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

source/trusted-firmware/trusted-firmware-a-2.8/drivers/renesas/common/delay/micro_delay.c

@@ -0,0 +1,31 @@
+/*
+ * Copyright (c) 2018-2020, Renesas Electronics Corporation. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <arch.h>
+#include <arch_helpers.h>
+
+#include "micro_delay.h"
+
+#define RCAR_CONV_MICROSEC		1000000U
+
+void
+#if IMAGE_BL31
+	__attribute__ ((section(".system_ram")))
+#endif
+	rcar_micro_delay(uint64_t micro_sec)
+{
+	uint64_t freq;
+	uint64_t base_count;
+	uint64_t get_count;
+	uint64_t wait_time = 0U;
+
+	freq = read_cntfrq_el0();
+	base_count = read_cntpct_el0();
+	while (micro_sec > wait_time) {
+		get_count = read_cntpct_el0();
+		wait_time = ((get_count - base_count) * RCAR_CONV_MICROSEC) / freq;
+	}
+}