m68knommu: external interrupt support to ColdFire intc-2 controller

The EDGE Port module of some ColdFire parts using the intc-2 interrupt
controller provides support for 7 external interrupts. These interrupts
go off-chip (that is they are not for internal peripherals). They need
some special handling and have some extra setup registers. Add code to
support them.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>

1 files changed, 81 insertions, 4 deletions

diff --git a/arch/m68knommu/platform/coldfire/intc-2.c b/arch/m68knommu/platform/coldfire/intc-2.c
index 66d4e47dd8d0..2cbfbf035db9 100644
--- a/arch/m68knommu/platform/coldfire/intc-2.c
+++ b/arch/m68knommu/platform/coldfire/intc-2.c
@@ -7,7 +7,10 @@
  * family, the 5270, 5271, 5274, 5275, and the 528x family which have two such
  * controllers, and the 547x and 548x families which have only one of them.
  *
- * (C) Copyright 2009, Greg Ungerer <gerg@snapgear.com>
+ * The external 7 fixed interrupts are part the the Edge Port unit of these
+ * ColdFire parts. They can be configured as level or edge triggered.
+ *
+ * (C) Copyright 2009-2011, Greg Ungerer <gerg@snapgear.com>
  *
  * This file is subject to the terms and conditions of the GNU General Public
  * License.  See the file COPYING in the main directory of this archive
@@ -30,6 +33,14 @@
 #define MCFSIM_ICR_LEVEL(l)     ((l)<<3)        /* Level l intr */
 #define MCFSIM_ICR_PRI(p)       (p)             /* Priority p intr */
 
+/*
+ *      The EDGE Port interrupts are the fixed 7 external interrupts.
+ *      They need some special treatment, for example they need to be acked.
+ */
+#define EINT0   64      /* Is not actually used, but spot reserved for it */
+#define EINT1   65      /* EDGE Port interrupt 1 */
+#define EINT7   71      /* EDGE Port interrupt 7 */
+
 #ifdef MCFICM_INTC1
 #define NR_VECS 128
 #else
@@ -76,9 +87,17 @@ static void intc_irq_unmask(struct irq_data *d)
         __raw_writel(val & ~imrbit, imraddr);
 }
 
-static int intc_irq_set_type(struct irq_data *d, unsigned int type)
+/*
+ *      Only the external (or EDGE Port) interrupts need to be acknowledged
+ *      here, as part of the IRQ handler. They only really need to be ack'ed
+ *      if they are in edge triggered mode, but there is no harm in doing it
+ *      for all types.
+ */
+static void intc_irq_ack(struct irq_data *d)
 {
-        return 0;
+        unsigned int irq = d->irq;
+
+        __raw_writeb(0x1 << (irq - EINT0), MCFEPORT_EPFR);
 }
 
 /*
@@ -104,15 +123,70 @@ static unsigned int intc_irq_startup(struct irq_data *d)
         if (__raw_readb(icraddr) == 0)
                 __raw_writeb(intc_intpri--, icraddr);
 
+        irq = d->irq;
+        if ((irq >= EINT1) && (irq <= EINT7)) {
+                u8 v;
+
+                irq -= EINT0;
+
+                /* Set EPORT line as input */
+                v = __raw_readb(MCFEPORT_EPDDR);
+                __raw_writeb(v & ~(0x1 << irq), MCFEPORT_EPDDR);
+
+                /* Set EPORT line as interrupt source */
+                v = __raw_readb(MCFEPORT_EPIER);
+                __raw_writeb(v | (0x1 << irq), MCFEPORT_EPIER);
+        }
+
         intc_irq_unmask(d);
         return 0;
 }
 
+static int intc_irq_set_type(struct irq_data *d, unsigned int type)
+{
+        unsigned int irq = d->irq;
+        u16 pa, tb;
+
+        switch (type) {
+        case IRQ_TYPE_EDGE_RISING:
+                tb = 0x1;
+                break;
+        case IRQ_TYPE_EDGE_FALLING:
+                tb = 0x2;
+                break;
+        case IRQ_TYPE_EDGE_BOTH:
+                tb = 0x3;
+                break;
+        default:
+                /* Level triggered */
+                tb = 0;
+                break;
+        }
+
+        if (tb)
+                set_irq_handler(irq, handle_edge_irq);
+
+        irq -= EINT0;
+        pa = __raw_readw(MCFEPORT_EPPAR);
+        pa = (pa & ~(0x3 << (irq * 2))) | (tb << (irq * 2));
+        __raw_writew(pa, MCFEPORT_EPPAR);
+        
+        return 0;
+}
+
 static struct irq_chip intc_irq_chip = {
         .name           = "CF-INTC",
         .irq_startup    = intc_irq_startup,
         .irq_mask       = intc_irq_mask,
         .irq_unmask     = intc_irq_unmask,
+};
+
+static struct irq_chip intc_irq_chip_edge_port = {
+        .name           = "CF-INTC-EP",
+        .irq_startup    = intc_irq_startup,
+        .irq_mask       = intc_irq_mask,
+        .irq_unmask     = intc_irq_unmask,
+        .irq_ack        = intc_irq_ack,
         .irq_set_type   = intc_irq_set_type,
 };
 
@@ -129,7 +203,10 @@ void __init init_IRQ(void)
 #endif
 
         for (irq = MCFINT_VECBASE; (irq < MCFINT_VECBASE + NR_VECS); irq++) {
-                set_irq_chip(irq, &intc_irq_chip);
+                if ((irq >= EINT1) && (irq <=EINT7))
+                        set_irq_chip(irq, &intc_irq_chip_edge_port);
+                else
+                        set_irq_chip(irq, &intc_irq_chip);
                 set_irq_type(irq, IRQ_TYPE_LEVEL_HIGH);
                 set_irq_handler(irq, handle_level_irq);
         }