u-boot/drivers/watchdog/cortina_wdt.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2020 Cortina-Access
*
*/
#include <common.h>
#include <dm.h>
#include <hang.h>
#include <asm/io.h>
#include <wdt.h>
#include <linux/bitops.h>
#define CA_WDT_CTRL 0x00
#define CA_WDT_PS 0x04
#define CA_WDT_DIV 0x08
#define CA_WDT_LD 0x0C
#define CA_WDT_LOADE 0x10
#define CA_WDT_CNT 0x14
#define CA_WDT_IE 0x18
#define CA_WDT_INT 0x1C
#define CA_WDT_STAT 0x20
/* CA_WDT_CTRL */
#define CTL_WDT_EN BIT(0)
#define CTL_WDT_RSTEN BIT(1)
#define CTL_WDT_CLK_SEL BIT(2)
/* CA_WDT_LOADE */
#define WDT_UPD BIT(0)
#define WDT_UPD_PS BIT(1)
/* Global config */
#define WDT_RESET_SUB BIT(4)
#define WDT_RESET_ALL_BLOCK BIT(6)
#define WDT_RESET_REMAP BIT(7)
#define WDT_EXT_RESET BIT(8)
#define WDT_RESET_DEFAULT (WDT_EXT_RESET | WDT_RESET_REMAP | \
WDT_RESET_ALL_BLOCK | WDT_RESET_SUB)
struct ca_wdt_priv {
void __iomem *base;
void __iomem *global_config;
};
static void cortina_wdt_set_timeout(struct udevice *dev, u64 timeout_ms)
{
struct ca_wdt_priv *priv = dev_get_priv(dev);
/* Prescale using millisecond unit */
writel(CORTINA_PER_IO_FREQ / 1000, priv->base + CA_WDT_PS);
/* Millisecond */
writel(1, priv->base + CA_WDT_DIV);
writel(timeout_ms, priv->base + CA_WDT_LD);
writel(WDT_UPD | WDT_UPD_PS, priv->base + CA_WDT_LOADE);
}
static int cortina_wdt_start(struct udevice *dev, u64 timeout, ulong flags)
{
struct ca_wdt_priv *priv = dev_get_priv(dev);
cortina_wdt_set_timeout(dev, timeout);
/* WDT Reset option */
setbits_32(priv->global_config, WDT_RESET_DEFAULT);
/* Enable WDT */
setbits_32(priv->base, CTL_WDT_EN | CTL_WDT_RSTEN | CTL_WDT_CLK_SEL);
return 0;
}
static int cortina_wdt_stop(struct udevice *dev)
{
struct ca_wdt_priv *priv = dev_get_priv(dev);
/* Disable WDT */
writel(0, priv->base);
return 0;
}
static int cortina_wdt_reset(struct udevice *dev)
{
struct ca_wdt_priv *priv = dev_get_priv(dev);
/* Reload WDT counter */
writel(WDT_UPD, priv->base + CA_WDT_LOADE);
return 0;
}
static int cortina_wdt_expire_now(struct udevice *dev, ulong flags)
{
/* Set 1ms timeout to reset system */
cortina_wdt_set_timeout(dev, 1);
hang();
return 0;
}
static int cortina_wdt_probe(struct udevice *dev)
{
struct ca_wdt_priv *priv = dev_get_priv(dev);
priv->base = dev_remap_addr_index(dev, 0);
if (!priv->base)
return -ENOENT;
priv->global_config = dev_remap_addr_index(dev, 1);
if (!priv->global_config)
return -ENOENT;
/* Stop WDT */
cortina_wdt_stop(dev);
return 0;
}
static const struct wdt_ops cortina_wdt_ops = {
.start = cortina_wdt_start,
.reset = cortina_wdt_reset,
.stop = cortina_wdt_stop,
.expire_now = cortina_wdt_expire_now,
};
static const struct udevice_id cortina_wdt_ids[] = {
{.compatible = "cortina,ca-wdt"},
{}
};
U_BOOT_DRIVER(cortina_wdt) = {
.name = "cortina_wdt",
.id = UCLASS_WDT,
.probe = cortina_wdt_probe,
.of_match = cortina_wdt_ids,
.ops = &cortina_wdt_ops,
};