s3c24xx pinctrl help

s3c24xx pinctrl help

[Heiko Stübner]

Hi Thomas,

taking you up on your offer of helping, I would be cool if you could simply
give me a push in the right direction :-) .


>From what I've seen so far, the bank handling itself is very similar between
exynos and s3c24xx as the underlying structures already handle multiple widths
of the register contents. More interesting is the eint handling around which I 
couldn't wrap my head yet.

The basic structure is again similar with special eint registers, but adds 
some quirks. EINT banks are gpf (8 eints) and gpg (8 or 16 eints depending on
the SoC).

The current way on Exynos seems to be to mark the offset in the eint register
and attach an irq_domain to the bank, which gets mapped to the eints starting
at the offset. The eints seem to have a parent interrupt that is provided via
the dt.

On the S3C24xx the gpg bank is doing this similar but gpf is very strange.

The first half of the bank (gpf0 to gpf3) is not handled in eintpend registers
but in the main interrupt controller (bits 0 to 3), while the second
half of gpf is handled in eintpend. The new interrupt declaration might show
this better, which can be found at [0].

An exception is the s3c2412 which adds still another quirk where each
interrupt of gpf0 to gpf3 is represented in both the normal intc and eint
registers, again for reference probably easier to see in [1].


So I'm still quite stumped on how this could fit into the current framework
and would be really glad for some small pointers :-)


Thanks
Heiko



[0] https://git.kernel.org/cgit/linux/kernel/git/kgene/linux-samsung.git/tree/arch/arm/mach-s3c24xx/irq.c?h=next/irq-s3c24xx-2&id=17453dd2e7df20612770ebbf1ab5d506a432210c#n574
[1] https://git.kernel.org/cgit/linux/kernel/git/kgene/linux-samsung.git/tree/arch/arm/mach-s3c24xx/irq.c?h=next/irq-s3c24xx-2&id=17453dd2e7df20612770ebbf1ab5d506a432210c#n712

Re: s3c24xx pinctrl help

[Tomasz Figa]

Hi Heiko,

On Friday 08 of March 2013 15:38:04 Heiko Stübner wrote:
> Hi Thomas,
> 
> taking you up on your offer of helping, I would be cool if you could
> simply give me a push in the right direction :-) .
> 
> 
> From what I've seen so far, the bank handling itself is very similar
> between exynos and s3c24xx as the underlying structures already handle
> multiple widths of the register contents. More interesting is the eint
> handling around which I couldn't wrap my head yet.
> 
> The basic structure is again similar with special eint registers, but
> adds some quirks. EINT banks are gpf (8 eints) and gpg (8 or 16 eints
> depending on the SoC).
> 
> The current way on Exynos seems to be to mark the offset in the eint
> register and attach an irq_domain to the bank, which gets mapped to the
> eints starting at the offset. The eints seem to have a parent interrupt
> that is provided via the dt.
> 
> On the S3C24xx the gpg bank is doing this similar but gpf is very
> strange.
> 
> The first half of the bank (gpf0 to gpf3) is not handled in eintpend
> registers but in the main interrupt controller (bits 0 to 3), while the
> second half of gpf is handled in eintpend. The new interrupt
> declaration might show this better, which can be found at [0].
> 
> An exception is the s3c2412 which adds still another quirk where each
> interrupt of gpf0 to gpf3 is represented in both the normal intc and
> eint registers, again for reference probably easier to see in [1].
> 
> 
> So I'm still quite stumped on how this could fit into the current
> framework and would be really glad for some small pointers :-)

I wonder if some of my patches for pinctrl on S3C64xx might be helpful:

https://github.com/tom3q/linux/commits/v3.8-s3c64xx-dt-pinctrl

Best regards,
Tomasz

Re: s3c24xx pinctrl help

[Heiko Stübner]

