Re: [RFC PATCH 16/19] powerpc: wii: hollywood interrupt controller support

2009-11-26 Thread Segher Boessenkool 

+static void hlwd_pic_mask_and_ack(unsigned int virq)
+{
+   int irq = virq_to_hw(virq);
+   void __iomem *io_base = get_irq_chip_data(virq);
+
+   clear_bit(irq, io_base + HW_BROADWAY_IMR);
+   set_bit(irq, io_base + HW_BROADWAY_ICR);
+}


Same comment as with flipper. BTW. It looks really similar, can't you
use the same driver ?


No, they aren't actually similar; the old PIC acks when the status reg
is read, the new PIC acks when you write a 1.  Also, the new PIC has
more registers, it is an interrupt controller for the ARM as well.  Not
that we use it, but still.


Segher

___
Linuxppc-dev mailing list
Linuxppc-dev@lists.ozlabs.org
https://lists.ozlabs.org/listinfo/linuxppc-dev

Re: [RFC PATCH 16/19] powerpc: wii: hollywood interrupt controller support

2009-11-26 Thread Benjamin Herrenschmidt 
On Thu, 2009-11-26 at 16:42 +0100, Albert Herranz wrote:
> Benjamin Herrenschmidt wrote:
> > On Sun, 2009-11-22 at 23:01 +0100, Albert Herranz wrote:
> > 
> >> +static void hlwd_pic_mask_and_ack(unsigned int virq)
> >> +{
> >> +  int irq = virq_to_hw(virq);
> >> +  void __iomem *io_base = get_irq_chip_data(virq);
> >> +
> >> +  clear_bit(irq, io_base + HW_BROADWAY_IMR);
> >> +  set_bit(irq, io_base + HW_BROADWAY_ICR);
> >> +}
> > 
> > Same comment as with flipper. BTW. It looks really similar, can't you
> > use the same driver ?
> > 
> 
> I'll look at it. Surely, parts of it would be mergeable.

If it's too much work, we can do that later. No big deal.

Cheers,
Ben.

> > Cheers,
> > Ben.
> > 
> 
> Thanks,
> Albert
> 
> > 
> > 


___
Linuxppc-dev mailing list
Linuxppc-dev@lists.ozlabs.org
https://lists.ozlabs.org/listinfo/linuxppc-dev

Re: [RFC PATCH 16/19] powerpc: wii: hollywood interrupt controller support

2009-11-26 Thread Albert Herranz 
Benjamin Herrenschmidt wrote:
> On Sun, 2009-11-22 at 23:01 +0100, Albert Herranz wrote:
> 
>> +static void hlwd_pic_mask_and_ack(unsigned int virq)
>> +{
>> +int irq = virq_to_hw(virq);
>> +void __iomem *io_base = get_irq_chip_data(virq);
>> +
>> +clear_bit(irq, io_base + HW_BROADWAY_IMR);
>> +set_bit(irq, io_base + HW_BROADWAY_ICR);
>> +}
> 
> Same comment as with flipper. BTW. It looks really similar, can't you
> use the same driver ?
> 

I'll look at it. Surely, parts of it would be mergeable.

> Cheers,
> Ben.
> 

Thanks,
Albert

> 
> 

___
Linuxppc-dev mailing list
Linuxppc-dev@lists.ozlabs.org
https://lists.ozlabs.org/listinfo/linuxppc-dev

Re: [RFC PATCH 16/19] powerpc: wii: hollywood interrupt controller support

2009-11-25 Thread Benjamin Herrenschmidt 
On Sun, 2009-11-22 at 23:01 +0100, Albert Herranz wrote:

> +static void hlwd_pic_mask_and_ack(unsigned int virq)
> +{
> + int irq = virq_to_hw(virq);
> + void __iomem *io_base = get_irq_chip_data(virq);
> +
> + clear_bit(irq, io_base + HW_BROADWAY_IMR);
> + set_bit(irq, io_base + HW_BROADWAY_ICR);
> +}

Same comment as with flipper. BTW. It looks really similar, can't you
use the same driver ?

