Hi, On 2/25/21 4:44 PM, Andy Shevchenko wrote: > 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. Sorry for being slow to respond. I agree that the of_node use is weird, so a patch which simply replaces the pdev->dev.of_node with NULL would be good. Otherwise I would just leave the code as is. Regards, Hans
