Messages in this thread | | | Date | Wed, 25 Mar 2015 11:43:27 +0200 | From | Mika Westerberg <> | Subject | Re: [PATCH] IIO: Adds ACPI support for ST gyroscopes |
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On Wed, Mar 25, 2015 at 09:44:34AM +0100, Linus Walleij wrote: > On Tue, Mar 24, 2015 at 4:06 PM, Mika Westerberg > <mika.westerberg@linux.intel.com> wrote: > > > This has few problems that I have not yet figured out. Maybe someone > > here can suggest what to do: > > > > 1) Who is responsible in releasing the GPIO? > > 2) What if the driver wants to use that pin as a GPIO instead? The GPIO > > is already requested by the I2C core. > > In the DT usecase we actually specify that in the DTS file > so we don't have the problem. Either the consumer accesses > the irqchip API with: > > interrupts = <nn nn>; > > or it accesses the GPIO API with: > > gpios = <nn nn>;
OK, I see.
> so in that sense it is clear what is requested. Then the core > of course uses gpiochip_lock/unlock_as_irq() to handle the > case where bugs make a collision (like if both were specified > and both APIs tries to access the same resource).
Where in the core code gpiochip_lock/unlock_as_irq() is called for these? At least of_irq_get() doesn't seem to be doing that. Maybe I'm looking at the wrong place.
> But as long as the DTS file is consistent there is no problem. > > So it seems the ACPI tables are lacking this semantic > information?
I think the GpioIo/GpioInt separation serves the same purpose. Of course both refer to GPIO controller instead of interrupt controller.
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