post/cpu/ppc4xx/ocm.c

   1 /*
   2  * (C) Copyright 2008 Ilya Yanok, EmCraft Systems, yanok@emcraft.com
   3  *
   4  * Developed for DENX Software Engineering GmbH
   5  *
   6  * SPDX-License-Identifier:     GPL-2.0+
   7  */
   8 #include <common.h>
   9
  10 /*
  11  * This test attempts to verify on-chip memory (OCM). Result is written
  12  * to the scratch register and if test succeed it won't be run till next
  13  * power on.
  14  */
  15
  16 #include <post.h>
  17
  18 #include <asm/io.h>
  19
  20 DECLARE_GLOBAL_DATA_PTR;
  21
  22 #define OCM_TEST_PATTERN1       0x55555555
  23 #define OCM_TEST_PATTERN2       0xAAAAAAAA
  24
  25 #if CONFIG_POST & CONFIG_SYS_POST_OCM
  26
  27 static uint ocm_status_read(void)
  28 {
  29         return in_be32((void *)CONFIG_SYS_OCM_STATUS_ADDR) &
  30                 CONFIG_SYS_OCM_STATUS_MASK;
  31 }
  32
  33 static void ocm_status_write(uint value)
  34 {
  35         out_be32((void *)CONFIG_SYS_OCM_STATUS_ADDR, value |
  36                 (in_be32((void *)CONFIG_SYS_OCM_STATUS_ADDR) &
  37                         ~CONFIG_SYS_OCM_STATUS_MASK));
  38 }
  39
  40 static inline int ocm_test_word(uint value, uint *address)
  41 {
  42         uint read_value;
  43
  44         *address = value;
  45         sync();
  46         read_value = *address;
  47
  48         return (read_value != value);
  49 }
  50
  51 int ocm_post_test(int flags)
  52 {
  53         uint   old_value;
  54         int    ret = 0;
  55         uint  *address = (uint*)CONFIG_SYS_OCM_BASE;
  56
  57         if (ocm_status_read() == CONFIG_SYS_OCM_STATUS_OK)
  58                 return 0;
  59         for (; address < (uint*)(CONFIG_SYS_OCM_BASE + CONFIG_SYS_OCM_SIZE); address++) {
  60                 old_value = *address;
  61                 if (ocm_test_word(OCM_TEST_PATTERN1, address) ||
  62                                 ocm_test_word(OCM_TEST_PATTERN2, address)) {
  63                         ret = 1;
  64                         *address = old_value;
  65                         printf("OCM POST failed at %p!\n", address);
  66                         break;
  67                 }
  68                 *address = old_value;
  69         }
  70         ocm_status_write(ret ? CONFIG_SYS_OCM_STATUS_FAIL : CONFIG_SYS_OCM_STATUS_OK);
  71         return ret;
  72 }
  73 #endif /* CONFIG_POST & CONFIG_SYS_POST_OCM */