linux/arch/mips/ralink/irq.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 *
   4 * Copyright (C) 2009 Gabor Juhos <juhosg@openwrt.org>
   5 * Copyright (C) 2013 John Crispin <john@phrozen.org>
   6 */
   7
   8#include <linux/io.h>
   9#include <linux/bitops.h>
  10#include <linux/of_platform.h>
  11#include <linux/of_address.h>
  12#include <linux/of_irq.h>
  13#include <linux/irqdomain.h>
  14#include <linux/interrupt.h>
  15
  16#include <asm/irq_cpu.h>
  17#include <asm/mipsregs.h>
  18
  19#include "common.h"
  20
  21#define INTC_INT_GLOBAL         BIT(31)
  22
  23#define RALINK_CPU_IRQ_INTC     (MIPS_CPU_IRQ_BASE + 2)
  24#define RALINK_CPU_IRQ_PCI      (MIPS_CPU_IRQ_BASE + 4)
  25#define RALINK_CPU_IRQ_FE       (MIPS_CPU_IRQ_BASE + 5)
  26#define RALINK_CPU_IRQ_WIFI     (MIPS_CPU_IRQ_BASE + 6)
  27#define RALINK_CPU_IRQ_COUNTER  (MIPS_CPU_IRQ_BASE + 7)
  28
  29/* we have a cascade of 8 irqs */
  30#define RALINK_INTC_IRQ_BASE    8
  31
  32/* we have 32 SoC irqs */
  33#define RALINK_INTC_IRQ_COUNT   32
  34
  35#define RALINK_INTC_IRQ_PERFC   (RALINK_INTC_IRQ_BASE + 9)
  36
  37enum rt_intc_regs_enum {
  38        INTC_REG_STATUS0 = 0,
  39        INTC_REG_STATUS1,
  40        INTC_REG_TYPE,
  41        INTC_REG_RAW_STATUS,
  42        INTC_REG_ENABLE,
  43        INTC_REG_DISABLE,
  44};
  45
  46static u32 rt_intc_regs[] = {
  47        [INTC_REG_STATUS0] = 0x00,
  48        [INTC_REG_STATUS1] = 0x04,
  49        [INTC_REG_TYPE] = 0x20,
  50        [INTC_REG_RAW_STATUS] = 0x30,
  51        [INTC_REG_ENABLE] = 0x34,
  52        [INTC_REG_DISABLE] = 0x38,
  53};
  54
  55static void __iomem *rt_intc_membase;
  56
  57static int rt_perfcount_irq;
  58
  59static inline void rt_intc_w32(u32 val, unsigned reg)
  60{
  61        __raw_writel(val, rt_intc_membase + rt_intc_regs[reg]);
  62}
  63
  64static inline u32 rt_intc_r32(unsigned reg)
  65{
  66        return __raw_readl(rt_intc_membase + rt_intc_regs[reg]);
  67}
  68
  69static void ralink_intc_irq_unmask(struct irq_data *d)
  70{
  71        rt_intc_w32(BIT(d->hwirq), INTC_REG_ENABLE);
  72}
  73
  74static void ralink_intc_irq_mask(struct irq_data *d)
  75{
  76        rt_intc_w32(BIT(d->hwirq), INTC_REG_DISABLE);
  77}
  78
  79static struct irq_chip ralink_intc_irq_chip = {
  80        .name           = "INTC",
  81        .irq_unmask     = ralink_intc_irq_unmask,
  82        .irq_mask       = ralink_intc_irq_mask,
  83        .irq_mask_ack   = ralink_intc_irq_mask,
  84};
  85
  86int get_c0_perfcount_int(void)
  87{
  88        return rt_perfcount_irq;
  89}
  90EXPORT_SYMBOL_GPL(get_c0_perfcount_int);
  91
  92unsigned int get_c0_compare_int(void)
  93{
  94        return CP0_LEGACY_COMPARE_IRQ;
  95}
  96
  97static void ralink_intc_irq_handler(struct irq_desc *desc)
  98{
  99        u32 pending = rt_intc_r32(INTC_REG_STATUS0);
 100
 101        if (pending) {
 102                struct irq_domain *domain = irq_desc_get_handler_data(desc);
 103                generic_handle_irq(irq_find_mapping(domain, __ffs(pending)));
 104        } else {
 105                spurious_interrupt();
 106        }
 107}
 108
 109asmlinkage void plat_irq_dispatch(void)
 110{
