Messages in this thread | | | Date | Thu, 4 Apr 2019 10:44:59 +0100 | From | Lee Jones <> | Subject | Re: [PATCH v1] mfd: Add support for Merrifield Basin Cove PMIC |
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On Thu, 04 Apr 2019, Andy Shevchenko wrote:
> On Thu, Apr 04, 2019 at 10:03:14AM +0100, Lee Jones wrote: > > On Thu, 04 Apr 2019, Andy Shevchenko wrote: > > > On Thu, Apr 04, 2019 at 08:03:57AM +0100, Lee Jones wrote: > > > > On Thu, 04 Apr 2019, Lee Jones wrote: > > > > > On Tue, 02 Apr 2019, Andy Shevchenko wrote: > > > > > > On Tue, Apr 02, 2019 at 06:12:11AM +0100, Lee Jones wrote: > > > > > > > On Mon, 18 Mar 2019, Andy Shevchenko wrote: > > > > > > > > Although succinct, dragging values from one platform device into > > > > > > > another doesn't sound that neat. > > > > > > > > > > > > So, how to split resources given in one _physical_ multi-functional device to > > > > > > several of them? Isn't it what MFD framework for? > > > > > > > > > > > > Any other approach here? I'm all ears! > > > > > > > > > > From the child: > > > > > > > > > > platform_get_irq(dev->parent, CLIENT_ID); > > > > > > So, instead of keeping a fragile approach in one driver, we will spread this > > > to all of them. > > > > No, the fragileness goes away with implicit definitions of IDs. > > Did you mean "explicit"?
Yes. Thank you for correcting my English. :)
> Something like we need to have a shared map of those indices?
Defining the IDs of the devices would lead to a more robust implementation, yes.
> > > > > > > Also, since the ordering of the > > > > > > > devices is critical in this implementation, it also comes across as > > > > > > > fragile. > > > > > > > > > > > > How fragile? In ACPI we don't have IRQ labeling scheme. Index is used for that. > > > > > > > > > > > > > Any reason why ACPI can't register all of the child devices, or for > > > > > > > the child devices to obtain their IRQ directly from the tables? > > > > > > > > > > > > And how are we supposed to enumerated them taking into consideration single > > > > > > ACPI ID given? > > > > > > > > > > This question was a little whimsical, since I have no idea how the > > > > > ACPI tables you're working with are laid out. > > > > > > There is one device node with several IRQ and other resources. > > > In pseudo code: > > > > > > device node { > > > device ID, > > > IRQ 0, > > > IRQ 1, > > > ... > > > MMIO 0, > > > ... > > > } > > > > Sure. Thanks for the explanation. > > > > Very well. I guess it's not too bad as it is. > > It represent real hardware 1:1. > Just out of curiosity how this case can be described in DT?
In DT you can have a sub-node for each child which can contain the IRQ. Without a sub-node you would define the IRQs in this file. If these IRQs do not change, that option is still available to you.
I can't think of an example where all of the children's IRQs have been listed in the parent's DT node in this way.
-- Lee Jones [李琼斯] Linaro Services Technical Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog
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