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 /*
  28  * This test verifies if the reason of last reset was an abnormal voltage
  29  * condition, than it performs watchdog test, measuing time required to
  30  * trigger watchdog reset.
  31  */
  32
  33 #ifdef CONFIG_POST
  34
  35 #include <post.h>
  36
  37 #if CONFIG_POST & CFG_POST_WATCHDOG
  38
  39 #include <watchdog.h>
  40 #include <asm/gpio.h>
  41 #include <asm/io.h>
  42
  43 static uint watchdog_magic_read(void)
  44 {
  45         return in_be32((void *)CFG_WATCHDOG_FLAGS_ADDR) &
  46                 CFG_WATCHDOG_MAGIC_MASK;
  47 }
  48
  49 static void watchdog_magic_write(uint value)
  50 {
  51         out_be32((void *)CFG_WATCHDOG_FLAGS_ADDR, value |
  52                 (in_be32((void *)CFG_WATCHDOG_FLAGS_ADDR) &
  53                         ~CFG_WATCHDOG_MAGIC_MASK));
  54 }
  55
  56 int sysmon1_post_test(int flags)
  57 {
  58         if (gpio_read_in_bit(CFG_GPIO_SYSMON_STATUS)) {
  59                 /*
  60                  * 3.1. GPIO62 is low
  61                  * Assuming system voltage failure.
  62                  */
  63                 post_log("Abnormal voltage detected (GPIO62)\n");
  64                 return 1;
  65         }
  66
  67         return 0;
  68 }
  69
  70 int lwmon5_watchdog_post_test(int flags)
  71 {
  72         ulong time;
  73
  74         /* On each reset scratch register 1 should be tested,
  75          * but first test GPIO62:
  76          */
  77         if (!(flags & POST_MANUAL) && sysmon1_post_test(flags)) {
  78                 /*
  79                  * 3.1. GPIO62 is low
  80                  * Assuming system voltage failure.
  81                  */
  82                 /* 3.1.1. Set scratch register 1 to 0x0000xxxx */
  83                 watchdog_magic_write(0);
  84                 /* 3.1.2. Mark test as failed due to voltage?! */
  85                 return 1;
  86         }
  87
  88         if (watchdog_magic_read() != CFG_WATCHDOG_MAGIC) {
  89                 /*
  90                  * 3.2. Scratch register 1 differs from magic value 0x1248xxxx
  91                  * Assuming PowerOn
  92                  */
  93                 int ints;
  94                 ulong base;
  95
  96                 /* 3.2.1. Set magic value to scratch register */
  97                 watchdog_magic_write(CFG_WATCHDOG_MAGIC);
  98
  99                 ints = disable_interrupts ();
 100                 /* 3.2.2. strobe watchdog once */
 101                 WATCHDOG_RESET();
 102                 out_be32((void *)CFG_WATCHDOG_TIME_ADDR, 0);
 103                 /* 3.2.3. save time of strobe in scratch register 2 */
 104                 base = post_time_ms (0);
 105
 106                 /* 3.2.4. Wait for 150 ms (enough for reset to happen) */
 107                 while ((time = post_time_ms (base)) < 150)
 108                         out_be32((void *)CFG_WATCHDOG_TIME_ADDR, time);
 109                 if (ints)
 110                         enable_interrupts ();
 111
 112                 /*
 113                  * 3.2.5. Reset didn't happen. - Set 0x0000xxxx
 114                  * into scratch register 1
 115                  */
 116                 watchdog_magic_write(0);
 117                 /* 3.2.6. Mark test as failed. */
 118                 post_log("hw watchdog time : %u ms, failed ", time);
 119                 return 2;
 120         }
 121
 122         /*
 123          * 3.3. Scratch register matches magic value 0x1248xxxx
 124          * Assume this is watchdog-initiated reset
 125          */
 126         /* 3.3.1. So, the test succeed, save measured time to syslog. */
 127         time = in_be32((void *)CFG_WATCHDOG_TIME_ADDR);
 128         post_log("hw watchdog time : %u ms, passed ", time);
 129         /* 3.3.2. Set scratch register 1 to 0x0000xxxx */
 130         watchdog_magic_write(0);
 131
 132         return 0;
 133 }
 134
 135 #endif /* CONFIG_POST & CFG_POST_WATCHDOG */
 136 #endif /* CONFIG_POST */