From 29a24134c170af1cda1b59e5f47071c8353ce3b9 Mon Sep 17 00:00:00 2001
From: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
Date: Wed, 6 Feb 2019 09:23:04 +0000
Subject: [PATCH] drivers: generic_delay_timer: Assert presence of Generic
 Timer

The Generic Timer is an optional extension to an ARMv7-A implementation.
The generic delay timer can be used from any architecture supported by
the Trusted Firmware. In ARMv7 it is needed to check that this feature
is present. In ARMv8 it is always present.

Change-Id: Ib7e8ec13ffbb2f64445d4ee48ed00f26e34b79b7
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
---
 drivers/delay_timer/generic_delay_timer.c | 5 ++++-
 include/arch/aarch32/arch.h               | 2 ++
 include/arch/aarch32/arch_features.h      | 6 ++++++
 include/arch/aarch64/arch_features.h      | 6 ++++++
 4 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/drivers/delay_timer/generic_delay_timer.c b/drivers/delay_timer/generic_delay_timer.c
index 4b67ed0d1..3d0a11f59 100644
--- a/drivers/delay_timer/generic_delay_timer.c
+++ b/drivers/delay_timer/generic_delay_timer.c
@@ -1,11 +1,12 @@
 /*
- * Copyright (c) 2016, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2016-2019, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
 #include <assert.h>
 
+#include <arch_features.h>
 #include <arch_helpers.h>
 #include <common/bl_common.h>
 #include <common/debug.h>
@@ -43,6 +44,8 @@ void generic_delay_timer_init_args(uint32_t mult, uint32_t div)
 
 void generic_delay_timer_init(void)
 {
+	assert(is_armv7_gentimer_present());
+
 	/* Value in ticks */
 	unsigned int mult = MHZ_TICKS_PER_SEC;
 
diff --git a/include/arch/aarch32/arch.h b/include/arch/aarch32/arch.h
index 4af3e9037..3421e042d 100644
--- a/include/arch/aarch32/arch.h
+++ b/include/arch/aarch32/arch.h
@@ -114,6 +114,8 @@
 #define ID_PFR1_VIRTEXT_MASK	U(0xf)
 #define GET_VIRT_EXT(id)	(((id) >> ID_PFR1_VIRTEXT_SHIFT) \
 				 & ID_PFR1_VIRTEXT_MASK)
+#define ID_PFR1_GENTIMER_SHIFT	U(16)
+#define ID_PFR1_GENTIMER_MASK	U(0xf)
 #define ID_PFR1_GIC_SHIFT	U(28)
 #define ID_PFR1_GIC_MASK	U(0xf)
 
diff --git a/include/arch/aarch32/arch_features.h b/include/arch/aarch32/arch_features.h
index d93410267..ddf09680b 100644
--- a/include/arch/aarch32/arch_features.h
+++ b/include/arch/aarch32/arch_features.h
@@ -11,6 +11,12 @@
 
 #include <arch_helpers.h>
 
+static inline bool is_armv7_gentimer_present(void)
+{
+	return ((read_id_pfr1() >> ID_PFR1_GENTIMER_SHIFT) &
+		ID_PFR1_GENTIMER_MASK) != 0U;
+}
+
 static inline bool is_armv8_2_ttcnp_present(void)
 {
 	return ((read_id_mmfr4() >> ID_MMFR4_CNP_SHIFT) &
diff --git a/include/arch/aarch64/arch_features.h b/include/arch/aarch64/arch_features.h
index 9bf43bf85..da8b6e4f1 100644
--- a/include/arch/aarch64/arch_features.h
+++ b/include/arch/aarch64/arch_features.h
@@ -11,6 +11,12 @@
 
 #include <arch_helpers.h>
 
+static inline bool is_armv7_gentimer_present(void)
+{
+	/* The Generic Timer is always present in an ARMv8-A implementation */
+	return true;
+}
+
 static inline bool is_armv8_2_ttcnp_present(void)
 {
 	return ((read_id_aa64mmfr2_el1() >> ID_AA64MMFR2_EL1_CNP_SHIFT) &