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 #define INTC_INT_GLOBAL BIT(31) 24 25 #define RALINK_CPU_IRQ_INTC (MIPS_CPU_IRQ_BASE + 2) 26 #define RALINK_CPU_IRQ_PCI (MIPS_CPU_IRQ_BASE + 4) 27 #define RALINK_CPU_IRQ_FE (MIPS_CPU_IRQ_BASE + 5) 28 #define RALINK_CPU_IRQ_WIFI (MIPS_CPU_IRQ_BASE + 6) 29 #define RALINK_CPU_IRQ_COUNTER (MIPS_CPU_IRQ_BASE + 7) 30 31 /* we have a cascade of 8 irqs */ 32 #define RALINK_INTC_IRQ_BASE 8 33 34 /* we have 32 SoC irqs */ 35 #define RALINK_INTC_IRQ_COUNT 32 36 37 #define RALINK_INTC_IRQ_PERFC (RALINK_INTC_IRQ_BASE + 9) 38 39 enum rt_intc_regs_enum { 40 INTC_REG_STATUS0 = 0, 41 INTC_REG_STATUS1, 42 INTC_REG_TYPE, 43 INTC_REG_RAW_STATUS, 44 INTC_REG_ENABLE, 45 INTC_REG_DISABLE, 46 }; 47 48 static u32 rt_intc_regs[] = { 49 [INTC_REG_STATUS0] = 0x00, 50 [INTC_REG_STATUS1] = 0x04, 51 [INTC_REG_TYPE] = 0x20, 52 [INTC_REG_RAW_STATUS] = 0x30, 53 [INTC_REG_ENABLE] = 0x34, 54 [INTC_REG_DISABLE] = 0x38, 55 }; 56 57 static void __iomem *rt_intc_membase; 58 59 static int rt_perfcount_irq; 60 61 static inline void rt_intc_w32(u32 val, unsigned reg) 62 { 63 __raw_writel(val, rt_intc_membase + rt_intc_regs[reg]); 64 } 65 66 static inline u32 rt_intc_r32(unsigned reg) 67 { 68 return __raw_readl(rt_intc_membase + rt_intc_regs[reg]); 69 } 70 71 static void ralink_intc_irq_unmask(struct irq_data *d) 72 { 73 rt_intc_w32(BIT(d->hwirq), INTC_REG_ENABLE); 74 } 75 76 static void ralink_intc_irq_mask(struct irq_data *d) 77 { 78 rt_intc_w32(BIT(d->hwirq), INTC_REG_DISABLE); 79 } 80 81 static struct irq_chip ralink_intc_irq_chip = { 82 .name = "INTC", 83 .irq_unmask = ralink_intc_irq_unmask, 84 .irq_mask = ralink_intc_irq_mask, 85 .irq_mask_ack = ralink_intc_irq_mask, 86 }; 87 88 int get_c0_perfcount_int(void) 89 { 90 return rt_perfcount_irq; 91 } 92 93 unsigned int get_c0_compare_int(void) 94 { 95 return CP0_LEGACY_COMPARE_IRQ; 96 } 97 98 static void ralink_intc_irq_handler(unsigned int irq, struct irq_desc *desc) 99 { 100 u32 pending = rt_intc_r32(INTC_REG_STATUS0); 101 102 if (pending) { 103 struct irq_domain *domain = irq_desc_get_handler_data(desc); 104 generic_handle_irq(irq_find_mapping(domain, __ffs(pending))); 105 } else { 106 spurious_interrupt(); 107 } 108 } 109 110 asmlinkage void plat_irq_dispatch(void) 111 { 112 unsigned long pending; 113 114 pending = read_c0_status() & read_c0_cause() & ST0_IM; 115 116 if (pending & STATUSF_IP7) 117 do_IRQ(RALINK_CPU_IRQ_COUNTER); 118 119 else if (pending & STATUSF_IP5) 120 do_IRQ(RALINK_CPU_IRQ_FE); 121 122 else if (pending & STATUSF_IP6) 123 do_IRQ(RALINK_CPU_IRQ_WIFI); 124 125 else if (pending & STATUSF_IP4) 126 do_IRQ(RALINK_CPU_IRQ_PCI); 127 128 else if (pending & STATUSF_IP2) 129 do_IRQ(RALINK_CPU_IRQ_INTC); 130 131 else 132 spurious_interrupt(); 133 } 134 135 static int intc_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw) 136 { 137 irq_set_chip_and_handler(irq, &ralink_intc_irq_chip, handle_level_irq); 138 139 return 0; 140 } 141 142 static const struct irq_domain_ops irq_domain_ops = { 143 .xlate = irq_domain_xlate_onecell, 144 .map = intc_map, 145 }; 146 147 static int __init intc_of_init(struct device_node *node, 148 struct device_node *parent) 149 { 150 struct resource res; 151 struct irq_domain *domain; 152 int irq; 153 154 if (!of_property_read_u32_array(node, "ralink,intc-registers", 155 rt_intc_regs, 6)) 156 pr_info("intc: using register map from devicetree\n"); 157 158 irq = irq_of_parse_and_map(node, 0); 159 if (!irq) 160 panic("Failed to get INTC IRQ"); 161 162 if (of_address_to_resource(node, 0, &res)) 163 panic("Failed to get intc memory range"); 164 165 if (request_mem_region(res.start, resource_size(&res), 166 res.name) < 0) 167 pr_err("Failed to request intc memory"); 168 169 rt_intc_membase = ioremap_nocache(res.start, 170 resource_size(&res)); 171 if (!rt_intc_membase) 172 panic("Failed to remap intc memory"); 173 174 /* disable all interrupts */ 175 rt_intc_w32(~0, INTC_REG_DISABLE); 176 177 /* route all INTC interrupts to MIPS HW0 interrupt */ 178 rt_intc_w32(0, INTC_REG_TYPE); 179 180 domain = irq_domain_add_legacy(node, RALINK_INTC_IRQ_COUNT, 181 RALINK_INTC_IRQ_BASE, 0, &irq_domain_ops, NULL); 182 if (!domain) 183 panic("Failed to add irqdomain"); 184 185 rt_intc_w32(INTC_INT_GLOBAL, INTC_REG_ENABLE); 186 187 irq_set_chained_handler(irq, ralink_intc_irq_handler); 188 irq_set_handler_data(irq, domain); 189 190 /* tell the kernel which irq is used for performance monitoring */ 191 rt_perfcount_irq = irq_create_mapping(domain, 9); 192 193 return 0; 194 } 195 196 static struct of_device_id __initdata of_irq_ids[] = { 197 { .compatible = "mti,cpu-interrupt-controller", .data = mips_cpu_irq_of_init }, 198 { .compatible = "ralink,rt2880-intc", .data = intc_of_init }, 199 {}, 200 }; 201 202 void __init arch_init_irq(void) 203 { 204 of_irq_init(of_irq_ids); 205 } 206 207