/*
* 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
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
*/
#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/of.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(unsigned int virq)
{
int irq = virq_to_hw(virq);
void __iomem *io_base = get_irq_chip_data(virq);
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(unsigned int virq)
{
int irq = virq_to_hw(virq);
void __iomem *io_base = get_irq_chip_data(virq);
/* this is at least needed for RSW */
out_be32(io_base + FLIPPER_ICR, 1 << irq);
}
static void flipper_pic_mask(unsigned int virq)
{
int irq = virq_to_hw(virq);
void __iomem *io_base = get_irq_chip_data(virq);
clrbits32(io_base + FLIPPER_IMR, 1 << irq);
}
static void flipper_pic_unmask(unsigned int virq)
{
int irq = virq_to_hw(virq);
void __iomem *io_base = get_irq_chip_data(virq);
setbits32(io_base + FLIPPER_IMR, 1 << irq);
}
static struct irq_chip flipper_pic = {
.name = "flipper-pic",
.ack = flipper_pic_ack,
.mask_ack = flipper_pic_mask_and_ack,
.mask = flipper_pic_mask,
.unmask = flipper_pic_unmask,
};
/*
* IRQ host hooks.
*
*/
static struct irq_host *flipper_irq_host;
static int flipper_pic_map(struct irq_host *h, unsigned int virq,
irq_hw_number_t hwirq)
{
set_irq_chip_data(virq, h->host_data);
irq_to_desc(virq)->status |= IRQ_LEVEL;
set_irq_chip_and_handler(virq, &flipper_pic, handle_level_irq);
return 0;
}
static void flipper_pic_unmap(struct irq_host *h, unsigned int irq)
{
set_irq_chip_data(irq, NULL);
set_irq_chip(irq, NULL);
}
static int flipper_pic_match(struct irq_host *h, struct device_node *np)
{
return 1;
}
static struct irq_host_ops flipper_irq_host_ops = {
.map = flipper_pic_map,
.unmap = flipper_pic_unmap,
.match = flipper_pic_match,
};
/*
* Platform hooks.
*
*/
static void __flipper_quiesce(void __iomem *io_base)
{
/* mask and ack all IRQs */
out_be32(io_base + FLIPPER_IMR, 0x00000000);
out_be32(io_base + FLIPPER_ICR, 0xffffffff);
}
struct irq_host * __init flipper_pic_init(struct device_node *np)
{
struct device_node *pi;
struct irq_host *irq_host = NULL;
struct resource res;
void __iomem *io_base;
int retval;
pi = of_get_parent(np);
if (!pi) {
pr_err("no parent found\n");
goto out;
}
if (!of_device_is_compatible(pi, "nintendo,flipper-pi")) {
pr_err("unexpected parent compatible\n");
goto out;
}
retval = of_address_to_resource(pi, 0, &res);
if (retval) {
pr_err("no io memory range found\n");
goto out;
}
io_base = ioremap(res.start, resource_size(&res));
pr_info("controller at 0x%08x mapped to 0x%p\n", res.start, io_base);
__flipper_quiesce(io_base);
irq_host = irq_alloc_host(np, IRQ_HOST_MAP_LINEAR, FLIPPER_NR_IRQS,
&flipper_irq_host_ops, -1);
if (!irq_host) {
pr_err("failed to allocate irq_host\n");
return NULL;
}
irq_host->host_data = io_base;
out:
return irq_host;
}
unsigned int flipper_pic_get_irq(void)
{
void __iomem *io_base = flipper_irq_host->host_data;
int irq;
u32 irq_status;
irq_status = in_be32(io_base + FLIPPER_ICR) &
in_be32(io_base + FLIPPER_IMR);
if (irq_status == 0)
return NO_IRQ; /* no more IRQs pending */
irq = __ffs(irq_status);
return irq_linear_revmap(flipper_irq_host, irq);
}
/*
* Probe function.
*
*/
void __init flipper_pic_probe(void)
{
struct device_node *np;
np = of_find_compatible_node(NULL, NULL, "nintendo,flipper-pic");
BUG_ON(!np);
flipper_irq_host = flipper_pic_init(np);
BUG_ON(!flipper_irq_host);
irq_set_default_host(flipper_irq_host);
of_node_put(np);
}
/*
* Misc functions related to the flipper chipset.
*
*/
/**
* flipper_quiesce() - quiesce flipper irq controller
*
* Mask and ack all interrupt sources.
*
*/
void flipper_quiesce(void)
{
void __iomem *io_base = flipper_irq_host->host_data;
__flipper_quiesce(io_base);
}
/*
* Resets the platform.
*/
void flipper_platform_reset(void)
{
void __iomem *io_base;
if (flipper_irq_host && flipper_irq_host->host_data) {
io_base = flipper_irq_host->host_data;
out_8(io_base + FLIPPER_RESET, 0x00);
}
}
/*
* Returns non-zero if the reset button is pressed.
*/
int flipper_is_reset_button_pressed(void)
{
void __iomem *io_base;
u32 icr;
if (flipper_irq_host && flipper_irq_host->host_data) {
io_base = flipper_irq_host->host_data;
icr = in_be32(io_base + FLIPPER_ICR);
return !(icr & FLIPPER_ICR_RSS);
}
return 0;
}
