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28 lines
390 B
C
28 lines
390 B
C
#include "common.h"
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// Timebase frequency is bus frequency / 4. Ignore roundoff, this
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// doesn't have to be very accurate.
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#define TICKS_PER_USEC (243/4)
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static u32 mftb(void)
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{
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u32 x;
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asm volatile("mftb %0" : "=r"(x));
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return x;
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}
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static void __delay(u32 ticks)
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{
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u32 start = mftb();
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while (mftb() - start < ticks)
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;
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}
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void udelay(u32 us)
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{
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__delay(TICKS_PER_USEC * us);
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}
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