[PATCH v2 1/3] input: keyboad: imx: add snvs power key driver

[Zhi Li]

On Wed, May 13, 2015 at 2:44 PM, Dmitry Torokhov
<dmitry.torokhov at gmail.com> wrote:
> On Wed, May 13, 2015 at 02:27:46PM -0500, Zhi Li wrote:
>> On Wed, May 13, 2015 at 2:10 PM, Joshua Clayton
>> <stillcompiling at gmail.com> wrote:
>> >
>> > Hi Frank.
>> >
>> > On Wednesday, May 13, 2015 01:27:39 PM Zhi Li wrote:
>> >> On Wed, May 13, 2015 at 11:40 AM, Dmitry Torokhov
>> >>
>> >> <dmitry.torokhov at gmail.com> wrote:
>> >> > Hi Frank,
>> >> >
>> >
>> >> >
>> >> >> +     pdata->ioaddr = of_iomap(np, 0);
>> >> >> +     if (IS_ERR(pdata->ioaddr))
>> >> >> +             return PTR_ERR(pdata->ioaddr);
>> >> >
>> >> > Umm, you are still leaking it on error path. Can you try doing:
>> >> >         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> >> >         pdata->ioaddr = devm_ioremap_resource(&pdev->dev, res);
>> >> >         if (IS_ERR(pdata->ioaddr))
>> >> >
>> >> >                 return PTR_ERR(pdata->ioaddr);
>> >>
>> >> Thank you for comments.
>> >> but I don't use of_iomap here because the resource is shared with the
>> >> other device.
>> >>
>> >> SNVS included a rtc, a power off, ON/OFF key.
>> >> If I use platform_get_resource and devm_ioremap_resource, rtc driver
>> >> fail to probe.
>> >>
>> >> best regards
>> >> Frank Li
>> >>
>> >
>> > The fact that you cannot use of_iomap() seems a clear warning of unsafe
>> > access.
>> > Since it is a shared resource, which you are writing to as well as reading,
>> > perhaps you should set it up for safe access using the  regmap API like the
>> > GPR registers.
>> > /include/linux/mfd/syscon/imx6q-iomuxc-gpr.h
>>
>> I read driver again clearfully. It is safed shared with rtc driver directly.
>> Because pwr key driver just read a irq status register and other one
>> register, which used only in this driver.
>>
>> Just w1c (write 1 clear) register. it is atomic access by hardware.
>
> It does not really matter, driver has to claim resources it is using to
> make sure other parties are not accessing its registers. If registers
> are shared you need to have a 3rd party mediator.

I can change to use syscon.
but other two driver(rtc and power off) need change also.

>
>>
>> PowerKey use difference irq number with RTC part.
>
> Yes and so they can run simultaneously and step on each other's feet,
> right?

Yes.

>
> Thanks.
>
> --
> Dmitry