147 lines
3.7 KiB
C
147 lines
3.7 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* drivers/irq/irq-nvic.c
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*
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* Copyright (C) 2008 ARM Limited, All Rights Reserved.
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* Copyright (C) 2013 Pengutronix
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*
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* Support for the Nested Vectored Interrupt Controller found on the
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* ARMv7-M CPUs (Cortex-M3/M4)
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/slab.h>
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#include <linux/err.h>
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#include <linux/io.h>
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#include <linux/of.h>
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#include <linux/of_address.h>
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#include <linux/irq.h>
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#include <linux/irqchip.h>
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#include <linux/irqdomain.h>
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#include <asm/v7m.h>
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#include <asm/exception.h>
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#define NVIC_ISER 0x000
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#define NVIC_ICER 0x080
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#define NVIC_IPR 0x400
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#define NVIC_MAX_BANKS 16
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/*
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* Each bank handles 32 irqs. Only the 16th (= last) bank handles only
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* 16 irqs.
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*/
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#define NVIC_MAX_IRQ ((NVIC_MAX_BANKS - 1) * 32 + 16)
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static struct irq_domain *nvic_irq_domain;
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asmlinkage void __exception_irq_entry
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nvic_handle_irq(irq_hw_number_t hwirq, struct pt_regs *regs)
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{
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unsigned int irq = irq_linear_revmap(nvic_irq_domain, hwirq);
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handle_IRQ(irq, regs);
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}
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static int nvic_irq_domain_translate(struct irq_domain *d,
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struct irq_fwspec *fwspec,
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unsigned long *hwirq, unsigned int *type)
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{
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if (WARN_ON(fwspec->param_count < 1))
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return -EINVAL;
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*hwirq = fwspec->param[0];
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*type = IRQ_TYPE_NONE;
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return 0;
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}
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static int nvic_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
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unsigned int nr_irqs, void *arg)
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{
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int i, ret;
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irq_hw_number_t hwirq;
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unsigned int type = IRQ_TYPE_NONE;
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struct irq_fwspec *fwspec = arg;
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ret = nvic_irq_domain_translate(domain, fwspec, &hwirq, &type);
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if (ret)
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return ret;
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for (i = 0; i < nr_irqs; i++)
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irq_map_generic_chip(domain, virq + i, hwirq + i);
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return 0;
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}
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static const struct irq_domain_ops nvic_irq_domain_ops = {
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.translate = nvic_irq_domain_translate,
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.alloc = nvic_irq_domain_alloc,
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.free = irq_domain_free_irqs_top,
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};
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static int __init nvic_of_init(struct device_node *node,
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struct device_node *parent)
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{
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unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
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unsigned int irqs, i, ret, numbanks;
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void __iomem *nvic_base;
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numbanks = (readl_relaxed(V7M_SCS_ICTR) &
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V7M_SCS_ICTR_INTLINESNUM_MASK) + 1;
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nvic_base = of_iomap(node, 0);
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if (!nvic_base) {
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pr_warn("unable to map nvic registers\n");
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return -ENOMEM;
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}
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irqs = numbanks * 32;
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if (irqs > NVIC_MAX_IRQ)
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irqs = NVIC_MAX_IRQ;
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nvic_irq_domain =
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irq_domain_add_linear(node, irqs, &nvic_irq_domain_ops, NULL);
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if (!nvic_irq_domain) {
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pr_warn("Failed to allocate irq domain\n");
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iounmap(nvic_base);
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return -ENOMEM;
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}
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ret = irq_alloc_domain_generic_chips(nvic_irq_domain, 32, 1,
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"nvic_irq", handle_fasteoi_irq,
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clr, 0, IRQ_GC_INIT_MASK_CACHE);
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if (ret) {
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pr_warn("Failed to allocate irq chips\n");
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irq_domain_remove(nvic_irq_domain);
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iounmap(nvic_base);
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return ret;
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}
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for (i = 0; i < numbanks; ++i) {
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struct irq_chip_generic *gc;
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gc = irq_get_domain_generic_chip(nvic_irq_domain, 32 * i);
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gc->reg_base = nvic_base + 4 * i;
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gc->chip_types[0].regs.enable = NVIC_ISER;
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gc->chip_types[0].regs.disable = NVIC_ICER;
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gc->chip_types[0].chip.irq_mask = irq_gc_mask_disable_reg;
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gc->chip_types[0].chip.irq_unmask = irq_gc_unmask_enable_reg;
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/* This is a no-op as end of interrupt is signaled by the
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* exception return sequence.
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*/
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gc->chip_types[0].chip.irq_eoi = irq_gc_noop;
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/* disable interrupts */
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writel_relaxed(~0, gc->reg_base + NVIC_ICER);
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}
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/* Set priority on all interrupts */
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for (i = 0; i < irqs; i += 4)
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writel_relaxed(0, nvic_base + NVIC_IPR + i);
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return 0;
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}
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IRQCHIP_DECLARE(armv7m_nvic, "arm,armv7m-nvic", nvic_of_init);
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