Am Freitag, 8. März 2013, 19:57:09 schrieb Tomasz Figa:
> Hi Heiko,
> 
> On Friday 08 of March 2013 15:38:04 Heiko Stübner wrote:
> > Hi Thomas,
> > 
> > taking you up on your offer of helping, I would be cool if you could
> > simply give me a push in the right direction :-) .
> > 
> > 
> > From what I've seen so far, the bank handling itself is very similar
> > between exynos and s3c24xx as the underlying structures already handle
> > multiple widths of the register contents. More interesting is the eint
> > handling around which I couldn't wrap my head yet.
> > 
> > The basic structure is again similar with special eint registers, but
> > adds some quirks. EINT banks are gpf (8 eints) and gpg (8 or 16 eints
> > depending on the SoC).
> > 
> > The current way on Exynos seems to be to mark the offset in the eint
> > register and attach an irq_domain to the bank, which gets mapped to the
> > eints starting at the offset. The eints seem to have a parent interrupt
> > that is provided via the dt.
> > 
> > On the S3C24xx the gpg bank is doing this similar but gpf is very
> > strange.
> > 
> > The first half of the bank (gpf0 to gpf3) is not handled in eintpend
> > registers but in the main interrupt controller (bits 0 to 3), while the
> > second half of gpf is handled in eintpend. The new interrupt
> > declaration might show this better, which can be found at [0].
> > 
> > An exception is the s3c2412 which adds still another quirk where each
> > interrupt of gpf0 to gpf3 is represented in both the normal intc and
> > eint registers, again for reference probably easier to see in [1].
> > 
> > 
> > So I'm still quite stumped on how this could fit into the current
> > framework and would be really glad for some small pointers :-)
> 
> I wonder if some of my patches for pinctrl on S3C64xx might be helpful:
> 
> https://github.com/tom3q/linux/commits/v3.8-s3c64xx-dt-pinctrl

Partially ... I got to know the (new to me) interrupt-map part of dt :-) .

But on the S3C64XX you also have the benefit of all eints being in dedictated 
eint registers. I'm still thinking on the best way to integrate the eints that 
live directly in the main interrupt controller.

One option I could think of, would be to add an optional to_irq callback to 
the bank definition and then do something like the following to handle the 
special case:

static int samsung_gpio_to_irq(struct gpio_chip *gc, unsigned offset)                                                                                                   
{                                                                                                                                                                       
	struct samsung_pin_bank *bank = gc_to_pin_bank(gc);                                                                                                             
	unsigned int virq;                                                                                                                                              

	if (bank->to_irq)
		return bank->to_irq(bank, offset);
                                                                                                                                                                        
	if (!bank->irq_domain)                                                                                                                                          
		return -ENXIO;                                                                                                                                          
                                                                                                                                                                        
	virq = irq_create_mapping(bank->irq_domain, offset);                                                                                                            
                                                                                                                                                                        
	return (virq) ? : -ENXIO;                                                                                                                                       
}                                                                                                                                                                       

The GPG bank could simply use the existing mechanisms, as it follows the 
generic paradigm, and for GPF the callback would handle the distinction 
between eints handled in the eint regs or in the main interrupt controller.


And as always, talking about stuff like this helps in hashing out ideas ... my 
thinking is now a bit clearer than yesterday ;-)


Thanks
Heiko

Re: s3c24xx pinctrl help

[Tomasz Figa]

