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https://github.com/saymrwulf/uhd.git
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89 lines
2.2 KiB
C
89 lines
2.2 KiB
C
/* -*- c -*- */
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/*
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* Copyright 2007 Free Software Foundation, Inc.
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include "pic.h"
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#include "hal_io.h"
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#include "memory_map.h"
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#define NVECTORS 8
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/*
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* Our secondary interrupt vector.
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*/
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irq_handler_t pic_vector[NVECTORS];
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void
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pic_init(void)
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{
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// uP is level triggered
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pic_regs->mask = ~0; // mask all interrupts
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pic_regs->edge_enable = PIC_ONETIME_INT | PIC_UNDERRUN_INT | PIC_OVERRUN_INT | PIC_PPS_INT;
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pic_regs->polarity = ~0 & ~PIC_PHY_INT; // rising edge
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pic_regs->pending = ~0; // clear all pending ints
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for (int i = 0; i < NVECTORS; i++){
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pic_vector[i] = pic_nop_handler;
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}
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}
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/*
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* This magic gets pic_interrupt_handler wired into the
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* system interrupt handler with the appropriate prologue and
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* epilogue.
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*/
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//FIXME zpu-gcc does not install interrupt_handler like this
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//void pic_interrupt_handler() __attribute__ ((interrupt_handler));
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void pic_interrupt_handler()
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{
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// pending and not masked interrupts
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int live = pic_regs->pending & ~pic_regs->mask;
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// FIXME loop while there are interrupts to service.
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// That will reduce our overhead.
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// handle the first one set
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int i;
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int mask;
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for (i=0, mask=1; i < NVECTORS; i++, mask <<= 1){
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if (mask & live){ // handle this one
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// puthex_nl(i);
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(*pic_vector[i])(i);
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pic_regs->pending = mask; // clear pending interrupt
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return;
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}
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}
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}
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void
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pic_register_handler(unsigned irq, irq_handler_t handler)
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{
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if (irq >= NVECTORS)
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return;
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pic_vector[irq] = handler;
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pic_regs->mask &= ~IRQ_TO_MASK(irq);
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}
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void
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pic_nop_handler(unsigned irq)
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{
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// nop
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}
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