u-boot/drivers/watchdog/imx_watchdog.c
Robert Hancock f2929d11a6 watchdog: imx: Use immediate reset bits for expire_now
The expire_now function was previously setting the watchdog timeout to
minimum and waiting for the watchdog to expire. However, this watchdog
also has bits to trigger immediate reset. Use those instead, like the
Linux imx2_wdt driver does.

Signed-off-by: Robert Hancock <hancock@sedsystems.ca>
2019-11-03 17:04:16 +01:00

166 lines
3.5 KiB
C

/*
* watchdog.c - driver for i.mx on-chip watchdog
*
* Licensed under the GPL-2 or later.
*/
#include <common.h>
#include <dm.h>
#include <asm/io.h>
#include <wdt.h>
#include <watchdog.h>
#include <asm/arch/imx-regs.h>
#ifdef CONFIG_FSL_LSCH2
#include <asm/arch/immap_lsch2.h>
#endif
#include <fsl_wdog.h>
static void imx_watchdog_expire_now(struct watchdog_regs *wdog, bool ext_reset)
{
u16 wcr = WCR_WDE;
if (ext_reset)
wcr |= WCR_SRS; /* do not assert internal reset */
else
wcr |= WCR_WDA; /* do not assert external reset */
/* Write 3 times to ensure it works, due to IMX6Q errata ERR004346 */
writew(wcr, &wdog->wcr);
writew(wcr, &wdog->wcr);
writew(wcr, &wdog->wcr);
while (1) {
/*
* spin before reset
*/
}
}
#if !defined(CONFIG_IMX_WATCHDOG) || \
(defined(CONFIG_IMX_WATCHDOG) && !CONFIG_IS_ENABLED(WDT))
void __attribute__((weak)) reset_cpu(ulong addr)
{
struct watchdog_regs *wdog = (struct watchdog_regs *)WDOG1_BASE_ADDR;
imx_watchdog_expire_now(wdog, true);
}
#endif
#if defined(CONFIG_IMX_WATCHDOG)
static void imx_watchdog_reset(struct watchdog_regs *wdog)
{
#ifndef CONFIG_WATCHDOG_RESET_DISABLE
writew(0x5555, &wdog->wsr);
writew(0xaaaa, &wdog->wsr);
#endif /* CONFIG_WATCHDOG_RESET_DISABLE*/
}
static void imx_watchdog_init(struct watchdog_regs *wdog, bool ext_reset)
{
u16 timeout;
u16 wcr;
/*
* The timer watchdog can be set between
* 0.5 and 128 Seconds. If not defined
* in configuration file, sets 128 Seconds
*/
#ifndef CONFIG_WATCHDOG_TIMEOUT_MSECS
#define CONFIG_WATCHDOG_TIMEOUT_MSECS 128000
#endif
timeout = (CONFIG_WATCHDOG_TIMEOUT_MSECS / 500) - 1;
#ifdef CONFIG_FSL_LSCH2
wcr = (WCR_WDA | WCR_SRS | WCR_WDE) << 8 | timeout;
#else
wcr = WCR_WDZST | WCR_WDBG | WCR_WDE | WCR_SRS |
WCR_WDA | SET_WCR_WT(timeout);
if (ext_reset)
wcr |= WCR_WDT;
#endif /* CONFIG_FSL_LSCH2*/
writew(wcr, &wdog->wcr);
imx_watchdog_reset(wdog);
}
#if !CONFIG_IS_ENABLED(WDT)
void hw_watchdog_reset(void)
{
struct watchdog_regs *wdog = (struct watchdog_regs *)WDOG1_BASE_ADDR;
imx_watchdog_reset(wdog);
}
void hw_watchdog_init(void)
{
struct watchdog_regs *wdog = (struct watchdog_regs *)WDOG1_BASE_ADDR;
imx_watchdog_init(wdog, true);
}
#else
struct imx_wdt_priv {
void __iomem *base;
bool ext_reset;
};
static int imx_wdt_reset(struct udevice *dev)
{
struct imx_wdt_priv *priv = dev_get_priv(dev);
imx_watchdog_reset(priv->base);
return 0;
}
static int imx_wdt_expire_now(struct udevice *dev, ulong flags)
{
struct imx_wdt_priv *priv = dev_get_priv(dev);
imx_watchdog_expire_now(priv->base, priv->ext_reset);
hang();
return 0;
}
static int imx_wdt_start(struct udevice *dev, u64 timeout, ulong flags)
{
struct imx_wdt_priv *priv = dev_get_priv(dev);
imx_watchdog_init(priv->base, priv->ext_reset);
return 0;
}
static int imx_wdt_probe(struct udevice *dev)
{
struct imx_wdt_priv *priv = dev_get_priv(dev);
priv->base = dev_read_addr_ptr(dev);
if (!priv->base)
return -ENOENT;
priv->ext_reset = dev_read_bool(dev, "fsl,ext-reset-output");
return 0;
}
static const struct wdt_ops imx_wdt_ops = {
.start = imx_wdt_start,
.reset = imx_wdt_reset,
.expire_now = imx_wdt_expire_now,
};
static const struct udevice_id imx_wdt_ids[] = {
{ .compatible = "fsl,imx21-wdt" },
{}
};
U_BOOT_DRIVER(imx_wdt) = {
.name = "imx_wdt",
.id = UCLASS_WDT,
.of_match = imx_wdt_ids,
.probe = imx_wdt_probe,
.ops = &imx_wdt_ops,
.priv_auto_alloc_size = sizeof(struct imx_wdt_priv),
.flags = DM_FLAG_PRE_RELOC,
};
#endif
#endif