On Saturday 09 of March 2013 13:56:25 Heiko Stübner wrote:
> Am Freitag, 8. März 2013, 19:57:09 schrieb Tomasz Figa:
> > Hi Heiko,
> > 
> > On Friday 08 of March 2013 15:38:04 Heiko Stübner wrote:
> > > Hi Thomas,
> > > 
> > > taking you up on your offer of helping, I would be cool if you could
> > > simply give me a push in the right direction :-) .
> > > 
> > > 
> > > From what I've seen so far, the bank handling itself is very similar
> > > between exynos and s3c24xx as the underlying structures already
> > > handle
> > > multiple widths of the register contents. More interesting is the
> > > eint
> > > handling around which I couldn't wrap my head yet.
> > > 
> > > The basic structure is again similar with special eint registers,
> > > but
> > > adds some quirks. EINT banks are gpf (8 eints) and gpg (8 or 16
> > > eints
> > > depending on the SoC).
> > > 
> > > The current way on Exynos seems to be to mark the offset in the eint
> > > register and attach an irq_domain to the bank, which gets mapped to
> > > the
> > > eints starting at the offset. The eints seem to have a parent
> > > interrupt
> > > that is provided via the dt.
> > > 
> > > On the S3C24xx the gpg bank is doing this similar but gpf is very
> > > strange.
> > > 
> > > The first half of the bank (gpf0 to gpf3) is not handled in eintpend
> > > registers but in the main interrupt controller (bits 0 to 3), while
> > > the
> > > second half of gpf is handled in eintpend. The new interrupt
> > > declaration might show this better, which can be found at [0].
> > > 
> > > An exception is the s3c2412 which adds still another quirk where
> > > each
> > > interrupt of gpf0 to gpf3 is represented in both the normal intc and
> > > eint registers, again for reference probably easier to see in [1].
> > > 
> > > 
> > > So I'm still quite stumped on how this could fit into the current
> > > framework and would be really glad for some small pointers :-)
> > 
> > I wonder if some of my patches for pinctrl on S3C64xx might be
> > helpful:
> > 
> > https://github.com/tom3q/linux/commits/v3.8-s3c64xx-dt-pinctrl
> 
> Partially ... I got to know the (new to me) interrupt-map part of dt :-)
> .
> 
> But on the S3C64XX you also have the benefit of all eints being in
> dedictated eint registers. I'm still thinking on the best way to
> integrate the eints that live directly in the main interrupt
> controller.
> 
> One option I could think of, would be to add an optional to_irq callback
> to the bank definition and then do something like the following to
> handle the special case:
> 
> static int samsung_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
> {
> 	struct samsung_pin_bank *bank = gc_to_pin_bank(gc);
> 	unsigned int virq;
> 
> 	if (bank->to_irq)
> 		return bank->to_irq(bank, offset);
> 
> 	if (!bank->irq_domain)
> 		return -ENXIO;
> 
> 	virq = irq_create_mapping(bank->irq_domain, offset);
> 
> 	return (virq) ? : -ENXIO;
> }
> 
> The GPG bank could simply use the existing mechanisms, as it follows the
> generic paradigm, and for GPF the callback would handle the distinction
> between eints handled in the eint regs or in the main interrupt
> controller.

Right, I checked how EINTs work on S3C2440A in documentation and indeed it 
is a bit different than I initially thought.

However this is still similar to S3C64xx in some aspects. On S3C64xx there 
is following hierarchy of interrupts in EINT0 group:

EINT0
EINT0


> And as always, talking about stuff like this helps in hashing out ideas
> ... my thinking is now a bit clearer than yesterday ;-)
> 
> 
> Thanks
> Heiko

Re: s3c24xx pinctrl help

[Tomasz Figa]

On Saturday 09 of March 2013 13:56:25 Heiko Stübner wrote:
> Am Freitag, 8. März 2013, 19:57:09 schrieb Tomasz Figa:
> > Hi Heiko,
> > 
> > On Friday 08 of March 2013 15:38:04 Heiko Stübner wrote:
> > > Hi Thomas,
> > > 
> > > taking you up on your offer of helping, I would be cool if you could
> > > simply give me a push in the right direction :-) .
> > > 
> > > 
> > > From what I've seen so far, the bank handling itself is very similar
> > > between exynos and s3c24xx as the underlying structures already
> > > handle
> > > multiple widths of the register contents. More interesting is the
> > > eint
> > > handling around which I couldn't wrap my head yet.
> > > 
> > > The basic structure is again similar with special eint registers,
> > > but
> > > adds some quirks. EINT banks are gpf (8 eints) and gpg (8 or 16
> > > eints
> > > depending on the SoC).
> > > 
> > > The current way on Exynos seems to be to mark the offset in the eint
> > > register and attach an irq_domain to the bank, which gets mapped to
> > > the
> > > eints starting at the offset. The eints seem to have a parent
> > > interrupt
> > > that is provided via the dt.
> > > 
> > > On the S3C24xx the gpg bank is doing this similar but gpf is very
> > > strange.
> > > 
> > > The first half of the bank (gpf0 to gpf3) is not handled in eintpend
> > > registers but in the main interrupt controller (bits 0 to 3), while
> > > the
> > > second half of gpf is handled in eintpend. The new interrupt
> > > declaration might show this better, which can be found at [0].
> > > 
> > > An exception is the s3c2412 which adds still another quirk where
> > > each
> > > interrupt of gpf0 to gpf3 is represented in both the normal intc and
> > > eint registers, again for reference probably easier to see in [1].
> > > 
> > > 
> > > So I'm still quite stumped on how this could fit into the current
> > > framework and would be really glad for some small pointers :-)
> > 
> > I wonder if some of my patches for pinctrl on S3C64xx might be
> > helpful:
> > 
> > https://github.com/tom3q/linux/commits/v3.8-s3c64xx-dt-pinctrl
> 
> Partially ... I got to know the (new to me) interrupt-map part of dt :-)
> .
> 
> But on the S3C64XX you also have the benefit of all eints being in
> dedictated eint registers. I'm still thinking on the best way to
> integrate the eints that live directly in the main interrupt
> controller.
> 
> One option I could think of, would be to add an optional to_irq callback
> to the bank definition and then do something like the following to
> handle the special case:
> 
> static int samsung_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
> {
> 	struct samsung_pin_bank *bank = gc_to_pin_bank(gc);
> 	unsigned int virq;
> 
> 	if (bank->to_irq)
> 		return bank->to_irq(bank, offset);
> 
> 	if (!bank->irq_domain)
> 		return -ENXIO;
> 
> 	virq = irq_create_mapping(bank->irq_domain, offset);
> 
> 	return (virq) ? : -ENXIO;
> }
> 
> The GPG bank could simply use the existing mechanisms, as it follows the
> generic paradigm, and for GPF the callback would handle the distinction
> between eints handled in the eint regs or in the main interrupt
> controller.

