1 files changed, 433 insertions, 0 deletions
diff --git a/arch/mips/lantiq/irq.c b/arch/mips/lantiq/irq.c
new file mode 100644
index 000000000..43c2f271e
--- /dev/null
+++ b/arch/mips/lantiq/irq.c
@@ -0,0 +1,433 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *
+ * Copyright (C) 2010 John Crispin <john@phrozen.org>
+ * Copyright (C) 2010 Thomas Langer <thomas.langer@lantiq.com>
+ */
+
+#include <linux/interrupt.h>
+#include <linux/ioport.h>
+#include <linux/sched.h>
+#include <linux/irqdomain.h>
+#include <linux/of_platform.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+
+#include <asm/bootinfo.h>
+#include <asm/irq_cpu.h>
+
+#include <lantiq_soc.h>
+#include <irq.h>
+
+/* register definitions - internal irqs */
+#define LTQ_ICU_ISR		0x0000
+#define LTQ_ICU_IER		0x0008
+#define LTQ_ICU_IOSR		0x0010
+#define LTQ_ICU_IRSR		0x0018
+#define LTQ_ICU_IMR		0x0020
+
+#define LTQ_ICU_IM_SIZE		0x28
+
+/* register definitions - external irqs */
+#define LTQ_EIU_EXIN_C		0x0000
+#define LTQ_EIU_EXIN_INIC	0x0004
+#define LTQ_EIU_EXIN_INC	0x0008
+#define LTQ_EIU_EXIN_INEN	0x000C
+
+/* number of external interrupts */
+#define MAX_EIU			6
+
+/* the performance counter */
+#define LTQ_PERF_IRQ		(INT_NUM_IM4_IRL0 + 31)
+
+/*
+ * irqs generated by devices attached to the EBU need to be acked in
+ * a special manner
+ */
+#define LTQ_ICU_EBU_IRQ		22
+
+#define ltq_icu_w32(vpe, m, x, y)	\
+	ltq_w32((x), ltq_icu_membase[vpe] + m*LTQ_ICU_IM_SIZE + (y))
+
+#define ltq_icu_r32(vpe, m, x)		\
+	ltq_r32(ltq_icu_membase[vpe] + m*LTQ_ICU_IM_SIZE + (x))
+
+#define ltq_eiu_w32(x, y)	ltq_w32((x), ltq_eiu_membase + (y))
+#define ltq_eiu_r32(x)		ltq_r32(ltq_eiu_membase + (x))
+
+/* we have a cascade of 8 irqs */
+#define MIPS_CPU_IRQ_CASCADE		8
+
+static int exin_avail;
+static u32 ltq_eiu_irq[MAX_EIU];
+static void __iomem *ltq_icu_membase[NR_CPUS];
+static void __iomem *ltq_eiu_membase;
+static struct irq_domain *ltq_domain;
+static DEFINE_SPINLOCK(ltq_eiu_lock);
+static DEFINE_RAW_SPINLOCK(ltq_icu_lock);
+static int ltq_perfcount_irq;
+
+int ltq_eiu_get_irq(int exin)
+{
+	if (exin < exin_avail)
+		return ltq_eiu_irq[exin];
+	return -1;
+}
+
+void ltq_disable_irq(struct irq_data *d)
+{
+	unsigned long offset = d->hwirq - MIPS_CPU_IRQ_CASCADE;
+	unsigned long im = offset / INT_NUM_IM_OFFSET;
+	unsigned long flags;
+	int vpe;
+
+	offset %= INT_NUM_IM_OFFSET;
+
+	raw_spin_lock_irqsave(&ltq_icu_lock, flags);
+	for_each_present_cpu(vpe) {
+		ltq_icu_w32(vpe, im,
+			    ltq_icu_r32(vpe, im, LTQ_ICU_IER) & ~BIT(offset),
+			    LTQ_ICU_IER);
+	}
+	raw_spin_unlock_irqrestore(&ltq_icu_lock, flags);
+}
+
+void ltq_mask_and_ack_irq(struct irq_data *d)
+{
+	unsigned long offset = d->hwirq - MIPS_CPU_IRQ_CASCADE;
+	unsigned long im = offset / INT_NUM_IM_OFFSET;
