On Thu, Feb 25, 2021 at 5:11 AM Hans de Goede <hdegoede@xxxxxxxxxx> wrote: > On 2/24/21 1:51 PM, Andy Shevchenko wrote: > > On Tue, Feb 23, 2021 at 08:25:35PM +0100, Hans de Goede wrote: > >> On 2/23/21 6:22 PM, Andy Shevchenko wrote: > >>> It's better to describe the I²C controller and associated IRQ domain with > >>> fwnode, so they will find their place in the hierarchy in sysfs and also > >>> make easier to debug. ... > >>> + set_primary_fwnode(&adap->adapter.dev, fwnode); > >> > >> So now we have the main PMIC device i2c-client, the platform-device instantiated > >> for the MFD-cell for the PMIC's builtin I2C-controller; and the device instantiated > >> for the adapter-device all 3 share the same ACPI-companion fwnode. > > > > Okay, this step in this patch maybe not needed (or should be a separate change, > > but I don't see clearly what would be the benefit out of it). Shall I leave this or should be removed in v2? ... > >>> - adap->irq_domain = irq_domain_add_linear(pdev->dev.of_node, 1, > >>> - &irq_domain_simple_ops, NULL); > >>> + adap->irq_domain = irq_domain_create_linear(fwnode, 1, > >>> + &irq_domain_simple_ops, NULL); > >> > >> Hmm, not sure this is right, admittedly the old code looks weird too, but now we > >> are creating a second irq_domain at the same level as the irq_domain created for > >> the IRQ-chip part of the PMIC. But this is really more of a child-domain of just > >> the I2C-controller MFD-cell. The IRQ-CHIP part of the PMIC has a single IRQ for the > >> I2C controller which gets raised both on i2c-transfer completions and when the > >> pin on the PMIC which is reserved as input for the IRQ coming out of the charger-chip > >> gets triggered. > >> > >> IOW we have this: > >> > >> > >> PMIC > >> | > >> ------------------------------ > >> | | | | > >> IRQ1 IRQ2 IRQ3 I2C-IRQ > >> | > >> ---------------------------------- > >> | | | | > >> READIRQ WRIRQ NACKIRQ CLIENT-IRQ > >> > >> Where READIRQ, WRIRQ and NACKIRQ are directly consumed > >> and the CLIENT-IRQ is being represented as a single IRQ on > >> a new irqchip so that we can pass it along to the i2c-driver > >> for the charger-chip which is connected to the Whiskey Cove's > >> builtin I2C controller. > >> > >> But doing as you suggest would model the IRQs as: > >> > >> PMIC > >> | > >> -------------------------------------------------- > >> | | | | | > >> IRQ1 IRQ2 IRQ3 I2C-IRQ CLIENT-IRQ > >> > >> Which is not the same really. I guess it is better then what we > >> have though ? > > > > Hmm... There should not be difference in the hierarchy. add_linear == > > create_linear. The propagation of *device* (not an IRQ) fwnode is just > > convenient way to have IRQ domain be named (instead of 'unknown-N' or so). > > Maybe I have read __irq_domain_add() code wrongly. > > Sorry, this is probably my bad. The first ASCII-art which I posted is > how things actually work in HW. The second one is how I assumed that > things would look like in some nested representation of the IRQ-domains > given that all the IRQs mentioned in the ASCII-art now use the same fwnode > as parent for their domain. But poking around in sysfs I don't see any > hierarchical representation of the domains at all. Actually I cannot > find any representation of the IRQ domains inside sysfs (I've never > looked at / into this before) ? I have enabled GENERIC_IRQ_DEBUGFS to see some information. > If what you say is right and the fwnode is only used to set a name (where can > I see those names ?) then your patch is probably correct. I have checked again and I don't see anything except it uses it as a domain name and takes reference count. > > Nevertheless, thinking more about it, why we don't add an IRQ chip via regmap > > IRQ API? > > There already is a regmap IRQ chip associated with the MFD device and the > IRQ handling required here is somewhat tricky (see the comments in the driver) > so I would prefer to keep this as is. Ah, that makes things complicated a bit. > >> Note I can test any changes made here, but I'm not 100% convinced that > >> the current version of this patch is correct. > > > > If we settle on the idea first. I'm (slowly) looking forward to check another > > CherryTrail device we have at the lab, but we lack of some (power) equipment > > right now to setup it properly. I hope it may have the Whiskey Cove PMIC there. > > More testing is always welcome :) With that said, testing these changes really > is not a lot of work for me. I would expect that we will have a clash with IRQ domain names and thus we would need our own fwnode here. I will think about it, but it sounds like we need to create a hierarchy of the IRQ domains and take the device's fwnode as a parent here. Overall, I stumbled over of_node use in pure ACPI case (simplest "fix" is to provide a NULL pointer there). If you think we can get rid of of_node as intermediate step, I will send v2 with that. -- With Best Regards, Andy Shevchenko