Cheers,
Ben.


___
Linuxppc-dev mailing list
Linuxppc-dev@lists.ozlabs.org
https://lists.ozlabs.org/listinfo/linuxppc-dev

Re: [RFC PATCH 16/19] powerpc: wii: hollywood interrupt controller support

2009-11-25 Thread Albert Herranz 
Segher Boessenkool wrote:
>> +config HLWD_PIC
> 
> Are vowels too expensive?  :-)
> 

Heh, you work/worked for IBM. Look at what they did with the CLI in the 
AS/400...

I thought here that hollywood is a rather large prefix and there is also a 
board called holly. So I came up with hlwd :)

>> +static void hlwd_pic_ack(unsigned int virq)
>> +{
>> +int irq = virq_to_hw(virq);
>> +void __iomem *io_base = get_irq_chip_data(virq);
>> +
>> +set_bit(irq, io_base + HW_BROADWAY_ICR);
>> +}
> 
> Same issue as with Flipper here.
> 

See my comments on the previous message.

>> +__asm__ __volatile__("cntlzw %0,%1" : "=r"(irq) : "r"(irq_status));
>> +return irq_linear_revmap(h, 31 - irq);
> 
> And here.
> 

Ditto.

>> +static void __hlwd_quiesce(void __iomem *io_base)
>> +{
>> +/* mask and ack all IRQs */
>> +out_be32(io_base + HW_BROADWAY_IMR, 0);
>> +out_be32(io_base + HW_BROADWAY_ICR, ~0);
>> +}
> 
> I would write 0x instead, it's clearer and slightly
> more robust.
> 

Ok.

>> +void hlwd_pic_probe(void)
>> +{
>> +struct irq_host *host;
>> +struct device_node *np;
>> +const u32 *interrupts;
>> +int cascade_virq;
>> +
>> +for_each_compatible_node(np, NULL, "nintendo,hollywood-pic") {
>> +interrupts = of_get_property(np, "interrupts", NULL);
>> +if (interrupts) {
>> +host = hlwd_pic_init(np);
>> +BUG_ON(!host);
>> +cascade_virq = irq_of_parse_and_map(np, 0);
>> +set_irq_data(cascade_virq, host);
>> +set_irq_chained_handler(cascade_virq,
>> +hlwd_pic_irq_cascade);
> 
> break;  here?  You do not handle more than one hollywood-pic elsewhere
> (which of course is fine).

Yup, thanks. I'll stop after the first pic.

Cheers,
Albert
___
Linuxppc-dev mailing list
Linuxppc-dev@lists.ozlabs.org
https://lists.ozlabs.org/listinfo/linuxppc-dev

Re: [RFC PATCH 16/19] powerpc: wii: hollywood interrupt controller support

2009-11-24 Thread Segher Boessenkool 

+config HLWD_PIC


Are vowels too expensive?  :-)


+static void hlwd_pic_ack(unsigned int virq)
+{
+   int irq = virq_to_hw(virq);
+   void __iomem *io_base = get_irq_chip_data(virq);
+
+   set_bit(irq, io_base + HW_BROADWAY_ICR);
+}


Same issue as with Flipper here.


+   __asm__ __volatile__("cntlzw %0,%1" : "=r"(irq) : "r"(irq_status));
+   return irq_linear_revmap(h, 31 - irq);


And here.


+static void __hlwd_quiesce(void __iomem *io_base)
+{
+   /* mask and ack all IRQs */
+   out_be32(io_base + HW_BROADWAY_IMR, 0);
+   out_be32(io_base + HW_BROADWAY_ICR, ~0);
+}


I would write 0x instead, it's clearer and slightly
more robust.


