u-boot/drivers/watchdog/bcm6345_wdt.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2017 Álvaro Fernández Rojas <noltari@gmail.com>
*
* Derived from linux/drivers/watchdog/bcm63xx_wdt.c:
* Copyright (C) 2007 Miguel Gaio <miguel.gaio@efixo.com>
* Copyright (C) 2008 Florian Fainelli <florian@openwrt.org>
*/
#include <common.h>
#include <dm.h>
#include <wdt.h>
#include <asm/io.h>
/* WDT Value register */
#define WDT_VAL_REG 0x0
#define WDT_VAL_MIN 0x00000002
#define WDT_VAL_MAX 0xfffffffe
/* WDT Control register */
#define WDT_CTL_REG 0x4
#define WDT_CTL_START1_MASK 0x0000ff00
#define WDT_CTL_START2_MASK 0x000000ff
#define WDT_CTL_STOP1_MASK 0x0000ee00
#define WDT_CTL_STOP2_MASK 0x000000ee
struct bcm6345_wdt_priv {
void __iomem *regs;
};
static int bcm6345_wdt_reset(struct udevice *dev)
{
struct bcm6345_wdt_priv *priv = dev_get_priv(dev);
writel_be(WDT_CTL_START1_MASK, priv->regs + WDT_CTL_REG);
writel_be(WDT_CTL_START2_MASK, priv->regs + WDT_CTL_REG);
return 0;
}
static int bcm6345_wdt_start(struct udevice *dev, u64 timeout, ulong flags)
{
struct bcm6345_wdt_priv *priv = dev_get_priv(dev);
if (timeout < WDT_VAL_MIN) {
debug("watchdog won't fire with less than 2 ticks\n");
timeout = WDT_VAL_MIN;
} else if (timeout > WDT_VAL_MAX) {
debug("maximum watchdog timeout exceeded\n");
timeout = WDT_VAL_MAX;
}
writel_be(timeout, priv->regs + WDT_VAL_REG);
return bcm6345_wdt_reset(dev);
}
static int bcm6345_wdt_expire_now(struct udevice *dev, ulong flags)
{
return bcm6345_wdt_start(dev, WDT_VAL_MIN, flags);
}
static int bcm6345_wdt_stop(struct udevice *dev)
{
struct bcm6345_wdt_priv *priv = dev_get_priv(dev);
writel_be(WDT_CTL_STOP1_MASK, priv->regs + WDT_CTL_REG);
writel_be(WDT_CTL_STOP2_MASK, priv->regs + WDT_CTL_REG);
return 0;
}
static const struct wdt_ops bcm6345_wdt_ops = {
.expire_now = bcm6345_wdt_expire_now,
.reset = bcm6345_wdt_reset,
.start = bcm6345_wdt_start,
.stop = bcm6345_wdt_stop,
};
static const struct udevice_id bcm6345_wdt_ids[] = {
{ .compatible = "brcm,bcm6345-wdt" },
{ /* sentinel */ }
};
static int bcm6345_wdt_probe(struct udevice *dev)
{
struct bcm6345_wdt_priv *priv = dev_get_priv(dev);
priv->regs = dev_remap_addr(dev);
if (!priv->regs)
return -EINVAL;
bcm6345_wdt_stop(dev);
return 0;
}
U_BOOT_DRIVER(wdt_bcm6345) = {
.name = "wdt_bcm6345",
.id = UCLASS_WDT,
.of_match = bcm6345_wdt_ids,
.ops = &bcm6345_wdt_ops,
.priv_auto_alloc_size = sizeof(struct bcm6345_wdt_priv),
.probe = bcm6345_wdt_probe,
};