+	unsigned long flags;
+	int vpe;
+
+	offset %= INT_NUM_IM_OFFSET;
+
+	raw_spin_lock_irqsave(&ltq_icu_lock, flags);
+	for_each_present_cpu(vpe) {
+		ltq_icu_w32(vpe, im,
+			    ltq_icu_r32(vpe, im, LTQ_ICU_IER) & ~BIT(offset),
+			    LTQ_ICU_IER);
+		ltq_icu_w32(vpe, im, BIT(offset), LTQ_ICU_ISR);
+	}
+	raw_spin_unlock_irqrestore(&ltq_icu_lock, flags);
+}
+
+static void ltq_ack_irq(struct irq_data *d)
+{
+	unsigned long offset = d->hwirq - MIPS_CPU_IRQ_CASCADE;
+	unsigned long im = offset / INT_NUM_IM_OFFSET;
+	unsigned long flags;
+	int vpe;
+
+	offset %= INT_NUM_IM_OFFSET;
+
+	raw_spin_lock_irqsave(&ltq_icu_lock, flags);
+	for_each_present_cpu(vpe) {
+		ltq_icu_w32(vpe, im, BIT(offset), LTQ_ICU_ISR);
+	}
+	raw_spin_unlock_irqrestore(&ltq_icu_lock, flags);
+}
+
+void ltq_enable_irq(struct irq_data *d)
+{
+	unsigned long offset = d->hwirq - MIPS_CPU_IRQ_CASCADE;
+	unsigned long im = offset / INT_NUM_IM_OFFSET;
+	unsigned long flags;
+	int vpe;
+
+	offset %= INT_NUM_IM_OFFSET;
+
+	vpe = cpumask_first(irq_data_get_effective_affinity_mask(d));
+
+	/* This shouldn't be even possible, maybe during CPU hotplug spam */
+	if (unlikely(vpe >= nr_cpu_ids))
+		vpe = smp_processor_id();
+
+	raw_spin_lock_irqsave(&ltq_icu_lock, flags);
+
+	ltq_icu_w32(vpe, im, ltq_icu_r32(vpe, im, LTQ_ICU_IER) | BIT(offset),
+		    LTQ_ICU_IER);
+
+	raw_spin_unlock_irqrestore(&ltq_icu_lock, flags);
+}
+
+static int ltq_eiu_settype(struct irq_data *d, unsigned int type)
+{
+	int i;
+	unsigned long flags;
+
+	for (i = 0; i < exin_avail; i++) {
+		if (d->hwirq == ltq_eiu_irq[i]) {
+			int val = 0;
+			int edge = 0;
+
+			switch (type) {
+			case IRQF_TRIGGER_NONE:
+				break;
+			case IRQF_TRIGGER_RISING:
+				val = 1;
+				edge = 1;
+				break;
+			case IRQF_TRIGGER_FALLING:
+				val = 2;
+				edge = 1;
+				break;
+			case IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING:
+				val = 3;
+				edge = 1;
+				break;
+			case IRQF_TRIGGER_HIGH:
+				val = 5;
+				break;
+			case IRQF_TRIGGER_LOW:
+				val = 6;
+				break;
+			default:
+				pr_err("invalid type %d for irq %ld\n",
+					type, d->hwirq);
+				return -EINVAL;
+			}
+
+			if (edge)
+				irq_set_handler(d->hwirq, handle_edge_irq);
+
+			spin_lock_irqsave(&ltq_eiu_lock, flags);
+			ltq_eiu_w32((ltq_eiu_r32(LTQ_EIU_EXIN_C) &
+				    (~(7 << (i * 4)))) | (val << (i * 4)),
+				    LTQ_EIU_EXIN_C);
+			spin_unlock_irqrestore(&ltq_eiu_lock, flags);
+		}
+	}
+
+	return 0;
+}
+
+static unsigned int ltq_startup_eiu_irq(struct irq_data *d)
+{
+	int i;
+
+	ltq_enable_irq(d);
+	for (i = 0; i < exin_avail; i++) {
+		if (d->hwirq == ltq_eiu_irq[i]) {
+			/* by default we are low level triggered */
+			ltq_eiu_settype(d, IRQF_TRIGGER_LOW);
+			/* clear all pending */