+void hlwd_pic_probe(void)
+{
+   struct irq_host *host;
+   struct device_node *np;
+   const u32 *interrupts;
+   int cascade_virq;
+
+   for_each_compatible_node(np, NULL, "nintendo,hollywood-pic") {
+   interrupts = of_get_property(np, "interrupts", NULL);
+   if (interrupts) {
+   host = hlwd_pic_init(np);
+   BUG_ON(!host);
+   cascade_virq = irq_of_parse_and_map(np, 0);
+   set_irq_data(cascade_virq, host);
+   set_irq_chained_handler(cascade_virq,
+   hlwd_pic_irq_cascade);


break;  here?  You do not handle more than one hollywood-pic elsewhere
(which of course is fine).


Segher

___
Linuxppc-dev mailing list
Linuxppc-dev@lists.ozlabs.org
https://lists.ozlabs.org/listinfo/linuxppc-dev

Re: [RFC PATCH 16/19] powerpc: wii: hollywood interrupt controller support

2009-11-23 Thread Albert Herranz 
Grant Likely wrote:
> On Sun, Nov 22, 2009 at 3:01 PM, Albert Herranz  
> wrote:
>> Add support for the dual interrupt controller included in the "Hollywood"
>> chipset of the Nintendo Wii video game console.
>> This interrupt controller serves both the Broadway processor (as a cascade)
>> and the Starlet processor, and is used to manage interrupts for the
>> non-classic hardware.
>>
>> Signed-off-by: Albert Herranz 
> 
> On brief glance...
> 
> Acked-by: Grant Likely 
> 

Uhmmm... I think I should use .name instead of .typename in struct irq_chip, no?

