drivers/bootcount/bootcount_at91.c

   1 /*
   2  * See file CREDITS for list of people who contributed to this
   3  * project.
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License as
   7  * published by the Free Software Foundation; either version 2 of
   8  * the License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  */
  16
  17 #include <common.h>
  18 #include <asm/io.h>
  19 #include <asm/arch/hardware.h>
  20 #include <asm/arch/at91_gpbr.h>
  21
  22 /*
  23  * We combine the BOOTCOUNT_MAGIC and bootcount in one 32-bit register.
  24  * This is done so we need to use only one of the four GPBR registers.
  25  */
  26 void bootcount_store(ulong a)
  27 {
  28         at91_gpbr_t *gpbr = (at91_gpbr_t *) ATMEL_BASE_GPBR;
  29
  30         writel((BOOTCOUNT_MAGIC & 0xffff0000) | (a & 0x0000ffff),
  31                 &gpbr->reg[AT91_GPBR_INDEX_BOOTCOUNT]);
  32 }
  33
  34 ulong bootcount_load(void)
  35 {
  36         at91_gpbr_t *gpbr = (at91_gpbr_t *) ATMEL_BASE_GPBR;
  37
  38         ulong val = readl(&gpbr->reg[AT91_GPBR_INDEX_BOOTCOUNT]);
  39         if ((val & 0xffff0000) != (BOOTCOUNT_MAGIC & 0xffff0000))
  40                 return 0;
  41         else
  42                 return val & 0x0000ffff;
  43 }