159 lines
		
	
	
		
			3.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			159 lines
		
	
	
		
			3.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* irq-mb93091.c: MB93091 FPGA interrupt handling
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|  *
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|  * Copyright (C) 2003 Red Hat, Inc. All Rights Reserved.
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|  * Written by David Howells (dhowells@redhat.com)
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|  *
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|  * This program is free software; you can redistribute it and/or
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|  * modify it under the terms of the GNU General Public License
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|  * as published by the Free Software Foundation; either version
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|  * 2 of the License, or (at your option) any later version.
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|  */
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| 
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| #include <linux/ptrace.h>
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| #include <linux/errno.h>
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| #include <linux/signal.h>
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| #include <linux/sched.h>
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| #include <linux/ioport.h>
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| #include <linux/interrupt.h>
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| #include <linux/init.h>
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| #include <linux/irq.h>
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| #include <linux/bitops.h>
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| 
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| #include <asm/io.h>
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| #include <asm/system.h>
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| #include <asm/delay.h>
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| #include <asm/irq.h>
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| #include <asm/irc-regs.h>
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| 
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| #define __reg16(ADDR) (*(volatile unsigned short *)(ADDR))
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| 
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| #define __get_IMR()	({ __reg16(0xffc00004); })
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| #define __set_IMR(M)	do { __reg16(0xffc00004) = (M); wmb(); } while(0)
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| #define __get_IFR()	({ __reg16(0xffc0000c); })
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| #define __clr_IFR(M)	do { __reg16(0xffc0000c) = ~(M); wmb(); } while(0)
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| 
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| 
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| /*
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|  * on-motherboard FPGA PIC operations
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|  */
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| static void frv_fpga_mask(unsigned int irq)
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| {
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| 	uint16_t imr = __get_IMR();
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| 
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| 	imr |= 1 << (irq - IRQ_BASE_FPGA);
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| 
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| 	__set_IMR(imr);
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| }
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| 
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| static void frv_fpga_ack(unsigned int irq)
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| {
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| 	__clr_IFR(1 << (irq - IRQ_BASE_FPGA));
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| }
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| 
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| static void frv_fpga_mask_ack(unsigned int irq)
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| {
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| 	uint16_t imr = __get_IMR();
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| 
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| 	imr |= 1 << (irq - IRQ_BASE_FPGA);
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| 	__set_IMR(imr);
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| 
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| 	__clr_IFR(1 << (irq - IRQ_BASE_FPGA));
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| }
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| 
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| static void frv_fpga_unmask(unsigned int irq)
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| {
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| 	uint16_t imr = __get_IMR();
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| 
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| 	imr &= ~(1 << (irq - IRQ_BASE_FPGA));
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| 
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| 	__set_IMR(imr);
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| }
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| 
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| static struct irq_chip frv_fpga_pic = {
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| 	.name		= "mb93091",
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| 	.ack		= frv_fpga_ack,
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| 	.mask		= frv_fpga_mask,
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| 	.mask_ack	= frv_fpga_mask_ack,
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| 	.unmask		= frv_fpga_unmask,
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| };
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| 
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| /*
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|  * FPGA PIC interrupt handler
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|  */
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| static irqreturn_t fpga_interrupt(int irq, void *_mask)
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| {
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| 	uint16_t imr, mask = (unsigned long) _mask;
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| 
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| 	imr = __get_IMR();
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| 	mask = mask & ~imr & __get_IFR();
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| 
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| 	/* poll all the triggered IRQs */
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| 	while (mask) {
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| 		int irq;
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| 
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| 		asm("scan %1,gr0,%0" : "=r"(irq) : "r"(mask));
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| 		irq = 31 - irq;
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| 		mask &= ~(1 << irq);
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| 
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| 		generic_handle_irq(IRQ_BASE_FPGA + irq);
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| 	}
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| 
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| 	return IRQ_HANDLED;
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| }
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| 
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| /*
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|  * define an interrupt action for each FPGA PIC output
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|  * - use dev_id to indicate the FPGA PIC input to output mappings
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|  */
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| static struct irqaction fpga_irq[4]  = {
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| 	[0] = {
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| 		.handler	= fpga_interrupt,
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| 		.flags		= IRQF_DISABLED | IRQF_SHARED,
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| 		.name		= "fpga.0",
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| 		.dev_id		= (void *) 0x0028UL,
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| 	},
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| 	[1] = {
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| 		.handler	= fpga_interrupt,
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| 		.flags		= IRQF_DISABLED | IRQF_SHARED,
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| 		.name		= "fpga.1",
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| 		.dev_id		= (void *) 0x0050UL,
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| 	},
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| 	[2] = {
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| 		.handler	= fpga_interrupt,
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| 		.flags		= IRQF_DISABLED | IRQF_SHARED,
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| 		.name		= "fpga.2",
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| 		.dev_id		= (void *) 0x1c00UL,
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| 	},
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| 	[3] = {
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| 		.handler	= fpga_interrupt,
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| 		.flags		= IRQF_DISABLED | IRQF_SHARED,
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| 		.name		= "fpga.3",
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| 		.dev_id		= (void *) 0x6386UL,
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| 	}
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| };
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| 
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| /*
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|  * initialise the motherboard FPGA's PIC
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|  */
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| void __init fpga_init(void)
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| {
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| 	int irq;
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| 
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| 	/* all PIC inputs are all set to be low-level driven, apart from the
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| 	 * NMI button (15) which is fixed at falling-edge
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| 	 */
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| 	__set_IMR(0x7ffe);
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| 	__clr_IFR(0x0000);
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| 
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| 	for (irq = IRQ_BASE_FPGA + 1; irq <= IRQ_BASE_FPGA + 14; irq++)
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| 		set_irq_chip_and_handler(irq, &frv_fpga_pic, handle_level_irq);
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| 
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| 	set_irq_chip_and_handler(IRQ_FPGA_NMI, &frv_fpga_pic, handle_edge_irq);
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| 
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| 	/* the FPGA drives the first four external IRQ inputs on the CPU PIC */
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| 	setup_irq(IRQ_CPU_EXTERNAL0, &fpga_irq[0]);
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| 	setup_irq(IRQ_CPU_EXTERNAL1, &fpga_irq[1]);
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| 	setup_irq(IRQ_CPU_EXTERNAL2, &fpga_irq[2]);
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| 	setup_irq(IRQ_CPU_EXTERNAL3, &fpga_irq[3]);
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| }
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