1 /* 2 * This program is free software; you can redistribute it and/or modify it 3 * under the terms of the GNU General Public License version 2 as published 4 * by the Free Software Foundation. 5 * 6 * Copyright (C) 2009 Gabor Juhos <juhosg@openwrt.org> 7 * Copyright (C) 2013 John Crispin <blogic@openwrt.org> 8 */ 9 10 #include <linux/io.h> 11 #include <linux/bitops.h> 12 #include <linux/of_platform.h> 13 #include <linux/of_address.h> 14 #include <linux/of_irq.h> 15 #include <linux/irqdomain.h> 16 #include <linux/interrupt.h> 17 18 #include <asm/irq_cpu.h> 19 #include <asm/mipsregs.h> 20 21 #include "common.h" 22 23 /* INTC register offsets */ 24 #define INTC_REG_STATUS0 0x00 25 #define INTC_REG_STATUS1 0x04 26 #define INTC_REG_TYPE 0x20 27 #define INTC_REG_RAW_STATUS 0x30 28 #define INTC_REG_ENABLE 0x34 29 #define INTC_REG_DISABLE 0x38 30 31 #define INTC_INT_GLOBAL BIT(31) 32 33 #define RALINK_CPU_IRQ_INTC (MIPS_CPU_IRQ_BASE + 2) 34 #define RALINK_CPU_IRQ_PCI (MIPS_CPU_IRQ_BASE + 4) 35 #define RALINK_CPU_IRQ_FE (MIPS_CPU_IRQ_BASE + 5) 36 #define RALINK_CPU_IRQ_WIFI (MIPS_CPU_IRQ_BASE + 6) 37 #define RALINK_CPU_IRQ_COUNTER (MIPS_CPU_IRQ_BASE + 7) 38 39 /* we have a cascade of 8 irqs */ 40 #define RALINK_INTC_IRQ_BASE 8 41 42 /* we have 32 SoC irqs */ 43 #define RALINK_INTC_IRQ_COUNT 32 44 45 #define RALINK_INTC_IRQ_PERFC (RALINK_INTC_IRQ_BASE + 9) 46 47 static void __iomem *rt_intc_membase; 48 49 static inline void rt_intc_w32(u32 val, unsigned reg) 50 { 51 __raw_writel(val, rt_intc_membase + reg); 52 } 53 54 static inline u32 rt_intc_r32(unsigned reg) 55 { 56 return __raw_readl(rt_intc_membase + reg); 57 } 58 59 static void ralink_intc_irq_unmask(struct irq_data *d) 60 { 61 rt_intc_w32(BIT(d->hwirq), INTC_REG_ENABLE); 62 } 63 64 static void ralink_intc_irq_mask(struct irq_data *d) 65 { 66 rt_intc_w32(BIT(d->hwirq), INTC_REG_DISABLE); 67 } 68 69 static struct irq_chip ralink_intc_irq_chip = { 70 .name = "INTC", 71 .irq_unmask = ralink_intc_irq_unmask, 72 .irq_mask = ralink_intc_irq_mask, 73 .irq_mask_ack = ralink_intc_irq_mask, 74 }; 75 76 unsigned int get_c0_compare_int(void) 77 { 78 return CP0_LEGACY_COMPARE_IRQ; 79 } 80 81 static void ralink_intc_irq_handler(unsigned int irq, struct irq_desc *desc) 82 { 83 u32 pending = rt_intc_r32(INTC_REG_STATUS0); 84 85 if (pending) { 86 struct irq_domain *domain = irq_get_handler_data(irq); 87 generic_handle_irq(irq_find_mapping(domain, __ffs(pending))); 88 } else { 89 spurious_interrupt(); 90 } 91 } 92 93 asmlinkage void plat_irq_dispatch(void) 94 { 95 unsigned long pending; 96 97 pending = read_c0_status() & read_c0_cause() & ST0_IM; 98 99 if (pending & STATUSF_IP7) 100 do_IRQ(RALINK_CPU_IRQ_COUNTER); 101 102 else if (pending & STATUSF_IP5) 103 do_IRQ(RALINK_CPU_IRQ_FE); 104 105 else if (pending & STATUSF_IP6) 106 do_IRQ(RALINK_CPU_IRQ_WIFI); 107 108 else if (pending & STATUSF_IP4) 109 do_IRQ(RALINK_CPU_IRQ_PCI); 110 111 else if (pending & STATUSF_IP2) 112 do_IRQ(RALINK_CPU_IRQ_INTC); 113 114 else 115 spurious_interrupt(); 116 } 117 118 static int intc_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw) 119 { 120 irq_set_chip_and_handler(irq, &ralink_intc_irq_chip, handle_level_irq); 121 122 return 0; 123 } 124 125 static const struct irq_domain_ops irq_domain_ops = { 126 .xlate = irq_domain_xlate_onecell, 127 .map = intc_map, 128 }; 129 130 static int __init intc_of_init(struct device_node *node, 131 struct device_node *parent) 132 { 133 struct resource res; 134 struct irq_domain *domain; 135 int irq; 136 137 irq = irq_of_parse_and_map(node, 0); 138 if (!irq) 139 panic("Failed to get INTC IRQ"); 140 141 if (of_address_to_resource(node, 0, &res)) 142 panic("Failed to get intc memory range"); 143 144 if (request_mem_region(res.start, resource_size(&res), 145 res.name) < 0) 146 pr_err("Failed to request intc memory"); 147 148 rt_intc_membase = ioremap_nocache(res.start, 149 resource_size(&res)); 150 if (!rt_intc_membase) 151 panic("Failed to remap intc memory"); 152 153 /* disable all interrupts */ 154 rt_intc_w32(~0, INTC_REG_DISABLE); 155 156 /* route all INTC interrupts to MIPS HW0 interrupt */ 157 rt_intc_w32(0, INTC_REG_TYPE); 158 159 domain = irq_domain_add_legacy(node, RALINK_INTC_IRQ_COUNT, 160 RALINK_INTC_IRQ_BASE, 0, &irq_domain_ops, NULL); 161 if (!domain) 162 panic("Failed to add irqdomain"); 163 164 rt_intc_w32(INTC_INT_GLOBAL, INTC_REG_ENABLE); 165 166 irq_set_chained_handler(irq, ralink_intc_irq_handler); 167 irq_set_handler_data(irq, domain); 168 169 /* tell the kernel which irq is used for performance monitoring */ 170 cp0_perfcount_irq = irq_create_mapping(domain, 9); 171 172 return 0; 173 } 174 175 static struct of_device_id __initdata of_irq_ids[] = { 176 { .compatible = "mti,cpu-interrupt-controller", .data = mips_cpu_intc_init }, 177 { .compatible = "ralink,rt2880-intc", .data = intc_of_init }, 178 {}, 179 }; 180 181 void __init arch_init_irq(void) 182 { 183 of_irq_init(of_irq_ids); 184 } 185 186