// SPDX-License-Identifier: GPL-2.0-only
/*
*
* Copyright (C) 2010 John Crispin <john@phrozen.org>
* Copyright (C) 2010 Thomas Langer <thomas.langer@lantiq.com>
*/
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/sched.h>
#include <linux/irqdomain.h>
#include <linux/of_platform.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <asm/bootinfo.h>
#include <asm/irq_cpu.h>
#include <lantiq_soc.h>
#include <irq.h>
/* register definitions - internal irqs */
#define LTQ_ICU_ISR 0x0000
#define LTQ_ICU_IER 0x0008
#define LTQ_ICU_IOSR 0x0010
#define LTQ_ICU_IRSR 0x0018
#define LTQ_ICU_IMR 0x0020
#define LTQ_ICU_IM_SIZE 0x28
/* register definitions - external irqs */
#define LTQ_EIU_EXIN_C 0x0000
#define LTQ_EIU_EXIN_INIC 0x0004
#define LTQ_EIU_EXIN_INC 0x0008
#define LTQ_EIU_EXIN_INEN 0x000C
/* number of external interrupts */
#define MAX_EIU 6
/* the performance counter */
#define LTQ_PERF_IRQ (INT_NUM_IM4_IRL0 + 31)
/*
* irqs generated by devices attached to the EBU need to be acked in
* a special manner
*/
#define LTQ_ICU_EBU_IRQ 22
#define ltq_icu_w32(vpe, m, x, y) \
ltq_w32((x), ltq_icu_membase[vpe] + m*LTQ_ICU_IM_SIZE + (y))
#define ltq_icu_r32(vpe, m, x) \
ltq_r32(ltq_icu_membase[vpe] + m*LTQ_ICU_IM_SIZE + (x))
#define ltq_eiu_w32(x, y) ltq_w32((x), ltq_eiu_membase + (y))
#define ltq_eiu_r32(x) ltq_r32(ltq_eiu_membase + (x))
/* we have a cascade of 8 irqs */
#define MIPS_CPU_IRQ_CASCADE 8
static int exin_avail;
static u32 ltq_eiu_irq[MAX_EIU];
static void __iomem *ltq_icu_membase[NR_CPUS];
static void __iomem *ltq_eiu_membase;
static struct irq_domain *ltq_domain;
static DEFINE_SPINLOCK(ltq_eiu_lock);
static DEFINE_RAW_SPINLOCK(ltq_icu_lock);
static int ltq_perfcount_irq;
int ltq_eiu_get_irq(int exin)
{
if (exin < exin_avail)
return ltq_eiu_irq[exin];
return -1;
}
void ltq_disable_irq(struct irq_data *d)
{
unsigned long offset = d->hwirq - MIPS_CPU_IRQ_CASCADE;
unsigned long im = offset / INT_NUM_IM_OFFSET;
unsigned long flags;
int vpe;
offset %= INT_NUM_IM_OFFSET;
raw_spin_lock_irqsave(<q_icu_lock, flags);
for_each_present_cpu(vpe) {
ltq_icu_w32(vpe, im,
ltq_icu_r32(vpe, im, LTQ_ICU_IER) & ~BIT(offset),
LTQ_ICU_IER);
}
raw_spin_unlock_irqrestore(<q_icu_lock, flags);
}
void ltq_mask_and_ack_irq(struct irq_data *d)
{
unsigned long offset = d->hwirq - MIPS_CPU_IRQ_CASCADE;
unsigned long im = offset / INT_NUM_IM_OFFSET;
unsigned long flags;
int vpe;
offset %= INT_NUM_IM_OFFSET;
raw_spin_lock_irqsave(<q_icu_lock, flags);
for_each_present_cpu(vpe) {
ltq_icu_w32(vpe, im,
ltq_icu_r32(vpe, im, LTQ_ICU_IER) & ~BIT(offset),
LTQ_ICU_IER);
ltq_icu_w32(vpe, im, BIT(offset), LTQ_ICU_ISR);
}
raw_spin_unlock_irqrestore(<q_icu_lock, flags);
}
static void ltq_ack_irq(struct irq_data *d)
{
unsigned long offset = d->hwirq - MIPS_CPU_IRQ_CASCADE;
unsigned long im = offset / INT_NUM_IM_OFFSET;
unsigned long flags;
int vpe;
offset %= INT_NUM_IM_OFFSET;
raw_spin_lock_irqsave(<q_icu_lock, flags);
for_each_present_cpu(vpe) {
ltq_icu_w32(vpe, im, BIT(offset), LTQ_ICU_ISR);
}
raw_spin_unlock_irqrestore(<q_icu_lock, flags);
}
void ltq_enable_irq(struct irq_data *d)
{
unsigned long offset = d->hwirq - MIPS_CPU_IRQ_CASCADE;
unsigned long im = offset / INT_NUM_IM_OFFSET;
unsigned long flags;
int vpe;
offset %= INT_NUM_IM_OFFSET;
