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
37 enum 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
46 static 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
55 static void __iomem *rt_intc_membase;
56
57 static int rt_perfcount_irq;
58
rt_intc_w32(u32 val,unsigned reg)59 static inline void rt_intc_w32(u32 val, unsigned reg)
60 {
61 __raw_writel(val, rt_intc_membase + rt_intc_regs[reg]);
62 }
63
rt_intc_r32(unsigned reg)64 static inline u32 rt_intc_r32(unsigned reg)
65 {
66 return __raw_readl(rt_intc_membase + rt_intc_regs[reg]);
67 }
68
ralink_intc_irq_unmask(struct irq_data * d)69 static void ralink_intc_irq_unmask(struct irq_data *d)
70 {
71 rt_intc_w32(BIT(d->hwirq), INTC_REG_ENABLE);
72 }
73
ralink_intc_irq_mask(struct irq_data * d)74 static void ralink_intc_irq_mask(struct irq_data *d)
75 {
76 rt_intc_w32(BIT(d->hwirq), INTC_REG_DISABLE);
77 }
78
79 static 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
get_c0_perfcount_int(void)86 int get_c0_perfcount_int(void)
87 {
88 return rt_perfcount_irq;
89 }
90 EXPORT_SYMBOL_GPL(get_c0_perfcount_int);
91
get_c0_compare_int(void)92 unsigned int get_c0_compare_int(void)
93 {
94 return CP0_LEGACY_COMPARE_IRQ;
95 }
96
ralink_intc_irq_handler(struct irq_desc * desc)97 static 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
plat_irq_dispatch(void)109 asmlinkage 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
intc_map(struct irq_domain * d,unsigned int irq,irq_hw_number_t hw)134 static 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
141 static const struct irq_domain_ops irq_domain_ops = {
142 .xlate = irq_domain_xlate_onecell,
143 .map = intc_map,
144 };
145
intc_of_init(struct device_node * node,struct device_node * parent)146 static 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
194 static 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
arch_init_irq(void)200 void __init arch_init_irq(void)
201 {
202 of_irq_init(of_irq_ids);
203 }
204
205