a4a3cd9d52
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@14082 a1c6a512-1295-4272-9138-f99709370657
100 lines
3.2 KiB
C
100 lines
3.2 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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* All files in this archive are subject to the GNU General Public License.
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* See the file COPYING in the source tree root for full license agreement.
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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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static struct mutex adc_mutex NOCACHEBSS_ATTR;
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unsigned short adc_scan(int channel)
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{
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int i, j;
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unsigned short data = 0;
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unsigned pval;
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(void)channel; /* there is only one */
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spinlock_lock(&adc_mutex);
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if ((IPOD_HW_REVISION >> 16) == 1)
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{
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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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pval = GPIOB_OUTPUT_VAL;
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GPIOB_OUTPUT_VAL = pval | 0x0a; /* B1, B3 -> high */
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while (!(GPIOB_INPUT_VAL & 0x04)); /* wait for B2 == 1 */
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GPIOB_OUTPUT_VAL = pval; /* B1, B3 -> low */
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while (GPIOB_INPUT_VAL & 0x04); /* wait for B2 == 0 */
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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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while (!(GPIOB_INPUT_VAL & 0x04)); /* wait for B2 == 1 */
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data = (data << 1) | ((GPIOB_INPUT_VAL & 0x10) >> 4);
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GPIOB_OUTPUT_VAL = pval; /* B1 -> 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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spinlock_unlock(&adc_mutex);
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return data;
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}
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void adc_init(void)
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{
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spinlock_init(&adc_mutex);
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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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