| /* |
| * 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> |
| |
| #define LOCAL_CONTROL 0x000 |
| #define LOCAL_PRESCALER 0x008 |
| |
| /* |
| * 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 |
| /* |
| * Mailbox 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 |
| #define LOCAL_MAILBOX3_SET0 0x08c |
| /* Mailbox write-to-clear bits. */ |
| #define LOCAL_MAILBOX0_CLR0 0x0c0 |
| #define LOCAL_MAILBOX3_CLR0 0x0cc |
| |
| #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 & 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_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, |
| }; |
| |
| int __init bcm2836_smp_boot_secondary(unsigned int cpu, |
| struct task_struct *idle) |
| { |
| unsigned long secondary_startup_phys = |
| (unsigned long)virt_to_phys((void *)secondary_startup); |
| |
| dsb(); |
| writel(secondary_startup_phys, |
| intc.base + LOCAL_MAILBOX3_SET0 + 16 * cpu); |
| |
| return 0; |
| } |
| |
| static const struct smp_operations bcm2836_smp_ops __initconst = { |
| .smp_boot_secondary = bcm2836_smp_boot_secondary, |
| }; |
| |
| #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); |
| smp_set_ops(&bcm2836_smp_ops); |
| #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("%s: unable to map local interrupt registers\n", |
| node->full_name); |
| } |
| |
| 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("%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); |