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

source/bootloader/u-boot-2020.01/arch/sh/lib/time_sh2.c

@@ -0,0 +1,88 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2007,2008 Nobobuhiro Iwamatsu <iwamatsu@nigauri.org>
+ * Copyright (C) 2008 Renesas Solutions Corp.
+ *
+ * (C) Copyright 2003
+ * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+ */
+
+#include <common.h>
+#include <time.h>
+#include <asm/io.h>
+#include <asm/processor.h>
+
+#define CMT_CMCSR_INIT	0x0001	/* PCLK/32 */
+#define CMT_CMCSR_CALIB 0x0000
+#define CMT_MAX_COUNTER (0xFFFFFFFF)
+#define CMT_TIMER_RESET (0xFFFF)
+
+static vu_long cmt0_timer;
+
+static void cmt_timer_start(unsigned int timer)
+{
+	writew(readw(CMSTR) | 0x01, CMSTR);
+}
+
+static void cmt_timer_stop(unsigned int timer)
+{
+	writew(readw(CMSTR) & ~0x01, CMSTR);
+}
+
+int timer_init(void)
+{
+	cmt0_timer = 0;
+	/* Divide clock by 32 */
+	readw(CMCSR_0);
+	writew(CMT_CMCSR_INIT, CMCSR_0);
+
+	/* User Device 0 only */
+	cmt_timer_stop(0);
+	writew(CMT_TIMER_RESET, CMCOR_0);
+	cmt_timer_start(0);
+
+	return 0;
+}
+
+unsigned long long get_ticks(void)
+{
+	return cmt0_timer;
+}
+
+static vu_long cmcnt = 0;
+static unsigned long get_usec (void)
+{
+	ulong data = readw(CMCNT_0);
+
+	if (data >= cmcnt)
+		cmcnt = data - cmcnt;
+	else
+		cmcnt = (CMT_TIMER_RESET - cmcnt) + data;
+
+	if ((cmt0_timer + cmcnt) > CMT_MAX_COUNTER)
+		cmt0_timer = ((cmt0_timer + cmcnt) - CMT_MAX_COUNTER);
+	else
+		cmt0_timer += cmcnt;
+
+	cmcnt = data;
+	return cmt0_timer;
+}
+
+/* return msec */
+ulong get_timer(ulong base)
+{
+	return (get_usec() / 1000) - base;
+}
+
+void __udelay(unsigned long usec)
+{
+	unsigned long end = get_usec() + usec;
+
+	while (get_usec() < end)
+		continue;
+}
+
+unsigned long get_tbclk(void)
+{
+	return CONFIG_SH_CMT_CLK_FREQ;
+}