// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2020 Birger Koblitz <[email protected]>
* Copyright (C) 2020 Bert Vermeulen <[email protected]>
* Copyright (C) 2020 John Crispin <[email protected]>
*/
#include <linux/of_irq.h>
#include <linux/irqchip.h>
#include <linux/spinlock.h>
#include <linux/of_address.h>
#include <linux/irqchip/chained_irq.h>
/* Global Interrupt Mask Register */
#define RTL_ICTL_GIMR 0x00
/* Global Interrupt Status Register */
#define RTL_ICTL_GISR 0x04
/* Interrupt Routing Registers */
#define RTL_ICTL_IRR0 0x08
#define RTL_ICTL_IRR1 0x0c
#define RTL_ICTL_IRR2 0x10
#define RTL_ICTL_IRR3 0x14
#define RTL_ICTL_NUM_INPUTS 32
#define REG(x) (realtek_ictl_base + x)
static DEFINE_RAW_SPINLOCK(irq_lock);
static void __iomem *realtek_ictl_base;
/*
* IRR0-IRR3 store 4 bits per interrupt, but Realtek uses inverted numbering,
* placing IRQ 31 in the first four bits. A routing value of '0' means the
* interrupt is left disconnected. Routing values {1..15} connect to output
* lines {0..14}.
*/
#define IRR_OFFSET(idx) (4 * (3 - (idx * 4) / 32))
#define IRR_SHIFT(idx) ((idx * 4) % 32)
static void write_irr(void __iomem *irr0, int idx, u32 value)
{
unsigned int offset = IRR_OFFSET(idx);
unsigned int shift = IRR_SHIFT(idx);
u32 irr;
irr = readl(irr0 + offset) & ~(0xf << shift);
irr |= (value & 0xf) << shift;
writel(irr, irr0 + offset);
}
static void realtek_ictl_unmask_irq(struct irq_data *i)
{
unsigned long flags;
u32 value;
raw_spin_lock_irqsave(&irq_lock, flags);
value = readl(REG(RTL_ICTL_GIMR));
value |= BIT(i->hwirq);
writel(value, REG(RTL_ICTL_GIMR));
raw_spin_unlock_irqrestore(&irq_lock, flags);
}
static void realtek_ictl_mask_irq(struct irq_data *i)
{
unsigned long flags;
u32 value;
raw_spin_lock_irqsave(&irq_lock, flags);
value = readl(REG(RTL_ICTL_GIMR));
value &= ~BIT(i->hwirq);
writel(value, REG(RTL_ICTL_GIMR));
raw_spin_unlock_irqrestore(&irq_lock, flags);
}
static struct irq_chip realtek_ictl_irq = {
.name = "realtek-rtl-intc",
.irq_mask = realtek_ictl_mask_irq,
.irq_unmask = realtek_ictl_unmask_irq,
};
static int intc_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw)
{
unsigned long flags;
irq_set_chip_and_handler(irq, &realtek_ictl_irq, handle_level_irq);
raw_spin_lock_irqsave(&irq_lock, flags);
write_irr(REG(RTL_ICTL_IRR0), hw, 1);
raw_spin_unlock_irqrestore(&irq_lock, flags);
return 0;
}
static const struct irq_domain_ops irq_domain_ops = {
.map = intc_map,
.xlate = irq_domain_xlate_onecell,
};
static void realtek_irq_dispatch(struct irq_desc *desc)
{
struct irq_chip *chip = irq_desc_get_chip(desc);
struct irq_domain *domain;
unsigned long pending;
unsigned int soc_int;
chained_irq_enter(chip, desc);
pending = readl(REG(RTL_ICTL_GIMR)) & readl(REG(RTL_ICTL_GISR));
if (unlikely(!pending)) {
spurious_interrupt();
goto out;
}
domain = irq_desc_get_handler_data(desc);
for_each_set_bit(soc_int, &pending, 32)
generic_handle_domain_irq(domain, soc_int);
out:
chained_irq_exit(chip, desc);
}
static int __init realtek_rtl_of_init(struct device_node *node, struct device_node *parent)
{
struct of_phandle_args oirq;
struct irq_domain *domain;
unsigned int soc_irq;
int parent_irq;
realtek_ictl_base = of_iomap(node, 0);
if (!realtek_ictl_base)
return -ENXIO;
/* Disable all cascaded interrupts and clear routing */
writel(0, REG(RTL_ICTL_GIMR));
for (soc_irq = 0; soc_irq < RTL_ICTL_NUM_INPUTS; soc_irq++)
write_irr(REG(RTL_ICTL_IRR0), soc_irq, 0);
if (WARN_ON(!of_irq_count(node))) {
/*
* If DT contains no parent interrupts, assume MIPS CPU IRQ 2
* (HW0) is connected to the first output. This is the case for
* all known hardware anyway. "interrupt-map" is deprecated, so
* don't bother trying to parse that.
*/
oirq.np = of_find_compatible_node(NULL, NULL, "mti,cpu-interrupt-controller");
oirq.args_count = 1;
oirq.args[0] = 2;
parent_irq = irq_create_of_mapping(&oirq);
of_node_put(oirq.np);
} else {
parent_irq = of_irq_get(node, 0);
}
if (parent_irq < 0)
return parent_irq;
else if (!parent_irq)
return -ENODEV;
domain = irq_domain_add_linear(node, RTL_ICTL_NUM_INPUTS, &irq_domain_ops, NULL);
if (!domain)
return -ENOMEM;
irq_set_chained_handler_and_data(parent_irq, realtek_irq_dispatch, domain);
return 0;
}
IRQCHIP_DECLARE(realtek_rtl_intc, "realtek,rtl-intc", realtek_rtl_of_init);
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