imx_watchdog.c
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/*
* watchdog.c - driver for i.mx on-chip watchdog
*
* Licensed under the GPL-2 or later.
*/
#include <common.h>
#include <cpu_func.h>
#include <dm.h>
#include <hang.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, false);
}
#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