1 files changed, 59 insertions, 0 deletions
diff --git a/drivers/delay_timer/generic_delay_timer.c b/drivers/delay_timer/generic_delay_timer.c
new file mode 100644
index 00000000..8a36c8ab
--- /dev/null
+++ b/drivers/delay_timer/generic_delay_timer.c
@@ -0,0 +1,59 @@
+/*
+ * Copyright (c) 2016, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <arch_helpers.h>
+#include <assert.h>
+#include <bl_common.h>
+#include <debug.h>
+#include <delay_timer.h>
+#include <generic_delay_timer.h>
+#include <platform.h>
+
+/* Ticks elapsed in one second by a signal of 1 MHz */
+#define MHZ_TICKS_PER_SEC 1000000
+
+static timer_ops_t ops;
+
+static uint32_t get_timer_value(void)
+{
+	/*
+	 * Generic delay timer implementation expects the timer to be a down
+	 * counter. We apply bitwise NOT operator to the tick values returned
+	 * by read_cntpct_el0() to simulate the down counter. The value is
+	 * clipped from 64 to 32 bits.
+	 */
+	return (uint32_t)(~read_cntpct_el0());
+}
+
+void generic_delay_timer_init_args(uint32_t mult, uint32_t div)
+{
+	ops.get_timer_value	= get_timer_value;
+	ops.clk_mult		= mult;
+	ops.clk_div		= div;
+
+	timer_init(&ops);
+
+	VERBOSE("Generic delay timer configured with mult=%u and div=%u\n",
+		mult, div);
+}
+
+void generic_delay_timer_init(void)
+{
+	/* Value in ticks */
+	unsigned int mult = MHZ_TICKS_PER_SEC;
+
+	/* Value in ticks per second (Hz) */
+	unsigned int div  = plat_get_syscnt_freq2();
+
+	/* Reduce multiplier and divider by dividing them repeatedly by 10 */
+	while ((mult % 10 == 0) && (div % 10 == 0)) {
+		mult /= 10;
+		div /= 10;
+	}
+
+	generic_delay_timer_init_args(mult, div);
+}
+