linux/arch/sh/boards/mach-cayman/irq.c

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/*
* arch/sh/mach-cayman/irq.c - SH-5 Cayman Interrupt Support
*
* This file handles the board specific parts of the Cayman interrupt system
*
* Copyright (C) 2002 Stuart Menefy
*
* 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/io.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/signal.h>
#include <cpu/irq.h>
#include <asm/page.h>
/* Setup for the SMSC FDC37C935 / LAN91C100FD */
#define SMSC_IRQ IRQ_IRL1
/* Setup for PCI Bus 2, which transmits interrupts via the EPLD */
#define PCI2_IRQ IRQ_IRL3
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)
{
printk(KERN_INFO "CAYMAN: spurious SMSC interrupt\n");
return IRQ_NONE;
}
static irqreturn_t cayman_interrupt_pci2(int irq, void *dev_id)
{
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 = __raw_readl(reg);
mask |= bit;
__raw_writel(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 = __raw_readl(reg);
mask &= ~bit;
__raw_writel(mask, reg);
local_irq_restore(flags);
}
static void ack_cayman_irq(unsigned int irq)
{
disable_cayman_irq(irq);
}
struct irq_chip cayman_irq_type = {
.name = "Cayman-IRQ",
.unmask = enable_cayman_irq,
.mask = disable_cayman_irq,
.mask_ack = ack_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 = __raw_readl(EPLD_STATUS_BASE) &
__raw_readl(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 = __raw_readl(EPLD_STATUS_BASE + 3 * sizeof(u32)) &
__raw_readl(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;
}
void init_cayman_irq(void)
{
int i;
epld_virt = (unsigned long)ioremap_nocache(EPLD_BASE, 1024);
if (!epld_virt) {
printk(KERN_ERR "Cayman IRQ: Unable to remap EPLD\n");
return;
}
for (i = 0; i < NR_EXT_IRQS; i++) {
set_irq_chip_and_handler(START_EXT_IRQS + i, &cayman_irq_type,
handle_level_irq);
}
/* Setup the SMSC interrupt */
setup_irq(SMSC_IRQ, &cayman_action_smsc);
setup_irq(PCI2_IRQ, &cayman_action_pci2);
}