// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2020, Jiaxun Yang <[email protected]>
* Loongson PCH PIC support
*/
#define pr_fmt(fmt) "pch-pic: " fmt
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/irqchip.h>
#include <linux/irqdomain.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/syscore_ops.h>
#include "irq-loongson.h"
/* Registers */
#define PCH_PIC_MASK 0x20
#define PCH_PIC_HTMSI_EN 0x40
#define PCH_PIC_EDGE 0x60
#define PCH_PIC_CLR 0x80
#define PCH_PIC_AUTO0 0xc0
#define PCH_PIC_AUTO1 0xe0
#define PCH_INT_ROUTE(irq) (0x100 + irq)
#define PCH_INT_HTVEC(irq) (0x200 + irq)
#define PCH_PIC_POL 0x3e0
#define PIC_COUNT_PER_REG 32
#define PIC_REG_COUNT 2
#define PIC_COUNT (PIC_COUNT_PER_REG * PIC_REG_COUNT)
#define PIC_REG_IDX(irq_id) ((irq_id) / PIC_COUNT_PER_REG)
#define PIC_REG_BIT(irq_id) ((irq_id) % PIC_COUNT_PER_REG)
#define PIC_UNDEF_VECTOR 255
static int nr_pics;
struct pch_pic {
void __iomem *base;
struct irq_domain *pic_domain;
u32 ht_vec_base;
raw_spinlock_t pic_lock;
u32 vec_count;
u32 gsi_base;
u32 saved_vec_en[PIC_REG_COUNT];
u32 saved_vec_pol[PIC_REG_COUNT];
u32 saved_vec_edge[PIC_REG_COUNT];
u8 table[PIC_COUNT];
int inuse;
};
static struct pch_pic *pch_pic_priv[MAX_IO_PICS];
struct fwnode_handle *pch_pic_handle[MAX_IO_PICS];
static inline u8 hwirq_to_bit(struct pch_pic *priv, int hirq)
{
return priv->table[hirq];
}
static void pch_pic_bitset(struct pch_pic *priv, int offset, int bit)
{
u32 reg;
void __iomem *addr = priv->base + offset + PIC_REG_IDX(bit) * 4;
raw_spin_lock(&priv->pic_lock);
reg = readl(addr);
reg |= BIT(PIC_REG_BIT(bit));
writel(reg, addr);
raw_spin_unlock(&priv->pic_lock);
}
static void pch_pic_bitclr(struct pch_pic *priv, int offset, int bit)
{
u32 reg;
void __iomem *addr = priv->base + offset + PIC_REG_IDX(bit) * 4;
raw_spin_lock(&priv->pic_lock);
reg = readl(addr);
reg &= ~BIT(PIC_REG_BIT(bit));
writel(reg, addr);
raw_spin_unlock(&priv->pic_lock);
}
static void pch_pic_mask_irq(struct irq_data *d)
{
struct pch_pic *priv = irq_data_get_irq_chip_data(d);
pch_pic_bitset(priv, PCH_PIC_MASK, hwirq_to_bit(priv, d->hwirq));
irq_chip_mask_parent(d);
}
static void pch_pic_unmask_irq(struct irq_data *d)
{
struct pch_pic *priv = irq_data_get_irq_chip_data(d);
int bit = hwirq_to_bit(priv, d->hwirq);
writel(BIT(PIC_REG_BIT(bit)),
priv->base + PCH_PIC_CLR + PIC_REG_IDX(bit) * 4);
irq_chip_unmask_parent(d);
pch_pic_bitclr(priv, PCH_PIC_MASK, bit);
}
static int pch_pic_set_type(struct irq_data *d, unsigned int type)
{
struct pch_pic *priv = irq_data_get_irq_chip_data(d);
int bit = hwirq_to_bit(priv, d->hwirq);
int ret = 0;
switch (type) {
case IRQ_TYPE_EDGE_RISING:
pch_pic_bitset(priv, PCH_PIC_EDGE, bit);
pch_pic_bitclr(priv, PCH_PIC_POL, bit);