Right, I checked how EINTs work on S3C2440A in documentation and indeed it 
is a bit different than I initially thought.

However this is still similar to S3C64xx in some aspects. On S3C64xx there 
is following hierarchy of interrupts in EINT0 group:

EINT0 
...     -------> VIC0 INT0
EINT3 

EINT4
...     -------> VIC0 INT1
EINT11

EINT12
...     -------> VIC1 INT0
EINT19

EINT20
...     -------> VIC1 INT1
EINT27

On S3C24xx it would look like this:

EINT0  -------> INT0

EINT1  -------> INT1

EINT2  -------> INT2

EINT3  -------> INT3

EINT4
...    -------> INT4
EINT7

EINT8
...    -------> INT5
EINT23

So you can look at all EINTs as being multiplexed, just with some groups 
consisting only of single interrupt signal.

The only thing that differs here is that, at least on S3C2440, there are 
no pending and mask bits for EINTs 0-3. Missing pending bits are not a 
problem here, since receiving INT0 would mean receiving EINT0, but no mask 
bits means that masking would have to be handled on interrupt controller 
level, probably by using enable_irq and disable_irq_nosync. This could be 
solved by assigning different irq chip to EINTs 0-3 and EINTs 4-7 in 
domain map callback.

Still, irq domain isn't really related with such low level things. As long 
as you have a way to map domain hwirq to appropriate bitfields in control 
registers and received interrupts to proper domain and its hwirq, you can 
do whatever mapping you want.

Best regards,
Tomasz

P.S. Sorry for previous message, clicked Send accidentally...

Re: s3c24xx pinctrl help

[Tomasz Figa]

