Messages in this thread Patch in this message | | | Subject | Re: [PATCH v1 2/2] watchdog: imx2_wdt: add set_pretimeout interface | From | Guenter Roeck <> | Date | Mon, 2 Nov 2015 20:19:12 -0800 |
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On 11/02/2015 07:29 PM, Robin Gong wrote: > Enable set_pretimeout interface and trigger the pretimeout interrupt before > watchdog timeout event happen. > > Signed-off-by: Robin Gong <b38343@freescale.com> > --- > drivers/watchdog/imx2_wdt.c | 67 ++++++++++++++++++++++++++++++++++++++++++++- > 1 file changed, 66 insertions(+), 1 deletion(-) > > diff --git a/drivers/watchdog/imx2_wdt.c b/drivers/watchdog/imx2_wdt.c > index 0bb1a1d..d3c6b07 100644 > --- a/drivers/watchdog/imx2_wdt.c > +++ b/drivers/watchdog/imx2_wdt.c > @@ -24,7 +24,9 @@ > #include <linux/clk.h> > #include <linux/delay.h> > #include <linux/init.h> > +#include <linux/interrupt.h> > #include <linux/io.h> > +#include <linux/irq.h>
Are those two new includes both needed ?
> #include <linux/jiffies.h> > #include <linux/kernel.h> > #include <linux/module.h> > @@ -52,12 +54,18 @@ > #define IMX2_WDT_WRSR 0x04 /* Reset Status Register */ > #define IMX2_WDT_WRSR_TOUT (1 << 1) /* -> Reset due to Timeout */ > > +#define IMX2_WDT_WICR 0x06 /*Interrupt Control Register*/ > +#define IMX2_WDT_WICR_WIE (1 << 15) /* -> Interrupt Enable */ > +#define IMX2_WDT_WICR_WTIS (1 << 14) /* -> Interrupt Status */ > +#define IMX2_WDT_WICR_WICT (0xFF << 0) /* Watchdog Interrupt Timeout */ > +
"<< 0" doesn't really add any value here.
> #define IMX2_WDT_WMCR 0x08 /* Misc Register */ > > #define IMX2_WDT_MAX_TIME 128 > #define IMX2_WDT_DEFAULT_TIME 60 /* in seconds */ > > #define WDOG_SEC_TO_COUNT(s) ((s * 2 - 1) << 8) > +#define WDOG_SEC_TO_PRECOUNT(s) (s * 2) /* set WDOG pre timeout count*/ > ((s) * 2)
Ah yes, WDOG_SEC_TO_COUNT should also use (s).
> struct imx2_wdt_device { > struct clk *clk; > @@ -80,7 +88,8 @@ MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds (default=" > > static const struct watchdog_info imx2_wdt_info = { > .identity = "imx2+ watchdog", > - .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE, > + .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE > + | WDIOF_PRETIMEOUT, > }; > > static int imx2_restart_handler(struct notifier_block *this, unsigned long mode, > @@ -207,12 +216,59 @@ static inline void imx2_wdt_ping_if_active(struct watchdog_device *wdog) > } > } > > +static int imx2_wdt_check_pretimeout_set(struct imx2_wdt_device *wdev) > +{ > + u32 val; > + > + regmap_read(wdev->regmap, IMX2_WDT_WICR, &val); > + return (val & IMX2_WDT_WICR_WIE) ? 1 : 0;
I don't understand the point of this function. You check if IMX2_WDT_WICR_WIE is set,
> +} > + > +static int imx2_wdt_set_pretimeout(struct watchdog_device *wdog, > + unsigned int new_timeout) > +{ > + struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog); > + u32 val; > + > + regmap_read(wdev->regmap, IMX2_WDT_WICR, &val); > + /* set the new pre-timeout value in the WSR */ > + val &= ~IMX2_WDT_WICR_WICT; > + val |= WDOG_SEC_TO_PRECOUNT(new_timeout); > +
What is the time here ? Is pretimeout the number of seconds until the interrupt occurs, or the number of seconds before the actual timeout (as per API) ?
> + if (!imx2_wdt_check_pretimeout_set(wdev)) > + val |= IMX2_WDT_WICR_WIE; /*enable*/
if IMX2_WDT_WICR_WIE is not set, you set it,
> + > + regmap_write(wdev->regmap, IMX2_WDT_WICR, val); > +
and write the result unconditionally. Unless I am missing something,
regmap_write, wdev->regmap, IMX2_WDT_WICR, val | IMX2_WDT_WICR_WIE);
would accomplish exactly the same.
> + wdog->pretimeout = new_timeout; > + > + return 0; > +} > + > +static irqreturn_t imx2_wdt_isr(int irq, void *dev_id) > +{ > + struct platform_device *pdev = dev_id; > + struct watchdog_device *wdog = platform_get_drvdata(pdev); > + struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog); > + u32 val; > + > + regmap_read(wdev->regmap, IMX2_WDT_WICR, &val); > + if (val & IMX2_WDT_WICR_WTIS) { > + /*clear interrupt status bit*/ > + regmap_write(wdev->regmap, IMX2_WDT_WICR, val); > + dev_warn(&pdev->dev, "pre-timeout:%d, %d Seconds remained\n", > + wdog->pretimeout, wdog->timeout - wdog->pretimeout);
The idea here is that this should trigger a panic.
> + } > + return IRQ_HANDLED; > +} > + > static const struct watchdog_ops imx2_wdt_ops = { > .owner = THIS_MODULE, > .start = imx2_wdt_start, > .stop = imx2_wdt_stop, > .ping = imx2_wdt_ping, > .set_timeout = imx2_wdt_set_timeout, > + .set_pretimeout = imx2_wdt_set_pretimeout, > }; > > static const struct regmap_config imx2_wdt_regmap_config = { > @@ -229,6 +285,7 @@ static int __init imx2_wdt_probe(struct platform_device *pdev) > struct resource *res; > void __iomem *base; > int ret; > + int irq; > u32 val; > > wdev = devm_kzalloc(&pdev->dev, sizeof(*wdev), GFP_KERNEL); > @@ -253,6 +310,14 @@ static int __init imx2_wdt_probe(struct platform_device *pdev) > return PTR_ERR(wdev->clk); > } > > + irq = platform_get_irq(pdev, 0);
This makes the irq mandatory. What if a platform doesn't have one configured ?
> + ret = devm_request_irq(&pdev->dev, irq, imx2_wdt_isr, 0, > + dev_name(&pdev->dev), pdev); > + if (ret) { > + dev_err(&pdev->dev, "can't get irq %d\n", irq);
You got it, but you could not request it.
This is also a bit early, as the interrupt handler uses variables which are not yet initialized.
> + return ret; > + } > + > wdog = &wdev->wdog; > wdog->info = &imx2_wdt_info; > wdog->ops = &imx2_wdt_ops; >
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