[ARM] 2884/1: BAST - fix PC104 IRQ routing

Patch from Ben Dooks

This has been broken for a while now, so fix the
problems with the code, test and bring up to date.
This also makes the code conditional on an
Kconfig option

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

3 files changed, 71 insertions, 18 deletions

diff --git a/arch/arm/mach-s3c2410/Kconfig b/arch/arm/mach-s3c2410/Kconfig
index da818344f954..06807c6ee68a 100644
--- a/arch/arm/mach-s3c2410/Kconfig
+++ b/arch/arm/mach-s3c2410/Kconfig
@@ -18,6 +18,14 @@ config ARCH_BAST
 
           Product page: <http://www.simtec.co.uk/products/EB2410ITX/>.
 
+config BAST_PC104_IRQ
+        bool "BAST PC104 IRQ support"
+        depends on ARCH_BAST
+        default y
+        help
+          Say Y here to enable the PC104 IRQ routing on the
+          Simtec BAST (EB2410ITX)
+
 config ARCH_H1940
         bool "IPAQ H1940"
         select CPU_S3C2410
diff --git a/arch/arm/mach-s3c2410/Makefile b/arch/arm/mach-s3c2410/Makefile
index 023c4f59a345..b4f1e051c768 100644
--- a/arch/arm/mach-s3c2410/Makefile
+++ b/arch/arm/mach-s3c2410/Makefile
@@ -26,6 +26,10 @@ obj-$(CONFIG_CPU_S3C2440)  += s3c2440.o s3c2440-dsc.o
 obj-$(CONFIG_CPU_S3C2440)  += s3c2440-irq.o
 obj-$(CONFIG_CPU_S3C2440)  += s3c2440-clock.o
 
+# bast extras
+
+obj-$(CONFIG_BAST_PC104_IRQ)    += bast-irq.o
+
 # machine specific support
 
 obj-$(CONFIG_MACH_ANUBIS)       += mach-anubis.o
diff --git a/arch/arm/mach-s3c2410/bast-irq.c b/arch/arm/mach-s3c2410/bast-irq.c
index 49914709fa09..fbbeb0553006 100644
--- a/arch/arm/mach-s3c2410/bast-irq.c
+++ b/arch/arm/mach-s3c2410/bast-irq.c
@@ -1,6 +1,6 @@
 /* linux/arch/arm/mach-s3c2410/bast-irq.c
  *
- * Copyright (c) 2004 Simtec Electronics
+ * Copyright (c) 2003,2005 Simtec Electronics
  *   Ben Dooks <ben@simtec.co.uk>
  *
  * http://www.simtec.co.uk/products/EB2410ITX/
@@ -21,7 +21,8 @@
  *
  * Modifications:
  *     08-Jan-2003 BJD  Moved from central IRQ code
- */
+ *     21-Aug-2005 BJD  Fixed missing code and compile errors
+*/
 
 
 #include <linux/init.h>
@@ -30,12 +31,19 @@
 #include <linux/ptrace.h>
 #include <linux/sysdev.h>
 
+#include <asm/mach-types.h>
+
 #include <asm/hardware.h>
 #include <asm/irq.h>
 #include <asm/io.h>
 
 #include <asm/mach/irq.h>
-#include <asm/hardware/s3c2410/irq.h>
+
+#include <asm/arch/regs-irq.h>
+#include <asm/arch/bast-map.h>
+#include <asm/arch/bast-irq.h>
+
+#include "irq.h"
 
 #if 0
 #include <asm/debug-ll.h>
@@ -79,15 +87,15 @@ bast_pc104_mask(unsigned int irqno)
         temp = __raw_readb(BAST_VA_PC104_IRQMASK);
         temp &= ~bast_pc104_irqmasks[irqno];
         __raw_writeb(temp, BAST_VA_PC104_IRQMASK);
-
-        if (temp == 0)
-                bast_extint_mask(IRQ_ISA);
 }
 
 static void
-bast_pc104_ack(unsigned int irqno)
+bast_pc104_maskack(unsigned int irqno)
 {
-        bast_extint_ack(IRQ_ISA);
+        struct irqdesc *desc = irq_desc + IRQ_ISA;
+
+        bast_pc104_mask(irqno);
+        desc->chip->ack(IRQ_ISA);
 }
 
 static void
@@ -98,14 +106,12 @@ bast_pc104_unmask(unsigned int irqno)
         temp = __raw_readb(BAST_VA_PC104_IRQMASK);
         temp |= bast_pc104_irqmasks[irqno];
         __raw_writeb(temp, BAST_VA_PC104_IRQMASK);
-
-        bast_extint_unmask(IRQ_ISA);
 }
 
-static struct bast_pc104_chip = {
+static struct irqchip  bast_pc104_chip = {
         .mask        = bast_pc104_mask,
         .unmask      = bast_pc104_unmask,
-        .ack         = bast_pc104_ack
+        .ack         = bast_pc104_maskack
 };
 
 static void
@@ -119,14 +125,49 @@ bast_irq_pc104_demux(unsigned int irq,
 
         stat = __raw_readb(BAST_VA_PC104_IRQREQ) & 0xf;
 
-        for (i = 0; i < 4 && stat != 0; i++) {
-                if (stat & 1) {
-                        irqno = bast_pc104_irqs[i];
-                        desc = irq_desc + irqno;
+        if (unlikely(stat == 0)) {
+                /* ack if we get an irq with nothing (ie, startup) */
+
+                desc = irq_desc + IRQ_ISA;
+                desc->chip->ack(IRQ_ISA);
+        } else {
+                /* handle the IRQ */
+
+                for (i = 0; stat != 0; i++, stat >>= 1) {
+                        if (stat & 1) {
+                                irqno = bast_pc104_irqs[i];
 
-                        desc_handle_irq(irqno, desc, regs);
+                                desc_handle_irq(irqno, irq_desc + irqno, regs);
+                        }
                 }
+        }
+}
 
-                stat >>= 1;
+static __init int bast_irq_init(void)
+{
+        unsigned int i;
+
+        if (machine_is_bast()) {
+                printk(KERN_INFO "BAST PC104 IRQ routing, (c) 2005 Simtec Electronics\n");
+
+                /* zap all the IRQs */
+
+                __raw_writeb(0x0, BAST_VA_PC104_IRQMASK);
+
+                set_irq_chained_handler(IRQ_ISA, bast_irq_pc104_demux);
+
+                /* reigster our IRQs */
+
+                for (i = 0; i < 4; i++) {
+                        unsigned int irqno = bast_pc104_irqs[i];
+
+                        set_irq_chip(irqno, &bast_pc104_chip);
+                        set_irq_handler(irqno, do_level_IRQ);
+                        set_irq_flags(irqno, IRQF_VALID);
+                }
         }
+
+        return 0;
 }
+
+arch_initcall(bast_irq_init);