linux/arch/powerpc/platforms/embedded6xx/hlwd-pic.c

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/*
* arch/powerpc/platforms/embedded6xx/hlwd-pic.c
*
* Nintendo Wii "Hollywood" interrupt controller support.
* Copyright (C) 2009 The GameCube Linux Team
* Copyright (C) 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 "hlwd-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 "hlwd-pic.h"
#define HLWD_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 asserting/clearing
* the corresponding bit in IMR. ACK'ing a request simply involves
* asserting the corresponding bit in ICR.
*/
#define HW_BROADWAY_ICR 0x00
#define HW_BROADWAY_IMR 0x04
/*
* IRQ chip hooks.
*
*/
static void hlwd_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 + HW_BROADWAY_IMR, mask);
out_be32(io_base + HW_BROADWAY_ICR, mask);
}
static void hlwd_pic_ack(unsigned int virq)
{
int irq = virq_to_hw(virq);
void __iomem *io_base = get_irq_chip_data(virq);
out_be32(io_base + HW_BROADWAY_ICR, 1 << irq);
}
static void hlwd_pic_mask(unsigned int virq)
{
int irq = virq_to_hw(virq);
void __iomem *io_base = get_irq_chip_data(virq);
clrbits32(io_base + HW_BROADWAY_IMR, 1 << irq);
}
static void hlwd_pic_unmask(unsigned int virq)
{
int irq = virq_to_hw(virq);
void __iomem *io_base = get_irq_chip_data(virq);
setbits32(io_base + HW_BROADWAY_IMR, 1 << irq);
}
static struct irq_chip hlwd_pic = {
.name = "hlwd-pic",
.ack = hlwd_pic_ack,
.mask_ack = hlwd_pic_mask_and_ack,
.mask = hlwd_pic_mask,
.unmask = hlwd_pic_unmask,
};
/*
* IRQ host hooks.
*
*/
static struct irq_host *hlwd_irq_host;
static int hlwd_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, &hlwd_pic, handle_level_irq);
return 0;
}
static void hlwd_pic_unmap(struct irq_host *h, unsigned int irq)
{
set_irq_chip_data(irq, NULL);
set_irq_chip(irq, NULL);
}
static struct irq_host_ops hlwd_irq_host_ops = {
.map = hlwd_pic_map,
.unmap = hlwd_pic_unmap,
};
static unsigned int __hlwd_pic_get_irq(struct irq_host *h)
{
void __iomem *io_base = h->host_data;
int irq;
u32 irq_status;
irq_status = in_be32(io_base + HW_BROADWAY_ICR) &
in_be32(io_base + HW_BROADWAY_IMR);
if (irq_status == 0)
return NO_IRQ; /* no more IRQs pending */
irq = __ffs(irq_status);
return irq_linear_revmap(h, irq);
}
static void hlwd_pic_irq_cascade(unsigned int cascade_virq,
struct irq_desc *desc)
{
struct irq_host *irq_host = get_irq_data(cascade_virq);
unsigned int virq;
raw_spin_lock(&desc->lock);
desc->chip->mask(cascade_virq); /* IRQ_LEVEL */
raw_spin_unlock(&desc->lock);
virq = __hlwd_pic_get_irq(irq_host);
if (virq != NO_IRQ)
generic_handle_irq(virq);
else
pr_err("spurious interrupt!\n");
raw_spin_lock(&desc->lock);
desc->chip->ack(cascade_virq); /* IRQ_LEVEL */
if (!(desc->status & IRQ_DISABLED) && desc->chip->unmask)
desc->chip->unmask(cascade_virq);
raw_spin_unlock(&desc->lock);
}
/*
* Platform hooks.
*
*/
static void __hlwd_quiesce(void __iomem *io_base)
{
/* mask and ack all IRQs */
out_be32(io_base + HW_BROADWAY_IMR, 0);
out_be32(io_base + HW_BROADWAY_ICR, 0xffffffff);
}
struct irq_host *hlwd_pic_init(struct device_node *np)
{
struct irq_host *irq_host;
struct resource res;
void __iomem *io_base;
int retval;
retval = of_address_to_resource(np, 0, &res);
if (retval) {
pr_err("no io memory range found\n");
return NULL;
}
io_base = ioremap(res.start, resource_size(&res));
if (!io_base) {
pr_err("ioremap failed\n");
return NULL;
}
pr_info("controller at 0x%08x mapped to 0x%p\n", res.start, io_base);
__hlwd_quiesce(io_base);
irq_host = irq_alloc_host(np, IRQ_HOST_MAP_LINEAR, HLWD_NR_IRQS,
&hlwd_irq_host_ops, -1);
if (!irq_host) {
pr_err("failed to allocate irq_host\n");
return NULL;
}
irq_host->host_data = io_base;
return irq_host;
}
unsigned int hlwd_pic_get_irq(void)
{
return __hlwd_pic_get_irq(hlwd_irq_host);
}
/*
* Probe function.
*
*/
void hlwd_pic_probe(void)
{
struct irq_host *host;
struct device_node *np;
const u32 *interrupts;
int cascade_virq;
for_each_compatible_node(np, NULL, "nintendo,hollywood-pic") {
interrupts = of_get_property(np, "interrupts", NULL);
if (interrupts) {
host = hlwd_pic_init(np);
BUG_ON(!host);
cascade_virq = irq_of_parse_and_map(np, 0);
set_irq_data(cascade_virq, host);
set_irq_chained_handler(cascade_virq,
hlwd_pic_irq_cascade);
hlwd_irq_host = host;
break;
}
}
}
/**
* hlwd_quiesce() - quiesce hollywood irq controller
*
* Mask and ack all interrupt sources.
*
*/
void hlwd_quiesce(void)
{
void __iomem *io_base = hlwd_irq_host->host_data;
__hlwd_quiesce(io_base);
}