73 lines
2.0 KiB
C
73 lines
2.0 KiB
C
/* wusbmote: Wiimote accessory to USB Adapter
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* Copyright (C) 2012-2014 Raphaël Assénat
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* The author may be contacted at raph@raphnet.net
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*/
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#include <avr/eeprom.h>
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#include <util/crc16.h>
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#include <stdint.h>
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#include <string.h>
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#include "eeprom.h"
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static uint16_t calc_geeprom_data_crc(void)
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{
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uint16_t crc = 0x0000;
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int i;
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/* Update the CRC */
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for (i=0; i<EEPROM_USED_SIZE_NOCRC; i++) {
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crc = _crc_xmodem_update(crc, ((uint8_t*)&g_eeprom_data)[i]);
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}
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return crc;
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}
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void eeprom_commit(void)
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{
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g_eeprom_data.crc16 = calc_geeprom_data_crc();
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/* Sync eeprom content */
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eeprom_update_block(&g_eeprom_data, EEPROM_BASE_PTR, EEPROM_USED_SIZE);
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}
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static char isCrcValid()
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{
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return g_eeprom_data.crc16 == calc_geeprom_data_crc();
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}
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// return 1 if eeprom was blank
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void eeprom_init(void)
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{
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eeprom_read_block(&g_eeprom_data, EEPROM_BASE_PTR, EEPROM_USED_SIZE);
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/* Detect new or corrupted content. Program default values if required. */
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if ((g_eeprom_data.magic != EEPROM_MAGIC) || !isCrcValid())
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{
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memset(&g_eeprom_data, 0, EEPROM_USED_SIZE);
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g_eeprom_data.magic = EEPROM_MAGIC;
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// Call application code to set application defaults
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eeprom_app_write_defaults();
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// Write the now valid content to the EEPROM at once.
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eeprom_commit();
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}
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eeprom_app_ready();
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}
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