Re: [2/2] drivers/watchdog: ASPEED reference dev tree properties for config

[Christopher Bostic]

On 6/24/17 5:17 PM, Guenter Roeck wrote:
> On Tue, Jun 13, 2017 at 03:38:18PM -0500, Christopher Bostic wrote:
> > Reference the system device tree when configuring the watchdog.
> > Configure for external signal generation if optional attribute
> > 'external-signal' is present in device tree.  Configure for
> > reset system after timeout if the optional attribute
> > 'no-system-reset' is not present.  Disabling system reset may be
> > required in situations where one of the other watchdogs in the
> > systems is responsible for this.
> >
> > Signed-off-by: Christopher Bostic <cbostic@xxxxxxxxxxxxxxxxxx>
> > ---
> >   drivers/watchdog/aspeed_wdt.c | 13 +++++++++++--
> >   1 file changed, 11 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/watchdog/aspeed_wdt.c b/drivers/watchdog/aspeed_wdt.c
> > index 1c65258..9deb4be 100644
> > --- a/drivers/watchdog/aspeed_wdt.c
> > +++ b/drivers/watchdog/aspeed_wdt.c
> > @@ -140,6 +140,7 @@ static int aspeed_wdt_probe(struct platform_device *pdev)
> >   {
> >   	struct aspeed_wdt *wdt;
> >   	struct resource *res;
> > +	struct device_node *np;
> >   	int ret;
> >   
> >   	wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
> > @@ -170,8 +171,16 @@ static int aspeed_wdt_probe(struct platform_device *pdev)
> >   	 * the SOC and not the full chip
> >   	 */
> >   	wdt->ctrl = WDT_CTRL_RESET_MODE_SOC |
> > -		WDT_CTRL_1MHZ_CLK |
> > -		WDT_CTRL_RESET_SYSTEM;
> > +		WDT_CTRL_1MHZ_CLK;
> > +
> > +	np = pdev->dev.of_node;
> > +	if (np && !of_get_property(np, "no-system-reset", NULL))
> > +		wdt->ctrl |= WDT_CTRL_RESET_SYSTEM;
> > +
> Please use of_property_read_bool(). Also, checking np for NULL is unnecessary
> since the called function does that. Note that the above code as written is
> wrong - if np is NULL, WDT_CTRL_RESET_SYSTEM will no longer be set.

Will make the suggested changes.

Thanks
-Chris

> The new properties should probably start with "aspeed," but I'll leave that
> up to DT maintainers to decide.
>
> > +	if (np && of_get_property(np, "external-signal", NULL))
> > +		wdt->ctrl |= WDT_CTRL_WDT_EXT;
> > +
> > +	writel(wdt->ctrl, wdt->base + WDT_CTRL);
> >   
> >   	if (readl(wdt->base + WDT_CTRL) & WDT_CTRL_ENABLE)  {
> >   		aspeed_wdt_start(&wdt->wdd);