Messages in this thread | | | Subject | Re: [PATCH RESEND V2 1/4] dt-bindings: fsl: scu: add watchdog binding | From | Guenter Roeck <> | Date | Sat, 23 Feb 2019 19:20:21 -0800 |
| |
On 2/23/19 7:04 PM, Anson Huang wrote: > Hi, Guenter/Rob > > Best Regards! > Anson Huang > >> -----Original Message----- >> From: Guenter Roeck [mailto:groeck7@gmail.com] On Behalf Of Guenter >> Roeck >> Sent: 2019年2月24日 1:08 >> To: Rob Herring <robh@kernel.org>; Anson Huang <anson.huang@nxp.com> >> Cc: mark.rutland@arm.com; shawnguo@kernel.org; >> s.hauer@pengutronix.de; kernel@pengutronix.de; festevam@gmail.com; >> catalin.marinas@arm.com; will.deacon@arm.com; wim@linux-watchdog.org; >> Aisheng Dong <aisheng.dong@nxp.com>; ulf.hansson@linaro.org; Daniel >> Baluta <daniel.baluta@nxp.com>; Andy Gross <andy.gross@linaro.org>; >> horms+renesas@verge.net.au; heiko@sntech.de; arnd@arndb.de; >> bjorn.andersson@linaro.org; jagan@amarulasolutions.com; >> enric.balletbo@collabora.com; marc.w.gonzalez@free.fr; olof@lixom.net; >> devicetree@vger.kernel.org; linux-kernel@vger.kernel.org; linux-arm- >> kernel@lists.infradead.org; linux-watchdog@vger.kernel.org; dl-linux-imx >> <linux-imx@nxp.com> >> Subject: Re: [PATCH RESEND V2 1/4] dt-bindings: fsl: scu: add watchdog >> binding >> >> On 2/22/19 11:52 AM, Rob Herring wrote: >>> On Mon, Feb 18, 2019 at 06:53:48AM +0000, Anson Huang wrote: >>>> Add i.MX8QXP system controller watchdog binding. >>>> >>>> Signed-off-by: Anson Huang <Anson.Huang@nxp.com> >>>> --- >>>> Changes since V1: >>>> - update dts node name to "watchdog"; >>>> --- >>>> Documentation/devicetree/bindings/arm/freescale/fsl,scu.txt | 10 >> ++++++++++ >>>> 1 file changed, 10 insertions(+) >>>> >>>> diff --git >>>> a/Documentation/devicetree/bindings/arm/freescale/fsl,scu.txt >>>> b/Documentation/devicetree/bindings/arm/freescale/fsl,scu.txt >>>> index 4b79751..f388ec6 100644 >>>> --- a/Documentation/devicetree/bindings/arm/freescale/fsl,scu.txt >>>> +++ b/Documentation/devicetree/bindings/arm/freescale/fsl,scu.txt >>>> @@ -136,6 +136,12 @@ Required properties: >>>> resource id for thermal driver to get temperature >> via >>>> SCU IPC. >>>> >>>> +Watchdog bindings based on SCU Message Protocol >>>> +------------------------------------------------------------ >>>> + >>>> +Required properties: >>>> +- compatible: should be "fsl,imx8qxp-sc-wdt"; >>>> + >>>> Example (imx8qxp): >>>> ------------- >>>> lsio_mu1: mailbox@5d1c0000 { >>>> @@ -188,6 +194,10 @@ firmware { >>>> tsens-num = <1>; >>>> #thermal-sensor-cells = <1>; >>>> }; >>>> + >>>> + watchdog: watchdog { >>>> + compatible = "fsl,imx8qxp-sc-wdt"; >>> >>> As-is, there's no reason for this to be in DT. The parent node's >>> driver can instantiate the wdog. >>> >> >> As the driver is currently written, you are correct, since it doesn't accept >> watchdog timeout configuration through devicetree. >> >> Question is if that is intended. Is it ? > > I am a little confused, do you mean we no need to have "watchdog" node in side "scu" > node? Or we need to modify the watchdog node's compatible string to " fsl,imx-sc-wdt" to make > it more generic for other platforms? If yes, I can resend the patch series to modify it. >
I think Rob suggested that the SCU parent driver should instantiate the watchdog without explicit watchdog node. That would be possible, but it currently uses devm_of_platform_populate() to do the instantiation, and changing that would be a mess. Besides, it does sem to me that your suggested node would describe the hardware, so I am not sure I understand the reasoning.
For my part I referred to watchdog_init_timeout(imx_sc_wdd, DEFAULT_TIMEOUT, &pdev->dev); in the driver, which guarantees that the timeout property will not be used to set the timeout. A more common implementation would have been
imx_sc_wdd->timeout = DEFAULT_TIMEOUT; ret = watchdog_init_timeout(imx_sc_wdd, timeout, &pdev->dev);
where 'timeout' is the module parameter. Which is actually not used in your driver. Hmm ... I wasn't careful enough with my review. The timeout initialization as-is doesn't make sense. I'll comment on that in the patch.
Guenter
> Anson. > >> >> Thanks, >> Guenter
| |