m68knommu: external interrupt support to ColdFire intc-simr controller

The EDGE Port module of some ColdFire parts using the intc-simr 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, 110 insertions, 4 deletions

diff --git a/arch/m68knommu/platform/coldfire/intc-simr.c b/arch/m68knommu/platform/coldfire/intc-simr.c
index 8876f434c125..e642b24ab729 100644
--- a/arch/m68knommu/platform/coldfire/intc-simr.c
+++ b/arch/m68knommu/platform/coldfire/intc-simr.c
@@ -3,7 +3,7 @@
  *
  * Interrupt controller code for the ColdFire 5208, 5207 & 532x parts.
  *
- * (C) Copyright 2009, Greg Ungerer <gerg@snapgear.com>
+ * (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
@@ -21,6 +21,44 @@
 #include <asm/traps.h>
 
 /*
+ *      The EDGE Port interrupts are the fixed 7 external interrupts.
+ *      They need some special treatment, for example they need to be acked.
+ */
+#ifdef CONFIG_M520x
+/*
+ *      The 520x parts only support a limited range of these external
+ *      interrupts, only 1, 4 and 7 (as interrupts 65, 66 and 67).
+ */
+#define EINT0   64      /* Is not actually used, but spot reserved for it */
+#define EINT1   65      /* EDGE Port interrupt 1 */
+#define EINT4   66      /* EDGE Port interrupt 4 */
+#define EINT7   67      /* EDGE Port interrupt 7 */
+
+static unsigned int irqebitmap[] = { 0, 1, 4, 7 };
+static unsigned int inline irq2ebit(unsigned int irq)
+{
+        return irqebitmap[irq - EINT0];
+}
+
+#else
+
+/*
+ *      Most of the ColdFire parts with the EDGE Port module just have
+ *      a strait direct mapping of the 7 external interrupts. Although
+ *      there is a bit reserved for 0, it is not used.
+ */
+#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 */
+
+static unsigned int inline irq2ebit(unsigned int irq)
+{
+        return irq - EINT0;
+}
+
+#endif
+
+/*
  *      There maybe one or two interrupt control units, each has 64
  *      interrupts. If there is no second unit then MCFINTC1_* defines
  *      will be 0 (and code for them optimized away).
@@ -46,21 +84,86 @@ static void intc_irq_unmask(struct irq_data *d)
                 __raw_writeb(irq, MCFINTC0_CIMR);
 }
 
-static int intc_irq_set_type(struct irq_data *d, unsigned int type)
+static void intc_irq_ack(struct irq_data *d)
 {
-        unsigned int irq = d->irq - MCFINT_VECBASE;
+        unsigned int ebit = irq2ebit(d->irq);
 
+        __raw_writeb(0x1 << ebit, MCFEPORT_EPFR);
+}
+
+static unsigned int intc_irq_startup(struct irq_data *d)
+{
+        unsigned int irq = d->irq;
+
+        if ((irq >= EINT1) && (irq <= EINT7)) {
+                unsigned int ebit = irq2ebit(irq);
+                u8 v;
+
+                /* Set EPORT line as input */
+                v = __raw_readb(MCFEPORT_EPDDR);
+                __raw_writeb(v & ~(0x1 << ebit), MCFEPORT_EPDDR);
+
+                /* Set EPORT line as interrupt source */
+                v = __raw_readb(MCFEPORT_EPIER);
+                __raw_writeb(v | (0x1 << ebit), MCFEPORT_EPIER);
+        }
+
+        irq -= MCFINT_VECBASE;
         if (MCFINTC1_ICR0 && (irq > 64))
                 __raw_writeb(5, MCFINTC1_ICR0 + irq - 64);
         else
                 __raw_writeb(5, MCFINTC0_ICR0 + irq);
+
+
+        intc_irq_unmask(d);
+        return 0;
+}
+
+static int intc_irq_set_type(struct irq_data *d, unsigned int type)
+{
+        unsigned int ebit, 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);
+
+        ebit = irq2ebit(irq) * 2;
+        pa = __raw_readw(MCFEPORT_EPPAR);
+        pa = (pa & ~(0x3 << ebit)) | (tb << ebit);
+        __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,
 };
 
@@ -77,7 +180,10 @@ void __init init_IRQ(void)
 
         eirq = MCFINT_VECBASE + 64 + (MCFINTC1_ICR0 ? 64 : 0);
         for (irq = MCFINT_VECBASE; (irq < eirq); 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);
         }