drivers/watchdog/wdt-uclass.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright 2017 Google, Inc
   4  */
   5
   6 #include <common.h>
   7 #include <dm.h>
   8 #include <errno.h>
   9 #include <hang.h>
  10 #include <log.h>
  11 #include <time.h>
  12 #include <wdt.h>
  13 #include <dm/device-internal.h>
  14 #include <dm/lists.h>
  15
  16 DECLARE_GLOBAL_DATA_PTR;
  17
  18 #define WATCHDOG_TIMEOUT_SECS   (CONFIG_WATCHDOG_TIMEOUT_MSECS / 1000)
  19
  20 /*
  21  * Reset every 1000ms, or however often is required as indicated by a
  22  * hw_margin_ms property.
  23  */
  24 static ulong reset_period = 1000;
  25
  26 int initr_watchdog(void)
  27 {
  28         u32 timeout = WATCHDOG_TIMEOUT_SECS;
  29
  30         /*
  31          * Init watchdog: This will call the probe function of the
  32          * watchdog driver, enabling the use of the device
  33          */
  34         if (uclass_get_device_by_seq(UCLASS_WDT, 0,
  35                                      (struct udevice **)&gd->watchdog_dev)) {
  36                 debug("WDT:   Not found by seq!\n");
  37                 if (uclass_get_device(UCLASS_WDT, 0,
  38                                       (struct udevice **)&gd->watchdog_dev)) {
  39                         printf("WDT:   Not found!\n");
  40                         return 0;
  41                 }
  42         }
  43
  44         if (CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)) {
  45                 timeout = dev_read_u32_default(gd->watchdog_dev, "timeout-sec",
  46                                                WATCHDOG_TIMEOUT_SECS);
  47                 reset_period = dev_read_u32_default(gd->watchdog_dev,
  48                                                     "hw_margin_ms",
  49                                                     4 * reset_period) / 4;
  50         }
  51
  52         wdt_start(gd->watchdog_dev, timeout * 1000, 0);
  53         gd->flags |= GD_FLG_WDT_READY;
  54         printf("WDT:   Started with%s servicing (%ds timeout)\n",
  55                IS_ENABLED(CONFIG_WATCHDOG) ? "" : "out", timeout);
  56
  57         return 0;
  58 }
  59
  60 int wdt_start(struct udevice *dev, u64 timeout_ms, ulong flags)
  61 {
  62         const struct wdt_ops *ops = device_get_ops(dev);
  63
  64         if (!ops->start)
  65                 return -ENOSYS;
  66
  67         return ops->start(dev, timeout_ms, flags);
  68 }
  69
  70 int wdt_stop(struct udevice *dev)
  71 {
  72         const struct wdt_ops *ops = device_get_ops(dev);
  73
  74         if (!ops->stop)
  75                 return -ENOSYS;
  76
  77         return ops->stop(dev);
  78 }
  79
  80 int wdt_reset(struct udevice *dev)
  81 {
  82         const struct wdt_ops *ops = device_get_ops(dev);
  83
  84         if (!ops->reset)
  85                 return -ENOSYS;
  86
  87         return ops->reset(dev);
  88 }
  89
  90 int wdt_expire_now(struct udevice *dev, ulong flags)
  91 {
  92         int ret = 0;
  93         const struct wdt_ops *ops;
  94
  95         debug("WDT Resetting: %lu\n", flags);
  96         ops = device_get_ops(dev);
  97         if (ops->expire_now) {
  98                 return ops->expire_now(dev, flags);
  99         } else {
 100                 if (!ops->start)
 101                         return -ENOSYS;
 102
 103                 ret = ops->start(dev, 1, flags);
 104                 if (ret < 0)
 105                         return ret;
 106
 107                 hang();
 108         }
 109
 110         return ret;
 111 }
 112
 113 #if defined(CONFIG_WATCHDOG)
 114 /*
 115  * Called by macro WATCHDOG_RESET. This function be called *very* early,
 116  * so we need to make sure, that the watchdog driver is ready before using
 117  * it in this function.
 118  */
 119 void watchdog_reset(void)
 120 {
 121         static ulong next_reset;
 122         ulong now;
 123
 124         /* Exit if GD is not ready or watchdog is not initialized yet */
 125         if (!gd || !(gd->flags & GD_FLG_WDT_READY))
 126                 return;
 127
 128         /* Do not reset the watchdog too often */
 129         now = get_timer(0);
 130         if (time_after(now, next_reset)) {
 131                 next_reset = now + reset_period;
 132                 wdt_reset(gd->watchdog_dev);
 133         }
 134 }
 135 #endif
 136
 137 static int wdt_post_bind(struct udevice *dev)
 138 {
 139 #if defined(CONFIG_NEEDS_MANUAL_RELOC)
 140         struct wdt_ops *ops = (struct wdt_ops *)device_get_ops(dev);
 141         static int reloc_done;
 142
 143         if (!reloc_done) {
 144                 if (ops->start)
 145                         ops->start += gd->reloc_off;
 146                 if (ops->stop)
 147                         ops->stop += gd->reloc_off;
 148                 if (ops->reset)
 149                         ops->reset += gd->reloc_off;
 150                 if (ops->expire_now)
 151                         ops->expire_now += gd->reloc_off;
 152
 153                 reloc_done++;
 154         }
 155 #endif
 156         return 0;
 157 }
 158
 159 UCLASS_DRIVER(wdt) = {
 160         .id             = UCLASS_WDT,
 161         .name           = "watchdog",
 162         .flags          = DM_UC_FLAG_SEQ_ALIAS,
 163         .post_bind      = wdt_post_bind,
 164 };