sh: add interrupt ack code to sh3

This patch adds interrupt acknowledge code for external interrupt
sources on sh3 processors. Only really required for edge triggered
interrupts, but we ack regardless of sense configuration.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/arch/sh/kernel/cpu/irq/intc.c b/arch/sh/kernel/cpu/irq/intc.c
index 84806b2..df36954 100644
--- a/arch/sh/kernel/cpu/irq/intc.c
+++ b/arch/sh/kernel/cpu/irq/intc.c
@@ -1,7 +1,7 @@
 /*
  * Shared interrupt handling code for IPR and INTC2 types of IRQs.
  *
- * Copyright (C) 2007 Magnus Damm
+ * Copyright (C) 2007, 2008 Magnus Damm
  *
  * Based on intc2.c and ipr.c
  *
@@ -62,6 +62,9 @@
 #endif
 
 static unsigned int intc_prio_level[NR_IRQS]; /* for now */
+#ifdef CONFIG_CPU_SH3
+static unsigned long ack_handle[NR_IRQS];
+#endif
 
 static inline struct intc_desc_int *get_intc_desc(unsigned int irq)
 {
@@ -219,6 +222,25 @@
 	}
 }
 
+#ifdef CONFIG_CPU_SH3
+static void intc_mask_ack(unsigned int irq)
+{
+	struct intc_desc_int *d = get_intc_desc(irq);
+	unsigned long handle = ack_handle[irq];
+	unsigned long addr;
+
+	intc_disable(irq);
+
+	/* read register and write zero only to the assocaited bit */
+
+	if (handle) {
+		addr = INTC_REG(d, _INTC_ADDR_D(handle), 0);
+		ctrl_inb(addr);
+		ctrl_outb(0x3f ^ set_field(0, 1, handle), addr);
+	}
+}
+#endif
+
 static struct intc_handle_int *intc_find_irq(struct intc_handle_int *hp,
 					     unsigned int nr_hp,
 					     unsigned int irq)
@@ -430,6 +452,40 @@
 	return 0;
 }
 
+#ifdef CONFIG_CPU_SH3
+static unsigned int __init intc_ack_data(struct intc_desc *desc,
+					  struct intc_desc_int *d,
+					  intc_enum enum_id)
+{
+	struct intc_mask_reg *mr = desc->ack_regs;
+	unsigned int i, j, fn, mode;
+	unsigned long reg_e, reg_d;
+
+	for (i = 0; mr && enum_id && i < desc->nr_ack_regs; i++) {
+		mr = desc->ack_regs + i;
+
+		for (j = 0; j < ARRAY_SIZE(mr->enum_ids); j++) {
+			if (mr->enum_ids[j] != enum_id)
+				continue;
+
+			fn = REG_FN_MODIFY_BASE;
+			mode = MODE_ENABLE_REG;
+			reg_e = mr->set_reg;
+			reg_d = mr->set_reg;
+
+			fn += (mr->reg_width >> 3) - 1;
+			return _INTC_MK(fn, mode,
+					intc_get_reg(d, reg_e),
+					intc_get_reg(d, reg_d),
+					1,
+					(mr->reg_width - 1) - j);
+		}
+	}
+
+	return 0;
+}
+#endif
+
 static unsigned int __init intc_sense_data(struct intc_desc *desc,
 					   struct intc_desc_int *d,
 					   intc_enum enum_id)
@@ -530,6 +586,11 @@
 
 	/* irq should be disabled by default */
 	d->chip.mask(irq);
+
+#ifdef CONFIG_CPU_SH3
+	if (desc->ack_regs)
+		ack_handle[irq] = intc_ack_data(desc, d, enum_id);
+#endif
 }
 
 static unsigned int __init save_reg(struct intc_desc_int *d,
@@ -560,6 +621,9 @@
 	d->nr_reg += desc->prio_regs ? desc->nr_prio_regs * 2 : 0;
 	d->nr_reg += desc->sense_regs ? desc->nr_sense_regs : 0;
 
+#ifdef CONFIG_CPU_SH3
+	d->nr_reg += desc->ack_regs ? desc->nr_ack_regs : 0;
+#endif
 	d->reg = alloc_bootmem(d->nr_reg * sizeof(*d->reg));
 #ifdef CONFIG_SMP
 	d->smp = alloc_bootmem(d->nr_reg * sizeof(*d->smp));
@@ -592,14 +656,23 @@
 		}
 	}
 
