/*
* PQ2 ADS-style PCI interrupt controller
*
* Copyright 2007 Freescale Semiconductor, Inc.
* Author: Scott Wood <scottwood@freescale.com>
*
* Loosely based on mpc82xx ADS support by Vitaly Bordug <vbordug@ru.mvista.com>
* Copyright (c) 2006 MontaVista Software, Inc.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published
* by the Free Software Foundation.
*/
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/irq.h>
#include <linux/types.h>
#include <linux/bootmem.h>
#include <asm/io.h>
#include <asm/prom.h>
#include <asm/cpm2.h>
#include "pq2.h"
static DEFINE_SPINLOCK(pci_pic_lock);
struct pq2ads_pci_pic {
struct device_node *node;
struct irq_host *host;
struct {
u32 stat;
u32 mask;
} __iomem *regs;
};
#define NUM_IRQS 32
static void pq2ads_pci_mask_irq(unsigned int virq)
{
struct pq2ads_pci_pic *priv = get_irq_chip_data(virq);
int irq = NUM_IRQS - virq_to_hw(virq) - 1;
if (irq != -1) {
unsigned long flags;
spin_lock_irqsave(&pci_pic_lock, flags);
setbits32(&priv->regs->mask, 1 << irq);
mb();
spin_unlock_irqrestore(&pci_pic_lock, flags);
}
}
static void pq2ads_pci_unmask_irq(unsigned int virq)
{
struct pq2ads_pci_pic *priv = get_irq_chip_data(virq);
int irq = NUM_IRQS - virq_to_hw(virq) - 1;
if (irq != -1) {
unsigned long flags;
spin_lock_irqsave(&pci_pic_lock, flags);
clrbits32(&priv->regs->mask, 1 << irq);
spin_unlock_irqrestore(&pci_pic_lock, flags);
}
}
static struct irq_chip pq2ads_pci_ic = {
.typename = "PQ2 ADS PCI",
.name = "PQ2 ADS PCI",
.end = pq2ads_pci_unmask_irq,
.mask = pq2ads_pci_mask_irq,
.mask_ack = pq2ads_pci_mask_irq,
.ack = pq2ads_pci_mask_irq,
.unmask = pq2ads_pci_unmask_irq,
.enable = pq2ads_pci_unmask_irq,
.disable = pq2ads_pci_mask_irq
};
static void pq2ads_pci_irq_demux(unsigned int irq, struct irq_desc *desc)
{
struct pq2ads_pci_pic *priv = desc->handler_data;
u32 stat, mask, pend;
int bit;
for (;;) {
stat = in_be32(&priv->regs->stat);
mask = in_be32(&priv->regs->mask);
pend = stat & ~mask;
if (!pend)
break;
for (bit = 0; pend != 0; ++bit, pend <<= 1) {
if (pend & 0x80000000) {
int virq = irq_linear_revmap(priv->host, bit);
generic_handle_irq(virq);
}
}
}
}
static int pci_pic_host_map(struct irq_host *h, unsigned int virq,
irq_hw_number_t hw)
{
get_irq_desc(virq)->status |= IRQ_LEVEL;
set_irq_chip_data(virq, h->host_data);
set_irq_chip(virq, &pq2ads_pci_ic);
return 0;
}
static void pci_host_unmap(struct irq_host *h, unsigned int virq)
{
/* remove chip and handler */
set_irq_chip_data(virq, NULL);
set_irq_chip(virq, NULL);
}
static struct irq_host_ops pci_pic_host_ops = {
.map = pci_pic_host_map,
.unmap = pci_host_unmap,
};
int __init pq2ads_pci_init_irq(void)
{
struct pq2ads_pci_pic *priv;
struct irq_host *host;
struct device_node *np;
int ret = -ENODEV;
int irq;
np = of_find_compatible_node(NULL, NULL, "fsl,pq2ads-pci-pic");
if (!np) {
printk(KERN_ERR "No pci pic node in device tree.\n");
of_node_put(np);
goto out;
}
irq = irq_of_parse_and_map(np, 0);
if (irq == NO_IRQ) {
printk(KERN_ERR "No interrupt in pci pic node.\n");
of_node_put(np);
goto out;
}
priv = alloc_bootmem(sizeof(struct pq2ads_pci_pic));
if (!priv) {
of_node_put(np);
ret = -ENOMEM;
goto out_unmap_irq;
}
/* PCI interrupt controller registers: status and mask */
priv->regs = of_iomap(np, 0);
if (!priv->regs) {
printk(KERN_ERR "Cannot map PCI PIC registers.\n");
goto out_free_bootmem;
}
/* mask all PCI interrupts */
out_be32(&priv->regs->mask, ~0);
mb();
host = irq_alloc_host(np, IRQ_HOST_MAP_LINEAR, NUM_IRQS,
&pci_pic_host_ops, NUM_IRQS);
if (!host) {
ret = -ENOMEM;
goto out_unmap_regs;
}
host->host_data = priv;
priv->host = host;
host->host_data = priv;
set_irq_data(irq, priv);
set_irq_chained_handler(irq, pq2ads_pci_irq_demux);
of_node_put(np);
return 0;
out_unmap_regs:
iounmap(priv->regs);
out_free_bootmem:
free_bootmem((unsigned long)priv,
sizeof(sizeof(struct pq2ads_pci_pic)));
of_node_put(np);
out_unmap_irq:
irq_dispose_mapping(irq);
out:
return ret;
}
