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/irqdomain.h> 15 #include <linux/of.h> 16 17 static u32 ienable; 18 19 asmlinkage void do_IRQ(int hwirq, struct pt_regs *regs) 20 { 21 struct pt_regs *oldregs = set_irq_regs(regs); 22 23 irq_enter(); 24 generic_handle_domain_irq(NULL, hwirq); 25 irq_exit(); 26 27 set_irq_regs(oldregs); 28 } 29 30 static void chip_unmask(struct irq_data *d) 31 { 32 ienable |= (1 << d->hwirq); 33 WRCTL(CTL_IENABLE, ienable); 34 } 35 36 static void chip_mask(struct irq_data *d) 37 { 38 ienable &= ~(1 << d->hwirq); 39 WRCTL(CTL_IENABLE, ienable); 40 } 41 42 static struct irq_chip m_irq_chip = { 43 .name = "NIOS2-INTC", 44 .irq_unmask = chip_unmask, 45 .irq_mask = chip_mask, 46 }; 47 48 static int irq_map(struct irq_domain *h, unsigned int virq, 49 irq_hw_number_t hw_irq_num) 50 { 51 irq_set_chip_and_handler(virq, &m_irq_chip, handle_level_irq); 52 53 return 0; 54 } 55 56 static const struct irq_domain_ops irq_ops = { 57 .map = irq_map, 58 .xlate = irq_domain_xlate_onecell, 59 }; 60 61 void __init init_IRQ(void) 62 { 63 struct irq_domain *domain; 64 struct device_node *node; 65 66 node = of_find_compatible_node(NULL, NULL, "altr,nios2-1.0"); 67 if (!node) 68 node = of_find_compatible_node(NULL, NULL, "altr,nios2-1.1"); 69 70 BUG_ON(!node); 71 72 domain = irq_domain_add_linear(node, NIOS2_CPU_NR_IRQS, &irq_ops, NULL); 73 BUG_ON(!domain); 74 75 irq_set_default_host(domain); 76 of_node_put(node); 77 /* Load the initial ienable value */ 78 ienable = RDCTL(CTL_IENABLE); 79 } 80