irq_set_handler_locked(d, handle_edge_irq);
break;
case IRQ_TYPE_EDGE_FALLING:
pch_pic_bitset(priv, PCH_PIC_EDGE, bit);
pch_pic_bitset(priv, PCH_PIC_POL, bit);
irq_set_handler_locked(d, handle_edge_irq);
break;
case IRQ_TYPE_LEVEL_HIGH:
pch_pic_bitclr(priv, PCH_PIC_EDGE, bit);
pch_pic_bitclr(priv, PCH_PIC_POL, bit);
irq_set_handler_locked(d, handle_level_irq);
break;
case IRQ_TYPE_LEVEL_LOW:
pch_pic_bitclr(priv, PCH_PIC_EDGE, bit);
pch_pic_bitset(priv, PCH_PIC_POL, bit);
irq_set_handler_locked(d, handle_level_irq);
break;
default:
ret = -EINVAL;
break;
}
return ret;
}
static void pch_pic_ack_irq(struct irq_data *d)
{
unsigned int reg;
struct pch_pic *priv = irq_data_get_irq_chip_data(d);
int bit = hwirq_to_bit(priv, d->hwirq);
reg = readl(priv->base + PCH_PIC_EDGE + PIC_REG_IDX(bit) * 4);
if (reg & BIT(PIC_REG_BIT(bit))) {
writel(BIT(PIC_REG_BIT(bit)),
priv->base + PCH_PIC_CLR + PIC_REG_IDX(bit) * 4);
}
irq_chip_ack_parent(d);
}
static struct irq_chip pch_pic_irq_chip = {
.name = "PCH PIC",
.irq_mask = pch_pic_mask_irq,
.irq_unmask = pch_pic_unmask_irq,
.irq_ack = pch_pic_ack_irq,
.irq_set_affinity = irq_chip_set_affinity_parent,
.irq_set_type = pch_pic_set_type,
.flags = IRQCHIP_SKIP_SET_WAKE,
};
static int pch_pic_domain_translate(struct irq_domain *d,
struct irq_fwspec *fwspec,
unsigned long *hwirq,
unsigned int *type)
{
struct pch_pic *priv = d->host_data;
struct device_node *of_node = to_of_node(fwspec->fwnode);
unsigned long flags;
int i;
if (of_node) {
if (fwspec->param_count < 2)
return -EINVAL;
*hwirq = fwspec->param[0];
*type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
} else {
if (fwspec->param_count < 1)
return -EINVAL;
*hwirq = fwspec->param[0] - priv->gsi_base;
if (fwspec->param_count > 1)
*type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
else
*type = IRQ_TYPE_NONE;
}
raw_spin_lock_irqsave(&priv->pic_lock, flags);
/* Check pic-table to confirm if the hwirq has been assigned */
for (i = 0; i < priv->inuse; i++) {
if (priv->table[i] == *hwirq) {
*hwirq = i;
break;
}
}
if (i == priv->inuse) {
/* Assign a new hwirq in pic-table */
if (priv->inuse >= PIC_COUNT) {
pr_err("pch-pic domain has no free vectors\n");
raw_spin_unlock_irqrestore(&priv->pic_lock, flags);
return -EINVAL;
}
priv->table[priv->inuse] = *hwirq;
*hwirq = priv->inuse++;
}
raw_spin_unlock_irqrestore(&priv->pic_lock, flags);
return 0;
}
static int pch_pic_alloc(struct irq_domain *domain, unsigned int virq,
unsigned int nr_irqs, void *arg)
{
int err;
unsigned int type;
unsigned long hwirq;
struct irq_fwspec *fwspec = arg;
struct irq_fwspec parent_fwspec;
struct pch_pic *priv = domain->host_data;
err = pch_pic_domain_translate(domain, fwspec, &hwirq, &type);
if (err)
return err;
