/*
* arch/powerpc/sysdev/uic.c
*
* IBM PowerPC 4xx Universal Interrupt Controller
*
* Copyright 2007 David Gibson <dwg@au1.ibm.com>, IBM Corporation.
*
* 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.
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/reboot.h>
#include <linux/slab.h>
#include <linux/stddef.h>
#include <linux/sched.h>
#include <linux/signal.h>
#include <linux/sysdev.h>
#include <linux/device.h>
#include <linux/bootmem.h>
#include <linux/spinlock.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/kernel_stat.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <asm/prom.h>
#include <asm/dcr.h>
#define NR_UIC_INTS 32
#define UIC_SR 0x0
#define UIC_ER 0x2
#define UIC_CR 0x3
#define UIC_PR 0x4
#define UIC_TR 0x5
#define UIC_MSR 0x6
#define UIC_VR 0x7
#define UIC_VCR 0x8
#define uic_irq_to_hw(virq) (irq_map[virq].hwirq)
struct uic *primary_uic;
struct uic {
int index;
int dcrbase;
spinlock_t lock;
/* The remapper for this UIC */
struct irq_host *irqhost;
/* For secondary UICs, the cascade interrupt's irqaction */
struct irqaction cascade;
};
static void uic_unmask_irq(unsigned int virq)
{
struct uic *uic = get_irq_chip_data(virq);
unsigned int src = uic_irq_to_hw(virq);
unsigned long flags;
u32 er;
spin_lock_irqsave(&uic->lock, flags);
er = mfdcr(uic->dcrbase + UIC_ER);
er |= 1 << (31 - src);
mtdcr(uic->dcrbase + UIC_ER, er);
spin_unlock_irqrestore(&uic->lock, flags);
}
static void uic_mask_irq(unsigned int virq)
{
struct uic *uic = get_irq_chip_data(virq);
unsigned int src = uic_irq_to_hw(virq);
unsigned long flags;
u32 er;
spin_lock_irqsave(&uic->lock, flags);
er = mfdcr(uic->dcrbase + UIC_ER);
er &= ~(1 << (31 - src));
mtdcr(uic->dcrbase + UIC_ER, er);
spin_unlock_irqrestore(&uic->lock, flags);
}
static void uic_ack_irq(unsigned int virq)
{
struct uic *uic = get_irq_chip_data(virq);
unsigned int src = uic_irq_to_hw(virq);
unsigned long flags;
spin_lock_irqsave(&uic->lock, flags);
mtdcr(uic->dcrbase + UIC_SR, 1 << (31-src));
spin_unlock_irqrestore(&uic->lock, flags);
}
static int uic_set_irq_type(unsigned int virq, unsigned int flow_type)
{
struct uic *uic = get_irq_chip_data(virq);
unsigned int src = uic_irq_to_hw(virq);
struct irq_desc *desc = get_irq_desc(virq);
unsigned long flags;
int trigger, polarity;
u32 tr, pr, mask;
switch (flow_type & IRQ_TYPE_SENSE_MASK) {
case IRQ_TYPE_NONE:
uic_mask_irq(virq);
return 0;
case IRQ_TYPE_EDGE_RISING:
trigger = 1; polarity = 1;
break;
case IRQ_TYPE_EDGE_FALLING:
trigger = 1; polarity = 0;
break;
case IRQ_TYPE_LEVEL_HIGH:
trigger = 0; polarity = 1;
break;
case IRQ_TYPE_LEVEL_LOW:
trigger = 0; polarity = 0;
break;
default:
return -EINVAL;
}
mask = ~(1 << (31 - src));
spin_lock_irqsave(&uic->lock, flags);
tr = mfdcr(uic->dcrbase + UIC_TR);
pr = mfdcr(uic->dcrbase + UIC_PR);
tr = (tr & mask) | (trigger << (31-src));
pr = (pr & mask) | (polarity << (31-src));
mtdcr(uic->dcrbase + UIC_PR, pr);
mtdcr(uic->dcrbase + UIC_TR, tr);
desc->status &= ~(IRQ_TYPE_SENSE_MASK | IRQ_LEVEL);
desc->status |= flow_type & IRQ_TYPE_SENSE_MASK;
if (!trigger)
desc->status |= IRQ_LEVEL;
