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// SPDX-License-Identifier: GPL-2.0+
/*
* DaVinci Watchdog driver
*
*/
#include <asm/io.h>
#include <clk.h>
#include <dm.h>
#include <wdt.h>
/* Control Register */
#define DAVINCI_WDT_ID 0x00
#define DAVINCI_WDT_TIM12 0x10
#define DAVINCI_WDT_TIM34 0x14
#define DAVINCI_WDT_PRD12 0x18
#define DAVINCI_WDT_PRD34 0x1C
#define DAVINCI_WDT_TCR 0x20
#define DAVINCI_WDT_TGCR 0x24
#define DAVINCI_WDT_WDTCR 0x28
#define DAVINCI_TCR_CONT_EN BIT(7)
#define DAVINCI_TGCR_PLUSEN BIT(4)
#define DAVINCI_TGCR_WDT_MODE BIT(3)
#define DAVINCI_TGCR_TIM34RS BIT(1)
#define DAVINCI_TGCR_TIM12RS BIT(0)
#define DAVINCI_WDTCR_INVALID_KEY (0x5555 << 16)
#define DAVINCI_WDTCR_WDKEY0 (0xA5C6 << 16)
#define DAVINCI_WDTCR_WDKEY1 (0xDA7E << 16)
#define DAVINCI_WDTCR_WDFLAG BIT(15)
#define DAVINCI_WDTCR_WDEN BIT(14)
#define DEFAULT_THRESHOLD 0xA03200000
struct davinci_wdt_priv {
void __iomem *base;
struct clk *ref_clk;
};
static int davinci_wdt_start(struct udevice *dev, u64 timeout_ms, ulong flags)
{
struct davinci_wdt_priv *priv = dev_get_priv(dev);
ulong rate = clk_get_rate(priv->ref_clk);
u64 threshold;
if (!rate)
threshold = DEFAULT_THRESHOLD;
else
threshold = rate * timeout_ms / 1000;
/* Reset control registers */
writel(0, priv->base + DAVINCI_WDT_TCR);
writel(0, priv->base + DAVINCI_WDT_TGCR);
/* Enable watchdog mode and timers */
writel(DAVINCI_TGCR_WDT_MODE | DAVINCI_TGCR_TIM12RS | DAVINCI_TGCR_TIM34RS,
priv->base + DAVINCI_WDT_TGCR);
/* Reset counters */
writel(0, priv->base + DAVINCI_WDT_TIM12);
writel(0, priv->base + DAVINCI_WDT_TIM34);
/* Set timeout threshold */
writel(threshold & 0xFFFFFFFF, priv->base + DAVINCI_WDT_PRD12);
writel(threshold >> 32, priv->base + DAVINCI_WDT_PRD34);
/* Enable counter */
writel(DAVINCI_TCR_CONT_EN, priv->base + DAVINCI_WDT_TCR);
/* Go to watchdog's active state */
writel(DAVINCI_WDTCR_WDEN | DAVINCI_WDTCR_WDKEY0, priv->base + DAVINCI_WDT_WDTCR);
writel(DAVINCI_WDTCR_WDEN | DAVINCI_WDTCR_WDKEY1, priv->base + DAVINCI_WDT_WDTCR);
return 0;
}
static int davinci_wdt_expire_now(struct udevice *dev, ulong flags)
{
struct davinci_wdt_priv *priv = dev_get_priv(dev);
writel(DAVINCI_WDTCR_INVALID_KEY, priv->base + DAVINCI_WDT_WDTCR);
return 0;
}
static int davinci_wdt_restart(struct udevice *dev)
{
struct davinci_wdt_priv *priv = dev_get_priv(dev);
writel(DAVINCI_WDTCR_WDEN | DAVINCI_WDTCR_WDKEY0, priv->base + DAVINCI_WDT_WDTCR);
writel(DAVINCI_WDTCR_WDEN | DAVINCI_WDTCR_WDKEY1, priv->base + DAVINCI_WDT_WDTCR);
return 0;
}
static int davinci_wdt_probe(struct udevice *dev)
{
struct davinci_wdt_priv *priv = dev_get_priv(dev);
priv->base = dev_remap_addr_index(dev, 0);
if (!priv->base)
return -EFAULT;
priv->ref_clk = devm_clk_get(dev, "ref");
if (IS_ERR(priv->ref_clk))
return PTR_ERR(priv->ref_clk);
return 0;
}
static const struct wdt_ops davinci_wdt_ops = {
.start = davinci_wdt_start,
.reset = davinci_wdt_restart,
.expire_now = davinci_wdt_expire_now,
};
static const struct udevice_id davinci_wdt_ids[] = {
{.compatible = "ti,davinci-wdt"},
{}
};
U_BOOT_DRIVER(davinci_wdt) = {
.name = "davinci_wdt",
.id = UCLASS_WDT,
.probe = davinci_wdt_probe,
.of_match = davinci_wdt_ids,
.ops = &davinci_wdt_ops,
.priv_auto = sizeof(struct davinci_wdt_priv),
};
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