/*
* Root interrupt controller for the BCM2836 (Raspberry Pi 2).
*
* Copyright 2015 Broadcom
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/cpu.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/irqchip.h>
#include <linux/irqdomain.h>
#include <asm/exception.h>
/*
* The low 2 bits identify the CPU that the GPU IRQ goes to, and the
* next 2 bits identify the CPU that the GPU FIQ goes to.
*/
#define LOCAL_GPU_ROUTING 0x00c
/* When setting bits 0-3, enables PMU interrupts on that CPU. */
#define LOCAL_PM_ROUTING_SET 0x010
/* When setting bits 0-3, disables PMU interrupts on that CPU. */
#define LOCAL_PM_ROUTING_CLR 0x014
/*
* The low 4 bits of this are the CPU's timer IRQ enables, and the
* next 4 bits are the CPU's timer FIQ enables (which override the IRQ
* bits).
*/
#define LOCAL_TIMER_INT_CONTROL0 0x040
/*
* The low 4 bits of this are the CPU's per-mailbox IRQ enables, and
* the next 4 bits are the CPU's per-mailbox FIQ enables (which
* override the IRQ bits).
*/
#define LOCAL_MAILBOX_INT_CONTROL0 0x050
/*
* The CPU's interrupt status register. Bits are defined by the the
* LOCAL_IRQ_* bits below.
*/
#define LOCAL_IRQ_PENDING0 0x060
/* Same status bits as above, but for FIQ. */
#define LOCAL_FIQ_PENDING0 0x070
/*
* Mailbox0 write-to-set bits. There are 16 mailboxes, 4 per CPU, and
* these bits are organized by mailbox number and then CPU number. We
* use mailbox 0 for IPIs. The mailbox's interrupt is raised while
* any bit is set.
*/
#define LOCAL_MAILBOX0_SET0 0x080
/* Mailbox0 write-to-clear bits. */
#define LOCAL_MAILBOX0_CLR0 0x0c0
#define LOCAL_IRQ_CNTPSIRQ 0
#define LOCAL_IRQ_CNTPNSIRQ 1
#define LOCAL_IRQ_CNTHPIRQ 2
#define LOCAL_IRQ_CNTVIRQ 3
#define LOCAL_IRQ_MAILBOX0 4
#define LOCAL_IRQ_MAILBOX1 5
#define LOCAL_IRQ_MAILBOX2 6
#define LOCAL_IRQ_MAILBOX3 7
#define LOCAL_IRQ_GPU_FAST 8
#define LOCAL_IRQ_PMU_FAST 9
#define LAST_IRQ LOCAL_IRQ_PMU_FAST
struct bcm2836_arm_irqchip_intc {
struct irq_domain *domain;
void __iomem *base;
};
static struct bcm2836_arm_irqchip_intc intc __read_mostly;
static void bcm2836_arm_irqchip_mask_per_cpu_irq(unsigned int reg_offset,
unsigned int bit,
int cpu)
{
void __iomem *reg = intc.base + reg_offset + 4 * cpu;
writel(readl(reg) & ~BIT(bit), reg);
}
static void bcm2836_arm_irqchip_unmask_per_cpu_irq(unsigned int reg_offset,
unsigned int bit,
int cpu)
{
void __iomem *reg = intc.base + reg_offset + 4 * cpu;
writel(readl(reg) | BIT(bit), reg);
}
static void bcm2836_arm_irqchip_mask_timer_irq(struct irq_data *d)
{
bcm2836_arm_irqchip_mask_per_cpu_irq(LOCAL_TIMER_INT_CONTROL0,
d->hwirq - LOCAL_IRQ_CNTPSIRQ,
smp_processor_id());
}
static void bcm2836_arm_irqchip_unmask_timer_irq(struct irq_data *d)
{
bcm2836_arm_irqchip_unmask_per_cpu_irq(LOCAL_TIMER_INT_CONTROL0,
d->hwirq - LOCAL_IRQ_CNTPSIRQ,
smp_processor_id());
}
static struct irq_chip bcm2836_arm_irqchip_timer = {
.name = "bcm2836-timer",
.irq_mask = bcm2836_arm_irqchip_mask_timer_irq,
.irq_unmask = bcm2836_arm_irqchip_unmask_timer_irq,
};
static void bcm2836_arm_irqchip_mask_pmu_irq(struct irq_data *d)
{
writel(1 << smp_processor_id(), intc.base + LOCAL_PM_ROUTING_CLR);
}
static void bcm2836_arm_irqchip_unmask_pmu_irq(struct irq_data *d)
{
writel(1 << smp_processor_id(), intc.base + LOCAL_PM_ROUTING_SET);
}
static struct irq_chip bcm2836_arm_irqchip_pmu = {
.name = "bcm2836-pmu",
.irq_mask = bcm2836_arm_irqchip_mask_pmu_irq,
.irq_unmask = bcm2836_arm_irqchip_unmask_pmu_irq,
};
static void bcm2836_arm_irqchip_mask_gpu_irq(struct irq_data *d)
{
}
