drivers/irqchip/irq-idt3243x.c

Source file repositories/reference/linux-study-clean/drivers/irqchip/irq-idt3243x.c

File Facts

System
Linux kernel
Corpus path
drivers/irqchip/irq-idt3243x.c
Extension
.c
Size
2842 bytes
Lines
123
Domain
Driver Families
Bucket
drivers/irqchip
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

struct idt_pic_data {
	void __iomem *base;
	struct irq_domain *irq_domain;
	struct irq_chip_generic *gc;
};

static void idt_irq_dispatch(struct irq_desc *desc)
{
	struct idt_pic_data *idtpic = irq_desc_get_handler_data(desc);
	struct irq_chip *host_chip = irq_desc_get_chip(desc);
	u32 pending, hwirq;

	chained_irq_enter(host_chip, desc);

	pending = irq_reg_readl(idtpic->gc, IDT_PIC_IRQ_PEND);
	pending &= ~idtpic->gc->mask_cache;
	while (pending) {
		hwirq = __fls(pending);
		generic_handle_domain_irq(idtpic->irq_domain, hwirq);
		pending &= ~(1 << hwirq);
	}

	chained_irq_exit(host_chip, desc);
}

static int idt_pic_init(struct device_node *of_node, struct device_node *parent)
{
	struct irq_domain *domain;
	struct idt_pic_data *idtpic;
	struct irq_chip_generic *gc;
	struct irq_chip_type *ct;
	unsigned int parent_irq;
	int ret = 0;

	idtpic = kzalloc_obj(*idtpic);
	if (!idtpic) {
		ret = -ENOMEM;
		goto out_err;
	}

	parent_irq = irq_of_parse_and_map(of_node, 0);
	if (!parent_irq) {
		pr_err("Failed to map parent IRQ!\n");
		ret = -EINVAL;
		goto out_free;
	}

	idtpic->base = of_iomap(of_node, 0);
	if (!idtpic->base) {
		pr_err("Failed to map base address!\n");
		ret = -ENOMEM;
		goto out_unmap_irq;
	}

	domain = irq_domain_create_linear(of_fwnode_handle(of_node), IDT_PIC_NR_IRQS,
				       &irq_generic_chip_ops, NULL);
	if (!domain) {
		pr_err("Failed to add irqdomain!\n");
		ret = -ENOMEM;
		goto out_iounmap;
	}
	idtpic->irq_domain = domain;

	ret = irq_alloc_domain_generic_chips(domain, 32, 1, "IDTPIC",
					     handle_level_irq, 0,
					     IRQ_NOPROBE | IRQ_LEVEL, 0);
	if (ret)
		goto out_domain_remove;

	gc = irq_get_domain_generic_chip(domain, 0);
	gc->reg_base = idtpic->base;
	gc->private = idtpic;

	ct = gc->chip_types;
	ct->regs.mask = IDT_PIC_IRQ_MASK;
	ct->chip.irq_mask = irq_gc_mask_set_bit;
	ct->chip.irq_unmask = irq_gc_mask_clr_bit;
	idtpic->gc = gc;

	/* Mask interrupts. */
	writel(0xffffffff, idtpic->base + IDT_PIC_IRQ_MASK);
	gc->mask_cache = 0xffffffff;

	irq_set_chained_handler_and_data(parent_irq,
					 idt_irq_dispatch, idtpic);

	return 0;

out_domain_remove:
	irq_domain_remove(domain);

Annotation

Implementation Notes