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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2020, Jiaxun Yang <jiaxun.yang@flygoat.com>
* Loongson HyperTransport Interrupt Vector support
*/
#define pr_fmt(fmt) "htvec: " fmt
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/irqchip.h>
#include <linux/irqdomain.h>
#include <linux/irqchip/chained_irq.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>
/* Registers */
#define HTVEC_EN_OFF 0x20
#define HTVEC_MAX_PARENT_IRQ 8
#define VEC_COUNT_PER_REG 32
#define VEC_REG_IDX(irq_id) ((irq_id) / VEC_COUNT_PER_REG)
#define VEC_REG_BIT(irq_id) ((irq_id) % VEC_COUNT_PER_REG)
struct htvec {
int num_parents;
void __iomem *base;
struct irq_domain *htvec_domain;
raw_spinlock_t htvec_lock;
};
static void htvec_irq_dispatch(struct irq_desc *desc)
{
int i;
u32 pending;
bool handled = false;
struct irq_chip *chip = irq_desc_get_chip(desc);
struct htvec *priv = irq_desc_get_handler_data(desc);
chained_irq_enter(chip, desc);
for (i = 0; i < priv->num_parents; i++) {
pending = readl(priv->base + 4 * i);
while (pending) {
int bit = __ffs(pending);
generic_handle_domain_irq(priv->htvec_domain,
bit + VEC_COUNT_PER_REG * i);
pending &= ~BIT(bit);
handled = true;
}
}
if (!handled)
spurious_interrupt();
chained_irq_exit(chip, desc);
}
static void htvec_ack_irq(struct irq_data *d)
{
struct htvec *priv = irq_data_get_irq_chip_data(d);
writel(BIT(VEC_REG_BIT(d->hwirq)),
priv->base + VEC_REG_IDX(d->hwirq) * 4);
}
static void htvec_mask_irq(struct irq_data *d)
{
u32 reg;
void __iomem *addr;
struct htvec *priv = irq_data_get_irq_chip_data(d);
raw_spin_lock(&priv->htvec_lock);
addr = priv->base + HTVEC_EN_OFF;
addr += VEC_REG_IDX(d->hwirq) * 4;
reg = readl(addr);
reg &= ~BIT(VEC_REG_BIT(d->hwirq));
writel(reg, addr);
raw_spin_unlock(&priv->htvec_lock);
}
static void htvec_unmask_irq(struct irq_data *d)
{
u32 reg;
void __iomem *addr;
struct htvec *priv = irq_data_get_irq_chip_data(d);
raw_spin_lock(&priv->htvec_lock);
addr = priv->base + HTVEC_EN_OFF;
addr += VEC_REG_IDX(d->hwirq) * 4;
reg = readl(addr);
reg |= BIT(VEC_REG_BIT(d->hwirq));
writel(reg, addr);
raw_spin_unlock(&priv->htvec_lock);
}
static struct irq_chip htvec_irq_chip = {
.name = "LOONGSON_HTVEC",
.irq_mask = htvec_mask_irq,
.irq_unmask = htvec_unmask_irq,
.irq_ack = htvec_ack_irq,
};
static int htvec_domain_alloc(struct irq_domain *domain, unsigned int virq,
unsigned int nr_irqs, void *arg)
{
int ret;
unsigned long hwirq;
unsigned int type, i;
struct htvec *priv = domain->host_data;
ret = irq_domain_translate_onecell(domain, arg, &hwirq, &type);
if (ret)
return ret;
for (i = 0; i < nr_irqs; i++) {
irq_domain_set_info(domain, virq + i, hwirq + i, &htvec_irq_chip,
priv, handle_edge_irq, NULL, NULL);
}
return 0;
}
static void htvec_domain_free(struct irq_domain *domain, unsigned int virq,
unsigned int nr_irqs)
{
int i;
for (i = 0; i < nr_irqs; i++) {
struct irq_data *d = irq_domain_get_irq_data(domain, virq + i);
irq_set_handler(virq + i, NULL);
irq_domain_reset_irq_data(d);
}
}
static const struct irq_domain_ops htvec_domain_ops = {
.translate = irq_domain_translate_onecell,
.alloc = htvec_domain_alloc,
.free = htvec_domain_free,
};
static void htvec_reset(struct htvec *priv)
{
u32 idx;
/* Clear IRQ cause registers, mask all interrupts */
for (idx = 0; idx < priv->num_parents; idx++) {
writel_relaxed(0x0, priv->base + HTVEC_EN_OFF + 4 * idx);
writel_relaxed(0xFFFFFFFF, priv->base + 4 * idx);
}
}
static int htvec_of_init(struct device_node *node,
struct device_node *parent)
{
struct htvec *priv;
int err, parent_irq[8], i;
priv = kzalloc(sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
raw_spin_lock_init(&priv->htvec_lock);
priv->base = of_iomap(node, 0);
if (!priv->base) {
err = -ENOMEM;
goto free_priv;
}
/* Interrupt may come from any of the 8 interrupt lines */
for (i = 0; i < HTVEC_MAX_PARENT_IRQ; i++) {
parent_irq[i] = irq_of_parse_and_map(node, i);
if (parent_irq[i] <= 0)
break;
priv->num_parents++;
}
if (!priv->num_parents) {
pr_err("Failed to get parent irqs\n");
err = -ENODEV;
goto iounmap_base;
}
priv->htvec_domain = irq_domain_create_linear(of_node_to_fwnode(node),
(VEC_COUNT_PER_REG * priv->num_parents),
&htvec_domain_ops, priv);
if (!priv->htvec_domain) {
pr_err("Failed to create IRQ domain\n");
err = -ENOMEM;
goto irq_dispose;
}
htvec_reset(priv);
for (i = 0; i < priv->num_parents; i++)
irq_set_chained_handler_and_data(parent_irq[i],
htvec_irq_dispatch, priv);
return 0;
irq_dispose:
for (; i > 0; i--)
irq_dispose_mapping(parent_irq[i - 1]);
iounmap_base:
iounmap(priv->base);
free_priv:
kfree(priv);
return err;
}
IRQCHIP_DECLARE(htvec, "loongson,htvec-1.0", htvec_of_init);
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