// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2020, Jiaxun Yang <[email protected]>
* 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/syscore_ops.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;
u32 saved_vec_en[HTVEC_MAX_PARENT_IRQ];
};
static struct htvec *htvec_priv;
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_suspend(void)
{
int i;
for (i = 0; i < htvec_priv->num_parents; i++)
htvec_priv->saved_vec_en[i] = readl(htvec_priv->base + HTVEC_EN_OFF + 4 * i);
return 0;
}
static void htvec_resume(void)
{
int i;
for (i = 0; i < htvec_priv->num_parents; i++)
writel(htvec_priv->saved_vec_en[i], htvec_priv->base + HTVEC_EN_OFF + 4 * i);
}
static struct syscore_ops htvec_syscore_ops = {
.suspend = htvec_suspend,
.resume = htvec_resume,
};
static int htvec_init(phys_addr_t addr, unsigned long size,
int num_parents, int parent_irq[], struct fwnode_handle *domain_handle)
{
int i;
struct htvec *priv;
priv = kzalloc(sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->num_parents = num_parents;
priv->base = ioremap(addr, size);
raw_spin_lock_init(&priv->htvec_lock);
/* Setup IRQ domain */
priv->htvec_domain = irq_domain_create_linear(domain_handle,
(VEC_COUNT_PER_REG * priv->num_parents),
&htvec_domain_ops, priv);
if (!priv->htvec_domain) {
pr_err("loongson-htvec: cannot add IRQ domain\n");
goto iounmap_base;
}
htvec_reset(priv);
for (i = 0; i < priv->num_parents; i++) {
irq_set_chained_handler_and_data(parent_irq[i],
htvec_irq_dispatch, priv);
}
htvec_priv = priv;
register_syscore_ops(&htvec_syscore_ops);
return 0;
iounmap_base:
iounmap(priv->base);
kfree(priv);
return -EINVAL;
}
#ifdef CONFIG_OF
static int htvec_of_init(struct device_node *node,
struct device_node *parent)
{
int i, err;
int parent_irq[8];
int num_parents = 0;
struct resource res;
if (of_address_to_resource(node, 0, &res))
return -EINVAL;
/* 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;
num_parents++;
}
err = htvec_init(res.start, resource_size(&res),
num_parents, parent_irq, of_node_to_fwnode(node));
if (err < 0)
return err;
return 0;
}
IRQCHIP_DECLARE(htvec, "loongson,htvec-1.0", htvec_of_init);
#endif
#ifdef CONFIG_ACPI
static int __init pch_pic_parse_madt(union acpi_subtable_headers *header,
const unsigned long end)
{
struct acpi_madt_bio_pic *pchpic_entry = (struct acpi_madt_bio_pic *)header;
return pch_pic_acpi_init(htvec_priv->htvec_domain, pchpic_entry);
}
static int __init pch_msi_parse_madt(union acpi_subtable_headers *header,
const unsigned long end)
{
struct acpi_madt_msi_pic *pchmsi_entry = (struct acpi_madt_msi_pic *)header;
return pch_msi_acpi_init(htvec_priv->htvec_domain, pchmsi_entry);
}
static int __init acpi_cascade_irqdomain_init(void)
{
int r;
r = acpi_table_parse_madt(ACPI_MADT_TYPE_BIO_PIC, pch_pic_parse_madt, 0);
if (r < 0)
return r;
r = acpi_table_parse_madt(ACPI_MADT_TYPE_MSI_PIC, pch_msi_parse_madt, 0);
if (r < 0)
return r;
return 0;
}
int __init htvec_acpi_init(struct irq_domain *parent,
struct acpi_madt_ht_pic *acpi_htvec)
{
int i, ret;
int num_parents, parent_irq[8];
struct fwnode_handle *domain_handle;
if (!acpi_htvec)
return -EINVAL;
num_parents = HTVEC_MAX_PARENT_IRQ;
domain_handle = irq_domain_alloc_fwnode(&acpi_htvec->address);
if (!domain_handle) {
pr_err("Unable to allocate domain handle\n");
return -ENOMEM;
}
/* Interrupt may come from any of the 8 interrupt lines */
for (i = 0; i < HTVEC_MAX_PARENT_IRQ; i++)
parent_irq[i] = irq_create_mapping(parent, acpi_htvec->cascade[i]);
ret = htvec_init(acpi_htvec->address, acpi_htvec->size,
num_parents, parent_irq, domain_handle);
if (ret == 0)
ret = acpi_cascade_irqdomain_init();
else
irq_domain_free_fwnode(domain_handle);
return ret;
}
#endif
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