sh: intc: Split up the INTC code.

This splits up the sh intc core in to something more vaguely resembling
a subsystem. Most of the functionality was alread fairly well
compartmentalized, and there were only a handful of interdependencies
that needed to be resolved in the process.

This also serves as future-proofing for the genirq and sparseirq rework,
which will make some of the split out functionality wholly generic,
allowing things to be killed off in place with minimal migration pain.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 215 insertions, 0 deletions

diff --git a/drivers/sh/intc/chip.c b/drivers/sh/intc/chip.c
new file mode 100644
index 000000000000..35c03706cc21
--- /dev/null
+++ b/drivers/sh/intc/chip.c
@@ -0,0 +1,215 @@
+/*
+ * IRQ chip definitions for INTC IRQs.
+ *
+ * Copyright (C) 2007, 2008 Magnus Damm
+ * Copyright (C) 2009, 2010 Paul Mundt
+ *
+ * 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
+ * for more details.
+ */
+#include <linux/cpumask.h>
+#include <linux/io.h>
+#include "internals.h"
+
+void _intc_enable(unsigned int irq, unsigned long handle)
+{
+	struct intc_desc_int *d = get_intc_desc(irq);
+	unsigned long addr;
+	unsigned int cpu;
+
+	for (cpu = 0; cpu < SMP_NR(d, _INTC_ADDR_E(handle)); cpu++) {
+#ifdef CONFIG_SMP
+		if (!cpumask_test_cpu(cpu, irq_to_desc(irq)->affinity))
+			continue;
+#endif
+		addr = INTC_REG(d, _INTC_ADDR_E(handle), cpu);
+		intc_enable_fns[_INTC_MODE(handle)](addr, handle, intc_reg_fns\
+						    [_INTC_FN(handle)], irq);
+	}
+
+	intc_balancing_enable(irq);
+}
+
+static void intc_enable(unsigned int irq)
+{
+	_intc_enable(irq, (unsigned long)get_irq_chip_data(irq));
+}
+
+static void intc_disable(unsigned int irq)
+{
+	struct intc_desc_int *d = get_intc_desc(irq);
+	unsigned long handle = (unsigned long)get_irq_chip_data(irq);
+	unsigned long addr;
+	unsigned int cpu;
+
+	intc_balancing_disable(irq);
+
+	for (cpu = 0; cpu < SMP_NR(d, _INTC_ADDR_D(handle)); cpu++) {
+#ifdef CONFIG_SMP
+		if (!cpumask_test_cpu(cpu, irq_to_desc(irq)->affinity))
+			continue;
+#endif
+		addr = INTC_REG(d, _INTC_ADDR_D(handle), cpu);
+		intc_disable_fns[_INTC_MODE(handle)](addr, handle,intc_reg_fns\
+						     [_INTC_FN(handle)], irq);
+	}
+}
+
+static int intc_set_wake(unsigned int irq, unsigned int on)
+{
+	return 0; /* allow wakeup, but setup hardware in intc_suspend() */
+}
+
+#ifdef CONFIG_SMP
+/*
+ * This is held with the irq desc lock held, so we don't require any
+ * additional locking here at the intc desc level. The affinity mask is
+ * later tested in the enable/disable paths.
+ */
+static int intc_set_affinity(unsigned int irq, const struct cpumask *cpumask)
+{
+	if (!cpumask_intersects(cpumask, cpu_online_mask))
+		return -1;
+
+	cpumask_copy(irq_to_desc(irq)->affinity, cpumask);
+
+	return 0;
+}
+#endif
+
+static void intc_mask_ack(unsigned int irq)
+{
+	struct intc_desc_int *d = get_intc_desc(irq);
+	unsigned long handle = intc_get_ack_handle(irq);
+	unsigned long addr;
+
+	intc_disable(irq);
+
+	/* read register and write zero only to the associated bit */
+	if (handle) {
+		unsigned int value;
+
+		addr = INTC_REG(d, _INTC_ADDR_D(handle), 0);
