linux/arch/mips/powertv/asic/asic_int.c

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/*
* Carsten Langgaard, carstenl@mips.com
* Copyright (C) 2000, 2001, 2004 MIPS Technologies, Inc.
* Copyright (C) 2001 Ralf Baechle
* Portions copyright (C) 2009 Cisco Systems, Inc.
*
* 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 PowerTV
* platform.
*
* The interrupt controller is located in the South Bridge a PIIX4 device
* with two internal 82C95 interrupt controllers.
*/
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/kernel_stat.h>
#include <linux/kernel.h>
#include <linux/random.h>
#include <asm/irq_cpu.h>
#include <linux/io.h>
#include <asm/irq_regs.h>
#include <asm/mips-boards/generic.h>
#include <asm/mach-powertv/asic_regs.h>
static DEFINE_RAW_SPINLOCK(asic_irq_lock);
static inline int get_int(void)
{
unsigned long flags;
int irq;
raw_spin_lock_irqsave(&asic_irq_lock, flags);
irq = (asic_read(int_int_scan) >> 4) - 1;
if (irq == 0 || irq >= NR_IRQS)
irq = -1;
raw_spin_unlock_irqrestore(&asic_irq_lock, flags);
return irq;
}
static void asic_irqdispatch(void)
{
int irq;
irq = get_int();
if (irq < 0)
return; /* interrupt has already been cleared */
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)
{
return fls(pending) - 1 + CAUSEB_IP;
}
/*
* TODO: check how it works under EIC mode.
*/
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 == CAUSEF_IP3)
asic_irqdispatch();
else if (irq >= 0)
do_IRQ(irq);
else
spurious_interrupt();
}
void __init arch_init_irq(void)
{
int i;
asic_irq_init();
/*
* Initialize interrupt exception vectors.
*/
if (cpu_has_veic || cpu_has_vint) {
int nvec = cpu_has_veic ? 64 : 8;
for (i = 0; i < nvec; i++)
set_vi_handler(i, asic_irqdispatch);
}
}