>> ---
>>  arch/powerpc/platforms/embedded6xx/Kconfig|5 +
>>  arch/powerpc/platforms/embedded6xx/Makefile   |1 +
>>  arch/powerpc/platforms/embedded6xx/hlwd-pic.c |  238 
>> +
>>  arch/powerpc/platforms/embedded6xx/hlwd-pic.h |   22 +++
>>  4 files changed, 266 insertions(+), 0 deletions(-)
>>  create mode 100644 arch/powerpc/platforms/embedded6xx/hlwd-pic.c
>>  create mode 100644 arch/powerpc/platforms/embedded6xx/hlwd-pic.h
>>
>> diff --git a/arch/powerpc/platforms/embedded6xx/Kconfig 
>> b/arch/powerpc/platforms/embedded6xx/Kconfig
>> index efb2ea1..490f89e 100644
>> --- a/arch/powerpc/platforms/embedded6xx/Kconfig
>> +++ b/arch/powerpc/platforms/embedded6xx/Kconfig
>> @@ -122,3 +122,8 @@ config GAMECUBE
>>  Select GAMECUBE if configuring for the Nintendo GameCube.
>>  More information at: 
>>
>> +config HLWD_PIC
>> +   bool
>> +   depends on STARLET_MINI
>> +   default y
>> +
>> diff --git a/arch/powerpc/platforms/embedded6xx/Makefile 
>> b/arch/powerpc/platforms/embedded6xx/Makefile
>> index b0324ed..c1dcc54 100644
>> --- a/arch/powerpc/platforms/embedded6xx/Makefile
>> +++ b/arch/powerpc/platforms/embedded6xx/Makefile
>> @@ -10,3 +10,4 @@ obj-$(CONFIG_PPC_C2K) += c2k.o
>>  obj-$(CONFIG_USBGECKO_UDBG)+= usbgecko_udbg.o
>>  obj-$(CONFIG_FLIPPER_PIC)  += flipper-pic.o
>>  obj-$(CONFIG_GAMECUBE) += gamecube.o gamecube_dev.o
>> +obj-$(CONFIG_HLWD_PIC) += hlwd-pic.o
>> diff --git a/arch/powerpc/platforms/embedded6xx/hlwd-pic.c 
>> b/arch/powerpc/platforms/embedded6xx/hlwd-pic.c
>> new file mode 100644
>> index 000..b024800
>> --- /dev/null
>> +++ b/arch/powerpc/platforms/embedded6xx/hlwd-pic.c
>> @@ -0,0 +1,238 @@
>> +/*
>> + * arch/powerpc/platforms/embedded6xx/hlwd-pic.c
>> + *
>> + * Nintendo Wii "Hollywood" interrupt controller support.
>> + * Copyright (C) 2009 The GameCube Linux Team
>> + * Copyright (C) 2009 Albert Herranz
>> + *
>> + * This program is free software; you can redistribute it and/or
>> + * modify it under the terms of the GNU General Public License
>> + * as published by the Free Software Foundation; either version 2
>> + * of the License, or (at your option) any later version.
>> + *
>> + */
>> +#define DRV_MODULE_NAME "hlwd-pic"
>> +#define pr_fmt(fmt) DRV_MODULE_NAME ": " fmt
>> +
>> +#include 
>> +#include 
>> +#include 
>> +#include 
>> +#include 
>> +
>> +#include "hlwd-pic.h"
>> +
>> +#define HLWD_NR_IRQS   32
>> +
>> +/*
>> + * Each interrupt has a corresponding bit in both
>> + * the Interrupt Cause (ICR) and Interrupt Mask (IMR) registers.
>> + *
>> + * Enabling/disabling an interrupt line involves asserting/clearing
>> + * the corresponding bit in IMR. ACK'ing a request simply involves
>> + * asserting the corresponding bit in ICR.
>> + */
>> +#define HW_BROADWAY_ICR0x00
>> +#define HW_BROADWAY_IMR0x04
>> +
>> +
>> +/*
>> + * IRQ chip hooks.
>> + *
>> + */
>> +
>> +static void hlwd_pic_mask_and_ack(unsigned int virq)
>> +{
>> +   int irq = virq_to_hw(virq);
>> +   void __iomem *io_base = get_irq_chip_data(virq);
>> +
>> +   clear_bit(irq, io_base + HW_BROADWAY_IMR);
>> +   set_bit(irq, io_base + HW_BROADWAY_ICR);
>> +}
>> +
>> +static void hlwd_pic_ack(unsigned int virq)
>> +{
>> +   int irq = virq_to_hw(virq);
>> +   void __iomem *io_base = get_irq_chip_data(virq);
>> +
>> +   set_bit(irq, io_base + HW_BROADWAY_ICR);
>> +}
>> +
>> +static void hlwd_pic_mask(unsigned int virq)
>> +{
>> +   int irq = virq_to_hw(virq);
>> +   void __iomem *io_base = get_irq_chip_data(virq);
>> +
>> +   clear_bit(irq, io_base + HW_BROADWAY_IMR);
>> +}
>> +
>> +static void hlwd_pic_unmask(unsigned int virq)
>> +{
>> +   int irq = virq_to_hw(virq);
>> +   void __iomem *io_base = get_irq_chip_data(virq);
>> +
>> +   set_bit(irq, io_base + HW_BROADWAY_IMR);
>> +}
>> +
>> +
>> +static struct irq_chip hlwd_pic = {
>> +   .typename   = "hlwd-pic",
>> +   .ack= hlwd_pic_ack,
>> +   .mask_ack   = hlwd_pic_mask_and_ack,
>> +   .mask   = hlwd_pic_mask,
>> +   .unmask = hlwd_pic_unmask,
>> +};
>> +
>> +/*
>> + * IRQ host hooks.
>> + *
>> + */
>> +
>> +static struct irq_host *hlwd_irq_host;
>> +
>> +static int hlwd_pic_map(struct irq_host *h, unsigned int virq,
>> +

Re: [RFC PATCH 16/19] powerpc: wii: hollywood interrupt controller support

2009-11-22 Thread Grant Likely 
On Sun, Nov 22, 2009 at 3:01 PM, Albert Herranz  wrote:
> Add support for the dual interrupt controller included in the "Hollywood"
> chipset of the Nintendo Wii video game console.
> This interrupt controller serves both the Broadway processor (as a cascade)
> and the Starlet processor, and is used to manage interrupts for the
> non-classic hardware.
>
> Signed-off-by: Albert Herranz 

On brief glance...