vpe = cpumask_first(irq_data_get_effective_affinity_mask(d));
/* This shouldn't be even possible, maybe during CPU hotplug spam */
if (unlikely(vpe >= nr_cpu_ids))
vpe = smp_processor_id();
raw_spin_lock_irqsave(<q_icu_lock, flags);
ltq_icu_w32(vpe, im, ltq_icu_r32(vpe, im, LTQ_ICU_IER) | BIT(offset),
LTQ_ICU_IER);
raw_spin_unlock_irqrestore(<q_icu_lock, flags);
}
static int ltq_eiu_settype(struct irq_data *d, unsigned int type)
{
int i;
unsigned long flags;
for (i = 0; i < exin_avail; i++) {
if (d->hwirq == ltq_eiu_irq[i]) {
int val = 0;
int edge = 0;
switch (type) {
case IRQF_TRIGGER_NONE:
break;
case IRQF_TRIGGER_RISING:
val = 1;
edge = 1;
break;
case IRQF_TRIGGER_FALLING:
val = 2;
edge = 1;
break;
case IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING:
val = 3;
edge = 1;
break;
case IRQF_TRIGGER_HIGH:
val = 5;
break;
case IRQF_TRIGGER_LOW:
val = 6;
break;
default:
pr_err("invalid type %d for irq %ld\n",
type, d->hwirq);
return -EINVAL;
}
if (edge)
irq_set_handler(d->hwirq, handle_edge_irq);
spin_lock_irqsave(<q_eiu_lock, flags);
ltq_eiu_w32((ltq_eiu_r32(LTQ_EIU_EXIN_C) &
(~(7 << (i * 4)))) | (val << (i * 4)),
LTQ_EIU_EXIN_C);
spin_unlock_irqrestore(<q_eiu_lock, flags);
}
}
return 0;
}
static unsigned int ltq_startup_eiu_irq(struct irq_data *d)
{
int i;
ltq_enable_irq(d);
for (i = 0; i < exin_avail; i++) {
if (d->hwirq == ltq_eiu_irq[i]) {
/* by default we are low level triggered */
ltq_eiu_settype(d, IRQF_TRIGGER_LOW);
/* clear all pending */
ltq_eiu_w32(ltq_eiu_r32(LTQ_EIU_EXIN_INC) & ~BIT(i),
LTQ_EIU_EXIN_INC);
/* enable */
ltq_eiu_w32(ltq_eiu_r32(LTQ_EIU_EXIN_INEN) | BIT(i),
LTQ_EIU_EXIN_INEN);
break;
}
}
return 0;
}
static void ltq_shutdown_eiu_irq(struct irq_data *d)
{
int i;
ltq_disable_irq(d);
for (i = 0; i < exin_avail; i++) {
if (d->hwirq == ltq_eiu_irq[i]) {
/* disable */
ltq_eiu_w32(ltq_eiu_r32(LTQ_EIU_EXIN_INEN) & ~BIT(i),
LTQ_EIU_EXIN_INEN);
break;
}
}
}
#if defined(CONFIG_SMP)
static int ltq_icu_irq_set_affinity(struct irq_data *d,
const struct cpumask *cpumask, bool force)
{
struct cpumask tmask;
if (!cpumask_and(&tmask, cpumask, cpu_online_mask))
return -EINVAL;
irq_data_update_effective_affinity(d, &tmask);
return IRQ_SET_MASK_OK;
}
#endif
static struct irq_chip ltq_irq_type = {
.name = "icu",
.irq_enable = ltq_enable_irq,
.irq_disable = ltq_disable_irq,
.irq_unmask = ltq_enable_irq,
.irq_ack = ltq_ack_irq,
.irq_mask = ltq_disable_irq,
.irq_mask_ack = ltq_mask_and_ack_irq,
#if defined(CONFIG_SMP)
.irq_set_affinity = ltq_icu_irq_set_affinity,
#endif
};
static struct irq_chip ltq_eiu_type = {
.name = "eiu",
.irq_startup = ltq_startup_eiu_irq,
.irq_shutdown = ltq_shutdown_eiu_irq,
.irq_enable = ltq_enable_irq,
.irq_disable = ltq_disable_irq,
.irq_unmask = ltq_enable_irq,
.irq_ack = ltq_ack_irq,
.irq_mask = ltq_disable_irq,
.irq_mask_ack = ltq_mask_and_ack_irq,
.irq_set_type = ltq_eiu_settype,
#if defined(CONFIG_SMP)
.irq_set_affinity = ltq_icu_irq_set_affinity,
#endif
};
static void ltq_hw_irq_handler(struct irq_desc *desc)
{
unsigned int module = irq_desc_get_irq(desc) - 2;
u32 irq;
irq_hw_number_t hwirq;
int vpe = smp_processor_id();
irq = ltq_icu_r32(vpe, module, LTQ_ICU_IOSR);
if (irq == 0)
return;
/*
* silicon bug causes only the msb set to 1 to be valid. all
