Re: [PATCH v2 5/7] watchdog: mtk: allow setting timeout in devicetree

[Marcus Folkesson <marcus.folkesson-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

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Hello Sean,

On Sat, Feb 10, 2018 at 07:10:02PM +0800, Sean Wang wrote:
> 
> Hi, Marcus
> 
> The changes you made for dt-bindings and driver should be put into
> separate patches.

I actually thought about it but chose to have it in the same patch because I
did not see any direct advantage to separating them.

But I can do that.
I will come up with a v3 with this change if no one thinks differently.

> 
> And the property timeout-sec seems to be generic enough to all devices,
> so why not add a common document to describe it and allow those devices
> to refer to, like other dt-bindings for other kinds of devices usually
> did.

It should be, but it requires that the driver is using
watchdog_init_timeout() to set timeout, most of the drivers does not.
Most drivers does not even use the watchdog API but register itself as
misc devices.

When we have all wdt drivers using the watchdog API, we should probably
move the dt-binding to a common document.

> 
> 	Sean
> 

Thanks,

Best regards
Marcus Folkesson

> On Sat, 2018-02-10 at 10:19 +0100, Marcus Folkesson wrote:
> > watchdog_init_timeout() will allways pick timeout_param since it
> > defaults to a valid timeout.
> > 
> > By following best practice described in
> > Documentation/watchdog/watchdog-kernel-api.txt, it also
> > let us to set timout-sec property in devicetree.
> > 
> > Signed-off-by: Marcus Folkesson <marcus.folkesson-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> > Reviewed-by: Guenter Roeck <linux-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org>
> > ---
> >  Documentation/devicetree/bindings/watchdog/mtk-wdt.txt | 4 ++++
> >  drivers/watchdog/mtk_wdt.c                             | 2 +-
> >  2 files changed, 5 insertions(+), 1 deletion(-)
> > 
> > diff --git a/Documentation/devicetree/bindings/watchdog/mtk-wdt.txt b/Documentation/devicetree/bindings/watchdog/mtk-wdt.txt
> > index 5b38a30e608c..859dee167b91 100644
> > --- a/Documentation/devicetree/bindings/watchdog/mtk-wdt.txt
> > +++ b/Documentation/devicetree/bindings/watchdog/mtk-wdt.txt
> > @@ -11,9 +11,13 @@ Required properties:
> >  
> >  - reg : Specifies base physical address and size of the registers.
> >  
> > +Optional properties:
> > +- timeout-sec: contains the watchdog timeout in seconds.
> > +
> >  Example:
> >  
> >  wdt: watchdog@10000000 {
> >  	compatible = "mediatek,mt6589-wdt";
> >  	reg = <0x10000000 0x18>;
> > +	timeout-sec = <10>;
> >  };
> > diff --git a/drivers/watchdog/mtk_wdt.c b/drivers/watchdog/mtk_wdt.c
> > index 7ed417a765c7..fcdc10ec28a3 100644
> > --- a/drivers/watchdog/mtk_wdt.c
> > +++ b/drivers/watchdog/mtk_wdt.c
> > @@ -57,7 +57,7 @@
> >  #define DRV_VERSION		"1.0"
> >  
> >  static bool nowayout = WATCHDOG_NOWAYOUT;
> > -static unsigned int timeout = WDT_MAX_TIMEOUT;
> > +static unsigned int timeout;
> >  
> >  struct mtk_wdt_dev {
> >  	struct watchdog_device wdt_dev;
> 
> 

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