Acked-by: Grant Likely 

> ---
>  arch/powerpc/platforms/embedded6xx/Kconfig    |    5 +
>  arch/powerpc/platforms/embedded6xx/Makefile   |    1 +
>  arch/powerpc/platforms/embedded6xx/hlwd-pic.c |  238 
> +
>  arch/powerpc/platforms/embedded6xx/hlwd-pic.h |   22 +++
>  4 files changed, 266 insertions(+), 0 deletions(-)
>  create mode 100644 arch/powerpc/platforms/embedded6xx/hlwd-pic.c
>  create mode 100644 arch/powerpc/platforms/embedded6xx/hlwd-pic.h
>
> diff --git a/arch/powerpc/platforms/embedded6xx/Kconfig 
> b/arch/powerpc/platforms/embedded6xx/Kconfig
> index efb2ea1..490f89e 100644
> --- a/arch/powerpc/platforms/embedded6xx/Kconfig
> +++ b/arch/powerpc/platforms/embedded6xx/Kconfig
> @@ -122,3 +122,8 @@ config GAMECUBE
>          Select GAMECUBE if configuring for the Nintendo GameCube.
>          More information at: 
>
> +config HLWD_PIC
> +       bool
> +       depends on STARLET_MINI
> +       default y
> +
> diff --git a/arch/powerpc/platforms/embedded6xx/Makefile 
> b/arch/powerpc/platforms/embedded6xx/Makefile
> index b0324ed..c1dcc54 100644
> --- a/arch/powerpc/platforms/embedded6xx/Makefile
> +++ b/arch/powerpc/platforms/embedded6xx/Makefile
> @@ -10,3 +10,4 @@ obj-$(CONFIG_PPC_C2K)         += c2k.o
>  obj-$(CONFIG_USBGECKO_UDBG)    += usbgecko_udbg.o
>  obj-$(CONFIG_FLIPPER_PIC)      += flipper-pic.o
>  obj-$(CONFIG_GAMECUBE)         += gamecube.o gamecube_dev.o
> +obj-$(CONFIG_HLWD_PIC)         += hlwd-pic.o
> diff --git a/arch/powerpc/platforms/embedded6xx/hlwd-pic.c 
> b/arch/powerpc/platforms/embedded6xx/hlwd-pic.c
> new file mode 100644
> index 000..b024800
> --- /dev/null
> +++ b/arch/powerpc/platforms/embedded6xx/hlwd-pic.c
> @@ -0,0 +1,238 @@
> +/*
> + * arch/powerpc/platforms/embedded6xx/hlwd-pic.c
> + *
> + * Nintendo Wii "Hollywood" interrupt controller support.
> + * Copyright (C) 2009 The GameCube Linux Team
> + * Copyright (C) 2009 Albert Herranz
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License
> + * as published by the Free Software Foundation; either version 2
> + * of the License, or (at your option) any later version.
> + *
> + */
> +#define DRV_MODULE_NAME "hlwd-pic"
> +#define pr_fmt(fmt) DRV_MODULE_NAME ": " fmt
> +
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +
> +#include "hlwd-pic.h"
> +
> +#define HLWD_NR_IRQS   32
> +
> +/*
> + * Each interrupt has a corresponding bit in both
> + * the Interrupt Cause (ICR) and Interrupt Mask (IMR) registers.
> + *
> + * Enabling/disabling an interrupt line involves asserting/clearing
> + * the corresponding bit in IMR. ACK'ing a request simply involves
> + * asserting the corresponding bit in ICR.
> + */
> +#define HW_BROADWAY_ICR                0x00
> +#define HW_BROADWAY_IMR                0x04
> +
> +
> +/*
> + * IRQ chip hooks.
> + *
> + */
> +
> +static void hlwd_pic_mask_and_ack(unsigned int virq)
> +{
> +       int irq = virq_to_hw(virq);
> +       void __iomem *io_base = get_irq_chip_data(virq);
> +
> +       clear_bit(irq, io_base + HW_BROADWAY_IMR);
> +       set_bit(irq, io_base + HW_BROADWAY_ICR);
> +}
> +
> +static void hlwd_pic_ack(unsigned int virq)
> +{
> +       int irq = virq_to_hw(virq);
> +       void __iomem *io_base = get_irq_chip_data(virq);
> +
> +       set_bit(irq, io_base + HW_BROADWAY_ICR);
> +}
> +
> +static void hlwd_pic_mask(unsigned int virq)
> +{
> +       int irq = virq_to_hw(virq);
> +       void __iomem *io_base = get_irq_chip_data(virq);
> +
> +       clear_bit(irq, io_base + HW_BROADWAY_IMR);
> +}
> +
> +static void hlwd_pic_unmask(unsigned int virq)
> +{
> +       int irq = virq_to_hw(virq);
> +       void __iomem *io_base = get_irq_chip_data(virq);
> +
> +       set_bit(irq, io_base + HW_BROADWAY_IMR);
> +}
> +
> +
> +static struct irq_chip hlwd_pic = {
> +       .typename       = "hlwd-pic",
> +       .ack            = hlwd_pic_ack,
> +       .mask_ack       = hlwd_pic_mask_and_ack,
> +       .mask           = hlwd_pic_mask,
> +       .unmask         = hlwd_pic_unmask,
> +};
> +
> +/*
> + * IRQ host hooks.
> + *
> + */
> +
> +static struct irq_host *hlwd_irq_host;
> +
> +static int hlwd_pic_map(struct irq_host *h, unsigned int virq,
> +                          irq_hw_number_t hwirq)
> +{
> +       set_irq_chip_data(virq, h->host_data);
> +       get_irq_desc(virq)->status |= IRQ_LEVEL;
> +       set_irq_chip_and_handler(virq, &hlwd_pic, handle_level_irq);
> +       return 0;
> +}
> +
> +static void hlwd_pic_unmap

