Messages in this thread | | | Date | Thu, 9 May 2024 10:03:43 +0300 | Subject | Re: [RFC PATCH 0/6] Support ROHM BD96801 scalable PMIC | From | Matti Vaittinen <> |
| |
On 5/9/24 08:08, Mark Brown wrote: > On Mon, Apr 22, 2024 at 01:52:27PM +0300, Matti Vaittinen wrote: >> On 4/5/24 12:19, Matti Vaittinen wrote: >>> On 4/4/24 16:15, Matti Vaittinen wrote: > >>>>> I would expect each parent interrupt to show up as a separate remap_irq. > >>>>> So if we arrange to supply a name when we register multiple domains >>>>> things should work fine? > >>> After my latest findings, yes, I think so. How to do this correctly is >>> beyond me though. The __irq_domain_create() seems to me that the name is >>> meant to be the dt-node name when the controller is backed by a real >>> dt-node. Naming of the irq_domain_alloc_named_fwnode() sounds to me like > > ... > >> If we wanted to support multiple HWIRQs / regmap-IRQ controller, it would >> require us to duplicate almost everything in the struct regmap_irq_chip for >> every new parent IRQ. The status/mask register information, IRQ type, etc. >> Naturally, it would require also duplicating lot of the data contained in >> the struct regmap_irq_chip_data. I am not sure if this could be done so the >> change is not reflected in the existing IRQ data initialization macros etc. >> Furthermore, some API changes would be required like changes to >> regmap_irq_get_domain(). > > I don't understand what the difficulty is here - we're creating multiple > interrupt controllers so I'd expect to have to have full definitions of > each, and since everything is referenced by name from the root > regmap_irq_chip which gets registered it's just a case of supplying > different names and all the helpers should be fine? > >> Thus, forcing the regmap-IRQ to support multiple parents instead of having >> own regmap-IRQ instance / parent IRQ feels like fitting square item to a >> round hole. I am sure fixing all the bugs I caused would give donate a lot >> of EXP-points though :rolleyes: > > Right, my suggestion is to register multiple regmap_irq instrances - one > per parent - and supply a name that allows all the display/debugfs stuff > that currently uses the dev_name() to deduplicate. You'd end up > sticking -primary, -secondary or whatever name was supplied onto the > names we currently use. > >> Another option I see, is trying to think if irq-domain name could be >> changed. (This is what the RFC v3 does, [ab]using the >> irq_domain_update_bus_token()). I was a bit put off by the idea of >> 'instantiating' multiple domains (or regmap-IRQ controllers) from a single >> node, but more I think of this, more I lean towards it. Besides, this is not > > Yes, register mutliple controllers with different names.
Thanks for the guidance Mark. The controller name is not a problem. Problem is that I don't see a (proper) way to supply a name for the IRQ domain which gets registered by regmap-IRQ. IRQ domain code picks the name for the domain by the device-tree node. Both of our IRQ controllers would be instantiated from same node => the IRQ domain will get same name => debugfs will conflict.
My "solution" was simply dropping the ERRB IRQ from the driver (for now at least). I did send that as a series without 'RFC' - but made a mistake and restarted the versioning from v1. I am currently working with 2 other PMICs, one of them does also provide similar setup of two IRQ lines. Thus, I think being able to provide a name (suffix?) for IRQ domain when registering it instead of just using the name of the DT node is something I should look into. It's just nice to know someone else thinks it is valid approach.
Thanks for the input!
Yours, -- Matti
-- Matti Vaittinen Linux kernel developer at ROHM Semiconductors Oulu Finland
~~ When things go utterly wrong vim users can always type :help! ~~
| |