Re: [PATCH 1/1] of/irq: store IRQ trigger/level in struct resource flags

[Tomasz Figa <tomasz.figa@gmail.com>]

On Thursday 06 of June 2013 10:50:39 Jean-Christophe PLAGNIOL-VILLARD 
wrote:
> On 00:26 Thu 06 Jun     , Grant Likely wrote:
> > On Tue, 09 Apr 2013 00:44:05 +0200, Javier Martinez Canillas 
<javier.martinez@collabora.co.uk> wrote:
> > > On 04/09/2013 12:05 AM, Rob Herring wrote:
> > > > On 04/05/2013 02:48 AM, Javier Martinez Canillas wrote:
> > > >> This means that drivers that need the IRQ type/level flags
> > > >> defined in
> > > >> the DT won't be able to get it.
> > > > 
> > > > But the interrupt controllers that need the information should be
> > > > able
> > > > to get to it via irqd_get_trigger_type. What problem exactly are
> > > > you
> > > > trying to fix? What driver would use this?
> > > 
> > > Yes but this is not about the interrupt controller wanting this
> > > information but a device driver that is using the IORESOURCE_IRQ
> > > struct resource that has the information about the virtual IRQ
> > > associated with a GPIO-IRQ.
> > > 
> > > The driver doesn't know neither care if its IRQ line is connected to
> > > a line of an real IRQ controller or to a GPIO controller that
> > > allows a GPIO line to be used as an IRQ.
> > > 
> > > > My understanding of the IORESOURCE_IRQ_xxx (and DMA) bits are they
> > > > are
> > > > ISA specific and therefore should not be used on non-ISA buses.
> > > 
> > > Many TI OMAP2+ SoC based boards have an SMSC LAN911x/912x controller
> > > (drivers/net/ethernet/smsc/smsc911x.c) that is connected to the OMAP
> > > processor through its General-Purpose Memory Controller (GPMC) and
> > > this LAN driver obtain its IRQ and I/O address space from a struct
> > > resource IORESOURCE_IRQ and IORESOURCE_MEM respectively, that is
> > > filled by the DeviceTree core.
> > > 
> > > It does this:
> > > 
> > > irq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
> > > irq_flags = irq_res->flags & IRQF_TRIGGER_MASK;
> > > 
> > > Since of_irq_to_resource() doesn't fill the trigger/level flags on
> > > the
> > > IORESOURCE_IRQ struct resource, irq_flags will always be 0 regarding
> > > the value specified on the second cell of the "interrupts" DT
> > > property.
> 
> why do you need to known this in you driver this need to be handle in
> the irq chip

There are devices that support multiple interrupt trigger types, like 
Broadcom WLAN chips, and drivers must configure them properly for 
requested trigger type, obtaining the information from flags field of the 
IRQ resource.

Best regards,
Tomasz