linux/arch/microblaze/kernel/intc.c
John Williams 892ee92b81 microblaze: Sane handling of missing timer/intc in device tree
This code path doesn't test any returned pointers for NULL, leading to a bad
kernel page fault if there's no timer/intc found.

Slightly better is to BUG(), but even better still would be a printk beforehand.

Signed-off-by: John Williams <john.williams@petalogix.com>
Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-08-18 10:33:30 +02:00

174 lines
4.4 KiB
C

/*
* Copyright (C) 2007-2009 Michal Simek <monstr@monstr.eu>
* Copyright (C) 2007-2009 PetaLogix
* Copyright (C) 2006 Atmark Techno, Inc.
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/init.h>
#include <linux/irq.h>
#include <asm/page.h>
#include <linux/io.h>
#include <linux/bug.h>
#include <asm/prom.h>
#include <asm/irq.h>
#ifdef CONFIG_SELFMOD_INTC
#include <asm/selfmod.h>
#define INTC_BASE BARRIER_BASE_ADDR
#else
static unsigned int intc_baseaddr;
#define INTC_BASE intc_baseaddr
#endif
unsigned int nr_irq;
/* No one else should require these constants, so define them locally here. */
#define ISR 0x00 /* Interrupt Status Register */
#define IPR 0x04 /* Interrupt Pending Register */
#define IER 0x08 /* Interrupt Enable Register */
#define IAR 0x0c /* Interrupt Acknowledge Register */
#define SIE 0x10 /* Set Interrupt Enable bits */
#define CIE 0x14 /* Clear Interrupt Enable bits */
#define IVR 0x18 /* Interrupt Vector Register */
#define MER 0x1c /* Master Enable Register */
#define MER_ME (1<<0)
#define MER_HIE (1<<1)
static void intc_enable_or_unmask(unsigned int irq)
{
pr_debug("enable_or_unmask: %d\n", irq);
out_be32(INTC_BASE + SIE, 1 << irq);
}
static void intc_disable_or_mask(unsigned int irq)
{
pr_debug("disable: %d\n", irq);
out_be32(INTC_BASE + CIE, 1 << irq);
}
static void intc_ack(unsigned int irq)
{
pr_debug("ack: %d\n", irq);
out_be32(INTC_BASE + IAR, 1 << irq);
}
static void intc_mask_ack(unsigned int irq)
{
unsigned long mask = 1 << irq;
pr_debug("disable_and_ack: %d\n", irq);
out_be32(INTC_BASE + CIE, mask);
out_be32(INTC_BASE + IAR, mask);
}
static void intc_end(unsigned int irq)
{
unsigned long mask = 1 << irq;
pr_debug("end: %d\n", irq);
if (!(irq_desc[irq].status & (IRQ_DISABLED | IRQ_INPROGRESS))) {
out_be32(INTC_BASE + SIE, mask);
/* ack level sensitive intr */
if (irq_desc[irq].status & IRQ_LEVEL)
out_be32(INTC_BASE + IAR, mask);
}
}
static struct irq_chip intc_dev = {
.name = "Xilinx INTC",
.unmask = intc_enable_or_unmask,
.mask = intc_disable_or_mask,
.ack = intc_ack,
.mask_ack = intc_mask_ack,
.end = intc_end,
};
unsigned int get_irq(struct pt_regs *regs)
{
int irq;
/*
* NOTE: This function is the one that needs to be improved in
* order to handle multiple interrupt controllers. It currently
* is hardcoded to check for interrupts only on the first INTC.
*/
irq = in_be32(INTC_BASE + IVR);
pr_debug("get_irq: %d\n", irq);
return irq;
}
void __init init_IRQ(void)
{
u32 i, j, intr_type;
struct device_node *intc = NULL;
#ifdef CONFIG_SELFMOD_INTC
unsigned int intc_baseaddr = 0;
static int arr_func[] = {
(int)&get_irq,
(int)&intc_enable_or_unmask,
(int)&intc_disable_or_mask,
(int)&intc_mask_ack,
(int)&intc_ack,
(int)&intc_end,
0
};
#endif
static char *intc_list[] = {
"xlnx,xps-intc-1.00.a",
"xlnx,opb-intc-1.00.c",
"xlnx,opb-intc-1.00.b",
"xlnx,opb-intc-1.00.a",
NULL
};
for (j = 0; intc_list[j] != NULL; j++) {
intc = of_find_compatible_node(NULL, NULL, intc_list[j]);
if (intc)
break;
}
BUG_ON(!intc);
intc_baseaddr = *(int *) of_get_property(intc, "reg", NULL);
intc_baseaddr = (unsigned long) ioremap(intc_baseaddr, PAGE_SIZE);
nr_irq = *(int *) of_get_property(intc, "xlnx,num-intr-inputs", NULL);
intr_type =
*(int *) of_get_property(intc, "xlnx,kind-of-intr", NULL);
if (intr_type >= (1 << (nr_irq + 1)))
printk(KERN_INFO " ERROR: Mismatch in kind-of-intr param\n");
#ifdef CONFIG_SELFMOD_INTC
selfmod_function((int *) arr_func, intc_baseaddr);
#endif
printk(KERN_INFO "%s #0 at 0x%08x, num_irq=%d, edge=0x%x\n",
intc_list[j], intc_baseaddr, nr_irq, intr_type);
/*
* Disable all external interrupts until they are
* explicity requested.
*/
out_be32(intc_baseaddr + IER, 0);
/* Acknowledge any pending interrupts just in case. */
out_be32(intc_baseaddr + IAR, 0xffffffff);
/* Turn on the Master Enable. */
out_be32(intc_baseaddr + MER, MER_HIE | MER_ME);
for (i = 0; i < nr_irq; ++i) {
if (intr_type & (0x00000001 << i)) {
set_irq_chip_and_handler_name(i, &intc_dev,
handle_edge_irq, intc_dev.name);
irq_desc[i].status &= ~IRQ_LEVEL;
} else {
set_irq_chip_and_handler_name(i, &intc_dev,
handle_level_irq, intc_dev.name);
irq_desc[i].status |= IRQ_LEVEL;
}
}
}