blob: 9ed1bc47366348b5b9066bc4873a317d82c011af [file] [log] [blame]
// 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>
#include <boot_param.h>
#define LIOINTC_CHIP_IRQ 32
#define LIOINTC_NUM_PARENT 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
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];
u8 map_cache[LIOINTC_CHIP_IRQ];
bool has_lpc_irq_errata;
};
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;
u32 pending;
chained_irq_enter(chip, desc);
pending = readl(gc->reg_base + LIOINTC_REG_INTC_STATUS);
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_irq(irq_find_mapping(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 const char * const parent_names[] = {"int0", "int1", "int2", "int3"};
int __init liointc_of_init(struct device_node *node,
struct device_node *parent)
{
struct irq_chip_generic *gc;
struct irq_domain *domain;
struct irq_chip_type *ct;
struct liointc_priv *priv;
void __iomem *base;
u32 of_parent_int_map[LIOINTC_NUM_PARENT];
int parent_irq[LIOINTC_NUM_PARENT];
bool have_parent = FALSE;
int sz, i, err = 0;
priv = kzalloc(sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
base = of_iomap(node, 0);
if (!base) {
err = -ENODEV;
goto out_free_priv;
}
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) {
err = -ENODEV;
goto out_iounmap;
}
sz = of_property_read_variable_u32_array(node,
"loongson,parent_int_map",
&of_parent_int_map[0],
LIOINTC_NUM_PARENT,
LIOINTC_NUM_PARENT);
if (sz < 4) {
pr_err("loongson-liointc: No parent_int_map\n");
err = -ENODEV;
goto out_iounmap;
}
for (i = 0; i < LIOINTC_NUM_PARENT; i++)
priv->handler[i].parent_int_map = of_parent_int_map[i];
/* Setup IRQ domain */
domain = irq_domain_add_linear(node, 32,
&irq_generic_chip_ops, priv);
if (!domain) {
pr_err("loongson-liointc: cannot add IRQ domain\n");
err = -EINVAL;
goto out_iounmap;
}
err = irq_alloc_domain_generic_chips(domain, 32, 1,
node->full_name, handle_level_irq,
IRQ_NOPROBE, 0, 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]);
}
return 0;
out_free_domain:
irq_domain_remove(domain);
out_iounmap:
iounmap(base);
out_free_priv:
kfree(priv);
return err;
}
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);