+			ltq_eiu_w32(ltq_eiu_r32(LTQ_EIU_EXIN_INC) & ~BIT(i),
+				LTQ_EIU_EXIN_INC);
+			/* enable */
+			ltq_eiu_w32(ltq_eiu_r32(LTQ_EIU_EXIN_INEN) | BIT(i),
+				LTQ_EIU_EXIN_INEN);
+			break;
+		}
+	}
+
+	return 0;
+}
+
+static void ltq_shutdown_eiu_irq(struct irq_data *d)
+{
+	int i;
+
+	ltq_disable_irq(d);
+	for (i = 0; i < exin_avail; i++) {
+		if (d->hwirq == ltq_eiu_irq[i]) {
+			/* disable */
+			ltq_eiu_w32(ltq_eiu_r32(LTQ_EIU_EXIN_INEN) & ~BIT(i),
+				LTQ_EIU_EXIN_INEN);
+			break;
+		}
+	}
+}
+
+#if defined(CONFIG_SMP)
+static int ltq_icu_irq_set_affinity(struct irq_data *d,
+				    const struct cpumask *cpumask, bool force)
+{
+	struct cpumask tmask;
+
+	if (!cpumask_and(&tmask, cpumask, cpu_online_mask))
+		return -EINVAL;
+
+	irq_data_update_effective_affinity(d, &tmask);
+
+	return IRQ_SET_MASK_OK;
+}
+#endif
+
+static struct irq_chip ltq_irq_type = {
+	.name = "icu",
+	.irq_enable = ltq_enable_irq,
+	.irq_disable = ltq_disable_irq,
+	.irq_unmask = ltq_enable_irq,
+	.irq_ack = ltq_ack_irq,
+	.irq_mask = ltq_disable_irq,
+	.irq_mask_ack = ltq_mask_and_ack_irq,
+#if defined(CONFIG_SMP)
+	.irq_set_affinity = ltq_icu_irq_set_affinity,
+#endif
+};
+
+static struct irq_chip ltq_eiu_type = {
+	.name = "eiu",
+	.irq_startup = ltq_startup_eiu_irq,
+	.irq_shutdown = ltq_shutdown_eiu_irq,
+	.irq_enable = ltq_enable_irq,
+	.irq_disable = ltq_disable_irq,
+	.irq_unmask = ltq_enable_irq,
+	.irq_ack = ltq_ack_irq,
+	.irq_mask = ltq_disable_irq,
+	.irq_mask_ack = ltq_mask_and_ack_irq,
+	.irq_set_type = ltq_eiu_settype,
+#if defined(CONFIG_SMP)
+	.irq_set_affinity = ltq_icu_irq_set_affinity,
+#endif
+};
+
+static void ltq_hw_irq_handler(struct irq_desc *desc)
+{
+	unsigned int module = irq_desc_get_irq(desc) - 2;
+	u32 irq;
+	irq_hw_number_t hwirq;
+	int vpe = smp_processor_id();
+
+	irq = ltq_icu_r32(vpe, module, LTQ_ICU_IOSR);
+	if (irq == 0)
+		return;
+
+	/*
+	 * silicon bug causes only the msb set to 1 to be valid. all
+	 * other bits might be bogus
+	 */
+	irq = __fls(irq);
+	hwirq = irq + MIPS_CPU_IRQ_CASCADE + (INT_NUM_IM_OFFSET * module);
+	generic_handle_irq(irq_linear_revmap(ltq_domain, hwirq));
+
+	/* if this is a EBU irq, we need to ack it or get a deadlock */
+	if (irq == LTQ_ICU_EBU_IRQ && !module && LTQ_EBU_PCC_ISTAT != 0)
+		ltq_ebu_w32(ltq_ebu_r32(LTQ_EBU_PCC_ISTAT) | 0x10,
+			LTQ_EBU_PCC_ISTAT);
+}
+
+static int icu_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw)
+{
+	struct irq_chip *chip = &ltq_irq_type;
+	struct irq_data *data;
+	int i;
+
+	if (hw < MIPS_CPU_IRQ_CASCADE)
+		return 0;
+
+	for (i = 0; i < exin_avail; i++)
+		if (hw == ltq_eiu_irq[i])
+			chip = &ltq_eiu_type;
+
+	data = irq_get_irq_data(irq);
+
+	irq_data_update_effective_affinity(data, cpumask_of(0));
+
+	irq_set_chip_and_handler(irq, chip, handle_level_irq);
