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	Signed-off-by: Wolfgang Denk <wd@denx.de> [trini: Fixup common/cmd_io.c] Signed-off-by: Tom Rini <trini@ti.com>
		
			
				
	
	
		
			117 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			117 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * (C) Copyright 2009
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|  * Graeme Russ, <graeme.russ@gmail.com>
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|  *
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|  * (C) Copyright 2002
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|  * Daniel Engström, Omicron Ceti AB, <daniel@omicron.se>
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|  *
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|  * SPDX-License-Identifier:	GPL-2.0+
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|  */
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| 
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| /*
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|  * This file provides the interrupt handling functionality for systems
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|  * based on the standard PC/AT architecture using two cascaded i8259
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|  * Programmable Interrupt Controllers.
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|  */
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| 
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| #include <common.h>
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| #include <asm/io.h>
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| #include <asm/i8259.h>
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| #include <asm/ibmpc.h>
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| #include <asm/interrupt.h>
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| 
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| #if CONFIG_SYS_NUM_IRQS != 16
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| #error "CONFIG_SYS_NUM_IRQS must equal 16 if CONFIG_SYS_NUM_IRQS is defined"
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| #endif
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| 
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| int interrupt_init(void)
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| {
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| 	u8 i;
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| 
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| 	disable_interrupts();
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| 
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| 	/* Mask all interrupts */
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| 	outb(0xff, MASTER_PIC + IMR);
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| 	outb(0xff, SLAVE_PIC + IMR);
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| 
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| 	/* Master PIC */
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| 	/* Place master PIC interrupts at INT20 */
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| 	/* ICW3, One slave PIC is present */
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| 	outb(ICW1_SEL|ICW1_EICW4, MASTER_PIC + ICW1);
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| 	outb(0x20, MASTER_PIC + ICW2);
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| 	outb(IR2, MASTER_PIC + ICW3);
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| 	outb(ICW4_PM, MASTER_PIC + ICW4);
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| 
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| 	for (i = 0; i < 8; i++)
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| 		outb(OCW2_SEOI | i, MASTER_PIC + OCW2);
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| 
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| 	/* Slave PIC */
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| 	/* Place slave PIC interrupts at INT28 */
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| 	/* Slave ID */
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| 	outb(ICW1_SEL|ICW1_EICW4, SLAVE_PIC + ICW1);
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| 	outb(0x28, SLAVE_PIC + ICW2);
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| 	outb(0x02, SLAVE_PIC + ICW3);
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| 	outb(ICW4_PM, SLAVE_PIC + ICW4);
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| 
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| 	for (i = 0; i < 8; i++)
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| 		outb(OCW2_SEOI | i, SLAVE_PIC + OCW2);
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| 
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| 	/*
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| 	 * Enable cascaded interrupts by unmasking the cascade IRQ pin of
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| 	 * the master PIC
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| 	 */
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| 	unmask_irq(2);
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| 
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| 	enable_interrupts();
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| 
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| 	return 0;
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| }
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| 
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| void mask_irq(int irq)
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| {
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| 	int imr_port;
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| 
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| 	if (irq >= CONFIG_SYS_NUM_IRQS)
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| 		return;
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| 
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| 	if (irq > 7)
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| 		imr_port = SLAVE_PIC + IMR;
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| 	else
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| 		imr_port = MASTER_PIC + IMR;
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| 
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| 	outb(inb(imr_port) | (1 << (irq & 7)), imr_port);
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| }
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| 
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| void unmask_irq(int irq)
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| {
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| 	int imr_port;
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| 
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| 	if (irq >= CONFIG_SYS_NUM_IRQS)
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| 		return;
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| 
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| 	if (irq > 7)
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| 		imr_port = SLAVE_PIC + IMR;
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| 	else
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| 		imr_port = MASTER_PIC + IMR;
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| 
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| 	outb(inb(imr_port) & ~(1 << (irq & 7)), imr_port);
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| }
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| 
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| void specific_eoi(int irq)
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| {
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| 	if (irq >= CONFIG_SYS_NUM_IRQS)
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| 		return;
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| 
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| 	if (irq > 7) {
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| 		/*
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| 		 *  IRQ is on the slave - Issue a corresponding EOI to the
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| 		 *  slave PIC and an EOI for IRQ2 (the cascade interrupt)
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| 		 *  on the master PIC
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| 		 */
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| 		outb(OCW2_SEOI | (irq & 7), SLAVE_PIC + OCW2);
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| 		irq = SEOI_IR2;
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| 	}
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| 
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| 	outb(OCW2_SEOI | irq, MASTER_PIC + OCW2);
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| }
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