[RFC PATCH 16/19] powerpc: wii: hollywood interrupt controller support

2009-11-22 Thread Albert Herranz 
Add support for the dual interrupt controller included in the "Hollywood"
chipset of the Nintendo Wii video game console.
This interrupt controller serves both the Broadway processor (as a cascade)
and the Starlet processor, and is used to manage interrupts for the
non-classic hardware.

Signed-off-by: Albert Herranz 
---
 arch/powerpc/platforms/embedded6xx/Kconfig|5 +
 arch/powerpc/platforms/embedded6xx/Makefile   |1 +
 arch/powerpc/platforms/embedded6xx/hlwd-pic.c |  238 +
 arch/powerpc/platforms/embedded6xx/hlwd-pic.h |   22 +++
 4 files changed, 266 insertions(+), 0 deletions(-)
 create mode 100644 arch/powerpc/platforms/embedded6xx/hlwd-pic.c
 create mode 100644 arch/powerpc/platforms/embedded6xx/hlwd-pic.h

diff --git a/arch/powerpc/platforms/embedded6xx/Kconfig 
b/arch/powerpc/platforms/embedded6xx/Kconfig
index efb2ea1..490f89e 100644
--- a/arch/powerpc/platforms/embedded6xx/Kconfig
+++ b/arch/powerpc/platforms/embedded6xx/Kconfig
@@ -122,3 +122,8 @@ config GAMECUBE
  Select GAMECUBE if configuring for the Nintendo GameCube.
  More information at: 
 
