Tegra: introduce delay timer support

This patch introduces the backend required for implementing the delay
timer API. Tegra has an on-chip free flowing us timer which can be
used as the delay timer.
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>

plat/nvidia/tegra/common/tegra_bl31_setup.c

@@ -161,6 +161,11 @@ void bl31_platform_setup(void)
 {
 	uint32_t tmp_reg;
 
+	/*
+	 * Initialize delay timer
+	 */
+	tegra_delay_timer_init();
+
 	/*
 	 * Setup secondary CPU POR infrastructure.
 	 */

plat/nvidia/tegra/common/tegra_common.mk

@@ -48,6 +48,7 @@ COMMON_DIR		:=	plat/nvidia/tegra/common
 BL31_SOURCES		+=	drivers/arm/gic/gic_v2.c			\
 				drivers/arm/gic/gic_v3.c			\
 				drivers/console/console.S			\
+				drivers/delay_timer/delay_timer.c		\
 				drivers/ti/uart/16550_console.S			\
 				lib/cpus/aarch64/cortex_a53.S			\
 				lib/cpus/aarch64/cortex_a57.S			\
@@ -57,6 +58,7 @@ BL31_SOURCES		+=	drivers/arm/gic/gic_v2.c			\
 				${COMMON_DIR}/drivers/pmc/pmc.c			\
 				${COMMON_DIR}/drivers/flowctrl/flowctrl.c	\
 				${COMMON_DIR}/tegra_bl31_setup.c		\
+				${COMMON_DIR}/tegra_delay_timer.c		\
 				${COMMON_DIR}/tegra_gic.c			\
 				${COMMON_DIR}/tegra_pm.c			\
 				${COMMON_DIR}/tegra_sip_calls.c			\

plat/nvidia/tegra/common/tegra_delay_timer.c

+/*
+ * Copyright (c) 2015, ARM Limited and Contributors. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ *
+ * Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * Neither the name of ARM nor the names of its contributors may be used
+ * to endorse or promote products derived from this software without specific
+ * prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <delay_timer.h>
+#include <mmio.h>
+#include <tegra_def.h>
+
+static uint32_t tegra_timerus_get_value(void)
+{
+	return mmio_read_32(TEGRA_TMRUS_BASE);
+}
+
+static const timer_ops_t tegra_timer_ops = {
+	.get_timer_value	= tegra_timerus_get_value,
+	.clk_mult		= 1,
+	.clk_div		= 1,
+};
+
+/*
+ * Initialise the on-chip free rolling us counter as the delay
+ * timer.
+ */
+void tegra_delay_timer_init(void)
+{
+	timer_init(&tegra_timer_ops);
+}

plat/nvidia/tegra/include/tegra_private.h

@@ -74,4 +74,7 @@ int tegra_prepare_cpu_on_finish(unsigned long mpidr);
 plat_params_from_bl2_t *bl31_get_plat_params(void);
 int bl31_check_ns_address(uint64_t base, uint64_t size_in_bytes);
 
+/* Declarations for tegra_delay_timer.c */
+void tegra_delay_timer_init(void);
+
 #endif /* __TEGRA_PRIVATE_H__ */