* other bits might be bogus
*/
irq = __fls(irq);
hwirq = irq + MIPS_CPU_IRQ_CASCADE + (INT_NUM_IM_OFFSET * module);
generic_handle_irq(irq_linear_revmap(ltq_domain, hwirq));
/* if this is a EBU irq, we need to ack it or get a deadlock */
if ((irq == LTQ_ICU_EBU_IRQ) && (module == 0) && LTQ_EBU_PCC_ISTAT)
ltq_ebu_w32(ltq_ebu_r32(LTQ_EBU_PCC_ISTAT) | 0x10,
LTQ_EBU_PCC_ISTAT);
}
static int icu_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw)
{
struct irq_chip *chip = <q_irq_type;
struct irq_data *data;
int i;
if (hw < MIPS_CPU_IRQ_CASCADE)
return 0;
for (i = 0; i < exin_avail; i++)
if (hw == ltq_eiu_irq[i])
chip = <q_eiu_type;
data = irq_get_irq_data(irq);
irq_data_update_effective_affinity(data, cpumask_of(0));
irq_set_chip_and_handler(irq, chip, handle_level_irq);
return 0;
}
static const struct irq_domain_ops irq_domain_ops = {
.xlate = irq_domain_xlate_onetwocell,
.map = icu_map,
};
int __init icu_of_init(struct device_node *node, struct device_node *parent)
{
struct device_node *eiu_node;
struct resource res;
int i, ret, vpe;
/* load register regions of available ICUs */
for_each_possible_cpu(vpe) {
if (of_address_to_resource(node, vpe, &res))
panic("Failed to get icu%i memory range", vpe);
if (!request_mem_region(res.start, resource_size(&res),
res.name))
pr_err("Failed to request icu%i memory\n", vpe);
ltq_icu_membase[vpe] = ioremap(res.start,
resource_size(&res));
if (!ltq_icu_membase[vpe])
panic("Failed to remap icu%i memory", vpe);
}
/* turn off all irqs by default */
for_each_possible_cpu(vpe) {
for (i = 0; i < MAX_IM; i++) {
/* make sure all irqs are turned off by default */
ltq_icu_w32(vpe, i, 0, LTQ_ICU_IER);
/* clear all possibly pending interrupts */
ltq_icu_w32(vpe, i, ~0, LTQ_ICU_ISR);
ltq_icu_w32(vpe, i, ~0, LTQ_ICU_IMR);
/* clear resend */
ltq_icu_w32(vpe, i, 0, LTQ_ICU_IRSR);
}
}
mips_cpu_irq_init();
for (i = 0; i < MAX_IM; i++)
irq_set_chained_handler(i + 2, ltq_hw_irq_handler);
ltq_domain = irq_domain_add_linear(node,
(MAX_IM * INT_NUM_IM_OFFSET) + MIPS_CPU_IRQ_CASCADE,
&irq_domain_ops, 0);
/* tell oprofile which irq to use */
ltq_perfcount_irq = irq_create_mapping(ltq_domain, LTQ_PERF_IRQ);
/* the external interrupts are optional and xway only */
eiu_node = of_find_compatible_node(NULL, NULL, "lantiq,eiu-xway");
if (eiu_node && !of_address_to_resource(eiu_node, 0, &res)) {
/* find out how many external irq sources we have */
exin_avail = of_property_count_u32_elems(eiu_node,
"lantiq,eiu-irqs");
if (exin_avail > MAX_EIU)
exin_avail = MAX_EIU;
ret = of_property_read_u32_array(eiu_node, "lantiq,eiu-irqs",
ltq_eiu_irq, exin_avail);
if (ret)
panic("failed to load external irq resources");
if (!request_mem_region(res.start, resource_size(&res),
res.name))
pr_err("Failed to request eiu memory");
ltq_eiu_membase = ioremap(res.start,
resource_size(&res));
if (!ltq_eiu_membase)
panic("Failed to remap eiu memory");
}
return 0;
}
int get_c0_perfcount_int(void)
{
return ltq_perfcount_irq;
}
EXPORT_SYMBOL_GPL(get_c0_perfcount_int);
unsigned int get_c0_compare_int(void)
{
return CP0_LEGACY_COMPARE_IRQ;
}
static const struct of_device_id of_irq_ids[] __initconst = {
{ .compatible = "lantiq,icu", .data = icu_of_init },
{},
};
void __init arch_init_irq(void)
{
of_irq_init(of_irq_ids);
}