/* Write vector ID */
writeb(priv->ht_vec_base + hwirq, priv->base + PCH_INT_HTVEC(hwirq_to_bit(priv, hwirq)));
parent_fwspec.fwnode = domain->parent->fwnode;
parent_fwspec.param_count = 1;
parent_fwspec.param[0] = hwirq + priv->ht_vec_base;
err = irq_domain_alloc_irqs_parent(domain, virq, 1, &parent_fwspec);
if (err)
return err;
irq_domain_set_info(domain, virq, hwirq,
&pch_pic_irq_chip, priv,
handle_level_irq, NULL, NULL);
irq_set_probe(virq);
return 0;
}
static const struct irq_domain_ops pch_pic_domain_ops = {
.translate = pch_pic_domain_translate,
.alloc = pch_pic_alloc,
.free = irq_domain_free_irqs_parent,
};
static void pch_pic_reset(struct pch_pic *priv)
{
int i;
for (i = 0; i < PIC_COUNT; i++) {
/* Write vector ID */
writeb(priv->ht_vec_base + i, priv->base + PCH_INT_HTVEC(hwirq_to_bit(priv, i)));
/* Hardcode route to HT0 Lo */
writeb(1, priv->base + PCH_INT_ROUTE(i));
}
for (i = 0; i < PIC_REG_COUNT; i++) {
/* Clear IRQ cause registers, mask all interrupts */
writel_relaxed(0xFFFFFFFF, priv->base + PCH_PIC_MASK + 4 * i);
writel_relaxed(0xFFFFFFFF, priv->base + PCH_PIC_CLR + 4 * i);
/* Clear auto bounce, we don't need that */
writel_relaxed(0, priv->base + PCH_PIC_AUTO0 + 4 * i);
writel_relaxed(0, priv->base + PCH_PIC_AUTO1 + 4 * i);
/* Enable HTMSI transformer */
writel_relaxed(0xFFFFFFFF, priv->base + PCH_PIC_HTMSI_EN + 4 * i);
}
}
static int pch_pic_suspend(void)
{
int i, j;
for (i = 0; i < nr_pics; i++) {
for (j = 0; j < PIC_REG_COUNT; j++) {
pch_pic_priv[i]->saved_vec_pol[j] =
readl(pch_pic_priv[i]->base + PCH_PIC_POL + 4 * j);
pch_pic_priv[i]->saved_vec_edge[j] =
readl(pch_pic_priv[i]->base + PCH_PIC_EDGE + 4 * j);
pch_pic_priv[i]->saved_vec_en[j] =
readl(pch_pic_priv[i]->base + PCH_PIC_MASK + 4 * j);
}
}
return 0;
}
static void pch_pic_resume(void)
{
int i, j;
for (i = 0; i < nr_pics; i++) {
pch_pic_reset(pch_pic_priv[i]);
for (j = 0; j < PIC_REG_COUNT; j++) {
writel(pch_pic_priv[i]->saved_vec_pol[j],
pch_pic_priv[i]->base + PCH_PIC_POL + 4 * j);
writel(pch_pic_priv[i]->saved_vec_edge[j],
pch_pic_priv[i]->base + PCH_PIC_EDGE + 4 * j);
writel(pch_pic_priv[i]->saved_vec_en[j],
pch_pic_priv[i]->base + PCH_PIC_MASK + 4 * j);
}
}
}
static struct syscore_ops pch_pic_syscore_ops = {
.suspend = pch_pic_suspend,
.resume = pch_pic_resume,
};
static int pch_pic_init(phys_addr_t addr, unsigned long size, int vec_base,
struct irq_domain *parent_domain, struct fwnode_handle *domain_handle,
u32 gsi_base)
{
struct pch_pic *priv;
int i;
priv = kzalloc(sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
raw_spin_lock_init(&priv->pic_lock);
priv->base = ioremap(addr, size);
if (!priv->base)
goto free_priv;
priv->inuse = 0;
for (i = 0; i < PIC_COUNT; i++)
priv->table[i] = PIC_UNDEF_VECTOR;
