drivers/watchdog/tangier_wdt.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (c) 2017 Intel Corporation
   4  */
   5 #include <common.h>
   6 #include <watchdog.h>
   7 #include <asm/scu.h>
   8
   9 /* Hardware timeout in seconds */
  10 #define WDT_PRETIMEOUT          15
  11 #define WDT_TIMEOUT_MIN         (1 + WDT_PRETIMEOUT)
  12 #define WDT_TIMEOUT_MAX         170
  13 #define WDT_DEFAULT_TIMEOUT     90
  14
  15 #ifndef CONFIG_WATCHDOG_TIMEOUT_MSECS
  16 #define WATCHDOG_HEARTBEAT 60000
  17 #else
  18 #define WATCHDOG_HEARTBEAT CONFIG_WATCHDOG_TIMEOUT_MSECS
  19 #endif
  20
  21 enum {
  22         SCU_WATCHDOG_START                      = 0,
  23         SCU_WATCHDOG_STOP                       = 1,
  24         SCU_WATCHDOG_KEEPALIVE                  = 2,
  25         SCU_WATCHDOG_SET_ACTION_ON_TIMEOUT      = 3,
  26 };
  27
  28 void hw_watchdog_reset(void)
  29 {
  30         static unsigned long last;
  31         unsigned long now;
  32
  33         if (gd->timer)
  34                 now = timer_get_us();
  35         else
  36                 now = rdtsc() / 1000;
  37
  38         /* Do not flood SCU */
  39         if (last > now)
  40                 last = 0;
  41
  42         if (unlikely((now - last) > (WDT_PRETIMEOUT / 2) * 1000000)) {
  43                 last = now;
  44                 scu_ipc_simple_command(IPCMSG_WATCHDOG_TIMER, SCU_WATCHDOG_KEEPALIVE);
  45         }
  46 }
  47
  48 int hw_watchdog_disable(void)
  49 {
  50         return scu_ipc_simple_command(IPCMSG_WATCHDOG_TIMER, SCU_WATCHDOG_STOP);
  51 }
  52
  53 void hw_watchdog_init(void)
  54 {
  55         u32 timeout = WATCHDOG_HEARTBEAT / 1000;
  56         int in_size;
  57         struct ipc_wd_start {
  58                 u32 pretimeout;
  59                 u32 timeout;
  60         } ipc_wd_start = { timeout - WDT_PRETIMEOUT, timeout };
  61
  62         /*
  63          * SCU expects the input size for watchdog IPC
  64          * to be based on 4 bytes
  65          */
  66         in_size = DIV_ROUND_UP(sizeof(ipc_wd_start), 4);
  67
  68         scu_ipc_command(IPCMSG_WATCHDOG_TIMER, SCU_WATCHDOG_START,
  69                         (u32 *)&ipc_wd_start, in_size, NULL, 0);
  70 }