drivers/irqchip/irq-idt3243x.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Driver for IDT/Renesas 79RC3243x Interrupt Controller.
   4  */
   5
   6 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   7
   8 #include <linux/interrupt.h>
   9 #include <linux/irq.h>
  10 #include <linux/irqchip.h>
  11 #include <linux/irqchip/chained_irq.h>
  12 #include <linux/irqdomain.h>
  13 #include <linux/of_address.h>
  14 #include <linux/of_irq.h>
  15
  16 #define IDT_PIC_NR_IRQS         32
  17
  18 #define IDT_PIC_IRQ_PEND                0x00
  19 #define IDT_PIC_IRQ_MASK                0x08
  20
  21 struct idt_pic_data {
  22         void __iomem *base;
  23         struct irq_domain *irq_domain;
  24         struct irq_chip_generic *gc;
  25 };
  26
  27 static void idt_irq_dispatch(struct irq_desc *desc)
  28 {
  29         struct idt_pic_data *idtpic = irq_desc_get_handler_data(desc);
  30         struct irq_chip *host_chip = irq_desc_get_chip(desc);
  31         u32 pending, hwirq;
  32
  33         chained_irq_enter(host_chip, desc);
  34
  35         pending = irq_reg_readl(idtpic->gc, IDT_PIC_IRQ_PEND);
  36         pending &= ~idtpic->gc->mask_cache;
  37         while (pending) {
  38                 hwirq = __fls(pending);
  39                 generic_handle_domain_irq(idtpic->irq_domain, hwirq);
  40                 pending &= ~(1 << hwirq);
  41         }
  42
  43         chained_irq_exit(host_chip, desc);
  44 }
  45
  46 static int idt_pic_init(struct device_node *of_node, struct device_node *parent)
  47 {
  48         struct irq_domain *domain;
  49         struct idt_pic_data *idtpic;
  50         struct irq_chip_generic *gc;
  51         struct irq_chip_type *ct;
  52         unsigned int parent_irq;
  53         int ret = 0;
  54
  55         idtpic = kzalloc(sizeof(*idtpic), GFP_KERNEL);
  56         if (!idtpic) {
  57                 ret = -ENOMEM;
  58                 goto out_err;
  59         }
  60
  61         parent_irq = irq_of_parse_and_map(of_node, 0);
  62         if (!parent_irq) {
  63                 pr_err("Failed to map parent IRQ!\n");
  64                 ret = -EINVAL;
  65                 goto out_free;
  66         }
  67
  68         idtpic->base = of_iomap(of_node, 0);
  69         if (!idtpic->base) {
  70                 pr_err("Failed to map base address!\n");
  71                 ret = -ENOMEM;
  72                 goto out_unmap_irq;
  73         }
  74
  75         domain = irq_domain_add_linear(of_node, IDT_PIC_NR_IRQS,
  76                                        &irq_generic_chip_ops, NULL);
  77         if (!domain) {
  78                 pr_err("Failed to add irqdomain!\n");
  79                 ret = -ENOMEM;
  80                 goto out_iounmap;
  81         }
  82         idtpic->irq_domain = domain;
  83
  84         ret = irq_alloc_domain_generic_chips(domain, 32, 1, "IDTPIC",
  85                                              handle_level_irq, 0,
  86                                              IRQ_NOPROBE | IRQ_LEVEL, 0);
  87         if (ret)
  88                 goto out_domain_remove;
  89
  90         gc = irq_get_domain_generic_chip(domain, 0);
  91         gc->reg_base = idtpic->base;
  92         gc->private = idtpic;
  93
  94         ct = gc->chip_types;
  95         ct->regs.mask = IDT_PIC_IRQ_MASK;
  96         ct->chip.irq_mask = irq_gc_mask_set_bit;
  97         ct->chip.irq_unmask = irq_gc_mask_clr_bit;
  98         idtpic->gc = gc;
  99
 100         /* Mask interrupts. */
 101         writel(0xffffffff, idtpic->base + IDT_PIC_IRQ_MASK);
 102         gc->mask_cache = 0xffffffff;
 103
 104         irq_set_chained_handler_and_data(parent_irq,
 105                                          idt_irq_dispatch, idtpic);
 106
 107         return 0;
 108
 109 out_domain_remove:
 110         irq_domain_remove(domain);
 111 out_iounmap:
 112         iounmap(idtpic->base);
 113 out_unmap_irq:
 114         irq_dispose_mapping(parent_irq);
 115 out_free:
 116         kfree(idtpic);
 117 out_err:
 118         pr_err("Failed to initialize! (errno = %d)\n", ret);
 119         return ret;
 120 }
 121
 122 IRQCHIP_DECLARE(idt_pic, "idt,32434-pic", idt_pic_init);