| /*************************************************************************** |
| * __________ __ ___. |
| * Open \______ \ ____ ____ | | _\_ |__ _______ ___ |
| * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / |
| * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < |
| * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ |
| * \/ \/ \/ \/ \/ |
| * $Id$ |
| * |
| * Copyright (C) 2004 by Jens Arnold |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version 2 |
| * of the License, or (at your option) any later version. |
| * |
| * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY |
| * KIND, either express or implied. |
| * |
| ****************************************************************************/ |
| #include "config.h" |
| #include "sdmmc.h" |
| |
| /* helper function to extract n (<=32) bits from an arbitrary position. |
| counting from MSB to LSB */ |
| unsigned long card_extract_bits( |
| const unsigned long *p, /* the start of the bitfield array */ |
| unsigned int start, /* bit no. to start reading */ |
| unsigned int size) /* how many bits to read */ |
| { |
| unsigned int long_index, bit_index; |
| unsigned long result; |
| |
| /* we assume words of CSD/CID are stored most significant word first */ |
| start = 127 - start; |
| |
| long_index = start / 32; |
| bit_index = start % 32; |
| |
| result = p[long_index] << bit_index; |
| |
| if (bit_index + size > 32) /* crossing longword boundary */ |
| result |= p[long_index+1] >> (32 - bit_index); |
| |
| result >>= 32 - size; |
| |
| return result; |
| } |