arch/powerpc/platforms/embedded6xx/flipper-pic.c

Source file repositories/reference/linux-study-clean/arch/powerpc/platforms/embedded6xx/flipper-pic.c

File Facts

System
Linux kernel
Corpus path
arch/powerpc/platforms/embedded6xx/flipper-pic.c
Extension
.c
Size
5255 bytes
Lines
246
Domain
Architecture Layer
Bucket
arch/powerpc
Inferred role
Architecture Layer: implementation source
Status
source implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * arch/powerpc/platforms/embedded6xx/flipper-pic.c
 *
 * Nintendo GameCube/Wii "Flipper" interrupt controller support.
 * Copyright (C) 2004-2009 The GameCube Linux Team
 * Copyright (C) 2007,2008,2009 Albert Herranz
 */
#define DRV_MODULE_NAME "flipper-pic"
#define pr_fmt(fmt) DRV_MODULE_NAME ": " fmt

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/irqdomain.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <asm/io.h>

#include "flipper-pic.h"

#define FLIPPER_NR_IRQS		32

/*
 * Each interrupt has a corresponding bit in both
 * the Interrupt Cause (ICR) and Interrupt Mask (IMR) registers.
 *
 * Enabling/disabling an interrupt line involves setting/clearing
 * the corresponding bit in IMR.
 * Except for the RSW interrupt, all interrupts get deasserted automatically
 * when the source deasserts the interrupt.
 */
#define FLIPPER_ICR		0x00
#define FLIPPER_ICR_RSS		(1<<16) /* reset switch state */

#define FLIPPER_IMR		0x04

#define FLIPPER_RESET		0x24


/*
 * IRQ chip hooks.
 *
 */

static void flipper_pic_mask_and_ack(struct irq_data *d)
{
	int irq = irqd_to_hwirq(d);
	void __iomem *io_base = irq_data_get_irq_chip_data(d);
	u32 mask = 1 << irq;

	clrbits32(io_base + FLIPPER_IMR, mask);
	/* this is at least needed for RSW */
	out_be32(io_base + FLIPPER_ICR, mask);
}

static void flipper_pic_ack(struct irq_data *d)
{
	int irq = irqd_to_hwirq(d);
	void __iomem *io_base = irq_data_get_irq_chip_data(d);

	/* this is at least needed for RSW */
	out_be32(io_base + FLIPPER_ICR, 1 << irq);
}

static void flipper_pic_mask(struct irq_data *d)
{
	int irq = irqd_to_hwirq(d);
	void __iomem *io_base = irq_data_get_irq_chip_data(d);

	clrbits32(io_base + FLIPPER_IMR, 1 << irq);
}

static void flipper_pic_unmask(struct irq_data *d)
{
	int irq = irqd_to_hwirq(d);
	void __iomem *io_base = irq_data_get_irq_chip_data(d);

	setbits32(io_base + FLIPPER_IMR, 1 << irq);
}


static struct irq_chip flipper_pic = {
	.name		= "flipper-pic",
	.irq_ack	= flipper_pic_ack,
	.irq_mask_ack	= flipper_pic_mask_and_ack,
	.irq_mask	= flipper_pic_mask,
	.irq_unmask	= flipper_pic_unmask,
};

Annotation

Implementation Notes