1 files changed, 378 insertions, 0 deletions

diff --git a/drivers/irqchip/irq-loongson-liointc.c b/drivers/irqchip/irq-loongson-liointc.c
new file mode 100644
index 000000000..c4584e2f0
--- /dev/null
+++ b/drivers/irqchip/irq-loongson-liointc.c
@@ -0,0 +1,378 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Copyright (C) 2020, Jiaxun Yang <jiaxun.yang@flygoat.com>
+ *  Loongson Local IO Interrupt Controller support
+ */
+
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/interrupt.h>
+#include <linux/ioport.h>
+#include <linux/irqchip.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/io.h>
+#include <linux/smp.h>
+#include <linux/irqchip/chained_irq.h>
+
+#ifdef CONFIG_MIPS
+#include <loongson.h>
+#else
+#include <asm/loongson.h>
+#endif
+
+#define LIOINTC_CHIP_IRQ	32
+#define LIOINTC_NUM_PARENT	4
+#define LIOINTC_NUM_CORES	4
+
+#define LIOINTC_INTC_CHIP_START	0x20
+
+#define LIOINTC_REG_INTC_STATUS	(LIOINTC_INTC_CHIP_START + 0x20)
+#define LIOINTC_REG_INTC_EN_STATUS	(LIOINTC_INTC_CHIP_START + 0x04)
+#define LIOINTC_REG_INTC_ENABLE	(LIOINTC_INTC_CHIP_START + 0x08)
+#define LIOINTC_REG_INTC_DISABLE	(LIOINTC_INTC_CHIP_START + 0x0c)
+#define LIOINTC_REG_INTC_POL	(LIOINTC_INTC_CHIP_START + 0x10)
+#define LIOINTC_REG_INTC_EDGE	(LIOINTC_INTC_CHIP_START + 0x14)
+
+#define LIOINTC_SHIFT_INTx	4
+
+#define LIOINTC_ERRATA_IRQ	10
+
+#if defined(CONFIG_MIPS)
+#define liointc_core_id get_ebase_cpunum()
+#else
+#define liointc_core_id get_csr_cpuid()
+#endif
+
+struct liointc_handler_data {
+	struct liointc_priv	*priv;
+	u32			parent_int_map;
+};
+
+struct liointc_priv {
+	struct irq_chip_generic		*gc;
+	struct liointc_handler_data	handler[LIOINTC_NUM_PARENT];
+	void __iomem			*core_isr[LIOINTC_NUM_CORES];
+	u8				map_cache[LIOINTC_CHIP_IRQ];
+	bool				has_lpc_irq_errata;
+};
+
+struct fwnode_handle *liointc_handle;
+
+static void liointc_chained_handle_irq(struct irq_desc *desc)
+{
+	struct liointc_handler_data *handler = irq_desc_get_handler_data(desc);
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+	struct irq_chip_generic *gc = handler->priv->gc;
+	int core = liointc_core_id % LIOINTC_NUM_CORES;
+	u32 pending;
+
+	chained_irq_enter(chip, desc);
+
+	pending = readl(handler->priv->core_isr[core]);
+
+	if (!pending) {
+		/* Always blame LPC IRQ if we have that bug */
+		if (handler->priv->has_lpc_irq_errata &&
+			(handler->parent_int_map & gc->mask_cache &
+			BIT(LIOINTC_ERRATA_IRQ)))
+			pending = BIT(LIOINTC_ERRATA_IRQ);
+		else
+			spurious_interrupt();
+	}
+
+	while (pending) {
+		int bit = __ffs(pending);
+
+		generic_handle_domain_irq(gc->domain, bit);
+		pending &= ~BIT(bit);
+	}
+
+	chained_irq_exit(chip, desc);
+}
+
+static void liointc_set_bit(struct irq_chip_generic *gc,
+				unsigned int offset,
+				u32 mask, bool set)
+{
+	if (set)
+		writel(readl(gc->reg_base + offset) | mask,
+				gc->reg_base + offset);
+	else
+		writel(readl(gc->reg_base + offset) & ~mask,
+				gc->reg_base + offset);
+}
+
+static int liointc_set_type(struct irq_data *data, unsigned int type)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
+	u32 mask = data->mask;
+	unsigned long flags;
+
+	irq_gc_lock_irqsave(gc, flags);
+	switch (type) {
+	case IRQ_TYPE_LEVEL_HIGH:
+		liointc_set_bit(gc, LIOINTC_REG_INTC_EDGE, mask, false);
+		liointc_set_bit(gc, LIOINTC_REG_INTC_POL, mask, true);
+		break;
+	case IRQ_TYPE_LEVEL_LOW:
+		liointc_set_bit(gc, LIOINTC_REG_INTC_EDGE, mask, false);
+		liointc_set_bit(gc, LIOINTC_REG_INTC_POL, mask, false);
