arch/c6x/kernel/irq.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  Copyright (C) 2011-2012 Texas Instruments Incorporated
   4  *
   5  *  This borrows heavily from powerpc version, which is:
   6  *
   7  *  Derived from arch/i386/kernel/irq.c
   8  *    Copyright (C) 1992 Linus Torvalds
   9  *  Adapted from arch/i386 by Gary Thomas
  10  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
  11  *  Updated and modified by Cort Dougan <cort@fsmlabs.com>
  12  *    Copyright (C) 1996-2001 Cort Dougan
  13  *  Adapted for Power Macintosh by Paul Mackerras
  14  *    Copyright (C) 1996 Paul Mackerras (paulus@cs.anu.edu.au)
  15  */
  16 #include <linux/slab.h>
  17 #include <linux/seq_file.h>
  18 #include <linux/radix-tree.h>
  19 #include <linux/module.h>
  20 #include <linux/of.h>
  21 #include <linux/of_irq.h>
  22 #include <linux/interrupt.h>
  23 #include <linux/kernel_stat.h>
  24
  25 #include <asm/megamod-pic.h>
  26 #include <asm/special_insns.h>
  27
  28 unsigned long irq_err_count;
  29
  30 static DEFINE_RAW_SPINLOCK(core_irq_lock);
  31
  32 static void mask_core_irq(struct irq_data *data)
  33 {
  34         unsigned int prio = data->hwirq;
  35
  36         raw_spin_lock(&core_irq_lock);
  37         and_creg(IER, ~(1 << prio));
  38         raw_spin_unlock(&core_irq_lock);
  39 }
  40
  41 static void unmask_core_irq(struct irq_data *data)
  42 {
  43         unsigned int prio = data->hwirq;
  44
  45         raw_spin_lock(&core_irq_lock);
  46         or_creg(IER, 1 << prio);
  47         raw_spin_unlock(&core_irq_lock);
  48 }
  49
  50 static struct irq_chip core_chip = {
  51         .name           = "core",
  52         .irq_mask       = mask_core_irq,
  53         .irq_unmask     = unmask_core_irq,
  54 };
  55
  56 static int prio_to_virq[NR_PRIORITY_IRQS];
  57
  58 asmlinkage void c6x_do_IRQ(unsigned int prio, struct pt_regs *regs)
  59 {
  60         struct pt_regs *old_regs = set_irq_regs(regs);
  61
  62         irq_enter();
  63
  64         generic_handle_irq(prio_to_virq[prio]);
  65
  66         irq_exit();
  67
  68         set_irq_regs(old_regs);
  69 }
  70
  71 static struct irq_domain *core_domain;
  72
  73 static int core_domain_map(struct irq_domain *h, unsigned int virq,
  74                            irq_hw_number_t hw)
  75 {
  76         if (hw < 4 || hw >= NR_PRIORITY_IRQS)
  77                 return -EINVAL;
  78
  79         prio_to_virq[hw] = virq;
  80
  81         irq_set_status_flags(virq, IRQ_LEVEL);
  82         irq_set_chip_and_handler(virq, &core_chip, handle_level_irq);
  83         return 0;
  84 }
  85
  86 static const struct irq_domain_ops core_domain_ops = {
  87         .map = core_domain_map,
  88         .xlate = irq_domain_xlate_onecell,
  89 };
  90
  91 void __init init_IRQ(void)
  92 {
  93         struct device_node *np;
  94
  95         /* Mask all priority IRQs */
  96         and_creg(IER, ~0xfff0);
  97
  98         np = of_find_compatible_node(NULL, NULL, "ti,c64x+core-pic");
  99         if (np != NULL) {
 100                 /* create the core host */
 101                 core_domain = irq_domain_add_linear(np, NR_PRIORITY_IRQS,
 102                                                     &core_domain_ops, NULL);
 103                 if (core_domain)
 104                         irq_set_default_host(core_domain);
 105                 of_node_put(np);
 106         }
 107
 108         printk(KERN_INFO "Core interrupt controller initialized\n");
 109
 110         /* now we're ready for other SoC controllers */
 111         megamod_pic_init();
 112
 113         /* Clear all general IRQ flags */
 114         set_creg(ICR, 0xfff0);
 115 }
 116
 117 void ack_bad_irq(int irq)
 118 {
 119         printk(KERN_ERR "IRQ: spurious interrupt %d\n", irq);
 120         irq_err_count++;
 121 }
 122
 123 int arch_show_interrupts(struct seq_file *p, int prec)
 124 {
 125         seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_count);
 126         return 0;
 127 }