+config HLWD_PIC
+   bool
+   depends on STARLET_MINI
+   default y
+
diff --git a/arch/powerpc/platforms/embedded6xx/Makefile 
b/arch/powerpc/platforms/embedded6xx/Makefile
index b0324ed..c1dcc54 100644
--- a/arch/powerpc/platforms/embedded6xx/Makefile
+++ b/arch/powerpc/platforms/embedded6xx/Makefile
@@ -10,3 +10,4 @@ obj-$(CONFIG_PPC_C2K) += c2k.o
 obj-$(CONFIG_USBGECKO_UDBG)+= usbgecko_udbg.o
 obj-$(CONFIG_FLIPPER_PIC)  += flipper-pic.o
 obj-$(CONFIG_GAMECUBE) += gamecube.o gamecube_dev.o
+obj-$(CONFIG_HLWD_PIC) += hlwd-pic.o
diff --git a/arch/powerpc/platforms/embedded6xx/hlwd-pic.c 
b/arch/powerpc/platforms/embedded6xx/hlwd-pic.c
new file mode 100644
index 000..b024800
--- /dev/null
+++ b/arch/powerpc/platforms/embedded6xx/hlwd-pic.c
@@ -0,0 +1,238 @@
+/*
+ * arch/powerpc/platforms/embedded6xx/hlwd-pic.c
+ *
+ * Nintendo Wii "Hollywood" interrupt controller support.
+ * Copyright (C) 2009 The GameCube Linux Team
+ * Copyright (C) 2009 Albert Herranz
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ */
+#define DRV_MODULE_NAME "hlwd-pic"
+#define pr_fmt(fmt) DRV_MODULE_NAME ": " fmt
+
+#include 
+#include 
+#include 
+#include 
+#include 
+
+#include "hlwd-pic.h"
+
+#define HLWD_NR_IRQS   32
+
+/*
+ * Each interrupt has a corresponding bit in both
+ * the Interrupt Cause (ICR) and Interrupt Mask (IMR) registers.
+ *
+ * Enabling/disabling an interrupt line involves asserting/clearing
+ * the corresponding bit in IMR. ACK'ing a request simply involves
+ * asserting the corresponding bit in ICR.
+ */
+#define HW_BROADWAY_ICR0x00
+#define HW_BROADWAY_IMR0x04
+
+
+/*
+ * IRQ chip hooks.
+ *
+ */
+
+static void hlwd_pic_mask_and_ack(unsigned int virq)
+{
+   int irq = virq_to_hw(virq);
+   void __iomem *io_base = get_irq_chip_data(virq);
+
+   clear_bit(irq, io_base + HW_BROADWAY_IMR);
+   set_bit(irq, io_base + HW_BROADWAY_ICR);
+}
+
+static void hlwd_pic_ack(unsigned int virq)
+{
+   int irq = virq_to_hw(virq);
+   void __iomem *io_base = get_irq_chip_data(virq);
+
+   set_bit(irq, io_base + HW_BROADWAY_ICR);
+}
+
+static void hlwd_pic_mask(unsigned int virq)
+{
+   int irq = virq_to_hw(virq);
+   void __iomem *io_base = get_irq_chip_data(virq);
+
+   clear_bit(irq, io_base + HW_BROADWAY_IMR);
+}
+
+static void hlwd_pic_unmask(unsigned int virq)
+{
+   int irq = virq_to_hw(virq);
+   void __iomem *io_base = get_irq_chip_data(virq);
+
+   set_bit(irq, io_base + HW_BROADWAY_IMR);
+}
+
+
+static struct irq_chip hlwd_pic = {
+   .typename   = "hlwd-pic",
+   .ack= hlwd_pic_ack,
+   .mask_ack   = hlwd_pic_mask_and_ack,
+   .mask   = hlwd_pic_mask,
+   .unmask = hlwd_pic_unmask,
+};
+
+/*
+ * IRQ host hooks.
+ *
+ */
+
+static struct irq_host *hlwd_irq_host;
+
+static int hlwd_pic_map(struct irq_host *h, unsigned int virq,
+  irq_hw_number_t hwirq)
+{
+   set_irq_chip_data(virq, h->host_data);
+   get_irq_desc(virq)->status |= IRQ_LEVEL;
+   set_irq_chip_and_handler(virq, &hlwd_pic, handle_level_irq);
+   return 0;
+}
+
+static void hlwd_pic_unmap(struct irq_host *h, unsigned int irq)
+{
+   set_irq_chip_data(irq, NULL);
+   set_irq_chip(irq, NULL);
+}
+
+static struct irq_host_ops hlwd_irq_host_ops = {
+   .map = hlwd_pic_map,
+   .unmap = hlwd_pic_unmap,
+};
+
+static unsigned int __hlwd_pic_get_irq(struct irq_host *h)
+{
+   void __iomem *io_base = h->host_data;
+   int irq;
+   u32 irq_status;
+
+   i