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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (c) Siemens AG, 2020
*
* Authors:
* Jan Kiszka <jan.kiszka@siemens.com>
*
* Derived from linux/drivers/watchdog/rti_wdt.c
*/
#include <common.h>
#include <clk.h>
#include <dm.h>
#include <power-domain.h>
#include <wdt.h>
#include <asm/io.h>
/* Timer register set definition */
#define RTIDWDCTRL 0x90
#define RTIDWDPRLD 0x94
#define RTIWDSTATUS 0x98
#define RTIWDKEY 0x9c
#define RTIDWDCNTR 0xa0
#define RTIWWDRXCTRL 0xa4
#define RTIWWDSIZECTRL 0xa8
#define RTIWWDRX_NMI 0xa
#define RTIWWDSIZE_50P 0x50
#define WDENABLE_KEY 0xa98559da
#define WDKEY_SEQ0 0xe51a
#define WDKEY_SEQ1 0xa35c
#define WDT_PRELOAD_SHIFT 13
#define WDT_PRELOAD_MAX 0xfff
struct rti_wdt_priv {
phys_addr_t regs;
unsigned int clk_khz;
};
static int rti_wdt_start(struct udevice *dev, u64 timeout_ms, ulong flags)
{
struct rti_wdt_priv *priv = dev_get_priv(dev);
u32 timer_margin;
int ret;
if (readl(priv->regs + RTIDWDCTRL) == WDENABLE_KEY)
return -EBUSY;
timer_margin = timeout_ms * priv->clk_khz / 1000;
timer_margin >>= WDT_PRELOAD_SHIFT;
if (timer_margin > WDT_PRELOAD_MAX)
timer_margin = WDT_PRELOAD_MAX;
writel(timer_margin, priv->regs + RTIDWDPRLD);
writel(RTIWWDRX_NMI, priv->regs + RTIWWDRXCTRL);
writel(RTIWWDSIZE_50P, priv->regs + RTIWWDSIZECTRL);
readl(priv->regs + RTIWWDSIZECTRL);
writel(WDENABLE_KEY, priv->regs + RTIDWDCTRL);
return 0;
}
static int rti_wdt_reset(struct udevice *dev)
{
struct rti_wdt_priv *priv = dev_get_priv(dev);
u32 prld;
/* Make sure we do not reset too early */
prld = readl(priv->regs + RTIDWDPRLD) << WDT_PRELOAD_SHIFT;
if (readl(priv->regs + RTIDWDCNTR) >= prld / 2)
return -EPERM;
writel(WDKEY_SEQ0, priv->regs + RTIWDKEY);
writel(WDKEY_SEQ1, priv->regs + RTIWDKEY);
return 0;
}
static int rti_wdt_probe(struct udevice *dev)
{
struct rti_wdt_priv *priv = dev_get_priv(dev);
struct clk clk;
int ret;
priv->regs = devfdt_get_addr(dev);
if (!priv->regs)
return -EINVAL;
ret = clk_get_by_index(dev, 0, &clk);
if (ret)
return ret;
priv->clk_khz = clk_get_rate(&clk);
return 0;
}
static const struct wdt_ops rti_wdt_ops = {
.start = rti_wdt_start,
.reset = rti_wdt_reset,
};
static const struct udevice_id rti_wdt_ids[] = {
{ .compatible = "ti,j7-rti-wdt" },
{ }
};
U_BOOT_DRIVER(rti_wdt) = {
.name = "rti_wdt",
.id = UCLASS_WDT,
.of_match = rti_wdt_ids,
.ops = &rti_wdt_ops,
.probe = rti_wdt_probe,
.priv_auto = sizeof(struct rti_wdt_priv),
.flags = DM_FLAG_LEAVE_PD_ON,
};
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