u-boot/drivers/watchdog/mpc8xxx_wdt.c
Christophe Leroy 0fd79138dc watchdog: mpc8xxx: Add support for mpc83xx
Introduce a new compatible "fsl,pq2pro-wdt"
On mpc83xx, the prescaling factor is 0x10000.

Don't write the watchdog configuration register in
start.S as it can be written only once.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
2023-04-06 14:50:03 +02:00

112 lines
2.8 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright 2017 CS Systemes d'Information
*/
#include <common.h>
#include <env.h>
#include <dm.h>
#include <wdt.h>
#include <clock_legacy.h>
#include <asm/io.h>
struct mpc8xxx_wdt {
__be32 res0;
__be32 swcrr; /* System watchdog control register */
#define SWCRR_SWTC 0xFFFF0000 /* Software Watchdog Time Count. */
#define SWCRR_BME 0x00000080 /* Bus monitor enable (mpc8xx) */
#define SWCRR_SWF 0x00000008 /* Software Watchdog Freeze (mpc8xx). */
#define SWCRR_SWEN 0x00000004 /* Watchdog Enable bit. */
#define SWCRR_SWRI 0x00000002 /* Software Watchdog Reset/Interrupt Select bit.*/
#define SWCRR_SWPR 0x00000001 /* Software Watchdog Counter Prescale bit. */
__be32 swcnr; /* System watchdog count register */
u8 res1[2];
__be16 swsrr; /* System watchdog service register */
u8 res2[0xf0];
};
struct mpc8xxx_wdt_priv {
struct mpc8xxx_wdt __iomem *base;
};
static int mpc8xxx_wdt_reset(struct udevice *dev)
{
struct mpc8xxx_wdt_priv *priv = dev_get_priv(dev);
out_be16(&priv->base->swsrr, 0x556c); /* write magic1 */
out_be16(&priv->base->swsrr, 0xaa39); /* write magic2 */
return 0;
}
static int mpc8xxx_wdt_start(struct udevice *dev, u64 timeout, ulong flags)
{
struct mpc8xxx_wdt_priv *priv = dev_get_priv(dev);
const char *mode = env_get("watchdog_mode");
ulong prescaler = dev_get_driver_data(dev);
u16 swtc = min_t(u16, timeout * get_board_sys_clk() / 1000 / prescaler, U16_MAX);
u32 val;
mpc8xxx_wdt_reset(dev);
if (strcmp(mode, "off") == 0)
val = (swtc << 16) | SWCRR_SWPR;
else if (strcmp(mode, "nmi") == 0)
val = (swtc << 16) | SWCRR_SWPR | SWCRR_SWEN;
else
val = (swtc << 16) | SWCRR_SWPR | SWCRR_SWEN | SWCRR_SWRI;
if (IS_ENABLED(CONFIG_WDT_MPC8xxx_BME))
val |= (CONFIG_WDT_MPC8xxx_BMT << 8) | SWCRR_BME;
out_be32(&priv->base->swcrr, val);
if (!(in_be32(&priv->base->swcrr) & SWCRR_SWEN))
return -EBUSY;
return 0;
}
static int mpc8xxx_wdt_stop(struct udevice *dev)
{
struct mpc8xxx_wdt_priv *priv = dev_get_priv(dev);
clrbits_be32(&priv->base->swcrr, SWCRR_SWEN);
if (in_be32(&priv->base->swcrr) & SWCRR_SWEN)
return -EBUSY;
return 0;
}
static int mpc8xxx_wdt_of_to_plat(struct udevice *dev)
{
struct mpc8xxx_wdt_priv *priv = dev_get_priv(dev);
priv->base = (void __iomem *)devfdt_remap_addr(dev);
if (!priv->base)
return -EINVAL;
return 0;
}
static const struct wdt_ops mpc8xxx_wdt_ops = {
.start = mpc8xxx_wdt_start,
.reset = mpc8xxx_wdt_reset,
.stop = mpc8xxx_wdt_stop,
};
static const struct udevice_id mpc8xxx_wdt_ids[] = {
{ .compatible = "fsl,pq1-wdt", .data = 0x800 },
{ .compatible = "fsl,pq2pro-wdt", .data = 0x10000 },
{}
};
U_BOOT_DRIVER(wdt_mpc8xxx) = {
.name = "wdt_mpc8xxx",
.id = UCLASS_WDT,
.of_match = mpc8xxx_wdt_ids,
.ops = &mpc8xxx_wdt_ops,
.of_to_plat = mpc8xxx_wdt_of_to_plat,
.priv_auto = sizeof(struct mpc8xxx_wdt_priv),
};