/*
* 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 <linux/irqchip/irq-bcm2836.h>
#include <asm/exception.h>
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 int bcm2836_map(struct irq_domain *d, unsigned int irq,
irq_hw_number_t hw)
{
struct irq_chip *chip;
switch (hw) {
case LOCAL_IRQ_CNTPSIRQ:
case LOCAL_IRQ_CNTPNSIRQ:
case LOCAL_IRQ_CNTHPIRQ:
case LOCAL_IRQ_CNTVIRQ:
chip = &bcm2836_arm_irqchip_timer;
break;
case LOCAL_IRQ_GPU_FAST:
chip = &bcm2836_arm_irqchip_gpu;
break;
case LOCAL_IRQ_PMU_FAST:
chip = &bcm2836_arm_irqchip_pmu;
break;
default:
pr_warn_once("Unexpected hw irq: %lu\n", hw);
return -EINVAL;
}
irq_set_percpu_devid(irq);
irq_domain_set_info(d, irq, hw, chip, d->host_data,
handle_percpu_devid_irq, NULL, NULL);
irq_set_status_flags(irq, IRQ_NOAUTOEN);
return 0;
}
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 & BIT(LOCAL_IRQ_MAILBOX0)) {
#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 if (stat) {
u32 hwirq = ffs(stat) - 1;
handle_domain_irq(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.
*/
smp_wmb();
for_each_cpu(cpu, mask) {
writel(1 << ipi, mailbox0_base + 16 * cpu);
}
}
static int bcm2836_cpu_starting(unsigned int cpu)
{
bcm2836_arm_irqchip_unmask_per_cpu_irq(LOCAL_MAILBOX_INT_CONTROL0, 0,
cpu);
return 0;
}
static int bcm2836_cpu_dying(unsigned int cpu)
{
bcm2836_arm_irqchip_mask_per_cpu_irq(LOCAL_MAILBOX_INT_CONTROL0, 0,
cpu);
return 0;
}
#endif
static const struct irq_domain_ops bcm2836_arm_irqchip_intc_ops = {
.xlate = irq_domain_xlate_onetwocell,
.map = bcm2836_map,
};
static void
bcm2836_arm_irqchip_smp_init(void)
{
#ifdef CONFIG_SMP
/* Unmask IPIs to the boot CPU. */
cpuhp_setup_state(CPUHP_AP_IRQ_BCM2836_STARTING,
"irqchip/bcm2836:starting", bcm2836_cpu_starting,
bcm2836_cpu_dying);
set_smp_cross_call(bcm2836_arm_irqchip_send_ipi);
#endif
}
/*
* The LOCAL_IRQ_CNT* timer firings are based off of the external
* oscillator with some scaling. The firmware sets up CNTFRQ to
* report 19.2Mhz, but doesn't set up the scaling registers.
*/
static void bcm2835_init_local_timer_frequency(void)
{
/*
* Set the timer to source from the 19.2Mhz crystal clock (bit
* 8 unset), and only increment by 1 instead of 2 (bit 9
* unset).
*/
writel(0, intc.base + LOCAL_CONTROL);
/*
* Set the timer prescaler to 1:1 (timer freq = input freq *
* 2**31 / prescaler)
*/
writel(0x80000000, intc.base + LOCAL_PRESCALER);
}
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("%pOF: unable to map local interrupt registers\n", node);
}
bcm2835_init_local_timer_frequency();
intc.domain = irq_domain_add_linear(node, LAST_IRQ + 1,
&bcm2836_arm_irqchip_intc_ops,
NULL);
if (!intc.domain)
panic("%pOF: unable to create IRQ domain\n", node);
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);
