138 lines
2.7 KiB
C
138 lines
2.7 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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//
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// Copyright 2003-2005 Simtec Electronics
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// Ben Dooks <ben@simtec.co.uk>
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//
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// http://www.simtec.co.uk/products/EB2410ITX/
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/ioport.h>
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#include <linux/device.h>
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#include <linux/io.h>
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#include <asm/irq.h>
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#include <asm/mach-types.h>
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#include <asm/mach/irq.h>
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#include "regs-irq.h"
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#include "irqs.h"
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#include "bast.h"
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#define irqdbf(x...)
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#define irqdbf2(x...)
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/* handle PC104 ISA interrupts from the system CPLD */
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/* table of ISA irq nos to the relevant mask... zero means
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* the irq is not implemented
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*/
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static const unsigned char bast_pc104_irqmasks[] = {
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0, /* 0 */
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0, /* 1 */
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0, /* 2 */
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1, /* 3 */
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0, /* 4 */
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2, /* 5 */
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0, /* 6 */
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4, /* 7 */
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0, /* 8 */
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0, /* 9 */
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8, /* 10 */
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0, /* 11 */
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0, /* 12 */
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0, /* 13 */
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0, /* 14 */
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0, /* 15 */
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};
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static const unsigned char bast_pc104_irqs[] = { 3, 5, 7, 10 };
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static void
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bast_pc104_mask(struct irq_data *data)
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{
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unsigned long temp;
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temp = __raw_readb(BAST_VA_PC104_IRQMASK);
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temp &= ~bast_pc104_irqmasks[data->irq];
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__raw_writeb(temp, BAST_VA_PC104_IRQMASK);
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}
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static void
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bast_pc104_maskack(struct irq_data *data)
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{
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struct irq_desc *desc = irq_to_desc(BAST_IRQ_ISA);
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bast_pc104_mask(data);
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desc->irq_data.chip->irq_ack(&desc->irq_data);
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}
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static void
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bast_pc104_unmask(struct irq_data *data)
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{
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unsigned long temp;
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temp = __raw_readb(BAST_VA_PC104_IRQMASK);
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temp |= bast_pc104_irqmasks[data->irq];
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__raw_writeb(temp, BAST_VA_PC104_IRQMASK);
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}
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static struct irq_chip bast_pc104_chip = {
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.irq_mask = bast_pc104_mask,
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.irq_unmask = bast_pc104_unmask,
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.irq_ack = bast_pc104_maskack
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};
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static void bast_irq_pc104_demux(struct irq_desc *desc)
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{
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unsigned int stat;
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unsigned int irqno;
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int i;
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stat = __raw_readb(BAST_VA_PC104_IRQREQ) & 0xf;
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if (unlikely(stat == 0)) {
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/* ack if we get an irq with nothing (ie, startup) */
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desc->irq_data.chip->irq_ack(&desc->irq_data);
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} else {
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/* handle the IRQ */
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for (i = 0; stat != 0; i++, stat >>= 1) {
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if (stat & 1) {
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irqno = bast_pc104_irqs[i];
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generic_handle_irq(irqno);
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}
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}
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}
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}
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static __init int bast_irq_init(void)
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{
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unsigned int i;
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if (machine_is_bast()) {
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printk(KERN_INFO "BAST PC104 IRQ routing, Copyright 2005 Simtec Electronics\n");
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/* zap all the IRQs */
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__raw_writeb(0x0, BAST_VA_PC104_IRQMASK);
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irq_set_chained_handler(BAST_IRQ_ISA, bast_irq_pc104_demux);
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/* register our IRQs */
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for (i = 0; i < 4; i++) {
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unsigned int irqno = bast_pc104_irqs[i];
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irq_set_chip_and_handler(irqno, &bast_pc104_chip,
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handle_level_irq);
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irq_clear_status_flags(irqno, IRQ_NOREQUEST);
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}
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}
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return 0;
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}
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arch_initcall(bast_irq_init);
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