drivers/bootcount/bootcount_blackfin.c

   1 /*
   2  * functions for handling bootcount support
   3  *
   4  * Copyright (c) 2010 Analog Devices Inc.
   5  *
   6  * Licensed under the 2-clause BSD.
   7  */
   8
   9 /* This version uses one 32bit storage and combines the magic/count */
  10
  11 #include <common.h>
  12
  13 /* We abuse the EVT0 MMR for bootcount storage by default */
  14 #ifndef CONFIG_SYS_BOOTCOUNT_ADDR
  15 # define CONFIG_SYS_BOOTCOUNT_ADDR EVT0
  16 #endif
  17
  18 #define MAGIC_MASK 0xffff0000
  19 #define COUNT_MASK 0x0000ffff
  20
  21 void bootcount_store(ulong cnt)
  22 {
  23         ulong magic = (BOOTCOUNT_MAGIC & MAGIC_MASK) | (cnt & COUNT_MASK);
  24         bfin_write32(CONFIG_SYS_BOOTCOUNT_ADDR, magic);
  25 }
  26
  27 ulong bootcount_load(void)
  28 {
  29         ulong magic = bfin_read32(CONFIG_SYS_BOOTCOUNT_ADDR);
  30         if ((magic & MAGIC_MASK) == (BOOTCOUNT_MAGIC & MAGIC_MASK))
  31                 return magic & COUNT_MASK;
  32         else
  33                 return 0;
  34 }