u-boot/drivers/watchdog/ast_wdt.c

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/*
* Copyright 2017 Google, Inc
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <dm.h>
#include <errno.h>
#include <wdt.h>
#include <asm/io.h>
#include <asm/arch/wdt.h>
#define WDT_AST2500 2500
#define WDT_AST2400 2400
DECLARE_GLOBAL_DATA_PTR;
struct ast_wdt_priv {
struct ast_wdt *regs;
};
static int ast_wdt_start(struct udevice *dev, u64 timeout, ulong flags)
{
struct ast_wdt_priv *priv = dev_get_priv(dev);
ulong driver_data = dev_get_driver_data(dev);
u32 reset_mode = ast_reset_mode_from_flags(flags);
clrsetbits_le32(&priv->regs->ctrl,
WDT_CTRL_RESET_MASK << WDT_CTRL_RESET_MODE_SHIFT,
reset_mode << WDT_CTRL_RESET_MODE_SHIFT);
if (driver_data >= WDT_AST2500 && reset_mode == WDT_CTRL_RESET_SOC)
writel(ast_reset_mask_from_flags(flags),
&priv->regs->reset_mask);
writel((u32) timeout, &priv->regs->counter_reload_val);
writel(WDT_COUNTER_RESTART_VAL, &priv->regs->counter_restart);
/*
* Setting CLK1MHZ bit is just for compatibility with ast2400 part.
* On ast2500 watchdog timer clock is fixed at 1MHz and the bit is
* read-only
*/
setbits_le32(&priv->regs->ctrl,
WDT_CTRL_EN | WDT_CTRL_RESET | WDT_CTRL_CLK1MHZ);
return 0;
}
static int ast_wdt_stop(struct udevice *dev)
{
struct ast_wdt_priv *priv = dev_get_priv(dev);
clrbits_le32(&priv->regs->ctrl, WDT_CTRL_EN);
return 0;
}
static int ast_wdt_reset(struct udevice *dev)
{
struct ast_wdt_priv *priv = dev_get_priv(dev);
writel(WDT_COUNTER_RESTART_VAL, &priv->regs->counter_restart);
return 0;
}
static int ast_wdt_expire_now(struct udevice *dev, ulong flags)
{
struct ast_wdt_priv *priv = dev_get_priv(dev);
int ret;
ret = ast_wdt_start(dev, 1, flags);
if (ret)
return ret;
while (readl(&priv->regs->ctrl) & WDT_CTRL_EN)
;
return ast_wdt_stop(dev);
}
static int ast_wdt_ofdata_to_platdata(struct udevice *dev)
{
struct ast_wdt_priv *priv = dev_get_priv(dev);
priv->regs = devfdt_get_addr_ptr(dev);
if (IS_ERR(priv->regs))
return PTR_ERR(priv->regs);
return 0;
}
static const struct wdt_ops ast_wdt_ops = {
.start = ast_wdt_start,
.reset = ast_wdt_reset,
.stop = ast_wdt_stop,
.expire_now = ast_wdt_expire_now,
};
static const struct udevice_id ast_wdt_ids[] = {
{ .compatible = "aspeed,wdt", .data = WDT_AST2500 },
{ .compatible = "aspeed,ast2500-wdt", .data = WDT_AST2500 },
{ .compatible = "aspeed,ast2400-wdt", .data = WDT_AST2400 },
{}
};
static int ast_wdt_probe(struct udevice *dev)
{
debug("%s() wdt%u\n", __func__, dev->seq);
ast_wdt_stop(dev);
return 0;
}
U_BOOT_DRIVER(ast_wdt) = {
.name = "ast_wdt",
.id = UCLASS_WDT,
.of_match = ast_wdt_ids,
.probe = ast_wdt_probe,
.priv_auto_alloc_size = sizeof(struct ast_wdt_priv),
.ofdata_to_platdata = ast_wdt_ofdata_to_platdata,
.ops = &ast_wdt_ops,
.flags = DM_FLAG_PRE_RELOC,
};