/*
* Copyright (C) 1999, 2000, 2006 MIPS Technologies, Inc.
* All rights reserved.
* Authors: Carsten Langgaard <carstenl@mips.com>
* Maciej W. Rozycki <macro@mips.com>
*
* ########################################################################
*
* This program is free software; you can distribute it and/or modify it
* under the terms of the GNU General Public License (Version 2) as
* published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
*
* ########################################################################
*
* Routines for generic manipulation of the interrupts found on the MIPS
* Atlas board.
*
*/
#include <linux/compiler.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/kernel_stat.h>
#include <asm/gdb-stub.h>
#include <asm/io.h>
#include <asm/irq_cpu.h>
#include <asm/msc01_ic.h>
#include <asm/mips-boards/atlas.h>
#include <asm/mips-boards/atlasint.h>
#include <asm/mips-boards/generic.h>
static struct atlas_ictrl_regs *atlas_hw0_icregs;
#if 0
#define DEBUG_INT(x...) printk(x)
#else
#define DEBUG_INT(x...)
#endif
void disable_atlas_irq(unsigned int irq_nr)
{
atlas_hw0_icregs->intrsten = 1 << (irq_nr - ATLAS_INT_BASE);
iob();
}
void enable_atlas_irq(unsigned int irq_nr)
{
atlas_hw0_icregs->intseten = 1 << (irq_nr - ATLAS_INT_BASE);
iob();
}
static void end_atlas_irq(unsigned int irq)
{
if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
enable_atlas_irq(irq);
}
static struct irq_chip atlas_irq_type = {
.typename = "Atlas",
.ack = disable_atlas_irq,
.mask = disable_atlas_irq,
.mask_ack = disable_atlas_irq,
.unmask = enable_atlas_irq,
.eoi = enable_atlas_irq,
.end = end_atlas_irq,
};
static inline int ls1bit32(unsigned int x)
{
int b = 31, s;
s = 16; if (x << 16 == 0) s = 0; b -= s; x <<= s;
s = 8; if (x << 8 == 0) s = 0; b -= s; x <<= s;
s = 4; if (x << 4 == 0) s = 0; b -= s; x <<= s;
s = 2; if (x << 2 == 0) s = 0; b -= s; x <<= s;
s = 1; if (x << 1 == 0) s = 0; b -= s;
return b;
}
static inline void atlas_hw0_irqdispatch(void)
{
unsigned long int_status;
int irq;
int_status = atlas_hw0_icregs->intstatus;
/* if int_status == 0, then the interrupt has already been cleared */
if (unlikely(int_status == 0))
return;
irq = ATLAS_INT_BASE + ls1bit32(int_status);
DEBUG_INT("atlas_hw0_irqdispatch: irq=%d\n", irq);
do_IRQ(irq);
}
static inline int clz(unsigned long x)
{
__asm__ (
" .set push \n"
" .set mips32 \n"
" clz %0, %1 \n"
" .set pop \n"
: "=r" (x)
: "r" (x));
return x;
}
/*
* Version of ffs that only looks at bits 12..15.
*/
static inline unsigned int irq_ffs(unsigned int pending)
{
#if defined(CONFIG_CPU_MIPS32) || defined(CONFIG_CPU_MIPS64)
return -clz(pending) + 31 - CAUSEB_IP;
#else
unsigned int a0 = 7;
unsigned int t0;
t0 = s0 & 0xf000;
t0 = t0 < 1;
t0 = t0 << 2;
a0 = a0 - t0;
s0 = s0 << t0;
t0 = s0 & 0xc000;
t0 = t0 < 1;
t0 = t0 << 1;
a0 = a0 - t0;
s0 = s0 << t0;
t0 = s0 & 0x8000;
t0 = t0 < 1;
//t0 = t0 << 2;
a0 = a0 - t0;
//s0 = s0 << t0;
return a0;
#endif
}
/*
* IRQs on the Atlas board look basically like (all external interrupt
* sources are combined together on hardware interrupt 0 (MIPS IRQ 2)):
*
* MIPS IRQ Source
* -------- ------
* 0 Software 0 (reschedule IPI on MT)
* 1 Software 1 (remote call IPI on MT)
* 2 Combined Atlas hardware interrupt (hw0)
* 3 Hardware (ignored)
* 4 Hardware (ignored)
* 5 Hardware (ignored)
* 6 Hardware (ignored)
* 7 R4k timer (what we use)
*
* We handle the IRQ according to _our_ priority which is:
*
* Highest ---- R4k Timer
* Lowest ---- Software 0
*
* then we just return, if multiple IRQs are pending then we will just take
* another exception, big deal.