spin_unlock_irqrestore(&uic->lock, flags);
return 0;
}
static struct irq_chip uic_irq_chip = {
.typename = " UIC ",
.unmask = uic_unmask_irq,
.mask = uic_mask_irq,
/* .mask_ack = uic_mask_irq_and_ack, */
.ack = uic_ack_irq,
.set_type = uic_set_irq_type,
};
/**
* handle_uic_irq - irq flow handler for UIC
* @irq: the interrupt number
* @desc: the interrupt description structure for this irq
*
* This is modified version of the generic handle_level_irq() suitable
* for the UIC. On the UIC, acking (i.e. clearing the SR bit) a level
* irq will have no effect if the interrupt is still asserted by the
* device, even if the interrupt is already masked. Therefore, unlike
* the standard handle_level_irq(), we must ack the interrupt *after*
* invoking the ISR (which should have de-asserted the interrupt in
* the external source). For edge interrupts we ack at the beginning
* instead of the end, to keep the window in which we can miss an
* interrupt as small as possible.
*/
void fastcall handle_uic_irq(unsigned int irq, struct irq_desc *desc)
{
unsigned int cpu = smp_processor_id();
struct irqaction *action;
irqreturn_t action_ret;
spin_lock(&desc->lock);
if (desc->status & IRQ_LEVEL)
desc->chip->mask(irq);
else
desc->chip->mask_ack(irq);
if (unlikely(desc->status & IRQ_INPROGRESS))
goto out_unlock;
desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
kstat_cpu(cpu).irqs[irq]++;
/*
* If its disabled or no action available
* keep it masked and get out of here
*/
action = desc->action;
if (unlikely(!action || (desc->status & IRQ_DISABLED))) {
desc->status |= IRQ_PENDING;
goto out_unlock;
}
desc->status |= IRQ_INPROGRESS;
desc->status &= ~IRQ_PENDING;
spin_unlock(&desc->lock);
action_ret = handle_IRQ_event(irq, action);
spin_lock(&desc->lock);
desc->status &= ~IRQ_INPROGRESS;
if (desc->status & IRQ_LEVEL)
desc->chip->ack(irq);
if (!(desc->status & IRQ_DISABLED) && desc->chip->unmask)
desc->chip->unmask(irq);
out_unlock:
spin_unlock(&desc->lock);
}
static int uic_host_match(struct irq_host *h, struct device_node *node)
{
return h->of_node == node;
}
static int uic_host_map(struct irq_host *h, unsigned int virq,
irq_hw_number_t hw)
{
struct uic *uic = h->host_data;
set_irq_chip_data(virq, uic);
/* Despite the name, handle_level_irq() works for both level
* and edge irqs on UIC. FIXME: check this is correct */
set_irq_chip_and_handler(virq, &uic_irq_chip, handle_uic_irq);
/* Set default irq type */
set_irq_type(virq, IRQ_TYPE_NONE);
return 0;
}
static int uic_host_xlate(struct irq_host *h, struct device_node *ct,
u32 *intspec, unsigned int intsize,
irq_hw_number_t *out_hwirq, unsigned int *out_type)
{
/* UIC intspecs must have 2 cells */
BUG_ON(intsize != 2);
*out_hwirq = intspec[0];
*out_type = intspec[1];
return 0;
}
static struct irq_host_ops uic_host_ops = {
.match = uic_host_match,
.map = uic_host_map,
.xlate = uic_host_xlate,
};
irqreturn_t uic_cascade(int virq, void *data)
{
struct uic *uic = data;
u32 msr;
int src;
int subvirq;
msr = mfdcr(uic->dcrbase + UIC_MSR);
if (!msr) /* spurious interrupt */
return IRQ_HANDLED;
