irq.c
/*
* 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.
*
* arch/sh64/kernel/irq_cayman.c
*
* SH-5 Cayman Interrupt Support
*
* This file handles the board specific parts of the Cayman interrupt system
*
* Copyright (C) 2002 Stuart Menefy
*/
#include <asm/irq.h>
#include <asm/page.h>
#include <asm/io.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/signal.h>
#include <asm/cayman.h>
unsigned long epld_virt;
#define EPLD_BASE 0x04002000
#define EPLD_STATUS_BASE (epld_virt + 0x10)
#define EPLD_MASK_BASE (epld_virt + 0x20)
/* Note the SMSC SuperIO chip and SMSC LAN chip interrupts are all muxed onto
the same SH-5 interrupt */
static irqreturn_t cayman_interrupt_smsc(int irq, void *dev_id, struct pt_regs *regs)
{
printk(KERN_INFO "CAYMAN: spurious SMSC interrupt\n");
return IRQ_NONE;
}
static irqreturn_t cayman_interrupt_pci2(int irq, void *dev_id, struct pt_regs *regs)
{
printk(KERN_INFO "CAYMAN: spurious PCI interrupt, IRQ %d\n", irq);
return IRQ_NONE;
}
static struct irqaction cayman_action_smsc = {
.name = "Cayman SMSC Mux",
.handler = cayman_interrupt_smsc,
.flags = IRQF_DISABLED,
};
static struct irqaction cayman_action_pci2 = {
.name = "Cayman PCI2 Mux",
.handler = cayman_interrupt_pci2,
.flags = IRQF_DISABLED,
};
static void enable_cayman_irq(unsigned int irq)
{
unsigned long flags;
unsigned long mask;
unsigned int reg;
unsigned char bit;
irq -= START_EXT_IRQS;
reg = EPLD_MASK_BASE + ((irq / 8) << 2);
bit = 1<<(irq % 8);
local_irq_save(flags);
mask = ctrl_inl(reg);
mask |= bit;
ctrl_outl(mask, reg);
local_irq_restore(flags);
}
void disable_cayman_irq(unsigned int irq)
{
unsigned long flags;
unsigned long mask;
unsigned int reg;
unsigned char bit;
irq -= START_EXT_IRQS;
reg = EPLD_MASK_BASE + ((irq / 8) << 2);
bit = 1<<(irq % 8);
local_irq_save(flags);
mask = ctrl_inl(reg);
mask &= ~bit;
ctrl_outl(mask, reg);
local_irq_restore(flags);
}
static void ack_cayman_irq(unsigned int irq)
{
disable_cayman_irq(irq);
}
static void end_cayman_irq(unsigned int irq)
{
if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
enable_cayman_irq(irq);
}
static unsigned int startup_cayman_irq(unsigned int irq)
{
enable_cayman_irq(irq);
return 0; /* never anything pending */
}
static void shutdown_cayman_irq(unsigned int irq)
{
disable_cayman_irq(irq);
}
struct hw_interrupt_type cayman_irq_type = {
.typename = "Cayman-IRQ",
.startup = startup_cayman_irq,
.shutdown = shutdown_cayman_irq,
.enable = enable_cayman_irq,
.disable = disable_cayman_irq,
.ack = ack_cayman_irq,
.end = end_cayman_irq,
};
int cayman_irq_demux(int evt)
{
int irq = intc_evt_to_irq[evt];
if (irq == SMSC_IRQ) {
unsigned long status;
int i;
status = ctrl_inl(EPLD_STATUS_BASE) &
ctrl_inl(EPLD_MASK_BASE) & 0xff;
if (status == 0) {
irq = -1;
} else {
for (i=0; i<8; i++) {
if (status & (1<<i))
break;
}
irq = START_EXT_IRQS + i;
}
}
if (irq == PCI2_IRQ) {
unsigned long status;
int i;
status = ctrl_inl(EPLD_STATUS_BASE + 3 * sizeof(u32)) &
ctrl_inl(EPLD_MASK_BASE + 3 * sizeof(u32)) & 0xff;
if (status == 0) {
irq = -1;
} else {
for (i=0; i<8; i++) {
if (status & (1<<i))
break;
}
irq = START_EXT_IRQS + (3 * 8) + i;
}
}
return irq;
}
#if defined(CONFIG_PROC_FS) && defined(CONFIG_SYSCTL)
int cayman_irq_describe(char* p, int irq)
{
if (irq < NR_INTC_IRQS) {
return intc_irq_describe(p, irq);
} else if (irq < NR_INTC_IRQS + 8) {
return sprintf(p, "(SMSC %d)", irq - NR_INTC_IRQS);
} else if ((irq >= NR_INTC_IRQS + 24) && (irq < NR_INTC_IRQS + 32)) {
return sprintf(p, "(PCI2 %d)", irq - (NR_INTC_IRQS + 24));
}
return 0;
}
#endif
void init_cayman_irq(void)
{
int i;
epld_virt = onchip_remap(EPLD_BASE, 1024, "EPLD");
if (!epld_virt) {
printk(KERN_ERR "Cayman IRQ: Unable to remap EPLD\n");
return;
}
for (i=0; i<NR_EXT_IRQS; i++) {
irq_desc[START_EXT_IRQS + i].chip = &cayman_irq_type;
}
/* Setup the SMSC interrupt */
setup_irq(SMSC_IRQ, &cayman_action_smsc);
setup_irq(PCI2_IRQ, &cayman_action_pci2);
}