From 384740dc49ea651ba350704d13ff6be9976e37fe Mon Sep 17 00:00:00 2001 From: Ralf Baechle Date: Tue, 16 Sep 2008 19:48:51 +0200 Subject: MIPS: Move headfiles to new location below arch/mips/include Signed-off-by: Ralf Baechle --- arch/mips/include/asm/i8259.h | 86 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 86 insertions(+) create mode 100644 arch/mips/include/asm/i8259.h (limited to 'arch/mips/include/asm/i8259.h') diff --git a/arch/mips/include/asm/i8259.h b/arch/mips/include/asm/i8259.h new file mode 100644 index 00000000000..8572a2d9048 --- /dev/null +++ b/arch/mips/include/asm/i8259.h @@ -0,0 +1,86 @@ +/* + * include/asm-mips/i8259.h + * + * i8259A interrupt definitions. + * + * Copyright (C) 2003 Maciej W. Rozycki + * Copyright (C) 2003 Ralf Baechle + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ +#ifndef _ASM_I8259_H +#define _ASM_I8259_H + +#include +#include + +#include +#include + +/* i8259A PIC registers */ +#define PIC_MASTER_CMD 0x20 +#define PIC_MASTER_IMR 0x21 +#define PIC_MASTER_ISR PIC_MASTER_CMD +#define PIC_MASTER_POLL PIC_MASTER_ISR +#define PIC_MASTER_OCW3 PIC_MASTER_ISR +#define PIC_SLAVE_CMD 0xa0 +#define PIC_SLAVE_IMR 0xa1 + +/* i8259A PIC related value */ +#define PIC_CASCADE_IR 2 +#define MASTER_ICW4_DEFAULT 0x01 +#define SLAVE_ICW4_DEFAULT 0x01 +#define PIC_ICW4_AEOI 2 + +extern spinlock_t i8259A_lock; + +extern int i8259A_irq_pending(unsigned int irq); +extern void make_8259A_irq(unsigned int irq); + +extern void init_i8259_irqs(void); + +/* + * Do the traditional i8259 interrupt polling thing. This is for the few + * cases where no better interrupt acknowledge method is available and we + * absolutely must touch the i8259. + */ +static inline int i8259_irq(void) +{ + int irq; + + spin_lock(&i8259A_lock); + + /* Perform an interrupt acknowledge cycle on controller 1. */ + outb(0x0C, PIC_MASTER_CMD); /* prepare for poll */ + irq = inb(PIC_MASTER_CMD) & 7; + if (irq == PIC_CASCADE_IR) { + /* + * Interrupt is cascaded so perform interrupt + * acknowledge on controller 2. + */ + outb(0x0C, PIC_SLAVE_CMD); /* prepare for poll */ + irq = (inb(PIC_SLAVE_CMD) & 7) + 8; + } + + if (unlikely(irq == 7)) { + /* + * This may be a spurious interrupt. + * + * Read the interrupt status register (ISR). If the most + * significant bit is not set then there is no valid + * interrupt. + */ + outb(0x0B, PIC_MASTER_ISR); /* ISR register */ + if(~inb(PIC_MASTER_ISR) & 0x80) + irq = -1; + } + + spin_unlock(&i8259A_lock); + + return likely(irq >= 0) ? irq + I8259A_IRQ_BASE : irq; +} + +#endif /* _ASM_I8259_H */ -- cgit v1.2.3