*/
asmlinkage void plat_irq_dispatch(void)
{
unsigned int pending = read_c0_cause() & read_c0_status() & ST0_IM;
int irq;
irq = irq_ffs(pending);
if (irq == MIPSCPU_INT_ATLAS)
atlas_hw0_irqdispatch();
else if (irq >= 0)
do_IRQ(MIPSCPU_INT_BASE + irq);
else
spurious_interrupt();
}
static inline void init_atlas_irqs (int base)
{
int i;
atlas_hw0_icregs = (struct atlas_ictrl_regs *)
ioremap(ATLAS_ICTRL_REGS_BASE,
sizeof(struct atlas_ictrl_regs *));
/*
* Mask out all interrupt by writing "1" to all bit position in
* the interrupt reset reg.
*/
atlas_hw0_icregs->intrsten = 0xffffffff;
for (i = ATLAS_INT_BASE; i <= ATLAS_INT_END; i++)
set_irq_chip_and_handler(i, &atlas_irq_type, handle_level_irq);
}
static struct irqaction atlasirq = {
.handler = no_action,
.name = "Atlas cascade"
};
msc_irqmap_t __initdata msc_irqmap[] = {
{MSC01C_INT_TMR, MSC01_IRQ_EDGE, 0},
{MSC01C_INT_PCI, MSC01_IRQ_LEVEL, 0},
};
int __initdata msc_nr_irqs = sizeof(msc_irqmap) / sizeof(*msc_irqmap);
msc_irqmap_t __initdata msc_eicirqmap[] = {
{MSC01E_INT_SW0, MSC01_IRQ_LEVEL, 0},
{MSC01E_INT_SW1, MSC01_IRQ_LEVEL, 0},
{MSC01E_INT_ATLAS, MSC01_IRQ_LEVEL, 0},
{MSC01E_INT_TMR, MSC01_IRQ_EDGE, 0},
{MSC01E_INT_PCI, MSC01_IRQ_LEVEL, 0},
{MSC01E_INT_PERFCTR, MSC01_IRQ_LEVEL, 0},
{MSC01E_INT_CPUCTR, MSC01_IRQ_LEVEL, 0}
};
int __initdata msc_nr_eicirqs = sizeof(msc_eicirqmap) / sizeof(*msc_eicirqmap);
void __init arch_init_irq(void)
{
init_atlas_irqs(ATLAS_INT_BASE);
if (!cpu_has_veic)
mips_cpu_irq_init(MIPSCPU_INT_BASE);
switch(mips_revision_corid) {
case MIPS_REVISION_CORID_CORE_MSC:
case MIPS_REVISION_CORID_CORE_FPGA2:
case MIPS_REVISION_CORID_CORE_FPGA3:
case MIPS_REVISION_CORID_CORE_24K:
case MIPS_REVISION_CORID_CORE_EMUL_MSC:
if (cpu_has_veic)
init_msc_irqs (MSC01E_INT_BASE,
msc_eicirqmap, msc_nr_eicirqs);
else
init_msc_irqs (MSC01C_INT_BASE,
msc_irqmap, msc_nr_irqs);
}
if (cpu_has_veic) {
set_vi_handler (MSC01E_INT_ATLAS, atlas_hw0_irqdispatch);
setup_irq (MSC01E_INT_BASE + MSC01E_INT_ATLAS, &atlasirq);
} else if (cpu_has_vint) {
set_vi_handler (MIPSCPU_INT_ATLAS, atlas_hw0_irqdispatch);
#ifdef CONFIG_MIPS_MT_SMTC
setup_irq_smtc (MIPSCPU_INT_BASE + MIPSCPU_INT_ATLAS,
&atlasirq, (0x100 << MIPSCPU_INT_ATLAS));
#else /* Not SMTC */
setup_irq(MIPSCPU_INT_BASE + MIPSCPU_INT_ATLAS, &atlasirq);
#endif /* CONFIG_MIPS_MT_SMTC */
} else
setup_irq(MIPSCPU_INT_BASE + MIPSCPU_INT_ATLAS, &atlasirq);
}
