     int i;
  75
  76     while(!RDY) {}
  77
  78     delay(10);  // < 470 us
  79
  80     CLRSS();
  81     delay(13); // > 22 us
  82
  83     for (i = 0; i < 24; i++) {
  84
  85         CLRCLK();
  86
  87         if (output & (1 << 23))
  88             SETMOSI();
  89         else
  90             CLRMOSI();
  91         output <<= 1;
  92
  93         delay(20); // >> 6.7 us
  94
  95         SETCLK();
  96
  97         input <<= 1;
  98         input |= MISO;
  99
 100         delay(20); // >> 6.7 us
 101     }
 102
 103     SETSS();
 104
 105     return (input);
 106 }
 107
 108