+
+	return 0;
+}
+
+static const struct irq_domain_ops irq_domain_ops = {
+	.xlate = irq_domain_xlate_onetwocell,
+	.map = icu_map,
+};
+
+int __init icu_of_init(struct device_node *node, struct device_node *parent)
+{
+	struct device_node *eiu_node;
+	struct resource res;
+	int i, ret, vpe;
+
+	/* load register regions of available ICUs */
+	for_each_possible_cpu(vpe) {
+		if (of_address_to_resource(node, vpe, &res))
+			panic("Failed to get icu%i memory range", vpe);
+
+		if (!request_mem_region(res.start, resource_size(&res),
+					res.name))
+			pr_err("Failed to request icu%i memory\n", vpe);
+
+		ltq_icu_membase[vpe] = ioremap(res.start,
+					resource_size(&res));
+
+		if (!ltq_icu_membase[vpe])
+			panic("Failed to remap icu%i memory", vpe);
+	}
+
+	/* turn off all irqs by default */
+	for_each_possible_cpu(vpe) {
+		for (i = 0; i < MAX_IM; i++) {
+			/* make sure all irqs are turned off by default */
+			ltq_icu_w32(vpe, i, 0, LTQ_ICU_IER);
+
+			/* clear all possibly pending interrupts */
+			ltq_icu_w32(vpe, i, ~0, LTQ_ICU_ISR);
+			ltq_icu_w32(vpe, i, ~0, LTQ_ICU_IMR);
+
+			/* clear resend */
+			ltq_icu_w32(vpe, i, 0, LTQ_ICU_IRSR);
+		}
+	}
+
+	mips_cpu_irq_init();
+
+	for (i = 0; i < MAX_IM; i++)
+		irq_set_chained_handler(i + 2, ltq_hw_irq_handler);
+
+	ltq_domain = irq_domain_add_linear(node,
+		(MAX_IM * INT_NUM_IM_OFFSET) + MIPS_CPU_IRQ_CASCADE,
+		&irq_domain_ops, 0);
+
+	/* tell oprofile which irq to use */
+	ltq_perfcount_irq = irq_create_mapping(ltq_domain, LTQ_PERF_IRQ);
+
+	/* the external interrupts are optional and xway only */
+	eiu_node = of_find_compatible_node(NULL, NULL, "lantiq,eiu-xway");
+	if (eiu_node && !of_address_to_resource(eiu_node, 0, &res)) {
+		/* find out how many external irq sources we have */
+		exin_avail = of_property_count_u32_elems(eiu_node,
+							 "lantiq,eiu-irqs");
+
+		if (exin_avail > MAX_EIU)
+			exin_avail = MAX_EIU;
+
+		ret = of_property_read_u32_array(eiu_node, "lantiq,eiu-irqs",
+						ltq_eiu_irq, exin_avail);
+		if (ret)
+			panic("failed to load external irq resources");
+
+		if (!request_mem_region(res.start, resource_size(&res),
+							res.name))
+			pr_err("Failed to request eiu memory");
+
+		ltq_eiu_membase = ioremap(res.start,
+							resource_size(&res));
+		if (!ltq_eiu_membase)
+			panic("Failed to remap eiu memory");
+	}
+
+	return 0;
+}
+
+int get_c0_perfcount_int(void)
+{
+	return ltq_perfcount_irq;
+}
+EXPORT_SYMBOL_GPL(get_c0_perfcount_int);
+
+unsigned int get_c0_compare_int(void)
+{
+	return CP0_LEGACY_COMPARE_IRQ;
+}
+
+static const struct of_device_id of_irq_ids[] __initconst = {
+	{ .compatible = "lantiq,icu", .data = icu_of_init },
+	{},
+};
+
+void __init arch_init_irq(void)
+{
+	of_irq_init(of_irq_ids);
+}