147 lines
3.0 KiB
C
147 lines
3.0 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Copyright (C) 2020, Jiaxun Yang <jiaxun.yang@flygoat.com>
|
|
* Loongson HTPIC IRQ support
|
|
*/
|
|
|
|
#include <linux/init.h>
|
|
#include <linux/of_address.h>
|
|
#include <linux/of_irq.h>
|
|
#include <linux/irqchip.h>
|
|
#include <linux/irqchip/chained_irq.h>
|
|
#include <linux/irq.h>
|
|
#include <linux/io.h>
|
|
#include <linux/syscore_ops.h>
|
|
|
|
#include <asm/i8259.h>
|
|
|
|
#define HTPIC_MAX_PARENT_IRQ 4
|
|
#define HTINT_NUM_VECTORS 8
|
|
#define HTINT_EN_OFF 0x20
|
|
|
|
struct loongson_htpic {
|
|
void __iomem *base;
|
|
struct irq_domain *domain;
|
|
};
|
|
|
|
static struct loongson_htpic *htpic;
|
|
|
|
static void htpic_irq_dispatch(struct irq_desc *desc)
|
|
{
|
|
struct loongson_htpic *priv = irq_desc_get_handler_data(desc);
|
|
struct irq_chip *chip = irq_desc_get_chip(desc);
|
|
uint32_t pending;
|
|
|
|
chained_irq_enter(chip, desc);
|
|
pending = readl(priv->base);
|
|
/* Ack all IRQs at once, otherwise IRQ flood might happen */
|
|
writel(pending, priv->base);
|
|
|
|
if (!pending)
|
|
spurious_interrupt();
|
|
|
|
while (pending) {
|
|
int bit = __ffs(pending);
|
|
|
|
if (unlikely(bit > 15)) {
|
|
spurious_interrupt();
|
|
break;
|
|
}
|
|
|
|
generic_handle_domain_irq(priv->domain, bit);
|
|
pending &= ~BIT(bit);
|
|
}
|
|
chained_irq_exit(chip, desc);
|
|
}
|
|
|
|
static void htpic_reg_init(void)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < HTINT_NUM_VECTORS; i++) {
|
|
/* Disable all HT Vectors */
|
|
writel(0x0, htpic->base + HTINT_EN_OFF + i * 0x4);
|
|
/* Read back to force write */
|
|
(void) readl(htpic->base + i * 0x4);
|
|
/* Ack all possible pending IRQs */
|
|
writel(GENMASK(31, 0), htpic->base + i * 0x4);
|
|
}
|
|
|
|
/* Enable 16 vectors for PIC */
|
|
writel(0xffff, htpic->base + HTINT_EN_OFF);
|
|
}
|
|
|
|
static void htpic_resume(void)
|
|
{
|
|
htpic_reg_init();
|
|
}
|
|
|
|
struct syscore_ops htpic_syscore_ops = {
|
|
.resume = htpic_resume,
|
|
};
|
|
|
|
static int __init htpic_of_init(struct device_node *node, struct device_node *parent)
|
|
{
|
|
unsigned int parent_irq[4];
|
|
int i, err;
|
|
int num_parents = 0;
|
|
|
|
if (htpic) {
|
|
pr_err("loongson-htpic: Only one HTPIC is allowed in the system\n");
|
|
return -ENODEV;
|
|
}
|
|
|
|
htpic = kzalloc(sizeof(*htpic), GFP_KERNEL);
|
|
if (!htpic)
|
|
return -ENOMEM;
|
|
|
|
htpic->base = of_iomap(node, 0);
|
|
if (!htpic->base) {
|
|
err = -ENODEV;
|
|
goto out_free;
|
|
}
|
|
|
|
htpic->domain = __init_i8259_irqs(node);
|
|
if (!htpic->domain) {
|
|
pr_err("loongson-htpic: Failed to initialize i8259 IRQs\n");
|
|
err = -ENOMEM;
|
|
goto out_iounmap;
|
|
}
|
|
|
|
/* Interrupt may come from any of the 4 interrupt line */
|
|
for (i = 0; i < HTPIC_MAX_PARENT_IRQ; i++) {
|
|
parent_irq[i] = irq_of_parse_and_map(node, i);
|
|
if (parent_irq[i] <= 0)
|
|
break;
|
|
|
|
num_parents++;
|
|
}
|
|
|
|
if (!num_parents) {
|
|
pr_err("loongson-htpic: Failed to get parent irqs\n");
|
|
err = -ENODEV;
|
|
goto out_remove_domain;
|
|
}
|
|
|
|
htpic_reg_init();
|
|
|
|
for (i = 0; i < num_parents; i++) {
|
|
irq_set_chained_handler_and_data(parent_irq[i],
|
|
htpic_irq_dispatch, htpic);
|
|
}
|
|
|
|
register_syscore_ops(&htpic_syscore_ops);
|
|
|
|
return 0;
|
|
|
|
out_remove_domain:
|
|
irq_domain_remove(htpic->domain);
|
|
out_iounmap:
|
|
iounmap(htpic->base);
|
|
out_free:
|
|
kfree(htpic);
|
|
return err;
|
|
}
|
|
|
|
IRQCHIP_DECLARE(loongson_htpic, "loongson,htpic-1.0", htpic_of_init);
|