124 lines
2.5 KiB
C
124 lines
2.5 KiB
C
// 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,
|
|
};
|