a12894c6dc
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@18066 a1c6a512-1295-4272-9138-f99709370657
125 lines
3.8 KiB
C
125 lines
3.8 KiB
C
/***************************************************************************
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* __________ __ ___.
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* Open \______ \ ____ ____ | | _\_ |__ _______ ___
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* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
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* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
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* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
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* \/ \/ \/ \/ \/
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* $Id$
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*
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* Copyright (C) 2007 by Jens Arnold
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
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* KIND, either express or implied.
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*
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****************************************************************************/
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#include "config.h"
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#include "cpu.h"
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#include "hwcompat.h"
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#include "kernel.h"
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#include "adc.h"
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#include "adc-target.h"
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static struct mutex adc_mtx SHAREDBSS_ATTR;
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/* used in the 2nd gen ADC interrupt */
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static unsigned int_data;
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static int int_status = -1;
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unsigned short adc_scan(int channel)
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{
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unsigned short data = 0;
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(void)channel; /* there is only one */
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mutex_lock(&adc_mtx);
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if ((IPOD_HW_REVISION >> 16) == 1)
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{
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int i, j;
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unsigned pval = GPIOB_OUTPUT_VAL;
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GPIOB_OUTPUT_VAL = pval | 0x04; /* B2 -> high */
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for (i = 32; i > 0; --i);
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GPIOB_OUTPUT_VAL = pval; /* B2 -> low */
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for (i = 200; i > 0; --i);
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for (j = 0; j < 8; j++)
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{
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GPIOB_OUTPUT_VAL = pval | 0x02; /* B1 -> high */
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for (i = 8; i > 0; --i);
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data = (data << 1) | ((GPIOB_INPUT_VAL & 0x08) >> 3);
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GPIOB_OUTPUT_VAL = pval; /* B1 -> low */
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for (i = 320; i > 0; --i);
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}
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}
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else if ((IPOD_HW_REVISION >> 16) == 2)
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{
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int_status = 0;
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GPIOB_INT_LEV |= 0x04; /* high active */
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GPIOB_INT_EN |= 0x04; /* enable interrupt */
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GPIOB_OUTPUT_VAL |= 0x0a; /* B1, B3 -> high: start conversion */
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while (int_status >= 0)
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yield();
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data = int_data & 0xff;
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}
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mutex_unlock(&adc_mtx);
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return data;
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}
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/* Used for 2nd gen only. Conversion can take several milliseconds there. */
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void ipod_2g_adc_int(void)
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{
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if (GPIOB_INPUT_VAL & 0x04)
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{
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int_data = (int_data << 1) | ((GPIOB_INPUT_VAL & 0x10) >> 4);
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GPIOB_OUTPUT_VAL &= ~0x0a; /* B1, B3 -> low */
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/* B3 needs to be set low in the first call only, but then stays low
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* anyway so no need for special handling */
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}
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else
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{
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if (++int_status > 8)
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{
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GPIOB_INT_EN &= ~0x04;
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int_status = -1;
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}
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else
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GPIOB_OUTPUT_VAL |= 0x02; /* B1 -> high */
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}
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GPIOB_INT_LEV ^= 0x04; /* toggle interrupt level */
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GPIOB_INT_CLR = 0x04; /* acknowledge interrupt */
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}
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void adc_init(void)
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{
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mutex_init(&adc_mtx);
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GPIOB_ENABLE |= 0x1e; /* enable B1..B4 */
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if ((IPOD_HW_REVISION >> 16) == 1)
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{
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GPIOB_OUTPUT_EN = (GPIOB_OUTPUT_EN & ~0x08) | 0x16;
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/* B1, B2, B4 -> output, B3 -> input */
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GPIOB_OUTPUT_VAL = (GPIOB_OUTPUT_VAL & ~0x06) | 0x10;
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/* B1, B2 -> low, B4 -> high */
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}
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else if ((IPOD_HW_REVISION >> 16) == 2)
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{
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GPIOB_OUTPUT_EN = (GPIOB_OUTPUT_EN & ~0x14) | 0x0a;
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/* B1, B3 -> output, B2, B4 -> input */
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GPIOB_OUTPUT_VAL &= ~0x0a; /* B1, B3 -> low */
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while (GPIOB_INPUT_VAL & 0x04); /* wait for B2 == 0 */
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}
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}
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