drivers/irqchip/irq-zevio.c

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

File Facts

System
Linux kernel
Corpus path
drivers/irqchip/irq-zevio.c
Extension
.c
Size
3249 bytes
Lines
121
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

// SPDX-License-Identifier: GPL-2.0-only
/*
 *  linux/drivers/irqchip/irq-zevio.c
 *
 *  Copyright (C) 2013 Daniel Tang <tangrs@tangrs.id.au>
 */

#include <linux/io.h>
#include <linux/irq.h>
#include <linux/irqchip.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>

#include <asm/mach/irq.h>
#include <asm/exception.h>

#define IO_STATUS	0x000
#define IO_RAW_STATUS	0x004
#define IO_ENABLE	0x008
#define IO_DISABLE	0x00C
#define IO_CURRENT	0x020
#define IO_RESET	0x028
#define IO_MAX_PRIOTY	0x02C

#define IO_IRQ_BASE	0x000
#define IO_FIQ_BASE	0x100

#define IO_INVERT_SEL	0x200
#define IO_STICKY_SEL	0x204
#define IO_PRIORITY_SEL	0x300

#define MAX_INTRS	32
#define FIQ_START	MAX_INTRS

static struct irq_domain *zevio_irq_domain;
static void __iomem *zevio_irq_io;

static void zevio_irq_ack(struct irq_data *irqd)
{
	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(irqd);
	struct irq_chip_regs *regs = &irq_data_get_chip_type(irqd)->regs;

	readl(gc->reg_base + regs->ack);
}

static void __exception_irq_entry zevio_handle_irq(struct pt_regs *regs)
{
	int irqnr;

	while (readl(zevio_irq_io + IO_STATUS)) {
		irqnr = readl(zevio_irq_io + IO_CURRENT);
		generic_handle_domain_irq(zevio_irq_domain, irqnr);
	}
}

static void __init zevio_init_irq_base(void __iomem *base)
{
	/* Disable all interrupts */
	writel(~0, base + IO_DISABLE);

	/* Accept interrupts of all priorities */
	writel(0xF, base + IO_MAX_PRIOTY);

	/* Reset existing interrupts */
	readl(base + IO_RESET);
}

static int __init zevio_of_init(struct device_node *node,
				struct device_node *parent)
{
	unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
	struct irq_chip_generic *gc;
	int ret;

	if (WARN_ON(zevio_irq_io || zevio_irq_domain))
		return -EBUSY;

	zevio_irq_io = of_iomap(node, 0);
	BUG_ON(!zevio_irq_io);

	/* Do not invert interrupt status bits */
	writel(~0, zevio_irq_io + IO_INVERT_SEL);

	/* Disable sticky interrupts */
	writel(0, zevio_irq_io + IO_STICKY_SEL);

	/* We don't use IRQ priorities. Set each IRQ to highest priority. */
	memset_io(zevio_irq_io + IO_PRIORITY_SEL, 0, MAX_INTRS * sizeof(u32));

Annotation

Implementation Notes