GK SDK 源码库: XMIPCLinuxV100R005C00SPC030 (kernel/tools/open_source excluded)

source/bootloader/u-boot-2020.01/arch/arm/cpu/arm920t/imx/timer.c

@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2002
+ * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
+ * Marius Groeger <mgroeger@sysgo.de>
+ *
+ * (C) Copyright 2002
+ * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
+ * Alex Zuepke <azu@sysgo.de>
+ *
+ * (C) Copyright 2002
+ * Gary Jennejohn, DENX Software Engineering, <garyj@denx.de>
+ */
+
+#include <common.h>
+#include <time.h>
+#if defined (CONFIG_IMX)
+
+#include <asm/arch/imx-regs.h>
+
+int timer_init (void)
+{
+	int i;
+	/* setup GP Timer 1 */
+	TCTL1 = TCTL_SWR;
+	for ( i=0; i<100; i++) TCTL1 = 0; /* We have no udelay by now */
+	TPRER1 = get_PERCLK1() / 1000000; /* 1 MHz */
+	TCTL1 |= TCTL_FRR | (1<<1); /* Freerun Mode, PERCLK1 input */
+
+	/* Reset the timer */
+	TCTL1 &= ~TCTL_TEN;
+	TCTL1 |= TCTL_TEN; /* Enable timer */
+
+	return (0);
+}
+
+/*
+ * timer without interrupts
+ */
+static ulong get_timer_masked (void)
+{
+	return TCN1;
+}
+
+ulong get_timer (ulong base)
+{
+	return get_timer_masked() - base;
+}
+
+void __udelay (unsigned long usec)
+{
+	ulong endtime = get_timer_masked() + usec;
+	signed long diff;
+
+	do {
+		ulong now = get_timer_masked ();
+		diff = endtime - now;
+	} while (diff >= 0);
+}
+
+/*
+ * This function is derived from PowerPC code (read timebase as long long).
+ * On ARM it just returns the timer value.
+ */
+unsigned long long get_ticks(void)
+{
+	return get_timer(0);
+}
+
+/*
+ * This function is derived from PowerPC code (timebase clock frequency).
+ * On ARM it returns the number of timer ticks per second.
+ */
+ulong get_tbclk (void)
+{
+	return CONFIG_SYS_HZ;
+}
+
+/*
+ * Reset the cpu by setting up the watchdog timer and let him time out
+ */
+void reset_cpu (ulong ignored)
+{
+	/* Disable watchdog and set Time-Out field to 0 */
+	WCR = 0x00000000;
+
+	/* Write Service Sequence */
+	WSR = 0x00005555;
+	WSR = 0x0000AAAA;
+
+	/* Enable watchdog */
+	WCR = 0x00000001;
+
+	while (1);
+	/*NOTREACHED*/
+}
+
+#endif /* defined (CONFIG_IMX) */