view target-utils/buzplayer/timer.c @ 964:a96cb97b66a2

ringtools/imy: fix duplicate definition of tdma_durations[] The bug was reported by Vadim Yanitskiy <fixeria@osmocom.org>, although the present fix is slightly different from the contributed patch: because main.c doesn't need this tdma_durations[] array at all, let's simply remove the reference to this array from main.c rather than turn it into an extern. I no longer remember my original thought flow that resulted (by mistake) in tdma_durations[] being multiply defined in main.c and durations.c. My intent might have been to define all globals in main.c and have the reference in durations.c be an extern - and I missed that extern - but without clear memory, I have no certainty. In any case, having this data array defined in the same module that fills it (durations.c) is sensible, so let's make it the new way.
author Mychaela Falconia <falcon@freecalypso.org>
date Thu, 31 Aug 2023 19:38:18 +0000
parents e3d40f49d8c4
children
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/*
 * FreeCalypso buzzer "melodies" have times measured in TDMA frames,
 * as that is the time unit in the main firmware which will ultimately
 * play them.  In this standalone buzzer player we simulate TDMA frame
 * timing by programming Calypso TIMER1 with the period of 1875, and
 * we detect timer overflow (one virtual TDMA frame time having passed)
 * by polling the read register to avoid the need for interrupt handling
 * infrastructure.
 */

#include "types.h"
#include "timer.h"

void
timer_init()
{
	TIMER1_REGS.cntl = CNTL_CLOCK_ENABLE;
	TIMER1_REGS.load = 1875;
	TIMER1_REGS.cntl = CNTL_CLOCK_ENABLE | CNTL_AUTO_RELOAD | CNTL_START;
}

void
wait_for_tdma_frame()
{
	u16 read1, read2;

	read1 = TIMER1_REGS.read;
	for (;;) {
		read2 = TIMER1_REGS.read;
		if (read2 > read1)
			return;
		read1 = read2;
	}
}