u-boot/include/wdt.h
Rasmus Villemoes b4d9452c44 watchdog: move initr_watchdog() to wdt-uclass.c
This function is a bit large for an inline function, and for U-Boot
proper, it is called via a function pointer anyway (in board_r.c), so
cannot be inlined.

It will shortly set a global variable to be used by the
watchdog_reset() function in wdt-uclass.c, so this also allows making
that variable local to wdt-uclass.c.

The WATCHDOG_TIMEOUT_SECS define is not used elsewhere.

Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Reviewed-by: Stefan Roese <sr@denx.de>
2020-04-15 08:53:55 +02:00

112 lines
3.1 KiB
C

/* 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);
};
int initr_watchdog(void);
#endif /* _WDT_H_ */