| Dave Chapman | 657dcb5 | 2006-08-31 19:19:35 +0000 | [diff] [blame] | 1 | /*************************************************************************** |
| 2 | * __________ __ ___. |
| 3 | * Open \______ \ ____ ____ | | _\_ |__ _______ ___ |
| 4 | * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / |
| 5 | * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < |
| 6 | * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ |
| 7 | * \/ \/ \/ \/ \/ |
| 8 | * $Id$ |
| 9 | * |
| 10 | * Copyright (C) 2006 by Barry Wardell |
| 11 | * |
| Daniel Stenberg | 2acc0ac | 2008-06-28 18:10:04 +0000 | [diff] [blame^] | 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. |
| Dave Chapman | 657dcb5 | 2006-08-31 19:19:35 +0000 | [diff] [blame] | 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 | static unsigned short adcdata[NUM_ADC_CHANNELS]; |
| 29 | |
| 30 | /* Scan ADC so that adcdata[channel] gets updated */ |
| 31 | unsigned short adc_scan(int channel) |
| 32 | { |
| 33 | unsigned int adc_data_1; |
| 34 | unsigned int adc_data_2; |
| 35 | |
| 36 | /* Initialise */ |
| 37 | ADC_ADDR=0x130; |
| 38 | ADC_STATUS=0; /* 4 bytes, 1 per channel. Each byte is 0 if the channel is |
| 39 | off, 0x40 if the channel is on */ |
| 40 | |
| 41 | /* Enable Channel */ |
| 42 | ADC_ADDR |= (0x1000000<<channel); |
| 43 | |
| 44 | /* Start? */ |
| 45 | ADC_ADDR |= 0x20000000; |
| 46 | ADC_ADDR |= 0x80000000; |
| 47 | |
| 48 | /* ADC_DATA_1 and ADC_DATA_2 are both four bytes, one byte per channel. |
| 49 | For each channel, ADC_DATA_1 stores the 8-bit msb, ADC_DATA_2 stores the |
| 50 | 2-bit lsb (in bits 0 and 1). Each channel is 10 bits total. */ |
| 51 | adc_data_1 = ((ADC_DATA_1 >> (8*channel)) & 0xff); |
| 52 | adc_data_2 = ((ADC_DATA_2 >> (8*channel+6)) & 0x3); |
| 53 | |
| 54 | adcdata[channel] = (adc_data_1<<2 | adc_data_2); |
| 55 | |
| 56 | return adcdata[channel]; |
| 57 | } |
| 58 | |
| 59 | /* Read 10-bit channel data */ |
| 60 | unsigned short adc_read(int channel) |
| 61 | { |
| 62 | return adcdata[channel]; |
| 63 | } |
| 64 | |
| 65 | static int adc_counter; |
| 66 | |
| 67 | static void adc_tick(void) |
| 68 | { |
| 69 | if(++adc_counter == HZ) |
| 70 | { |
| 71 | adc_counter = 0; |
| 72 | adc_scan(ADC_BATTERY); |
| 73 | adc_scan(ADC_UNKNOWN_1); |
| 74 | adc_scan(ADC_UNKNOWN_2); |
| 75 | adc_scan(ADC_SCROLLPAD); |
| 76 | } |
| 77 | } |
| 78 | |
| 79 | void adc_init(void) |
| 80 | { |
| 81 | /* Enable ADC */ |
| 82 | ADC_ENABLE_ADDR |= ADC_ENABLE; |
| 83 | |
| 84 | /* Initialise */ |
| 85 | ADC_INIT=0; |
| 86 | ADC_ADDR=0x130; |
| 87 | ADC_STATUS=0; |
| 88 | |
| 89 | /* Enable Channels 1-4 */ |
| 90 | ADC_ADDR |= 0x1000000; |
| 91 | ADC_ADDR |= 0x2000000; |
| 92 | ADC_ADDR |= 0x4000000; |
| 93 | ADC_ADDR |= 0x8000000; |
| 94 | |
| 95 | /* Start? */ |
| 96 | ADC_ADDR |= 0x20000000; |
| 97 | ADC_ADDR |= 0x80000000; |
| 98 | |
| 99 | /* Wait 50ms for things to settle */ |
| 100 | sleep(HZ/20); |
| 101 | |
| 102 | tick_add_task(adc_tick); |
| 103 | } |