priv->ht_vec_base = vec_base;
priv->vec_count = ((readq(priv->base) >> 48) & 0xff) + 1;
priv->gsi_base = gsi_base;
priv->pic_domain = irq_domain_create_hierarchy(parent_domain, 0,
priv->vec_count, domain_handle,
&pch_pic_domain_ops, priv);
if (!priv->pic_domain) {
pr_err("Failed to create IRQ domain\n");
goto iounmap_base;
}
pch_pic_reset(priv);
pch_pic_handle[nr_pics] = domain_handle;
pch_pic_priv[nr_pics++] = priv;
if (nr_pics == 1)
register_syscore_ops(&pch_pic_syscore_ops);
return 0;
iounmap_base:
iounmap(priv->base);
free_priv:
kfree(priv);
return -EINVAL;
}
#ifdef CONFIG_OF
static int pch_pic_of_init(struct device_node *node,
struct device_node *parent)
{
int err, vec_base;
struct resource res;
struct irq_domain *parent_domain;
if (of_address_to_resource(node, 0, &res))
return -EINVAL;
parent_domain = irq_find_host(parent);
if (!parent_domain) {
pr_err("Failed to find the parent domain\n");
return -ENXIO;
}
if (of_property_read_u32(node, "loongson,pic-base-vec", &vec_base)) {
pr_err("Failed to determine pic-base-vec\n");
return -EINVAL;
}
err = pch_pic_init(res.start, resource_size(&res), vec_base,
parent_domain, of_node_to_fwnode(node), 0);
if (err < 0)
return err;
return 0;
}
IRQCHIP_DECLARE(pch_pic, "loongson,pch-pic-1.0", pch_pic_of_init);
#endif
#ifdef CONFIG_ACPI
int find_pch_pic(u32 gsi)
{
int i;
/* Find the PCH_PIC that manages this GSI. */
for (i = 0; i < MAX_IO_PICS; i++) {
struct pch_pic *priv = pch_pic_priv[i];
if (!priv)
return -1;
if (gsi >= priv->gsi_base && gsi < (priv->gsi_base + priv->vec_count))
return i;
}
pr_err("ERROR: Unable to locate PCH_PIC for GSI %d\n", gsi);
return -1;
}
static int __init pch_lpc_parse_madt(union acpi_subtable_headers *header,
const unsigned long end)
{
struct acpi_madt_lpc_pic *pchlpc_entry = (struct acpi_madt_lpc_pic *)header;
return pch_lpc_acpi_init(pch_pic_priv[0]->pic_domain, pchlpc_entry);
}
static int __init acpi_cascade_irqdomain_init(void)
{
int r;
r = acpi_table_parse_madt(ACPI_MADT_TYPE_LPC_PIC, pch_lpc_parse_madt, 0);
if (r < 0)
return r;
return 0;
}
int __init pch_pic_acpi_init(struct irq_domain *parent,
struct acpi_madt_bio_pic *acpi_pchpic)
{
int ret;
struct fwnode_handle *domain_handle;
if (find_pch_pic(acpi_pchpic->gsi_base) >= 0)
return 0;
domain_handle = irq_domain_alloc_fwnode(&acpi_pchpic->address);
if (!domain_handle) {
pr_err("Unable to allocate domain handle\n");
return -ENOMEM;
}
ret = pch_pic_init(acpi_pchpic->address, acpi_pchpic->size,
0, parent, domain_handle, acpi_pchpic->gsi_base);
if (ret < 0) {
irq_domain_free_fwnode(domain_handle);
return ret;
}
if (acpi_pchpic->id == 0)
ret = acpi_cascade_irqdomain_init();
return ret;
}
#endif
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