1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (C) 2013 Altera Corporation 4 * Copyright (C) 2011 Tobias Klauser <tklauser@distanz.ch> 5 * Copyright (C) 2008 Thomas Chou <thomas@wytron.com.tw> 6 * 7 * based on irq.c from m68k which is: 8 * 9 * Copyright (C) 2007 Greg Ungerer <gerg@snapgear.com> 10 */ 11 12 #include <linux/init.h> 13 #include <linux/interrupt.h> 14 #include <linux/of.h> 15 16 static u32 ienable; 17 18 asmlinkage void do_IRQ(int hwirq, struct pt_regs *regs) 19 { 20 struct pt_regs *oldregs = set_irq_regs(regs); 21 int irq; 22 23 irq_enter(); 24 irq = irq_find_mapping(NULL, hwirq); 25 generic_handle_irq(irq); 26 irq_exit(); 27 28 set_irq_regs(oldregs); 29 } 30 31 static void chip_unmask(struct irq_data *d) 32 { 33 ienable |= (1 << d->hwirq); 34 WRCTL(CTL_IENABLE, ienable); 35 } 36 37 static void chip_mask(struct irq_data *d) 38 { 39 ienable &= ~(1 << d->hwirq); 40 WRCTL(CTL_IENABLE, ienable); 41 } 42 43 static struct irq_chip m_irq_chip = { 44 .name = "NIOS2-INTC", 45 .irq_unmask = chip_unmask, 46 .irq_mask = chip_mask, 47 }; 48 49 static int irq_map(struct irq_domain *h, unsigned int virq, 50 irq_hw_number_t hw_irq_num) 51 { 52 irq_set_chip_and_handler(virq, &m_irq_chip, handle_level_irq); 53 54 return 0; 55 } 56 57 static const struct irq_domain_ops irq_ops = { 58 .map = irq_map, 59 .xlate = irq_domain_xlate_onecell, 60 }; 61 62 void __init init_IRQ(void) 63 { 64 struct irq_domain *domain; 65 struct device_node *node; 66 67 node = of_find_compatible_node(NULL, NULL, "altr,nios2-1.0"); 68 if (!node) 69 node = of_find_compatible_node(NULL, NULL, "altr,nios2-1.1"); 70 71 BUG_ON(!node); 72 73 domain = irq_domain_add_linear(node, NIOS2_CPU_NR_IRQS, &irq_ops, NULL); 74 BUG_ON(!domain); 75 76 irq_set_default_host(domain); 77 of_node_put(node); 78 /* Load the initial ienable value */ 79 ienable = RDCTL(CTL_IENABLE); 80 } 81