firmware/target/arm/adc-pp5020.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2006 by Barry Wardell
  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 "config.h"
  22 #include "cpu.h"
  23 #include "system.h"
  24 #include "kernel.h"
  25 #include "thread.h"
  26 #include "adc.h"
  27
  28 #define ADC_ADDR            (*(volatile unsigned long*)(0x7000ad00))
  29 #define ADC_STATUS          (*(volatile unsigned long*)(0x7000ad04))
  30 #define ADC_DATA_1          (*(volatile unsigned long*)(0x7000ad20))
  31 #define ADC_DATA_2          (*(volatile unsigned long*)(0x7000ad24))
  32 #define ADC_INIT            (*(volatile unsigned long*)(0x7000ad2c))
  33
  34 static unsigned short adcdata[NUM_ADC_CHANNELS];
  35
  36 /* Scan ADC so that adcdata[channel] gets updated. */
  37 unsigned short adc_scan(int channel)
  38 {
  39     unsigned int adc_data_1;
  40     unsigned int adc_data_2;
  41
  42     if (channel >= NUM_ADC_CHANNELS)
  43         return 0;
  44
  45     /* Start conversion */
  46     ADC_ADDR |= 0x80000000;
  47
  48     /* Wait for conversion to complete */
  49     while((ADC_STATUS & (0x40<<8*channel))==0);
  50
  51     /* Stop conversion */
  52     ADC_ADDR &=~ 0x80000000;
  53
  54     /* ADC_DATA_1 and ADC_DATA_2 are both four bytes, one byte per channel.
  55        For each channel, ADC_DATA_1 stores the 8-bit msb, ADC_DATA_2 stores the
  56        2-bit lsb (in bits 0 and 1). Each channel is 10 bits total. */
  57     adc_data_1 = ((ADC_DATA_1 >> (8*channel)) & 0xff);
  58     adc_data_2 = ((ADC_DATA_2 >> (8*channel+6)) & 0x3);
  59
  60     adcdata[channel] = (adc_data_1<<2 | adc_data_2);
  61
  62 #if !defined(PHILIPS_HDD1630)
  63     /* ADC values read low if PLL is enabled */
  64     if(PLL_CONTROL & 0x80000000){
  65         adcdata[channel] += 0x14;
  66         if(adcdata[channel] > 0x400)
  67             adcdata[channel] = 0x400;
  68     }
  69 #endif
  70
  71     return adcdata[channel];
  72 }
  73
  74 /* Read 10-bit channel data */
  75 unsigned short adc_read(int channel)
  76 {
  77     return adcdata[channel];
  78 }
  79
  80 static int adc_counter;
  81
  82 static void adc_tick(void)
  83 {
  84     if(++adc_counter == HZ)
  85     {
  86         adc_counter = 0;
  87         adc_scan(0);
  88         adc_scan(1);
  89         adc_scan(2);
  90         adc_scan(3);
  91     }
  92 }
  93
  94 /* Figured out from how the OF does things */
  95 void adc_init(void)
  96 {
  97 #if defined(PHILIPS_HDD1630)
  98     ADC_INIT = 0;
  99 #else
 100     ADC_INIT |= 1;
 101     ADC_INIT |= 0x40000000;
 102 #endif
 103     udelay(100);
 104
 105     /* Reset ADC */
 106     DEV_RS2 |= 0x20;
 107     udelay(100);
 108
 109     DEV_RS2 &=~ 0x20;
 110     udelay(100);
 111
 112     /* Enable ADC */
 113     DEV_EN2 |= 0x20;
 114     udelay(100);
 115
 116     ADC_CLOCK_SRC |= 0x3;
 117     udelay(100);
 118
 119     ADC_ADDR = 0;
 120     ADC_ADDR |= 0x40;
 121
 122 #if !defined(PHILIPS_HDD1630)
 123     ADC_ADDR |= 0x20000000;
 124     udelay(100);
 125
 126     ADC_INIT;
 127     ADC_INIT = 0;
 128     udelay(100);
 129 #endif
 130
 131     ADC_STATUS = 0;
 132
 133     /* Enable channel 0 (battery) */
 134     DEV_INIT1  &=~0x3;
 135     ADC_ADDR   |= 0x1000000;
 136     ADC_STATUS |= 0x20;
 137
 138     /* Enable channel 1 (unknown) */
 139     DEV_INIT1  &=~30;
 140     ADC_ADDR   |= 0x2000000;
 141     ADC_STATUS |= 0x2000;
 142
 143 #if defined (IRIVER_H10) || defined(IRIVER_H10_5GB) || \
 144     defined(MROBE_100)
 145     /* Enable channel 2 (H10:remote) */
 146     DEV_INIT1  &=~0x300;
 147     DEV_INIT1  |= 0x100;
 148     ADC_ADDR   |= 0x4000000;
 149     ADC_STATUS |= 0x200000;
 150
 151     /* Enable channel 3 (H10:scroll pad) */
 152     DEV_INIT1  &=~0x3000;
 153     DEV_INIT1  |= 0x1000;
 154     ADC_ADDR   |= 0x8000000;
 155     ADC_STATUS |= 0x20000000;
 156 #endif
 157
 158 #if defined(PHILIPS_HDD1630)
 159     ADC_INIT |= 0x80000000;
 160     udelay(100);
 161     ADC_INIT = 0;
 162 #endif
 163
 164     /* Force a scan of all channels to get initial values */
 165     adc_scan(0);
 166     adc_scan(1);
 167     adc_scan(2);
 168     adc_scan(3);
 169
 170     tick_add_task(adc_tick);
 171 }