mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-12-24 20:13:39 +00:00
bba4ec81fd
This patch adds watchdog support for the Mediatek MT7620 SoC Reviewed-by: Stefan Roese <sr@denx.de> Reviewed-by: Jagan Teki <jagan@amarulasolutions.com> Signed-off-by: Weijie Gao <weijie.gao@mediatek.com>
142 lines
2.9 KiB
C
142 lines
2.9 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Copyright (C) 2020 MediaTek Inc.
|
|
*
|
|
* Author: Weijie Gao <weijie.gao@mediatek.com>
|
|
*
|
|
* Watchdog timer for MT7620 and earlier SoCs
|
|
*/
|
|
|
|
#include <div64.h>
|
|
#include <dm.h>
|
|
#include <reset.h>
|
|
#include <wdt.h>
|
|
#include <linux/bitops.h>
|
|
#include <linux/io.h>
|
|
|
|
struct mt7620_wdt {
|
|
void __iomem *regs;
|
|
u64 timeout;
|
|
};
|
|
|
|
#define TIMER_FREQ 40000000
|
|
#define TIMER_MASK 0xffff
|
|
#define TIMER_PRESCALE 65536
|
|
|
|
#define TIMER_LOAD 0x00
|
|
#define TIMER_CTL 0x08
|
|
|
|
#define TIMER_ENABLE BIT(7)
|
|
#define TIMER_MODE_SHIFT 4
|
|
#define TIMER_MODE_WDT 3
|
|
#define TIMER_PRESCALE_SHIFT 0
|
|
#define TIMER_PRESCALE_65536 15
|
|
|
|
static void mt7620_wdt_ping(struct mt7620_wdt *priv)
|
|
{
|
|
u64 val;
|
|
|
|
val = (TIMER_FREQ / TIMER_PRESCALE) * priv->timeout;
|
|
do_div(val, 1000);
|
|
|
|
if (val > TIMER_MASK)
|
|
val = TIMER_MASK;
|
|
|
|
writel(val, priv->regs + TIMER_LOAD);
|
|
}
|
|
|
|
static int mt7620_wdt_start(struct udevice *dev, u64 ms, ulong flags)
|
|
{
|
|
struct mt7620_wdt *priv = dev_get_priv(dev);
|
|
|
|
priv->timeout = ms;
|
|
mt7620_wdt_ping(priv);
|
|
|
|
writel(TIMER_ENABLE | (TIMER_MODE_WDT << TIMER_MODE_SHIFT) |
|
|
(TIMER_PRESCALE_65536 << TIMER_PRESCALE_SHIFT),
|
|
priv->regs + TIMER_CTL);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int mt7620_wdt_stop(struct udevice *dev)
|
|
{
|
|
struct mt7620_wdt *priv = dev_get_priv(dev);
|
|
|
|
mt7620_wdt_ping(priv);
|
|
|
|
clrbits_32(priv->regs + TIMER_CTL, TIMER_ENABLE);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int mt7620_wdt_reset(struct udevice *dev)
|
|
{
|
|
struct mt7620_wdt *priv = dev_get_priv(dev);
|
|
|
|
mt7620_wdt_ping(priv);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int mt7620_wdt_expire_now(struct udevice *dev, ulong flags)
|
|
{
|
|
struct mt7620_wdt *priv = dev_get_priv(dev);
|
|
|
|
mt7620_wdt_start(dev, 1, flags);
|
|
|
|
/*
|
|
* 0 will disable the timer directly, a positive number must be used
|
|
* instead. Since the timer is a countdown timer, 1 (tick) is used.
|
|
*
|
|
* For a timer with input clock = 40MHz, 1 timer tick is short
|
|
* enough to trigger a timeout immediately.
|
|
*
|
|
* Restore prescale to 1, and load timer with 1 to trigger timeout.
|
|
*/
|
|
writel(TIMER_ENABLE | (TIMER_MODE_WDT << TIMER_MODE_SHIFT),
|
|
priv->regs + TIMER_CTL);
|
|
writel(1, priv->regs + TIMER_LOAD);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int mt7620_wdt_probe(struct udevice *dev)
|
|
{
|
|
struct mt7620_wdt *priv = dev_get_priv(dev);
|
|
struct reset_ctl reset_wdt;
|
|
int ret;
|
|
|
|
ret = reset_get_by_index(dev, 0, &reset_wdt);
|
|
if (!ret)
|
|
reset_deassert(&reset_wdt);
|
|
|
|
priv->regs = dev_remap_addr(dev);
|
|
if (!priv->regs)
|
|
return -EINVAL;
|
|
|
|
mt7620_wdt_stop(dev);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct wdt_ops mt7620_wdt_ops = {
|
|
.start = mt7620_wdt_start,
|
|
.reset = mt7620_wdt_reset,
|
|
.stop = mt7620_wdt_stop,
|
|
.expire_now = mt7620_wdt_expire_now,
|
|
};
|
|
|
|
static const struct udevice_id mt7620_wdt_ids[] = {
|
|
{ .compatible = "mediatek,mt7620-wdt" },
|
|
{}
|
|
};
|
|
|
|
U_BOOT_DRIVER(mt7620_wdt) = {
|
|
.name = "mt7620_wdt",
|
|
.id = UCLASS_WDT,
|
|
.of_match = mt7620_wdt_ids,
|
|
.probe = mt7620_wdt_probe,
|
|
.priv_auto = sizeof(struct mt7620_wdt),
|
|
.ops = &mt7620_wdt_ops,
|
|
};
|