Commit 1bbce779 authored by Wang Qing's avatar Wang Qing Committed by Wim Van Sebroeck
Browse files

watchdog: mtk: support pre-timeout when the bark irq is available 



Use the bark interrupt as the pretimeout notifier if available.

When the watchdog timer expires in dual mode, an interrupt will be
triggered first, then the timing restarts. The reset signal will be
initiated when the timer expires again.

The pretimeout notification shall occur at timeout-sec/2.

V2:
- panic() by default if WATCHDOG_PRETIMEOUT_GOV is not enabled.

V3:
- Modify the pretimeout behavior, manually reset after the pretimeout
- is processed and wait until timeout.

V4:
- Remove pretimeout related processing.
- Add dual mode control separately.

V5:
- Fix some formatting and printing problems.

V6:
- Realize pretimeout processing through dualmode.

V7:
- Add set_pretimeout().

V8/V9:
- Fix some formatting problems.

Signed-off-by: default avatarWang Qing <wangqing@vivo.com>
Reviewed-by: default avatarGuenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/1619315527-8171-2-git-send-email-wangqing@vivo.com


Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
Signed-off-by: default avatarWim Van Sebroeck <wim@linux-watchdog.org>
parent 4700df05

drivers/watchdog/mtk_wdt.c

+72 −5
Original line number Diff line number Diff line
@@ -25,9 +25,10 @@ 
#include <linux/reset-controller.h>

#include <linux/types.h>

#include <linux/watchdog.h>

#include <linux/interrupt.h>



#define WDT_MAX_TIMEOUT		31

#define WDT_MIN_TIMEOUT		1

#define WDT_MIN_TIMEOUT		2

#define WDT_LENGTH_TIMEOUT(n)	((n) << 5)



#define WDT_LENGTH		0x04
@@ -187,12 +188,19 @@ static int mtk_wdt_set_timeout(struct watchdog_device *wdt_dev, 
	u32 reg;



	wdt_dev->timeout = timeout;

	/*

	 * In dual mode, irq will be triggered at timeout / 2

	 * the real timeout occurs at timeout

	 */

	if (wdt_dev->pretimeout)

		wdt_dev->pretimeout = timeout / 2;



	/*

	 * One bit is the value of 512 ticks

	 * The clock has 32 KHz

	 */

	reg = WDT_LENGTH_TIMEOUT(timeout << 6) | WDT_LENGTH_KEY;

	reg = WDT_LENGTH_TIMEOUT((timeout - wdt_dev->pretimeout) << 6)

			| WDT_LENGTH_KEY;

	iowrite32(reg, wdt_base + WDT_LENGTH);



	mtk_wdt_ping(wdt_dev);
@@ -239,6 +247,9 @@ static int mtk_wdt_start(struct watchdog_device *wdt_dev) 
		return ret;



	reg = ioread32(wdt_base + WDT_MODE);

	if (wdt_dev->pretimeout)

		reg |= (WDT_MODE_IRQ_EN | WDT_MODE_DUAL_EN);

	else

		reg &= ~(WDT_MODE_IRQ_EN | WDT_MODE_DUAL_EN);

	reg |= (WDT_MODE_EN | WDT_MODE_KEY);

	iowrite32(reg, wdt_base + WDT_MODE);
@@ -246,6 +257,38 @@ static int mtk_wdt_start(struct watchdog_device *wdt_dev) 
	return 0;

}



static int mtk_wdt_set_pretimeout(struct watchdog_device *wdd,

				  unsigned int timeout)

{

	struct mtk_wdt_dev *mtk_wdt = watchdog_get_drvdata(wdd);

	void __iomem *wdt_base = mtk_wdt->wdt_base;

	u32 reg = ioread32(wdt_base + WDT_MODE);



	if (timeout && !wdd->pretimeout) {

		wdd->pretimeout = wdd->timeout / 2;

		reg |= (WDT_MODE_IRQ_EN | WDT_MODE_DUAL_EN);

	} else if (!timeout && wdd->pretimeout) {

		wdd->pretimeout = 0;

		reg &= ~(WDT_MODE_IRQ_EN | WDT_MODE_DUAL_EN);

	} else {

		return 0;

	}



	reg |= WDT_MODE_KEY;

	iowrite32(reg, wdt_base + WDT_MODE);



	return mtk_wdt_set_timeout(wdd, wdd->timeout);

}



static irqreturn_t mtk_wdt_isr(int irq, void *arg)

{

	struct watchdog_device *wdd = arg;



	watchdog_notify_pretimeout(wdd);



	return IRQ_HANDLED;

}



static const struct watchdog_info mtk_wdt_info = {

	.identity	= DRV_NAME,

	.options	= WDIOF_SETTIMEOUT |
@@ -253,12 +296,21 @@ static const struct watchdog_info mtk_wdt_info = { 
			  WDIOF_MAGICCLOSE,

};



static const struct watchdog_info mtk_wdt_pt_info = {

	.identity	= DRV_NAME,

	.options	= WDIOF_SETTIMEOUT |

			  WDIOF_PRETIMEOUT |

			  WDIOF_KEEPALIVEPING |

			  WDIOF_MAGICCLOSE,

};



static const struct watchdog_ops mtk_wdt_ops = {

	.owner		= THIS_MODULE,

	.start		= mtk_wdt_start,

	.stop		= mtk_wdt_stop,

	.ping		= mtk_wdt_ping,

	.set_timeout	= mtk_wdt_set_timeout,

	.set_pretimeout	= mtk_wdt_set_pretimeout,

	.restart	= mtk_wdt_restart,

};
@@ -267,7 +319,7 @@ static int mtk_wdt_probe(struct platform_device *pdev) 
	struct device *dev = &pdev->dev;

	struct mtk_wdt_dev *mtk_wdt;

	const struct mtk_wdt_data *wdt_data;

	int err;

	int err, irq;



	mtk_wdt = devm_kzalloc(dev, sizeof(*mtk_wdt), GFP_KERNEL);

	if (!mtk_wdt)
@@ -279,7 +331,22 @@ static int mtk_wdt_probe(struct platform_device *pdev) 
	if (IS_ERR(mtk_wdt->wdt_base))

		return PTR_ERR(mtk_wdt->wdt_base);



	irq = platform_get_irq(pdev, 0);

	if (irq > 0) {

		err = devm_request_irq(&pdev->dev, irq, mtk_wdt_isr, 0, "wdt_bark",

				       &mtk_wdt->wdt_dev);

		if (err)

			return err;



		mtk_wdt->wdt_dev.info = &mtk_wdt_pt_info;

		mtk_wdt->wdt_dev.pretimeout = WDT_MAX_TIMEOUT / 2;

	} else {

		if (irq == -EPROBE_DEFER)

			return -EPROBE_DEFER;



		mtk_wdt->wdt_dev.info = &mtk_wdt_info;

	}



	mtk_wdt->wdt_dev.ops = &mtk_wdt_ops;

	mtk_wdt->wdt_dev.timeout = WDT_MAX_TIMEOUT;

	mtk_wdt->wdt_dev.max_hw_heartbeat_ms = WDT_MAX_TIMEOUT * 1000;