+		break;
+	case IRQ_TYPE_EDGE_RISING:
+		liointc_set_bit(gc, LIOINTC_REG_INTC_EDGE, mask, true);
+		liointc_set_bit(gc, LIOINTC_REG_INTC_POL, mask, true);
+		break;
+	case IRQ_TYPE_EDGE_FALLING:
+		liointc_set_bit(gc, LIOINTC_REG_INTC_EDGE, mask, true);
+		liointc_set_bit(gc, LIOINTC_REG_INTC_POL, mask, false);
+		break;
+	default:
+		irq_gc_unlock_irqrestore(gc, flags);
+		return -EINVAL;
+	}
+	irq_gc_unlock_irqrestore(gc, flags);
+
+	irqd_set_trigger_type(data, type);
+	return 0;
+}
+
+static void liointc_resume(struct irq_chip_generic *gc)
+{
+	struct liointc_priv *priv = gc->private;
+	unsigned long flags;
+	int i;
+
+	irq_gc_lock_irqsave(gc, flags);
+	/* Disable all at first */
+	writel(0xffffffff, gc->reg_base + LIOINTC_REG_INTC_DISABLE);
+	/* Restore map cache */
+	for (i = 0; i < LIOINTC_CHIP_IRQ; i++)
+		writeb(priv->map_cache[i], gc->reg_base + i);
+	/* Restore mask cache */
+	writel(gc->mask_cache, gc->reg_base + LIOINTC_REG_INTC_ENABLE);
+	irq_gc_unlock_irqrestore(gc, flags);
+}
+
+static int parent_irq[LIOINTC_NUM_PARENT];
+static u32 parent_int_map[LIOINTC_NUM_PARENT];
+static const char *const parent_names[] = {"int0", "int1", "int2", "int3"};
+static const char *const core_reg_names[] = {"isr0", "isr1", "isr2", "isr3"};
+
+static int liointc_domain_xlate(struct irq_domain *d, struct device_node *ctrlr,
+			     const u32 *intspec, unsigned int intsize,
+			     unsigned long *out_hwirq, unsigned int *out_type)
+{
+	if (WARN_ON(intsize < 1))
+		return -EINVAL;
+	*out_hwirq = intspec[0] - GSI_MIN_CPU_IRQ;
+	*out_type = IRQ_TYPE_NONE;
+	return 0;
+}
+
+static const struct irq_domain_ops acpi_irq_gc_ops = {
+	.map	= irq_map_generic_chip,
+	.unmap  = irq_unmap_generic_chip,
+	.xlate	= liointc_domain_xlate,
+};
+
+static int liointc_init(phys_addr_t addr, unsigned long size, int revision,
+		struct fwnode_handle *domain_handle, struct device_node *node)
+{
+	int i, err;
+	void __iomem *base;
+	struct irq_chip_type *ct;
+	struct irq_chip_generic *gc;
+	struct irq_domain *domain;
+	struct liointc_priv *priv;
+
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	base = ioremap(addr, size);
+	if (!base)
+		goto out_free_priv;
+
+	for (i = 0; i < LIOINTC_NUM_CORES; i++)
+		priv->core_isr[i] = base + LIOINTC_REG_INTC_STATUS;
+
+	for (i = 0; i < LIOINTC_NUM_PARENT; i++)
+		priv->handler[i].parent_int_map = parent_int_map[i];
+
+	if (revision > 1) {
+		for (i = 0; i < LIOINTC_NUM_CORES; i++) {
+			int index = of_property_match_string(node,
+					"reg-names", core_reg_names[i]);
+
+			if (index < 0)
+				continue;
+
+			priv->core_isr[i] = of_iomap(node, index);
+		}
+
+		if (!priv->core_isr[0])
+			goto out_iounmap;
+	}
+
+	/* Setup IRQ domain */
+	if (!acpi_disabled)
+		domain = irq_domain_create_linear(domain_handle, LIOINTC_CHIP_IRQ,
+					&acpi_irq_gc_ops, priv);
+	else
+		domain = irq_domain_create_linear(domain_handle, LIOINTC_CHIP_IRQ,
+					&irq_generic_chip_ops, priv);
+	if (!domain) {
+		pr_err("loongson-liointc: cannot add IRQ domain\n");
+		goto out_iounmap;
+	}
+
+	err = irq_alloc_domain_generic_chips(domain, LIOINTC_CHIP_IRQ, 1,
+					(node ? node->full_name : "LIOINTC"),
+					handle_level_irq, 0, IRQ_NOPROBE, 0);
+	if (err) {
+		pr_err("loongson-liointc: unable to register IRQ domain\n");
+		goto out_free_domain;
+	}
+
+
+	/* Disable all IRQs */
+	writel(0xffffffff, base + LIOINTC_REG_INTC_DISABLE);
+	/* Set to level triggered */
+	writel(0x0, base + LIOINTC_REG_INTC_EDGE);
+