+		value = intc_set_field_from_handle(0, 1, handle);
+
+		switch (_INTC_FN(handle)) {
+		case REG_FN_MODIFY_BASE + 0:	/* 8bit */
+			__raw_readb(addr);
+			__raw_writeb(0xff ^ value, addr);
+			break;
+		case REG_FN_MODIFY_BASE + 1:	/* 16bit */
+			__raw_readw(addr);
+			__raw_writew(0xffff ^ value, addr);
+			break;
+		case REG_FN_MODIFY_BASE + 3:	/* 32bit */
+			__raw_readl(addr);
+			__raw_writel(0xffffffff ^ value, addr);
+			break;
+		default:
+			BUG();
+			break;
+		}
+	}
+}
+
+static struct intc_handle_int *intc_find_irq(struct intc_handle_int *hp,
+					     unsigned int nr_hp,
+					     unsigned int irq)
+{
+	int i;
+
+	/*
+	 * this doesn't scale well, but...
+	 *
+	 * this function should only be used for cerain uncommon
+	 * operations such as intc_set_priority() and intc_set_type()
+	 * and in those rare cases performance doesn't matter that much.
+	 * keeping the memory footprint low is more important.
+	 *
+	 * one rather simple way to speed this up and still keep the
+	 * memory footprint down is to make sure the array is sorted
+	 * and then perform a bisect to lookup the irq.
+	 */
+	for (i = 0; i < nr_hp; i++) {
+		if ((hp + i)->irq != irq)
+			continue;
+
+		return hp + i;
+	}
+
+	return NULL;
+}
+
+int intc_set_priority(unsigned int irq, unsigned int prio)
+{
+	struct intc_desc_int *d = get_intc_desc(irq);
+	struct intc_handle_int *ihp;
+
+	if (!intc_get_prio_level(irq) || prio <= 1)
+		return -EINVAL;
+
+	ihp = intc_find_irq(d->prio, d->nr_prio, irq);
+	if (ihp) {
+		if (prio >= (1 << _INTC_WIDTH(ihp->handle)))
+			return -EINVAL;
+
+		intc_set_prio_level(irq, prio);
+
+		/*
+		 * only set secondary masking method directly
+		 * primary masking method is using intc_prio_level[irq]
+		 * priority level will be set during next enable()
+		 */
+		if (_INTC_FN(ihp->handle) != REG_FN_ERR)
+			_intc_enable(irq, ihp->handle);
+	}
+	return 0;
+}
+
+#define VALID(x) (x | 0x80)
+
+static unsigned char intc_irq_sense_table[IRQ_TYPE_SENSE_MASK + 1] = {
+	[IRQ_TYPE_EDGE_FALLING] = VALID(0),
+	[IRQ_TYPE_EDGE_RISING] = VALID(1),
+	[IRQ_TYPE_LEVEL_LOW] = VALID(2),
+	/* SH7706, SH7707 and SH7709 do not support high level triggered */
+#if !defined(CONFIG_CPU_SUBTYPE_SH7706) && \
+    !defined(CONFIG_CPU_SUBTYPE_SH7707) && \
+    !defined(CONFIG_CPU_SUBTYPE_SH7709)
+	[IRQ_TYPE_LEVEL_HIGH] = VALID(3),
+#endif
+};
+
+static int intc_set_type(unsigned int irq, unsigned int type)
+{
+	struct intc_desc_int *d = get_intc_desc(irq);
+	unsigned char value = intc_irq_sense_table[type & IRQ_TYPE_SENSE_MASK];
+	struct intc_handle_int *ihp;
+	unsigned long addr;
+
+	if (!value)
+		return -EINVAL;
+
+	ihp = intc_find_irq(d->sense, d->nr_sense, irq);
+	if (ihp) {
+		addr = INTC_REG(d, _INTC_ADDR_E(ihp->handle), 0);
+		intc_reg_fns[_INTC_FN(ihp->handle)](addr, ihp->handle, value);
+	}
+
+	return 0;
+}
+
+struct irq_chip intc_irq_chip	= {
+	.mask		= intc_disable,
+	.unmask		= intc_enable,
+	.mask_ack	= intc_mask_ack,
+	.enable		= intc_enable,
+	.disable	= intc_disable,
+	.shutdown	= intc_disable,
+	.set_type	= intc_set_type,
+	.set_wake	= intc_set_wake,
+#ifdef CONFIG_SMP
+	.set_affinity	= intc_set_affinity,
+#endif
+};