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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
292ec080 UKK |
2 | /* |
3 | * drivers/irq/irq-nvic.c | |
4 | * | |
5 | * Copyright (C) 2008 ARM Limited, All Rights Reserved. | |
6 | * Copyright (C) 2013 Pengutronix | |
7 | * | |
292ec080 UKK |
8 | * Support for the Nested Vectored Interrupt Controller found on the |
9 | * ARMv7-M CPUs (Cortex-M3/M4) | |
10 | */ | |
11 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt | |
12 | ||
13 | #include <linux/init.h> | |
14 | #include <linux/kernel.h> | |
15 | #include <linux/slab.h> | |
16 | #include <linux/err.h> | |
17 | #include <linux/io.h> | |
18 | #include <linux/of.h> | |
19 | #include <linux/of_address.h> | |
20 | #include <linux/irq.h> | |
41a83e06 | 21 | #include <linux/irqchip.h> |
292ec080 UKK |
22 | #include <linux/irqdomain.h> |
23 | ||
24 | #include <asm/v7m.h> | |
25 | #include <asm/exception.h> | |
26 | ||
292ec080 UKK |
27 | #define NVIC_ISER 0x000 |
28 | #define NVIC_ICER 0x080 | |
c5e0cbe2 | 29 | #define NVIC_IPR 0x400 |
292ec080 UKK |
30 | |
31 | #define NVIC_MAX_BANKS 16 | |
32 | /* | |
33 | * Each bank handles 32 irqs. Only the 16th (= last) bank handles only | |
34 | * 16 irqs. | |
35 | */ | |
36 | #define NVIC_MAX_IRQ ((NVIC_MAX_BANKS - 1) * 32 + 16) | |
37 | ||
38 | static struct irq_domain *nvic_irq_domain; | |
39 | ||
0953fb26 | 40 | static void __nvic_handle_irq(irq_hw_number_t hwirq) |
a7b0872e | 41 | { |
0953fb26 | 42 | generic_handle_domain_irq(nvic_irq_domain, hwirq); |
a7b0872e MR |
43 | } |
44 | ||
45 | /* | |
46 | * TODO: restructure the ARMv7M entry logic so that this entry logic can live | |
47 | * in arch code. | |
48 | */ | |
292ec080 UKK |
49 | asmlinkage void __exception_irq_entry |
50 | nvic_handle_irq(irq_hw_number_t hwirq, struct pt_regs *regs) | |
51 | { | |
a7b0872e MR |
52 | struct pt_regs *old_regs; |
53 | ||
54 | irq_enter(); | |
55 | old_regs = set_irq_regs(regs); | |
0953fb26 | 56 | __nvic_handle_irq(hwirq); |
a7b0872e MR |
57 | set_irq_regs(old_regs); |
58 | irq_exit(); | |
292ec080 UKK |
59 | } |
60 | ||
2d9f59f7 SA |
61 | static int nvic_irq_domain_alloc(struct irq_domain *domain, unsigned int virq, |
62 | unsigned int nr_irqs, void *arg) | |
63 | { | |
64 | int i, ret; | |
65 | irq_hw_number_t hwirq; | |
66 | unsigned int type = IRQ_TYPE_NONE; | |
f833f57f | 67 | struct irq_fwspec *fwspec = arg; |
2d9f59f7 | 68 | |
459c3bc8 | 69 | ret = irq_domain_translate_onecell(domain, fwspec, &hwirq, &type); |
2d9f59f7 SA |
70 | if (ret) |
71 | return ret; | |
72 | ||
73 | for (i = 0; i < nr_irqs; i++) | |
74 | irq_map_generic_chip(domain, virq + i, hwirq + i); | |
75 | ||
76 | return 0; | |
77 | } | |
78 | ||
79 | static const struct irq_domain_ops nvic_irq_domain_ops = { | |
459c3bc8 | 80 | .translate = irq_domain_translate_onecell, |
2d9f59f7 SA |
81 | .alloc = nvic_irq_domain_alloc, |
82 | .free = irq_domain_free_irqs_top, | |
83 | }; | |
84 | ||
292ec080 UKK |
85 | static int __init nvic_of_init(struct device_node *node, |
86 | struct device_node *parent) | |
87 | { | |
88 | unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN; | |
89 | unsigned int irqs, i, ret, numbanks; | |
90 | void __iomem *nvic_base; | |
91 | ||
92 | numbanks = (readl_relaxed(V7M_SCS_ICTR) & | |
93 | V7M_SCS_ICTR_INTLINESNUM_MASK) + 1; | |
94 | ||
95 | nvic_base = of_iomap(node, 0); | |
96 | if (!nvic_base) { | |
97 | pr_warn("unable to map nvic registers\n"); | |
98 | return -ENOMEM; | |
99 | } | |
100 | ||
101 | irqs = numbanks * 32; | |
102 | if (irqs > NVIC_MAX_IRQ) | |
103 | irqs = NVIC_MAX_IRQ; | |
104 | ||
105 | nvic_irq_domain = | |
2d9f59f7 SA |
106 | irq_domain_add_linear(node, irqs, &nvic_irq_domain_ops, NULL); |
107 | ||
292ec080 UKK |
108 | if (!nvic_irq_domain) { |
109 | pr_warn("Failed to allocate irq domain\n"); | |
110 | return -ENOMEM; | |
111 | } | |
112 | ||
5b8aae48 | 113 | ret = irq_alloc_domain_generic_chips(nvic_irq_domain, 32, 1, |
292ec080 UKK |
114 | "nvic_irq", handle_fasteoi_irq, |
115 | clr, 0, IRQ_GC_INIT_MASK_CACHE); | |
116 | if (ret) { | |
117 | pr_warn("Failed to allocate irq chips\n"); | |
118 | irq_domain_remove(nvic_irq_domain); | |
119 | return ret; | |
120 | } | |
121 | ||
122 | for (i = 0; i < numbanks; ++i) { | |
123 | struct irq_chip_generic *gc; | |
124 | ||
125 | gc = irq_get_domain_generic_chip(nvic_irq_domain, 32 * i); | |
126 | gc->reg_base = nvic_base + 4 * i; | |
127 | gc->chip_types[0].regs.enable = NVIC_ISER; | |
128 | gc->chip_types[0].regs.disable = NVIC_ICER; | |
129 | gc->chip_types[0].chip.irq_mask = irq_gc_mask_disable_reg; | |
130 | gc->chip_types[0].chip.irq_unmask = irq_gc_unmask_enable_reg; | |
8b53ec26 DT |
131 | /* This is a no-op as end of interrupt is signaled by the |
132 | * exception return sequence. | |
133 | */ | |
134 | gc->chip_types[0].chip.irq_eoi = irq_gc_noop; | |
292ec080 UKK |
135 | |
136 | /* disable interrupts */ | |
137 | writel_relaxed(~0, gc->reg_base + NVIC_ICER); | |
138 | } | |
139 | ||
140 | /* Set priority on all interrupts */ | |
141 | for (i = 0; i < irqs; i += 4) | |
142 | writel_relaxed(0, nvic_base + NVIC_IPR + i); | |
143 | ||
144 | return 0; | |
145 | } | |
146 | IRQCHIP_DECLARE(armv7m_nvic, "arm,armv7m-nvic", nvic_of_init); |