On Mon, Sep 17, 2018 at 02:28:01PM +0200, Thomas Gleixner wrote: > On Mon, 17 Sep 2018, Thierry Reding wrote: > > On Fri, Sep 14, 2018 at 12:31:18PM +0200, Thomas Gleixner wrote: > > > Now, you need the PMC for both, the GPIOs and the RTC. What you can do here > > > is to provide two irq domains in PMC. One which has GIC as its parent and > > > one which has no parent. Surely they need to share some resources, but > > > that should be a solvable problem. > > > > I think I have this working to some degree, finally. GPIO is still > > proving difficult, but RTC seems to be working fine. I've currently > > solved this by making the PMC an interrupt controller and then have > > an interrupt-map property in its device tree node that lists those > > wake events that we're interested in. It looks something like this: > > > > pmc: pmc@c360000 { > > compatible = "nvidia,tegra194-pmc"; > > reg = <0x0c360000 0x10000>, > > <0x0c370000 0x10000>, > > <0x0c380000 0x10000>, > > <0x0c390000 0x10000>, > > <0x0c3a0000 0x10000>; > > reg-names = "pmc", "wake", "aotag", "scratch", "misc"; > > > > #interrupt-cells = <1>; > > interrupt-controller; > > > > interrupt-map = /*<29 &gpio_aon TEGRA194_AON_GPIO(EE, 4) > > IRQ_TYPE_LEVEL_HIGH>,*/ > > <73 &gic GIC_SPI 10 > > IRQ_TYPE_LEVEL_HIGH>; > > }; > > > > Note that I've commented out the GPIO wake event (this is for the power > > button) because that currently crashes in the GPIO driver, probably > > because I misunderstood how to properly implement this. > > I'm not a DT wizerd, but the GPIO cannot be linked there I think. > > RTC ---------------------------> [ PMC domain 1] -----> GIC > > Button --> [GPIO domain] ------> [ PMC domain 2] > > The RTC is connected to PMC domain 1 and that allocates the GIC irq. > > The button is conntected to the GPIO which connect to the PMC domain > 2. That PMC domain has no connection to anything. It ends there. Interesting, I was assuming the following: Button --> [PMC domain 2] --> [GPIO domain] based on the hardware documentation that maps the wake events to specific signals on the chip. > > When I use the above code on the PMC/GPIO domain, then I see crashes > > because the GPIO controller doesn't implement things like the ->alloc() > > callback for its IRQ domain. But perhaps this is what I misunderstand. > > Are you saying that for the case of GPIO I can just *not* pass through > > all other operations and just let them be NULL? So that the only > > callback will be ->irq_set_wake()? What I don't quite understand is how > > the IRQ code would know how to properly set up the GPIO interrupt in > > that case. > > Let's look at the PMC level first: > > The PMC has a fixed number of interrupts which are avail > > domain 1: > > That domain is used for interrupts which have a dedicated GIC > interrupt line, e.g. the RTC > > The interrupt domain needs at least: > > alloc = pmc_domain1_alloc > > The interrupt chip has: > > irq_mask = irq_chip_mask_parent > irq_unmask = irq_chip_unmask_parent > irq_eoi = irq_chip_eoi_parent > irq_set_affinity = irq_chip_set_affinity_parent > irq_set_type = irq_chip_set_type_parent > irq_set_wake = pmc_set_wake > > domain 2: > > That domain is used for interrupts which are not related to the GIC > directly, e.g. GPIO > > The interrupt domain needs at least: > > alloc = pmc_domain2_alloc > > The interrupt chip has: > > irq_set_wake = pmc_set_wake > > > Now the GPIO domain builds on top of PMC domain2 > > i.e. the parent of the GPIO domain is PMC domain2, which means that > it's part of a hierarchy and therefore needs an alloc function in > the domain ops. > > The GPIO irq chip gains one extra callback: > > irq_set_wake = irq_chip_set_wake_parent, This looks interesting. I'm going to give that a try, though it may take me a little to rework everything. > So, I don't know how GPIOs are mapped into the PMC when they are a wakeup > source. It might be all of them have the ability so there is some 1:1 > relation ship or if the whole GPIO -> PMC connection can be built at run > time, but that's just an implementation detail. There's a fixed mapping for which signals go to which wake event. Some of those events are mapped to GPIOs, others to different signals, such as the RTC alarm. I think I should be able to build a GPIO -> PMC map at runtime using a static table. Thanks, Thierry
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