diff options
Diffstat (limited to 'drivers/irqchip/irq-nvic.c')
| -rw-r--r-- | drivers/irqchip/irq-nvic.c | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/drivers/irqchip/irq-nvic.c b/drivers/irqchip/irq-nvic.c new file mode 100644 index 000000000..330beb62d --- /dev/null +++ b/drivers/irqchip/irq-nvic.c @@ -0,0 +1,149 @@ +/* + * drivers/irq/irq-nvic.c + * + * Copyright (C) 2008 ARM Limited, All Rights Reserved. + * Copyright (C) 2013 Pengutronix + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * Support for the Nested Vectored Interrupt Controller found on the + * ARMv7-M CPUs (Cortex-M3/M4) + */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/err.h> +#include <linux/io.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/irq.h> +#include <linux/irqchip.h> +#include <linux/irqdomain.h> + +#include <asm/v7m.h> +#include <asm/exception.h> + +#define NVIC_ISER 0x000 +#define NVIC_ICER 0x080 +#define NVIC_IPR 0x400 + +#define NVIC_MAX_BANKS 16 +/* + * Each bank handles 32 irqs. Only the 16th (= last) bank handles only + * 16 irqs. + */ +#define NVIC_MAX_IRQ ((NVIC_MAX_BANKS - 1) * 32 + 16) + +static struct irq_domain *nvic_irq_domain; + +asmlinkage void __exception_irq_entry +nvic_handle_irq(irq_hw_number_t hwirq, struct pt_regs *regs) +{ + unsigned int irq = irq_linear_revmap(nvic_irq_domain, hwirq); + + handle_IRQ(irq, regs); +} + +static int nvic_irq_domain_translate(struct irq_domain *d, + struct irq_fwspec *fwspec, + unsigned long *hwirq, unsigned int *type) +{ + if (WARN_ON(fwspec->param_count < 1)) + return -EINVAL; + *hwirq = fwspec->param[0]; + *type = IRQ_TYPE_NONE; + return 0; +} + +static int nvic_irq_domain_alloc(struct irq_domain *domain, unsigned int virq, + unsigned int nr_irqs, void *arg) +{ + int i, ret; + irq_hw_number_t hwirq; + unsigned int type = IRQ_TYPE_NONE; + struct irq_fwspec *fwspec = arg; + + ret = nvic_irq_domain_translate(domain, fwspec, &hwirq, &type); + if (ret) + return ret; + + for (i = 0; i < nr_irqs; i++) + irq_map_generic_chip(domain, virq + i, hwirq + i); + + return 0; +} + +static const struct irq_domain_ops nvic_irq_domain_ops = { + .translate = nvic_irq_domain_translate, + .alloc = nvic_irq_domain_alloc, + .free = irq_domain_free_irqs_top, +}; + +static int __init nvic_of_init(struct device_node *node, + struct device_node *parent) +{ + unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN; + unsigned int irqs, i, ret, numbanks; + void __iomem *nvic_base; + + numbanks = (readl_relaxed(V7M_SCS_ICTR) & + V7M_SCS_ICTR_INTLINESNUM_MASK) + 1; + + nvic_base = of_iomap(node, 0); + if (!nvic_base) { + pr_warn("unable to map nvic registers\n"); + return -ENOMEM; + } + + irqs = numbanks * 32; + if (irqs > NVIC_MAX_IRQ) + irqs = NVIC_MAX_IRQ; + + nvic_irq_domain = + irq_domain_add_linear(node, irqs, &nvic_irq_domain_ops, NULL); + + if (!nvic_irq_domain) { + pr_warn("Failed to allocate irq domain\n"); + iounmap(nvic_base); + return -ENOMEM; + } + + ret = irq_alloc_domain_generic_chips(nvic_irq_domain, 32, 1, + "nvic_irq", handle_fasteoi_irq, + clr, 0, IRQ_GC_INIT_MASK_CACHE); + if (ret) { + pr_warn("Failed to allocate irq chips\n"); + irq_domain_remove(nvic_irq_domain); + iounmap(nvic_base); + return ret; + } + + for (i = 0; i < numbanks; ++i) { + struct irq_chip_generic *gc; + + gc = irq_get_domain_generic_chip(nvic_irq_domain, 32 * i); + gc->reg_base = nvic_base + 4 * i; + gc->chip_types[0].regs.enable = NVIC_ISER; + gc->chip_types[0].regs.disable = NVIC_ICER; + gc->chip_types[0].chip.irq_mask = irq_gc_mask_disable_reg; + gc->chip_types[0].chip.irq_unmask = irq_gc_unmask_enable_reg; + /* This is a no-op as end of interrupt is signaled by the + * exception return sequence. + */ + gc->chip_types[0].chip.irq_eoi = irq_gc_noop; + + /* disable interrupts */ + writel_relaxed(~0, gc->reg_base + NVIC_ICER); + } + + /* Set priority on all interrupts */ + for (i = 0; i < irqs; i += 4) + writel_relaxed(0, nvic_base + NVIC_IPR + i); + + return 0; +} +IRQCHIP_DECLARE(armv7m_nvic, "arm,armv7m-nvic", nvic_of_init); |