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

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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: Wang Qing <wangqing@vivo.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/1619315527-8171-2-git-send-email-wangqing@vivo.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
This commit is contained in:
Wang Qing 2021-04-25 09:52:06 +08:00 committed by Wim Van Sebroeck
parent 4700df05d3
commit 1bbce7792b
1 changed files with 72 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

77
drivers/watchdog/mtk_wdt.c
View File

@ -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);
@ -239,13 +247,48 @@ static int mtk_wdt_start(struct watchdog_device *wdt_dev)
return ret;
reg = ioread32(wdt_base + WDT_MODE);
reg &= ~(WDT_MODE_IRQ_EN | WDT_MODE_DUAL_EN);
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);
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);
mtk_wdt->wdt_dev.info = &mtk_wdt_info;
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;