Re: [PATCH 2/2] watchdog: Add the Software Watchdog Timer for the NXP S32 platform

[Daniel Lezcano]

On 29/03/2025 05:55, Krzysztof Kozlowski wrote:
> On 28/03/2025 16:15, Daniel Lezcano wrote:
> > +
> > +struct s32g_wdt_device {
> > +	int rate;
> > +	void __iomem *base;
> > +	struct watchdog_device wdog;
> > +};
> > +
> > +static bool nowayout = WATCHDOG_NOWAYOUT;
> > +module_param(nowayout, bool, 0);
> > +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
> > +		 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
> > +
> > +static unsigned int timeout_param = S32G_WDT_DEFAULT_TIMEOUT;
> > +module_param(timeout_param, uint, 0);
> > +MODULE_PARM_DESC(timeout_param, "Watchdog timeout in seconds (default="
> > +		 __MODULE_STRING(S32G_WDT_DEFAULT_TIMEOUT) ")");
>
> Timeout is provided by DT.

Yes, but we may want to change the default timeout when loading the driver.

[ ... ]

> > +static int s32g_wdt_ping(struct watchdog_device *wdog)
> > +{
> > +	struct s32g_wdt_device *wdev = wdd_to_s32g_wdt(wdog);
> > +
> > +	__raw_writel(S32G_WDT_SEQ1, S32G_SWT_SR(wdev->base));
> > +	__raw_writel(S32G_WDT_SEQ2, S32G_SWT_SR(wdev->base));
>
> I am confused why you do not use standard writel or don't have any
> barriers here. I think this is very error prone and in general
> discouraged practice (was for example raised by Arnd multiple times on
> the lists).

Yes, that's a good point. I'll sort it out with Arnd

> > +static int s32g_wdt_start(struct watchdog_device *wdog)
> > +{
> > +	struct s32g_wdt_device *wdev = wdd_to_s32g_wdt(wdog);
> > +	unsigned long val;
> > +
> > +	val = __raw_readl(S32G_SWT_CR(wdev->base));
> > +
> > +	val |= S32G_SWT_CR_WEN;
> > +
> > +	__raw_writel(val, S32G_SWT_CR(wdev->base));
> > +
> > +	return 0;
> > +}
> > +
>
> ...

[ ... ]

> > +static struct platform_driver s32g_wdt_driver = {
> > +	.probe = s32g_wdt_probe,
> > +	.driver = {
> > +		.name = DRIVER_NAME,
> > +		.owner = THIS_MODULE,
>
> Drop, that's some ancient downstream code.
>
> > +		.of_match_table = s32g_wdt_dt_ids,
> > +	},
> > +};
> > +
> > +module_platform_driver(s32g_wdt_driver);
> > +
> > +MODULE_AUTHOR("NXP");
> > +MODULE_DESCRIPTION("Watchdog driver for S32G SoC");
> > +MODULE_LICENSE("GPL");
> > +MODULE_ALIAS("platform:" DRIVER_NAME);
>
> Drop, not needed. Fix your table module device Id instead... or start
> from other recent driver as a skeleton to avoid repeating the same
> issues we already fixed.

Ok, thanks for spotting it



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