On Saturday 09 of March 2013 13:56:25 Heiko Stübner wrote:
> Am Freitag, 8. März 2013, 19:57:09 schrieb Tomasz Figa:
> > Hi Heiko,
> > 
> > On Friday 08 of March 2013 15:38:04 Heiko Stübner wrote:
> > > Hi Thomas,
> > > 
> > > taking you up on your offer of helping, I would be cool if you could
> > > simply give me a push in the right direction :-) .
> > > 
> > > 
> > > From what I've seen so far, the bank handling itself is very similar
> > > between exynos and s3c24xx as the underlying structures already
> > > handle
> > > multiple widths of the register contents. More interesting is the
> > > eint
> > > handling around which I couldn't wrap my head yet.
> > > 
> > > The basic structure is again similar with special eint registers,
> > > but
> > > adds some quirks. EINT banks are gpf (8 eints) and gpg (8 or 16
> > > eints
> > > depending on the SoC).
> > > 
> > > The current way on Exynos seems to be to mark the offset in the eint
> > > register and attach an irq_domain to the bank, which gets mapped to
> > > the
> > > eints starting at the offset. The eints seem to have a parent
> > > interrupt
> > > that is provided via the dt.
> > > 
> > > On the S3C24xx the gpg bank is doing this similar but gpf is very
> > > strange.
> > > 
> > > The first half of the bank (gpf0 to gpf3) is not handled in eintpend
> > > registers but in the main interrupt controller (bits 0 to 3), while
> > > the
> > > second half of gpf is handled in eintpend. The new interrupt
> > > declaration might show this better, which can be found at [0].
> > > 
> > > An exception is the s3c2412 which adds still another quirk where
> > > each
> > > interrupt of gpf0 to gpf3 is represented in both the normal intc and
> > > eint registers, again for reference probably easier to see in [1].
> > > 
> > > 
> > > So I'm still quite stumped on how this could fit into the current
> > > framework and would be really glad for some small pointers :-)
> > 
> > I wonder if some of my patches for pinctrl on S3C64xx might be
> > helpful:
> > 
> > https://github.com/tom3q/linux/commits/v3.8-s3c64xx-dt-pinctrl
> 
> Partially ... I got to know the (new to me) interrupt-map part of dt :-)
> .
> 
> But on the S3C64XX you also have the benefit of all eints being in
> dedictated eint registers. I'm still thinking on the best way to
> integrate the eints that live directly in the main interrupt
> controller.
> 
> One option I could think of, would be to add an optional to_irq callback
> to the bank definition and then do something like the following to
> handle the special case:
> 
> static int samsung_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
> {
> 	struct samsung_pin_bank *bank = gc_to_pin_bank(gc);
> 	unsigned int virq;
> 
> 	if (bank->to_irq)
> 		return bank->to_irq(bank, offset);
> 
> 	if (!bank->irq_domain)
> 		return -ENXIO;
> 
> 	virq = irq_create_mapping(bank->irq_domain, offset);
> 
> 	return (virq) ? : -ENXIO;
> }

I forgot one more thing in my previous reply. Your solution would not 
allow GPIO bank-based specification of EINTs 0-3 in device tree.

Consider following example:

device-0 {
	...
	interrupt-parent = <&gpf>;
	interrupts = <2 0>;
	...
};

This would explicitly go through irq_create_mapping() without calling 
gpio_to_irq.

Of course you could say that this kind of specification is not valid for 
EINTs0-3 and interrupt contoller has to be specified in interrupt-parent 
specifier, not gpf bank. I guess it's just a matter of preference, though.

Best regards,
Tomasz

Re: s3c24xx pinctrl help

[Heiko Stübner]

