59 lines
1.5 KiB
C
59 lines
1.5 KiB
C
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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 version 2
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* as published by the Free Software Foundation
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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
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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static unsigned int fsdi_table[] = { 16, 24, 32, 40, 48, 64, 96, 128, 256 };
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int iso14443_fsdi_to_fsd(unsigned int *fsd, unsigned char fsdi)
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{
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/* ISO 14443-4:2000(E) Section 5.1. */
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if (fsdi > sizeof(fsdi_table)/sizeof(unsigned int))
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return -1;
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*fsd = fsdi_table[fsdi];
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return 0;
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}
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int iso14443_fsd_to_fsdi(unsigned char *fsdi, unsigned int fsd)
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{
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int i;
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for (i = 0; i < sizeof(fsdi_table)/sizeof(unsigned int); i++) {
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if (fsdi_table[i] == fsd) {
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*fsdi = i;
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return 0;
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}
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}
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return -1;
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}
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/* calculate the fsd that is equal or the closest smaller value
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* that can be coded as fsd */
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unsigned int iso14443_fsd_approx(unsigned int fsd)
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{
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unsigned int tbl_size = sizeof(fsdi_table)/sizeof(unsigned int);
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int i;
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for (i = tbl_size-1; i >= 0; i--) {
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if (fsdi_table[i] <= fsd)
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return fsdi_table[i];
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}
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/* not reached: return smallest possible FSD */
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return fsdi_table[0];
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}
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