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// 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)
goto out_iounmap;
priv->core_isr[i] = of_iomap(node, index);
}
}
/* 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