-	BUG_ON(k > 256); /* _INTC_ADDR_E() and _INTC_ADDR_D() are 8 bits */
-
 	d->chip.name = desc->name;
 	d->chip.mask = intc_disable;
 	d->chip.unmask = intc_enable;
 	d->chip.mask_ack = intc_disable;
 	d->chip.set_type = intc_set_sense;
 
+#ifdef CONFIG_CPU_SH3
+	if (desc->ack_regs) {
+		for (i = 0; i < desc->nr_ack_regs; i++)
+			k += save_reg(d, k, desc->ack_regs[i].set_reg, 0);
+
+		d->chip.mask_ack = intc_mask_ack;
+	}
+#endif
+
+	BUG_ON(k > 256); /* _INTC_ADDR_E() and _INTC_ADDR_D() are 8 bits */
+
 	for (i = 0; i < desc->nr_vectors; i++) {
 		struct intc_vect *vect = desc->vectors + i;
 
diff --git a/arch/sh/kernel/cpu/sh3/setup-sh3.c b/arch/sh/kernel/cpu/sh3/setup-sh3.c
index 28e7d65..c988468 100644
--- a/arch/sh/kernel/cpu/sh3/setup-sh3.c
+++ b/arch/sh/kernel/cpu/sh3/setup-sh3.c
@@ -35,15 +35,22 @@
 	{ 0xa4000018, 0, 16, 4, /* IPRD */ { 0, 0, IRQ5, IRQ4 } },
 };
 
+static struct intc_mask_reg ack_registers[] __initdata = {
+	{ 0xa4000004, 0, 8, /* IRR0 */
+	  { 0, 0, IRQ5, IRQ4, IRQ3, IRQ2, IRQ1, IRQ0 } },
+};
+
 static struct intc_sense_reg sense_registers[] __initdata = {
 	{ 0xa4000010, 16, 2, { 0, 0, IRQ5, IRQ4, IRQ3, IRQ2, IRQ1, IRQ0 } },
 };
 
-static DECLARE_INTC_DESC(intc_desc_irq0123, "sh3-irq0123", vectors_irq0123,
-			 NULL, NULL, prio_registers, sense_registers);
+static DECLARE_INTC_DESC_ACK(intc_desc_irq0123, "sh3-irq0123",
+			     vectors_irq0123, NULL, NULL,
+			     prio_registers, sense_registers, ack_registers);
 
-static DECLARE_INTC_DESC(intc_desc_irq45, "sh3-irq45", vectors_irq45,
-			 NULL, NULL, prio_registers, sense_registers);
+static DECLARE_INTC_DESC_ACK(intc_desc_irq45, "sh3-irq45",
+			     vectors_irq45, NULL, NULL,
+			     prio_registers, sense_registers, ack_registers);
 
 #define INTC_ICR1		0xa4000010UL
 #define INTC_ICR1_IRQLVL	(1<<14)
diff --git a/include/asm-sh/hw_irq.h b/include/asm-sh/hw_irq.h
index 9d7003c..7438d1e 100644
--- a/include/asm-sh/hw_irq.h
+++ b/include/asm-sh/hw_irq.h
@@ -79,6 +79,10 @@
 	struct intc_sense_reg *sense_regs;
 	unsigned int nr_sense_regs;
 	char *name;
+#ifdef CONFIG_CPU_SH3
+	struct intc_mask_reg *ack_regs;
+	unsigned int nr_ack_regs;
+#endif
 };
 
 #define _INTC_ARRAY(a) a, sizeof(a)/sizeof(*a)
@@ -91,6 +95,18 @@
 	chipname,							\
 }
 
+#ifdef CONFIG_CPU_SH3
+#define DECLARE_INTC_DESC_ACK(symbol, chipname, vectors, groups,	\
+	mask_regs, prio_regs, sense_regs, ack_regs)			\
+struct intc_desc symbol __initdata = {					\
+	_INTC_ARRAY(vectors), _INTC_ARRAY(groups),			\
+	_INTC_ARRAY(mask_regs), _INTC_ARRAY(prio_regs),			\
+	_INTC_ARRAY(sense_regs),					\
+	chipname,							\
+	_INTC_ARRAY(ack_regs),						\
+}
+#endif
+
 void __init register_intc_controller(struct intc_desc *desc);
 int intc_set_priority(unsigned int irq, unsigned int prio);