 111        unsigned long pending;
 112
 113        pending = read_c0_status() & read_c0_cause() & ST0_IM;
 114
 115        if (pending & STATUSF_IP7)
 116                do_IRQ(RALINK_CPU_IRQ_COUNTER);
 117
 118        else if (pending & STATUSF_IP5)
 119                do_IRQ(RALINK_CPU_IRQ_FE);
 120
 121        else if (pending & STATUSF_IP6)
 122                do_IRQ(RALINK_CPU_IRQ_WIFI);
 123
 124        else if (pending & STATUSF_IP4)
 125                do_IRQ(RALINK_CPU_IRQ_PCI);
 126
 127        else if (pending & STATUSF_IP2)
 128                do_IRQ(RALINK_CPU_IRQ_INTC);
 129
 130        else
 131                spurious_interrupt();
 132}
 133
 134static int intc_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw)
 135{
 136        irq_set_chip_and_handler(irq, &ralink_intc_irq_chip, handle_level_irq);
 137
 138        return 0;
 139}
 140
 141static const struct irq_domain_ops irq_domain_ops = {
 142        .xlate = irq_domain_xlate_onecell,
 143        .map = intc_map,
 144};
 145
 146static int __init intc_of_init(struct device_node *node,
 147                               struct device_node *parent)
 148{
 149        struct resource res;
 150        struct irq_domain *domain;
 151        int irq;
 152
 153        if (!of_property_read_u32_array(node, "ralink,intc-registers",
 154                                        rt_intc_regs, 6))
 155                pr_info("intc: using register map from devicetree\n");
 156
 157        irq = irq_of_parse_and_map(node, 0);
 158        if (!irq)
 159                panic("Failed to get INTC IRQ");
 160
 161        if (of_address_to_resource(node, 0, &res))
 162                panic("Failed to get intc memory range");
 163
 164        if (!request_mem_region(res.start, resource_size(&res),
 165                                res.name))
 166                pr_err("Failed to request intc memory");
 167
 168        rt_intc_membase = ioremap(res.start,
 169                                        resource_size(&res));
 170        if (!rt_intc_membase)
 171                panic("Failed to remap intc memory");
 172
 173        /* disable all interrupts */
 174        rt_intc_w32(~0, INTC_REG_DISABLE);
 175
 176        /* route all INTC interrupts to MIPS HW0 interrupt */
 177        rt_intc_w32(0, INTC_REG_TYPE);
 178
 179        domain = irq_domain_add_legacy(node, RALINK_INTC_IRQ_COUNT,
 180                        RALINK_INTC_IRQ_BASE, 0, &irq_domain_ops, NULL);
 181        if (!domain)
 182                panic("Failed to add irqdomain");
 183
 184        rt_intc_w32(INTC_INT_GLOBAL, INTC_REG_ENABLE);
 185
 186        irq_set_chained_handler_and_data(irq, ralink_intc_irq_handler, domain);
 187
 188        /* tell the kernel which irq is used for performance monitoring */
 189        rt_perfcount_irq = irq_create_mapping(domain, 9);
 190
 191        return 0;
 192}
 193
 194static struct of_device_id __initdata of_irq_ids[] = {
 195        { .compatible = "mti,cpu-interrupt-controller", .data = mips_cpu_irq_of_init },
 196        { .compatible = "ralink,rt2880-intc", .data = intc_of_init },
 197        {},
 198};
 199
 200void __init arch_init_irq(void)
 201{
 202        of_irq_init(of_irq_ids);
 203}
 204
 205