From 700e35c6ac74a64719fbc38fe66386dd422613f3 Mon Sep 17 00:00:00 2001
From: Kevin O'Connor <kevin@koconnor.net>
Date: Sun, 9 Jun 2019 20:26:30 -0400
Subject: armcm_timer: Unify udelay() implementation

Move the udelay() code from various arm board directories into the
src/generic/armcm_timer.c code.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
---
 src/generic/armcm_timer.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

(limited to 'src/generic/armcm_timer.c')

diff --git a/src/generic/armcm_timer.c b/src/generic/armcm_timer.c
index a9c8ab9f..7f11cd68 100644
--- a/src/generic/armcm_timer.c
+++ b/src/generic/armcm_timer.c
@@ -54,6 +54,20 @@ timer_kick(void)
     SCB->ICSR = SCB_ICSR_PENDSTSET_Msk;
 }
 
+// Implement simple early-boot delay mechanism
+void
+udelay(uint32_t usecs)
+{
+    if (!(CoreDebug->DEMCR & CoreDebug_DEMCR_TRCENA_Msk)) {
+        CoreDebug->DEMCR |= CoreDebug_DEMCR_TRCENA_Msk;
+        DWT->CTRL |= DWT_CTRL_CYCCNTENA_Msk;
+    }
+
+    uint32_t end = timer_read_time() + timer_from_us(usecs);
+    while (timer_is_before(timer_read_time(), end))
+        ;
+}
+
 void
 timer_init(void)
 {
-- 
cgit v1.2.3-70-g09d2