+	/* Generate parent INT part of map cache */
+	for (i = 0; i < LIOINTC_NUM_PARENT; i++) {
+		u32 pending = priv->handler[i].parent_int_map;
+
+		while (pending) {
+			int bit = __ffs(pending);
+
+			priv->map_cache[bit] = BIT(i) << LIOINTC_SHIFT_INTx;
+			pending &= ~BIT(bit);
+		}
+	}
+
+	for (i = 0; i < LIOINTC_CHIP_IRQ; i++) {
+		/* Generate core part of map cache */
+		priv->map_cache[i] |= BIT(loongson_sysconf.boot_cpu_id);
+		writeb(priv->map_cache[i], base + i);
+	}
+
+	gc = irq_get_domain_generic_chip(domain, 0);
+	gc->private = priv;
+	gc->reg_base = base;
+	gc->domain = domain;
+	gc->resume = liointc_resume;
+
+	ct = gc->chip_types;
+	ct->regs.enable = LIOINTC_REG_INTC_ENABLE;
+	ct->regs.disable = LIOINTC_REG_INTC_DISABLE;
+	ct->chip.irq_unmask = irq_gc_unmask_enable_reg;
+	ct->chip.irq_mask = irq_gc_mask_disable_reg;
+	ct->chip.irq_mask_ack = irq_gc_mask_disable_reg;
+	ct->chip.irq_set_type = liointc_set_type;
+
+	gc->mask_cache = 0;
+	priv->gc = gc;
+
+	for (i = 0; i < LIOINTC_NUM_PARENT; i++) {
+		if (parent_irq[i] <= 0)
+			continue;
+
+		priv->handler[i].priv = priv;
+		irq_set_chained_handler_and_data(parent_irq[i],
+				liointc_chained_handle_irq, &priv->handler[i]);
+	}
+
+	liointc_handle = domain_handle;
+	return 0;
+
+out_free_domain:
+	irq_domain_remove(domain);
+out_iounmap:
+	iounmap(base);
+out_free_priv:
+	kfree(priv);
+
+	return -EINVAL;
+}
+
+#ifdef CONFIG_OF
+
+static int __init liointc_of_init(struct device_node *node,
+				  struct device_node *parent)
+{
+	bool have_parent = FALSE;
+	int sz, i, index, revision, err = 0;
+	struct resource res;
+
+	if (!of_device_is_compatible(node, "loongson,liointc-2.0")) {
+		index = 0;
+		revision = 1;
+	} else {
+		index = of_property_match_string(node, "reg-names", "main");
+		revision = 2;
+	}
+
+	if (of_address_to_resource(node, index, &res))
+		return -EINVAL;
+
+	for (i = 0; i < LIOINTC_NUM_PARENT; i++) {
+		parent_irq[i] = of_irq_get_byname(node, parent_names[i]);
+		if (parent_irq[i] > 0)
+			have_parent = TRUE;
+	}
+	if (!have_parent)
+		return -ENODEV;
+
+	sz = of_property_read_variable_u32_array(node,
+						"loongson,parent_int_map",
+						&parent_int_map[0],
+						LIOINTC_NUM_PARENT,
+						LIOINTC_NUM_PARENT);
+	if (sz < 4) {
+		pr_err("loongson-liointc: No parent_int_map\n");
+		return -ENODEV;
+	}
+
+	err = liointc_init(res.start, resource_size(&res),
+			revision, of_node_to_fwnode(node), node);
+	if (err < 0)
+		return err;
+
+	return 0;
+}
+
+IRQCHIP_DECLARE(loongson_liointc_1_0, "loongson,liointc-1.0", liointc_of_init);
+IRQCHIP_DECLARE(loongson_liointc_1_0a, "loongson,liointc-1.0a", liointc_of_init);
+IRQCHIP_DECLARE(loongson_liointc_2_0, "loongson,liointc-2.0", liointc_of_init);
+
+#endif
+
+#ifdef CONFIG_ACPI
+int __init liointc_acpi_init(struct irq_domain *parent, struct acpi_madt_lio_pic *acpi_liointc)
+{
+	int ret;
+	struct fwnode_handle *domain_handle;
+
+	parent_int_map[0] = acpi_liointc->cascade_map[0];
+	parent_int_map[1] = acpi_liointc->cascade_map[1];
+
+	parent_irq[0] = irq_create_mapping(parent, acpi_liointc->cascade[0]);
+	parent_irq[1] = irq_create_mapping(parent, acpi_liointc->cascade[1]);
+
+	domain_handle = irq_domain_alloc_fwnode(&acpi_liointc->address);
+	if (!domain_handle) {
+		pr_err("Unable to allocate domain handle\n");
+		return -ENOMEM;
+	}
+	ret = liointc_init(acpi_liointc->address, acpi_liointc->size,
+			   1, domain_handle, NULL);
+	if (ret)
+		irq_domain_free_fwnode(domain_handle);
+
+	return ret;
+}
+#endif