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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 | /* SPDX-License-Identifier: GPL-2.0+ */ /* * Copyright 2017 Google, Inc */ #ifndef _WDT_H_ #define _WDT_H_ #include <dm.h> #include <dm/read.h> /* * Implement a simple watchdog uclass. Watchdog is basically a timer that * is used to detect or recover from malfunction. During normal operation * the watchdog would be regularly reset to prevent it from timing out. * If, due to a hardware fault or program error, the computer fails to reset * the watchdog, the timer will elapse and generate a timeout signal. * The timeout signal is used to initiate corrective action or actions, * which typically include placing the system in a safe, known state. */ /* * Start the timer * * @dev: WDT Device * @timeout_ms: Number of ticks (milliseconds) before timer expires * @flags: Driver specific flags. This might be used to specify * which action needs to be executed when the timer expires * @return: 0 if OK, -ve on error */ int wdt_start(struct udevice *dev, u64 timeout_ms, ulong flags); /* * Stop the timer, thus disabling the Watchdog. Use wdt_start to start it again. * * @dev: WDT Device * @return: 0 if OK, -ve on error */ int wdt_stop(struct udevice *dev); /* * Reset the timer, typically restoring the counter to * the value configured by start() * * @dev: WDT Device * @return: 0 if OK, -ve on error */ int wdt_reset(struct udevice *dev); /* * Expire the timer, thus executing its action immediately. * This is typically used to reset the board or peripherals. * * @dev: WDT Device * @flags: Driver specific flags * @return 0 if OK -ve on error. If wdt action is system reset, * this function may never return. */ int wdt_expire_now(struct udevice *dev, ulong flags); /* * struct wdt_ops - Driver model wdt operations * * The uclass interface is implemented by all wdt devices which use * driver model. */ struct wdt_ops { /* * Start the timer * * @dev: WDT Device * @timeout_ms: Number of ticks (milliseconds) before the timer expires * @flags: Driver specific flags. This might be used to specify * which action needs to be executed when the timer expires * @return: 0 if OK, -ve on error */ int (*start)(struct udevice *dev, u64 timeout_ms, ulong flags); /* * Stop the timer * * @dev: WDT Device * @return: 0 if OK, -ve on error */ int (*stop)(struct udevice *dev); /* * Reset the timer, typically restoring the counter to * the value configured by start() * * @dev: WDT Device * @return: 0 if OK, -ve on error */ int (*reset)(struct udevice *dev); /* * Expire the timer, thus executing the action immediately (optional) * * If this function is not provided, a default implementation * will be used, which sets the counter to 1 * and waits forever. This is good enough for system level * reset, where the function is not expected to return, but might not be * good enough for other use cases. * * @dev: WDT Device * @flags: Driver specific flags * @return 0 if OK -ve on error. May not return. */ int (*expire_now)(struct udevice *dev, ulong flags); }; #if CONFIG_IS_ENABLED(WDT) #ifndef CONFIG_WATCHDOG_TIMEOUT_MSECS #define CONFIG_WATCHDOG_TIMEOUT_MSECS (60 * 1000) #endif #define WATCHDOG_TIMEOUT_SECS (CONFIG_WATCHDOG_TIMEOUT_MSECS / 1000) static inline int initr_watchdog(void) { u32 timeout = WATCHDOG_TIMEOUT_SECS; /* * Init watchdog: This will call the probe function of the * watchdog driver, enabling the use of the device */ if (uclass_get_device_by_seq(UCLASS_WDT, 0, (struct udevice **)&gd->watchdog_dev)) { debug("WDT: Not found by seq!\n"); if (uclass_get_device(UCLASS_WDT, 0, (struct udevice **)&gd->watchdog_dev)) { printf("WDT: Not found!\n"); return 0; } } if (CONFIG_IS_ENABLED(OF_CONTROL)) { timeout = dev_read_u32_default(gd->watchdog_dev, "timeout-sec", WATCHDOG_TIMEOUT_SECS); } wdt_start(gd->watchdog_dev, timeout * 1000, 0); gd->flags |= GD_FLG_WDT_READY; printf("WDT: Started with%s servicing (%ds timeout)\n", IS_ENABLED(CONFIG_WATCHDOG) ? "" : "out", timeout); return 0; } #endif #endif /* _WDT_H_ */ |