Subject: [PATCH 1/1] ARM:lib32: add architected timer

Renaud Barbier Renaud.Barbier at ametek.com
Tue Mar 7 08:17:08 PST 2023


In preparation for the introduction of the LS1021A support,
add a specific timer support based on the LS1046A support so
that delays can be used in the PBL.

Signed-off-by: Renaud Barbier <renaud.barbier at ametek.com>
---
 arch/arm/lib32/Makefile                |  2 ++
 arch/arm/lib32/arm_architected_timer.c | 17 +++++++++++++++++
 include/clock.h                        |  2 ++
 3 files changed, 21 insertions(+)
 create mode 100644 arch/arm/lib32/arm_architected_timer.c

diff --git a/arch/arm/lib32/Makefile b/arch/arm/lib32/Makefile
index 82507fffc0..d54fb7644c 100644
--- a/arch/arm/lib32/Makefile
+++ b/arch/arm/lib32/Makefile
@@ -31,6 +31,8 @@ extra-y += barebox.lds
 pbl-y	+= lib1funcs.o
 pbl-y	+= ashldi3.o
 pbl-y	+= div0.o
+pbl-$(CONFIG_CPU_32v7)	+= arm_architected_timer.o
+CFLAGS_arm_architected_timer.o := -march=armv7-a
 
 obj-pbl-y	+= setjmp.o
 
diff --git a/arch/arm/lib32/arm_architected_timer.c b/arch/arm/lib32/arm_architected_timer.c
new file mode 100644
index 0000000000..54eca13f8b
--- /dev/null
+++ b/arch/arm/lib32/arm_architected_timer.c
@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <asm/system.h>
+#include <clock.h>
+#include <common.h>
+
+/* Unlike the ARMv8, the timer is not generic to ARM32 */
+void arm_architected_timer_udelay(unsigned long us)
+{
+	unsigned long long ticks, cntfrq = get_cntfrq();
+	unsigned long long start = get_cntpct();
+
+	ticks = DIV_ROUND_DOWN_ULL((us * cntfrq), 1000000);
+
+	while ((long)(start + ticks - get_cntpct()) > 0)
+		;
+}
diff --git a/include/clock.h b/include/clock.h
index e6197e7eb0..8e07c35d37 100644
--- a/include/clock.h
+++ b/include/clock.h
@@ -35,6 +35,8 @@ uint32_t clocksource_hz2mult(uint32_t hz, uint32_t shift_constant);
 int is_timeout(uint64_t start_ns, uint64_t time_offset_ns);
 int is_timeout_non_interruptible(uint64_t start_ns, uint64_t time_offset_ns);
 
+void arm_architected_timer_udelay(unsigned long us);
+
 void ndelay(unsigned long nsecs);
 void udelay(unsigned long usecs);
 void mdelay(unsigned long msecs);
-- 
2.27.0



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