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

236 lines
5.2 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* 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
*/
#define DRV_MODULE_NAME "hlwd-pic"
#define pr_fmt(fmt) DRV_MODULE_NAME ": " fmt
#include <linux/kernel.h>
#include <linux/irq.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.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
#define HW_STARLET_ICR 0x08
#define HW_STARLET_IMR 0x0c
/*
* IRQ chip hooks.
*
*/
static void hlwd_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 + HW_BROADWAY_IMR, mask);
out_be32(io_base + HW_BROADWAY_ICR, mask);
}
static void hlwd_pic_ack(struct irq_data *d)
{
int irq = irqd_to_hwirq(d);
void __iomem *io_base = irq_data_get_irq_chip_data(d);
out_be32(io_base + HW_BROADWAY_ICR, 1 << irq);
}
static void hlwd_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 + HW_BROADWAY_IMR, 1 << irq);
}
static void hlwd_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 + HW_BROADWAY_IMR, 1 << irq);
/* Make sure the ARM (aka. Starlet) doesn't handle this interrupt. */
clrbits32(io_base + HW_STARLET_IMR, 1 << irq);
}
static struct irq_chip hlwd_pic = {
.name = "hlwd-pic",
.irq_ack = hlwd_pic_ack,
.irq_mask_ack = hlwd_pic_mask_and_ack,
.irq_mask = hlwd_pic_mask,
.irq_unmask = hlwd_pic_unmask,
};
/*
* IRQ host hooks.
*
*/
static struct irq_domain *hlwd_irq_host;
static int hlwd_pic_map(struct irq_domain *h, unsigned int virq,
irq_hw_number_t hwirq)
{
irq_set_chip_data(virq, h->host_data);
irq_set_status_flags(virq, IRQ_LEVEL);
irq_set_chip_and_handler(virq, &hlwd_pic, handle_level_irq);
return 0;
}
static const struct irq_domain_ops hlwd_irq_domain_ops = {
.map = hlwd_pic_map,
};
static unsigned int __hlwd_pic_get_irq(struct irq_domain *h)
{
void __iomem *io_base = h->host_data;
u32 irq_status;
irq_status = in_be32(io_base + HW_BROADWAY_ICR) &
in_be32(io_base + HW_BROADWAY_IMR);
if (irq_status == 0)
return 0; /* no more IRQs pending */
return __ffs(irq_status);
}
static void hlwd_pic_irq_cascade(struct irq_desc *desc)
{
struct irq_chip *chip = irq_desc_get_chip(desc);
struct irq_domain *irq_domain = irq_desc_get_handler_data(desc);
unsigned int hwirq;
raw_spin_lock(&desc->lock);
chip->irq_mask(&desc->irq_data); /* IRQ_LEVEL */
raw_spin_unlock(&desc->lock);
hwirq = __hlwd_pic_get_irq(irq_domain);
if (hwirq)
generic_handle_domain_irq(irq_domain, hwirq);
else
pr_err("spurious interrupt!\n");
raw_spin_lock(&desc->lock);
chip->irq_ack(&desc->irq_data); /* IRQ_LEVEL */
if (!irqd_irq_disabled(&desc->irq_data) && chip->irq_unmask)
chip->irq_unmask(&desc->irq_data);
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);
}
static struct irq_domain *__init hlwd_pic_init(struct device_node *np)
{
struct irq_domain *irq_domain;
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%pa mapped to 0x%p\n", &res.start, io_base);
__hlwd_quiesce(io_base);
irq_domain = irq_domain_add_linear(np, HLWD_NR_IRQS,
&hlwd_irq_domain_ops, io_base);
if (!irq_domain) {
pr_err("failed to allocate irq_domain\n");
iounmap(io_base);
return NULL;
}
return irq_domain;
}
unsigned int hlwd_pic_get_irq(void)
{
unsigned int hwirq = __hlwd_pic_get_irq(hlwd_irq_host);
return hwirq ? irq_linear_revmap(hlwd_irq_host, hwirq) : 0;
}
/*
* Probe function.
*
*/
void __init hlwd_pic_probe(void)
{
struct irq_domain *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);
irq_set_handler_data(cascade_virq, host);
irq_set_chained_handler(cascade_virq,
hlwd_pic_irq_cascade);
hlwd_irq_host = host;
of_node_put(np);
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);
}