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292ec080 UKK |
1 | /* |
2 | * drivers/irq/irq-nvic.c | |
3 | * | |
4 | * Copyright (C) 2008 ARM Limited, All Rights Reserved. | |
5 | * Copyright (C) 2013 Pengutronix | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 as | |
9 | * published by the Free Software Foundation. | |
10 | * | |
11 | * Support for the Nested Vectored Interrupt Controller found on the | |
12 | * ARMv7-M CPUs (Cortex-M3/M4) | |
13 | */ | |
14 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt | |
15 | ||
16 | #include <linux/init.h> | |
17 | #include <linux/kernel.h> | |
18 | #include <linux/slab.h> | |
19 | #include <linux/err.h> | |
20 | #include <linux/io.h> | |
21 | #include <linux/of.h> | |
22 | #include <linux/of_address.h> | |
23 | #include <linux/irq.h> | |
24 | #include <linux/irqdomain.h> | |
25 | ||
26 | #include <asm/v7m.h> | |
27 | #include <asm/exception.h> | |
28 | ||
29 | #include "irqchip.h" | |
30 | ||
31 | #define NVIC_ISER 0x000 | |
32 | #define NVIC_ICER 0x080 | |
33 | #define NVIC_IPR 0x300 | |
34 | ||
35 | #define NVIC_MAX_BANKS 16 | |
36 | /* | |
37 | * Each bank handles 32 irqs. Only the 16th (= last) bank handles only | |
38 | * 16 irqs. | |
39 | */ | |
40 | #define NVIC_MAX_IRQ ((NVIC_MAX_BANKS - 1) * 32 + 16) | |
41 | ||
42 | static struct irq_domain *nvic_irq_domain; | |
43 | ||
44 | asmlinkage void __exception_irq_entry | |
45 | nvic_handle_irq(irq_hw_number_t hwirq, struct pt_regs *regs) | |
46 | { | |
47 | unsigned int irq = irq_linear_revmap(nvic_irq_domain, hwirq); | |
48 | ||
49 | handle_IRQ(irq, regs); | |
50 | } | |
51 | ||
52 | static void nvic_eoi(struct irq_data *d) | |
53 | { | |
54 | /* | |
55 | * This is a no-op as end of interrupt is signaled by the exception | |
56 | * return sequence. | |
57 | */ | |
58 | } | |
59 | ||
60 | static int __init nvic_of_init(struct device_node *node, | |
61 | struct device_node *parent) | |
62 | { | |
63 | unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN; | |
64 | unsigned int irqs, i, ret, numbanks; | |
65 | void __iomem *nvic_base; | |
66 | ||
67 | numbanks = (readl_relaxed(V7M_SCS_ICTR) & | |
68 | V7M_SCS_ICTR_INTLINESNUM_MASK) + 1; | |
69 | ||
70 | nvic_base = of_iomap(node, 0); | |
71 | if (!nvic_base) { | |
72 | pr_warn("unable to map nvic registers\n"); | |
73 | return -ENOMEM; | |
74 | } | |
75 | ||
76 | irqs = numbanks * 32; | |
77 | if (irqs > NVIC_MAX_IRQ) | |
78 | irqs = NVIC_MAX_IRQ; | |
79 | ||
80 | nvic_irq_domain = | |
81 | irq_domain_add_linear(node, irqs, &irq_generic_chip_ops, NULL); | |
82 | if (!nvic_irq_domain) { | |
83 | pr_warn("Failed to allocate irq domain\n"); | |
84 | return -ENOMEM; | |
85 | } | |
86 | ||
5b8aae48 | 87 | ret = irq_alloc_domain_generic_chips(nvic_irq_domain, 32, 1, |
292ec080 UKK |
88 | "nvic_irq", handle_fasteoi_irq, |
89 | clr, 0, IRQ_GC_INIT_MASK_CACHE); | |
90 | if (ret) { | |
91 | pr_warn("Failed to allocate irq chips\n"); | |
92 | irq_domain_remove(nvic_irq_domain); | |
93 | return ret; | |
94 | } | |
95 | ||
96 | for (i = 0; i < numbanks; ++i) { | |
97 | struct irq_chip_generic *gc; | |
98 | ||
99 | gc = irq_get_domain_generic_chip(nvic_irq_domain, 32 * i); | |
100 | gc->reg_base = nvic_base + 4 * i; | |
101 | gc->chip_types[0].regs.enable = NVIC_ISER; | |
102 | gc->chip_types[0].regs.disable = NVIC_ICER; | |
103 | gc->chip_types[0].chip.irq_mask = irq_gc_mask_disable_reg; | |
104 | gc->chip_types[0].chip.irq_unmask = irq_gc_unmask_enable_reg; | |
105 | gc->chip_types[0].chip.irq_eoi = nvic_eoi; | |
106 | ||
107 | /* disable interrupts */ | |
108 | writel_relaxed(~0, gc->reg_base + NVIC_ICER); | |
109 | } | |
110 | ||
111 | /* Set priority on all interrupts */ | |
112 | for (i = 0; i < irqs; i += 4) | |
113 | writel_relaxed(0, nvic_base + NVIC_IPR + i); | |
114 | ||
115 | return 0; | |
116 | } | |
117 | IRQCHIP_DECLARE(armv7m_nvic, "arm,armv7m-nvic", nvic_of_init); |