src = 32 - ffs(msr);
subvirq = irq_linear_revmap(uic->irqhost, src);
generic_handle_irq(subvirq);
return IRQ_HANDLED;
}
static struct uic * __init uic_init_one(struct device_node *node)
{
struct uic *uic;
const u32 *indexp, *dcrreg;
int len;
BUG_ON(! of_device_is_compatible(node, "ibm,uic"));
uic = alloc_bootmem(sizeof(*uic));
if (! uic)
return NULL; /* FIXME: panic? */
memset(uic, 0, sizeof(*uic));
spin_lock_init(&uic->lock);
indexp = of_get_property(node, "cell-index", &len);
if (!indexp || (len != sizeof(u32))) {
printk(KERN_ERR "uic: Device node %s has missing or invalid "
"cell-index property\n", node->full_name);
return NULL;
}
uic->index = *indexp;
dcrreg = of_get_property(node, "dcr-reg", &len);
if (!dcrreg || (len != 2*sizeof(u32))) {
printk(KERN_ERR "uic: Device node %s has missing or invalid "
"dcr-reg property\n", node->full_name);
return NULL;
}
uic->dcrbase = *dcrreg;
uic->irqhost = irq_alloc_host(of_node_get(node), IRQ_HOST_MAP_LINEAR,
NR_UIC_INTS, &uic_host_ops, -1);
if (! uic->irqhost) {
of_node_put(node);
return NULL; /* FIXME: panic? */
}
uic->irqhost->host_data = uic;
/* Start with all interrupts disabled, level and non-critical */
mtdcr(uic->dcrbase + UIC_ER, 0);
mtdcr(uic->dcrbase + UIC_CR, 0);
mtdcr(uic->dcrbase + UIC_TR, 0);
/* Clear any pending interrupts, in case the firmware left some */
mtdcr(uic->dcrbase + UIC_SR, 0xffffffff);
printk ("UIC%d (%d IRQ sources) at DCR 0x%x\n", uic->index,
NR_UIC_INTS, uic->dcrbase);
return uic;
}
void __init uic_init_tree(void)
{
struct device_node *np;
struct uic *uic;
const u32 *interrupts;
/* First locate and initialize the top-level UIC */
np = of_find_compatible_node(NULL, NULL, "ibm,uic");
while (np) {
interrupts = of_get_property(np, "interrupts", NULL);
if (! interrupts)
break;
np = of_find_compatible_node(np, NULL, "ibm,uic");
}
BUG_ON(!np); /* uic_init_tree() assumes there's a UIC as the
* top-level interrupt controller */
primary_uic = uic_init_one(np);
if (! primary_uic)
panic("Unable to initialize primary UIC %s\n", np->full_name);
irq_set_default_host(primary_uic->irqhost);
of_node_put(np);
/* The scan again for cascaded UICs */
np = of_find_compatible_node(NULL, NULL, "ibm,uic");
while (np) {
interrupts = of_get_property(np, "interrupts", NULL);
if (interrupts) {
/* Secondary UIC */
int cascade_virq;
int ret;
uic = uic_init_one(np);
if (! uic)
panic("Unable to initialize a secondary UIC %s\n",
np->full_name);
cascade_virq = irq_of_parse_and_map(np, 0);
uic->cascade.handler = uic_cascade;
uic->cascade.name = "UIC cascade";
uic->cascade.dev_id = uic;
ret = setup_irq(cascade_virq, &uic->cascade);
if (ret)
printk(KERN_ERR "Failed to setup_irq(%d) for "
"UIC%d cascade\n", cascade_virq,
uic->index);
/* FIXME: setup critical cascade?? */
}
np = of_find_compatible_node(np, NULL, "ibm,uic");
}
}
/* Return an interrupt vector or NO_IRQ if no interrupt is pending. */
unsigned int uic_get_irq(void)
{
u32 msr;
int src;
BUG_ON(! primary_uic);
msr = mfdcr(primary_uic->dcrbase + UIC_MSR);
src = 32 - ffs(msr);
return irq_linear_revmap(primary_uic->irqhost, src);
}
