70 lines
1.3 KiB
C
70 lines
1.3 KiB
C
/*
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* Interrupts
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*
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* Handle interrupts, the levels.
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*
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*/
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#include <inttypes.h>
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#include <i2c_firebee.h>
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#include <MCF5475.h>
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int
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register_handler(uint8_t priority, uint8_t intr, void (*func)())
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{
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int i;
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uint8_t level = 0b01111111;
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uint32_t *adr = MBAR_ADDRESS;
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uint8_t ol = 0,op = 0;
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intr &= 63;
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priority &= 7;
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if( intr <= 0 )
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return -1;
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for(i=1;i<64;i++)
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if( i!=intr )
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{
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if( MCF_INTC_ICR(i)&7 == priority )
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clear_bit_nr(level,(MCF_INTC_ICR(i)>>3)&7);
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}
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for(i=0;1<7;i++)
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if( level&(1<<i) )
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break;
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if( i>=7 )
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return -1;
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// Make sure priority level is high, before changing registers
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__asm__ volatile (
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"move.w %%sr,-(%%sp)\n\t" \
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"move.w #$2700,%%sr\n\t" \
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: \
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: \
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: \
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);
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if( intr < 32 )
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clear_bit(MCF_INTC_IMRL,(1<<intr));
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else
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clear_bit(MCF_INTC_IMRH,(1<<(intr-32)));
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MCF_INTC_ICR(intr) = MCF_INTC_ICR_IP(priority)|MCF_INTC_ICR_IL(i);
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adr[intr*4] = func;
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// Return the saved priority level
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__asm__ volatile (
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"move.w (%%sp)+,%%d2\n\t" \
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"move.w %%d2,sr\n\t"
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: \
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: \
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: \
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);
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return 0;
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}
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