static void bcm2836_arm_irqchip_unmask_gpu_irq(struct irq_data *d)
{
}
static struct irq_chip bcm2836_arm_irqchip_gpu = {
.name = "bcm2836-gpu",
.irq_mask = bcm2836_arm_irqchip_mask_gpu_irq,
.irq_unmask = bcm2836_arm_irqchip_unmask_gpu_irq,
};
static void bcm2836_arm_irqchip_register_irq(int hwirq, struct irq_chip *chip)
{
int irq = irq_create_mapping(intc.domain, hwirq);
irq_set_percpu_devid(irq);
irq_set_chip_and_handler(irq, chip, handle_percpu_devid_irq);
irq_set_status_flags(irq, IRQ_NOAUTOEN);
}
static void
__exception_irq_entry bcm2836_arm_irqchip_handle_irq(struct pt_regs *regs)
{
int cpu = smp_processor_id();
u32 stat;
stat = readl_relaxed(intc.base + LOCAL_IRQ_PENDING0 + 4 * cpu);
if (stat & 0x10) {
#ifdef CONFIG_SMP
void __iomem *mailbox0 = (intc.base +
LOCAL_MAILBOX0_CLR0 + 16 * cpu);
u32 mbox_val = readl(mailbox0);
u32 ipi = ffs(mbox_val) - 1;
writel(1 << ipi, mailbox0);
handle_IPI(ipi, regs);
#endif
} else {
u32 hwirq = ffs(stat) - 1;
handle_IRQ(irq_linear_revmap(intc.domain, hwirq), regs);
}
}
#ifdef CONFIG_SMP
static void bcm2836_arm_irqchip_send_ipi(const struct cpumask *mask,
unsigned int ipi)
{
int cpu;
void __iomem *mailbox0_base = intc.base + LOCAL_MAILBOX0_SET0;
/*
* Ensure that stores to normal memory are visible to the
* other CPUs before issuing the IPI.
*/
dsb();
for_each_cpu(cpu, mask) {
writel(1 << ipi, mailbox0_base + 16 * cpu);
}
}
/* Unmasks the IPI on the CPU when it's online. */
static int bcm2836_arm_irqchip_cpu_notify(struct notifier_block *nfb,
unsigned long action, void *hcpu)
{
unsigned int cpu = (unsigned long)hcpu;
unsigned int int_reg = LOCAL_MAILBOX_INT_CONTROL0;
unsigned int mailbox = 0;
if (action == CPU_STARTING || action == CPU_STARTING_FROZEN)
bcm2836_arm_irqchip_unmask_per_cpu_irq(int_reg, mailbox, cpu);
else if (action == CPU_DYING)
bcm2836_arm_irqchip_mask_per_cpu_irq(int_reg, mailbox, cpu);
return NOTIFY_OK;
}
static struct notifier_block bcm2836_arm_irqchip_cpu_notifier = {
.notifier_call = bcm2836_arm_irqchip_cpu_notify,
.priority = 100,
};
#endif
static const struct irq_domain_ops bcm2836_arm_irqchip_intc_ops = {
.xlate = irq_domain_xlate_onecell
};
static void
bcm2836_arm_irqchip_smp_init(void)
{
#ifdef CONFIG_SMP
/* Unmask IPIs to the boot CPU. */
bcm2836_arm_irqchip_cpu_notify(&bcm2836_arm_irqchip_cpu_notifier,
CPU_STARTING,
(void *)smp_processor_id());
register_cpu_notifier(&bcm2836_arm_irqchip_cpu_notifier);
set_smp_cross_call(bcm2836_arm_irqchip_send_ipi);
#endif
}
static int __init bcm2836_arm_irqchip_l1_intc_of_init(struct device_node *node,
struct device_node *parent)
{
intc.base = of_iomap(node, 0);
if (!intc.base) {
panic("%s: unable to map local interrupt registers\n",
node->full_name);
}
intc.domain = irq_domain_add_linear(node, LAST_IRQ + 1,
&bcm2836_arm_irqchip_intc_ops,
NULL);
if (!intc.domain)
panic("%s: unable to create IRQ domain\n", node->full_name);
bcm2836_arm_irqchip_register_irq(LOCAL_IRQ_CNTPSIRQ,
&bcm2836_arm_irqchip_timer);
bcm2836_arm_irqchip_register_irq(LOCAL_IRQ_CNTPNSIRQ,
&bcm2836_arm_irqchip_timer);
bcm2836_arm_irqchip_register_irq(LOCAL_IRQ_CNTHPIRQ,
&bcm2836_arm_irqchip_timer);
bcm2836_arm_irqchip_register_irq(LOCAL_IRQ_CNTVIRQ,
&bcm2836_arm_irqchip_timer);
bcm2836_arm_irqchip_register_irq(LOCAL_IRQ_GPU_FAST,
&bcm2836_arm_irqchip_gpu);
bcm2836_arm_irqchip_register_irq(LOCAL_IRQ_PMU_FAST,
&bcm2836_arm_irqchip_pmu);
bcm2836_arm_irqchip_smp_init();
set_handle_irq(bcm2836_arm_irqchip_handle_irq);
return 0;
}
IRQCHIP_DECLARE(bcm2836_arm_irqchip_l1_intc, "brcm,bcm2836-l1-intc",
bcm2836_arm_irqchip_l1_intc_of_init);