RE: [PATCH V2] dt-bindings: timer: gpt: update binding doc

Anson Huang
2018-12-19T07:11:50Z

Hi, Rob

Best Regards!
Anson Huang

> -----Original Message-----
> From: Rob Herring [mailto:robh@kernel.org]
> Sent: 2018年12月19日 1:12
> To: Anson Huang <anson.huang@nxp.com>
> Cc: daniel.lezcano@linaro.org; tglx@linutronix.de; mark.rutland@arm.com;
> linux-kernel@vger.kernel.org; devicetree@vger.kernel.org; dl-linux-imx
> <linux-imx@nxp.com>
> Subject: Re: [PATCH V2] dt-bindings: timer: gpt: update binding doc
>
> On Wed, Dec 12, 2018 at 07:20:44AM +0000, Anson Huang wrote:
> > The i.MX GPT timer driver binding doc is out of date, update it
> > according to current GPT timer driver.
> >
> > Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
> > ---
> > .../devicetree/bindings/timer/fsl,imxgpt.txt | 28
> +++++++++++++++++-----
> > 1 file changed, 22 insertions(+), 6 deletions(-)
> >
> > diff --git a/Documentation/devicetree/bindings/timer/fsl,imxgpt.txt
> > b/Documentation/devicetree/bindings/timer/fsl,imxgpt.txt
> > index 9809b11..2ed84ad 100644
> > --- a/Documentation/devicetree/bindings/timer/fsl,imxgpt.txt
> > +++ b/Documentation/devicetree/bindings/timer/fsl,imxgpt.txt
> > @@ -2,17 +2,33 @@ Freescale i.MX General Purpose Timer (GPT)
> >
> > Required properties:
> >
> > -- compatible : should be "fsl,<soc>-gpt"
> > -- reg : Specifies base physical address and size of the registers.
> > -- interrupts : A list of 4 interrupts; one per timer channel.
> > -- clocks : The clocks provided by the SoC to drive the timer.
> > +- compatible : must be one of following:
> > + - "fsl,imx1-gpt",
> > + - "fsl,imx21-gpt",
> > + - "fsl,imx27-gpt",
> > + - "fsl,imx31-gpt",
> > + - "fsl,imx25-gpt",
> > + - "fsl,imx50-gpt",
> > + - "fsl,imx51-gpt",
> > + - "fsl,imx53-gpt",
> > + - "fsl,imx6q-gpt",
> > + - "fsl,imx6dl-gpt",
> > + - "fsl,imx6sl-gpt",
> > + - "fsl,imx6sx-gpt".
>
> You need to list fall-backs here. IOW, what are the valid combinations?

I listed the combinations in V3 patch;

>
> > +- reg : specifies base physical address and size of the registers.
> > +- interrupts : should be the clock event device interrupt.
>
> 'clock event' is a Linux thing and shouldn't be part of the binding.
>
> What happened to the 4 interrupts?

Yes, using "gpt interrupt" is better than "clock event", and looks like the i.MX GPT
driver does NOT support 4 interrupts at all, ONLY 1 general GPT interrupt is needed,
so I updated it;

>
> > +- clocks : the clocks provided by the SoC to drive the timer, must contain
> > + an entry for each entry in clock-names.
> > +- clock-names : must include "ipg" entry first, then "per" entry, "osc_per"
> > + can be a substitute of "per" entry on some SoCs.
>
> per or osc_per should be deprecated so only one is used going forward.

osc_per is just a special case for i.MX6Q, so I remove it, just mention the ipg and per clock.
Please help review V3, thanks.

Anson.

>
> >
> > Example:
> >
> > gpt1: timer@10003000 {
> > - compatible = "fsl,imx27-gpt", "fsl,imx1-gpt";
> > + compatible = "fsl,imx27-gpt", "fsl,imx21-gpt";
> > reg = <0x10003000 0x1000>;
> > interrupts = <26>;
> > - clocks = <&clks 46>, <&clks 61>;
> > + clocks = <&clks IMX27_CLK_GPT1_IPG_GATE>,
> > + <&clks IMX27_CLK_PER1_GATE>;
> > clock-names = "ipg", "per";
> > };
> > --
> > 2.7.4
> >