post/board/lwmon5/watchdog.c

   1 /*
   2  * (C) Copyright 2008 Dmitry Rakhchev, EmCraft Systems, rda@emcraft.com
   3  *
   4  * Developed for DENX Software Engineering GmbH
   5  *
   6  * See file CREDITS for list of people who contributed to this
   7  * project.
   8  *
   9  * This program is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU General Public License as
  11  * published by the Free Software Foundation; either version 2 of
  12  * the License, or (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  22  * MA 02111-1307 USA
  23  */
  24
  25 #include <common.h>
  26
  27 /* This test verifies if the reason of last reset was an abnormal voltage
  28  * condition, than it performs watchdog test, measuing time required to
  29  * trigger watchdog reset.
  30  */
  31
  32 #include <post.h>
  33
  34 #if CONFIG_POST & CFG_POST_WATCHDOG
  35
  36 #include <watchdog.h>
  37 #include <asm/gpio.h>
  38 #include <asm/io.h>
  39
  40 static uint watchdog_magic_read(void)
  41 {
  42         return in_be32((void *)CFG_WATCHDOG_FLAGS_ADDR) &
  43                 CFG_WATCHDOG_MAGIC_MASK;
  44 }
  45
  46 static void watchdog_magic_write(uint value)
  47 {
  48         out_be32((void *)CFG_WATCHDOG_FLAGS_ADDR, value |
  49                 (in_be32((void *)CFG_WATCHDOG_FLAGS_ADDR) &
  50                         ~CFG_WATCHDOG_MAGIC_MASK));
  51 }
  52
  53 int sysmon1_post_test(int flags)
  54 {
  55         if (gpio_read_in_bit(CFG_GPIO_SYSMON_STATUS) == 0) {
  56                 /*
  57                  * 3.1. GPIO62 is low
  58                  * Assuming system voltage failure.
  59                  */
  60                 post_log("Abnormal voltage detected (GPIO62)\n");
  61                 return 1;
  62         }
  63
  64         return 0;
  65 }
  66
  67 int lwmon5_watchdog_post_test(int flags)
  68 {
  69         /* On each reset scratch register 1 should be tested,
  70          * but first test GPIO62:
  71          */
  72         if (!(flags & POST_MANUAL) && sysmon1_post_test(flags)) {
  73                 /* 3.1. GPIO62 is low
  74                  * Assuming system voltage failure.
  75                  */
  76                 /* 3.1.1. Set scratch register 1 to 0x0000xxxx */
  77                 watchdog_magic_write(0);
  78                 /* 3.1.2. Mark test as failed due to voltage?! */
  79                 return 1;
  80         }
  81
  82         if (watchdog_magic_read() != CFG_WATCHDOG_MAGIC) {
  83                 /* 3.2. Scratch register 1 differs from magic value 0x1248xxxx
  84                  * Assuming PowerOn
  85                  */
  86                 int ints;
  87                 ulong base;
  88                 ulong time;
  89
  90                 /* 3.2.1. Set magic value to scratch register */
  91                 watchdog_magic_write(CFG_WATCHDOG_MAGIC);
  92
  93                 ints = disable_interrupts ();
  94                 /* 3.2.2. strobe watchdog once */
  95                 WATCHDOG_RESET();
  96                 out_be32((void *)CFG_WATCHDOG_TIME_ADDR, 0);
  97                 /* 3.2.3. save time of strobe in scratch register 2 */
  98                 base = post_time_ms (0);
  99
 100                 /* 3.2.4. Wait for 150 ms (enough for reset to happen) */
 101                 while ((time = post_time_ms (base)) < 150)
 102                         out_be32((void *)CFG_WATCHDOG_TIME_ADDR, time);
 103                 if (ints)
 104                         enable_interrupts ();
 105
 106                 /* 3.2.5. Reset didn't happen. - Set 0x0000xxxx
 107                  * into scratch register 1
 108                  */
 109                 watchdog_magic_write(0);
 110                 /* 3.2.6. Mark test as failed. */
 111                 post_log("hw watchdog time : %u ms, failed ", time);
 112                 return 2;
 113         } else {
 114                 /* 3.3. Scratch register matches magic value 0x1248xxxx
 115                  * Assume this is watchdog-initiated reset
 116                  */
 117                 ulong time;
 118                 /* 3.3.1. So, the test succeed, save measured time to syslog. */
 119                 time = in_be32((void *)CFG_WATCHDOG_TIME_ADDR);
 120                 post_log("hw watchdog time : %u ms, passed ", time);
 121                 /* 3.3.2. Set scratch register 1 to 0x0000xxxx */
 122                 watchdog_magic_write(0);
 123                 return 0;
 124         }
 125         return -1;
 126 }
 127
 128 #endif /* CONFIG_POST & CFG_POST_WATCHDOG */