u-boot/drivers/watchdog/wdt-uclass.c
Samuel Holland a8f63d18bb watchdog: Automatically register device with sysreset
Add an option to automatically register watchdog devices with the
wdt_reboot driver for use with sysreset. This allows sysreset to be a
drop-in replacement for platform-specific watchdog reset code, without
needing any device tree changes.

Signed-off-by: Samuel Holland <samuel@sholland.org>
Reviewed-by: Stefan Roese <sr@denx.de>
2021-11-04 08:57:19 +01:00

285 lines
5.7 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright 2017 Google, Inc
*/
#define LOG_CATEGORY UCLASS_WDT
#include <common.h>
#include <dm.h>
#include <errno.h>
#include <hang.h>
#include <log.h>
#include <sysreset.h>
#include <time.h>
#include <wdt.h>
#include <asm/global_data.h>
#include <dm/device-internal.h>
#include <dm/lists.h>
DECLARE_GLOBAL_DATA_PTR;
#define WATCHDOG_TIMEOUT_SECS (CONFIG_WATCHDOG_TIMEOUT_MSECS / 1000)
struct wdt_priv {
/* Timeout, in seconds, to configure this device to. */
u32 timeout;
/*
* Time, in milliseconds, between calling the device's ->reset()
* method from watchdog_reset().
*/
ulong reset_period;
/*
* Next time (as returned by get_timer(0)) to call
* ->reset().
*/
ulong next_reset;
/* Whether watchdog_start() has been called on the device. */
bool running;
};
static void init_watchdog_dev(struct udevice *dev)
{
struct wdt_priv *priv;
int ret;
priv = dev_get_uclass_priv(dev);
if (IS_ENABLED(CONFIG_SYSRESET_WATCHDOG_AUTO)) {
ret = sysreset_register_wdt(dev);
if (ret)
printf("WDT: Failed to register %s for sysreset\n",
dev->name);
}
if (!IS_ENABLED(CONFIG_WATCHDOG_AUTOSTART)) {
printf("WDT: Not starting %s\n", dev->name);
return;
}
ret = wdt_start(dev, priv->timeout * 1000, 0);
if (ret != 0) {
printf("WDT: Failed to start %s\n", dev->name);
return;
}
printf("WDT: Started %s with%s servicing (%ds timeout)\n", dev->name,
IS_ENABLED(CONFIG_WATCHDOG) ? "" : "out", priv->timeout);
}
int initr_watchdog(void)
{
struct udevice *dev;
struct uclass *uc;
int ret;
ret = uclass_get(UCLASS_WDT, &uc);
if (ret) {
log_debug("Error getting UCLASS_WDT: %d\n", ret);
return 0;
}
uclass_foreach_dev(dev, uc) {
ret = device_probe(dev);
if (ret) {
log_debug("Error probing %s: %d\n", dev->name, ret);
continue;
}
init_watchdog_dev(dev);
}
gd->flags |= GD_FLG_WDT_READY;
return 0;
}
int wdt_start(struct udevice *dev, u64 timeout_ms, ulong flags)
{
const struct wdt_ops *ops = device_get_ops(dev);
int ret;
if (!ops->start)
return -ENOSYS;
ret = ops->start(dev, timeout_ms, flags);
if (ret == 0) {
struct wdt_priv *priv = dev_get_uclass_priv(dev);
priv->running = true;
}
return ret;
}
int wdt_stop(struct udevice *dev)
{
const struct wdt_ops *ops = device_get_ops(dev);
int ret;
if (!ops->stop)
return -ENOSYS;
ret = ops->stop(dev);
if (ret == 0) {
struct wdt_priv *priv = dev_get_uclass_priv(dev);
priv->running = false;
}
return ret;
}
int wdt_stop_all(void)
{
struct wdt_priv *priv;
struct udevice *dev;
struct uclass *uc;
int ret, err;
ret = uclass_get(UCLASS_WDT, &uc);
if (ret)
return ret;
uclass_foreach_dev(dev, uc) {
if (!device_active(dev))
continue;
priv = dev_get_uclass_priv(dev);
if (!priv->running)
continue;
err = wdt_stop(dev);
if (!ret)
ret = err;
}
return ret;
}
int wdt_reset(struct udevice *dev)
{
const struct wdt_ops *ops = device_get_ops(dev);
if (!ops->reset)
return -ENOSYS;
return ops->reset(dev);
}
int wdt_expire_now(struct udevice *dev, ulong flags)
{
int ret = 0;
const struct wdt_ops *ops;
debug("WDT Resetting: %lu\n", flags);
ops = device_get_ops(dev);
if (ops->expire_now) {
return ops->expire_now(dev, flags);
} else {
ret = wdt_start(dev, 1, flags);
if (ret < 0)
return ret;
hang();
}
return ret;
}
#if defined(CONFIG_WATCHDOG)
/*
* Called by macro WATCHDOG_RESET. This function be called *very* early,
* so we need to make sure, that the watchdog driver is ready before using
* it in this function.
*/
void watchdog_reset(void)
{
struct wdt_priv *priv;
struct udevice *dev;
struct uclass *uc;
ulong now;
/* Exit if GD is not ready or watchdog is not initialized yet */
if (!gd || !(gd->flags & GD_FLG_WDT_READY))
return;
if (uclass_get(UCLASS_WDT, &uc))
return;
/*
* All devices bound to the wdt uclass should have been probed
* in initr_watchdog(). But just in case something went wrong,
* check device_active() before accessing the uclass private
* data.
*/
uclass_foreach_dev(dev, uc) {
if (!device_active(dev))
continue;
priv = dev_get_uclass_priv(dev);
if (!priv->running)
continue;
/* Do not reset the watchdog too often */
now = get_timer(0);
if (time_after_eq(now, priv->next_reset)) {
priv->next_reset = now + priv->reset_period;
wdt_reset(dev);
}
}
}
#endif
static int wdt_post_bind(struct udevice *dev)
{
#if defined(CONFIG_NEEDS_MANUAL_RELOC)
struct wdt_ops *ops = (struct wdt_ops *)device_get_ops(dev);
static int reloc_done;
if (!reloc_done) {
if (ops->start)
ops->start += gd->reloc_off;
if (ops->stop)
ops->stop += gd->reloc_off;
if (ops->reset)
ops->reset += gd->reloc_off;
if (ops->expire_now)
ops->expire_now += gd->reloc_off;
reloc_done++;
}
#endif
return 0;
}
static int wdt_pre_probe(struct udevice *dev)
{
u32 timeout = WATCHDOG_TIMEOUT_SECS;
/*
* Reset every 1000ms, or however often is required as
* indicated by a hw_margin_ms property.
*/
ulong reset_period = 1000;
struct wdt_priv *priv;
if (CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)) {
timeout = dev_read_u32_default(dev, "timeout-sec", timeout);
reset_period = dev_read_u32_default(dev, "hw_margin_ms",
4 * reset_period) / 4;
}
priv = dev_get_uclass_priv(dev);
priv->timeout = timeout;
priv->reset_period = reset_period;
/*
* Pretend this device was last reset "long" ago so the first
* watchdog_reset will actually call its ->reset method.
*/
priv->next_reset = get_timer(0);
return 0;
}
UCLASS_DRIVER(wdt) = {
.id = UCLASS_WDT,
.name = "watchdog",
.flags = DM_UC_FLAG_SEQ_ALIAS,
.post_bind = wdt_post_bind,
.pre_probe = wdt_pre_probe,
.per_device_auto = sizeof(struct wdt_priv),
};