Am Samstag, 9. März 2013, 14:31:53 schrieb Tomasz Figa:
> On Saturday 09 of March 2013 13:56:25 Heiko Stübner wrote:
> > Am Freitag, 8. März 2013, 19:57:09 schrieb Tomasz Figa:
> > > Hi Heiko,
> > > 
> > > On Friday 08 of March 2013 15:38:04 Heiko Stübner wrote:
> > > > Hi Thomas,
> > > > 
> > > > taking you up on your offer of helping, I would be cool if you could
> > > > simply give me a push in the right direction :-) .
> > > > 
> > > > 
> > > > From what I've seen so far, the bank handling itself is very similar
> > > > between exynos and s3c24xx as the underlying structures already
> > > > handle
> > > > multiple widths of the register contents. More interesting is the
> > > > eint
> > > > handling around which I couldn't wrap my head yet.
> > > > 
> > > > The basic structure is again similar with special eint registers,
> > > > but
> > > > adds some quirks. EINT banks are gpf (8 eints) and gpg (8 or 16
> > > > eints
> > > > depending on the SoC).
> > > > 
> > > > The current way on Exynos seems to be to mark the offset in the eint
> > > > register and attach an irq_domain to the bank, which gets mapped to
> > > > the
> > > > eints starting at the offset. The eints seem to have a parent
> > > > interrupt
> > > > that is provided via the dt.
> > > > 
> > > > On the S3C24xx the gpg bank is doing this similar but gpf is very
> > > > strange.
> > > > 
> > > > The first half of the bank (gpf0 to gpf3) is not handled in eintpend
> > > > registers but in the main interrupt controller (bits 0 to 3), while
> > > > the
> > > > second half of gpf is handled in eintpend. The new interrupt
> > > > declaration might show this better, which can be found at [0].
> > > > 
> > > > An exception is the s3c2412 which adds still another quirk where
> > > > each
> > > > interrupt of gpf0 to gpf3 is represented in both the normal intc and
> > > > eint registers, again for reference probably easier to see in [1].
> > > > 
> > > > 
> > > > So I'm still quite stumped on how this could fit into the current
> > > > framework and would be really glad for some small pointers :-)
> > > 
> > > I wonder if some of my patches for pinctrl on S3C64xx might be
> > > helpful:
> > > 
> > > https://github.com/tom3q/linux/commits/v3.8-s3c64xx-dt-pinctrl
> > 
> > Partially ... I got to know the (new to me) interrupt-map part of dt :-)
> > .
> > 
> > But on the S3C64XX you also have the benefit of all eints being in
> > dedictated eint registers. I'm still thinking on the best way to
> > integrate the eints that live directly in the main interrupt
> > controller.
> > 
> > One option I could think of, would be to add an optional to_irq callback
> > to the bank definition and then do something like the following to
> > handle the special case:
> > 
> > static int samsung_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
> > {
> > 
> > 	struct samsung_pin_bank *bank = gc_to_pin_bank(gc);
> > 	unsigned int virq;
> > 	
> > 	if (bank->to_irq)
> > 	
> > 		return bank->to_irq(bank, offset);
> > 	
> > 	if (!bank->irq_domain)
> > 	
> > 		return -ENXIO;
> > 	
> > 	virq = irq_create_mapping(bank->irq_domain, offset);
> > 	
> > 	return (virq) ? : -ENXIO;
> > 
> > }
> > 
> > The GPG bank could simply use the existing mechanisms, as it follows the
> > generic paradigm, and for GPF the callback would handle the distinction
> > between eints handled in the eint regs or in the main interrupt
> > controller.
> 
> Right, I checked how EINTs work on S3C2440A in documentation and indeed it
> is a bit different than I initially thought.
> 
> However this is still similar to S3C64xx in some aspects. On S3C64xx there
> is following hierarchy of interrupts in EINT0 group:
> 
> EINT0
> ...     -------> VIC0 INT0
> EINT3
> 
> EINT4
> ...     -------> VIC0 INT1
> EINT11
> 
> EINT12
> ...     -------> VIC1 INT0
> EINT19
> 
> EINT20
> ...     -------> VIC1 INT1
> EINT27
> 
> On S3C24xx it would look like this:
> 
> EINT0  -------> INT0
> 
> EINT1  -------> INT1
> 
> EINT2  -------> INT2
> 
> EINT3  -------> INT3
> 
> EINT4
> ...    -------> INT4
> EINT7
> 
> EINT8
> ...    -------> INT5
> EINT23
> 
> So you can look at all EINTs as being multiplexed, just with some groups
> consisting only of single interrupt signal.
> 
> The only thing that differs here is that, at least on S3C2440, there are
> no pending and mask bits for EINTs 0-3.

Yep, that's the standard handling for all s3c24xx except the s3c2412 which 
does the eint0 ---> eint0, eint1 ---> eint1 mapping and contains the necessary 
bits in eintpend.


> Missing pending bits are not a
> problem here, since receiving INT0 would mean receiving EINT0, but no mask
> bits means that masking would have to be handled on interrupt controller
> level, probably by using enable_irq and disable_irq_nosync. This could be
> solved by assigning different irq chip to EINTs 0-3 and EINTs 4-7 in
> domain map callback.

This thought is really intriguing, as it would solve a lot of problems. 


[from the second mail]:
> I forgot one more thing in my previous reply. Your solution would not
> allow GPIO bank-based specification of EINTs 0-3 in device tree.
> 
> Consider following example:
> 
> device-0 {
> 	...
> 	interrupt-parent = <&gpf>;
> 	interrupts = <2 0>;
> 	...
> };
> 
> This would explicitly go through irq_create_mapping() without calling
> gpio_to_irq.
> 
> Of course you could say that this kind of specification is not valid for
> EINTs0-3 and interrupt contoller has to be specified in interrupt-parent
> specifier, not gpf bank. I guess it's just a matter of preference, though.

Yep, that was also one of my concerns, especially, as the handling of the 
extint settings would then also need to be done in both the pinctrl and 
interrupt controller for the respective parts, not to speak of the access to 
the eint setting-registers needed from the interrupt controller code.

Also, I like the idea above (having everything in the pinctrl driver) a lot 
better, which would solve all this quite cleanly :-) .


Heiko