mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-12-03 18:10:13 +00:00
89c4fecd9b
This driver supports the bcm2835 watchdog found on Raspberry Pi boards. It is derived from the Linux driver and was tested on two Raspberry Pi board versions (B+ and 3B+). Signed-off-by: Etienne Dublé <etienne.duble@imag.fr> Reviewed-by: Stefan Roese <sr@denx.de>
132 lines
3 KiB
C
132 lines
3 KiB
C
// SPDX-License-Identifier: GPL-2.0+
|
|
/*
|
|
* Copyright (C) 2013 Lubomir Rintel <lkundrak@v3.sk>
|
|
* Copyright (C) 2023 Etienne Dublé (CNRS) <etienne.duble@imag.fr>
|
|
*
|
|
* This code is mostly derived from the linux driver.
|
|
*/
|
|
|
|
#include <dm.h>
|
|
#include <wdt.h>
|
|
#include <asm/io.h>
|
|
#include <linux/delay.h>
|
|
|
|
#define PM_RSTC 0x1c
|
|
#define PM_WDOG 0x24
|
|
|
|
#define PM_PASSWORD 0x5a000000
|
|
|
|
/* The hardware supports a maximum timeout value of 0xfffff ticks
|
|
* (just below 16 seconds).
|
|
*/
|
|
#define PM_WDOG_MAX_TICKS 0x000fffff
|
|
#define PM_RSTC_WRCFG_CLR 0xffffffcf
|
|
#define PM_RSTC_WRCFG_FULL_RESET 0x00000020
|
|
#define PM_RSTC_RESET 0x00000102
|
|
|
|
#define MS_TO_WDOG_TICKS(x) (((x) << 16) / 1000)
|
|
|
|
struct bcm2835_wdt_priv {
|
|
void __iomem *base;
|
|
u64 timeout_ticks;
|
|
};
|
|
|
|
static int bcm2835_wdt_start_ticks(struct udevice *dev,
|
|
u64 timeout_ticks, ulong flags)
|
|
{
|
|
struct bcm2835_wdt_priv *priv = dev_get_priv(dev);
|
|
void __iomem *base = priv->base;
|
|
u32 cur;
|
|
|
|
writel(PM_PASSWORD | timeout_ticks, base + PM_WDOG);
|
|
cur = readl(base + PM_RSTC);
|
|
writel(PM_PASSWORD | (cur & PM_RSTC_WRCFG_CLR) | PM_RSTC_WRCFG_FULL_RESET,
|
|
base + PM_RSTC);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int bcm2835_wdt_start(struct udevice *dev, u64 timeout_ms, ulong flags)
|
|
{
|
|
struct bcm2835_wdt_priv *priv = dev_get_priv(dev);
|
|
|
|
priv->timeout_ticks = MS_TO_WDOG_TICKS(timeout_ms);
|
|
|
|
if (priv->timeout_ticks > PM_WDOG_MAX_TICKS) {
|
|
printf("bcm2835_wdt: the timeout value is too high, using ~16s instead.\n");
|
|
priv->timeout_ticks = PM_WDOG_MAX_TICKS;
|
|
}
|
|
|
|
return bcm2835_wdt_start_ticks(dev, priv->timeout_ticks, flags);
|
|
}
|
|
|
|
static int bcm2835_wdt_reset(struct udevice *dev)
|
|
{
|
|
struct bcm2835_wdt_priv *priv = dev_get_priv(dev);
|
|
|
|
/* restart the timer with the value of priv->timeout_ticks
|
|
* saved from the last bcm2835_wdt_start() call.
|
|
*/
|
|
return bcm2835_wdt_start_ticks(dev, priv->timeout_ticks, 0);
|
|
}
|
|
|
|
static int bcm2835_wdt_stop(struct udevice *dev)
|
|
{
|
|
struct bcm2835_wdt_priv *priv = dev_get_priv(dev);
|
|
void __iomem *base = priv->base;
|
|
|
|
writel(PM_PASSWORD | PM_RSTC_RESET, base + PM_RSTC);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int bcm2835_wdt_expire_now(struct udevice *dev, ulong flags)
|
|
{
|
|
int ret;
|
|
|
|
/* use a timeout of 10 ticks (~150us) */
|
|
ret = bcm2835_wdt_start_ticks(dev, 10, flags);
|
|
if (ret)
|
|
return ret;
|
|
|
|
mdelay(500);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct wdt_ops bcm2835_wdt_ops = {
|
|
.reset = bcm2835_wdt_reset,
|
|
.start = bcm2835_wdt_start,
|
|
.stop = bcm2835_wdt_stop,
|
|
.expire_now = bcm2835_wdt_expire_now,
|
|
};
|
|
|
|
static const struct udevice_id bcm2835_wdt_ids[] = {
|
|
{ .compatible = "brcm,bcm2835-pm" },
|
|
{ .compatible = "brcm,bcm2835-pm-wdt" },
|
|
{ /* sentinel */ }
|
|
};
|
|
|
|
static int bcm2835_wdt_probe(struct udevice *dev)
|
|
{
|
|
struct bcm2835_wdt_priv *priv = dev_get_priv(dev);
|
|
|
|
priv->base = dev_remap_addr(dev);
|
|
if (!priv->base)
|
|
return -EINVAL;
|
|
|
|
priv->timeout_ticks = PM_WDOG_MAX_TICKS;
|
|
|
|
bcm2835_wdt_stop(dev);
|
|
|
|
return 0;
|
|
}
|
|
|
|
U_BOOT_DRIVER(bcm2835_wdt) = {
|
|
.name = "bcm2835_wdt",
|
|
.id = UCLASS_WDT,
|
|
.of_match = bcm2835_wdt_ids,
|
|
.probe = bcm2835_wdt_probe,
|
|
.priv_auto = sizeof(struct bcm2835_wdt_priv),
|
|
.ops = &bcm2835_wdt_ops,
|
|
};
|