From bcff09a3898898b9609d41c8205efa1f19417fd7 Mon Sep 17 00:00:00 2001
From: Wolfvak <soherrera1@hotmail.com>
Date: Wed, 17 Apr 2019 15:54:47 -0300
Subject: [PATCH] added a small 10ms wait before turning on the backlight,
 thanks to profi for reminding me of that

---
 arm11/source/arm/timer.c  | 49 +++++++++++++++++++++++----------------
 arm11/source/arm/timer.h  | 26 +++++++++++----------
 arm11/source/system/sys.c |  5 +++-
 3 files changed, 47 insertions(+), 33 deletions(-)

diff --git a/arm11/source/arm/timer.c b/arm11/source/arm/timer.c
index 16e2386..81e5a17 100755
--- a/arm11/source/arm/timer.c
+++ b/arm11/source/arm/timer.c
@@ -1,20 +1,29 @@
-#include <types.h>
-#include <arm.h>
-
-#include "arm/gic.h"
-#include "arm/timer.h"
-
-#define TIMER_INTERRUPT	(0x1E)
-
-#define REG_TIMER(c, n)	REG_ARM_PMR(0x700 + ((c) * 0x100) + (n), u32)
-#define TIMER_THIS_CPU	(-1)
-
-#define REG_TIMER_LOAD(c)	*REG_TIMER((c), 0x00)
-#define REG_TIMER_COUNT(c)	*REG_TIMER((c), 0x04)
-#define REG_TIMER_CNT(c)	*REG_TIMER((c), 0x08)
-#define REG_TIMER_IRQ(c)	*REG_TIMER((c), 0x0C)
-
-#define TIMER_CNT_SCALE(n)	((n) << 8)
-#define TIMER_CNT_INT_EN	BIT(2)
-#define TIMER_CNT_RELOAD	BIT(1)
-#define TIMER_CNT_ENABLE	BIT(0)
+#include <types.h>
+#include <arm.h>
+
+#include "arm/gic.h"
+#include "arm/timer.h"
+
+#define TIMER_INTERRUPT	(0x1E)
+
+#define REG_TIMER(c, n)	REG_ARM_PMR(0x700 + ((c) * 0x100) + (n), u32)
+#define TIMER_THIS_CPU	(-1)
+
+#define REG_TIMER_LOAD(c)	*REG_TIMER((c), 0x00)
+#define REG_TIMER_COUNT(c)	*REG_TIMER((c), 0x04)
+#define REG_TIMER_CNT(c)	*REG_TIMER((c), 0x08)
+#define REG_TIMER_IRQ(c)	*REG_TIMER((c), 0x0C)
+
+#define TIMER_CNT_SCALE(n)	((n) << 8)
+#define TIMER_CNT_INT_EN	BIT(2)
+#define TIMER_CNT_RELOAD	BIT(1)
+#define TIMER_CNT_ENABLE	BIT(0)
+
+void TIMER_WaitTicks(u32 ticks)
+{
+	REG_TIMER_IRQ(TIMER_THIS_CPU) = 1;
+	REG_TIMER_CNT(TIMER_THIS_CPU) = 0;
+	REG_TIMER_LOAD(TIMER_THIS_CPU) = ticks;
+	REG_TIMER_CNT(TIMER_THIS_CPU) = TIMER_CNT_ENABLE;
+	while(REG_TIMER_COUNT(TIMER_THIS_CPU));
+}
diff --git a/arm11/source/arm/timer.h b/arm11/source/arm/timer.h
index 578de15..b8d21ee 100755
--- a/arm11/source/arm/timer.h
+++ b/arm11/source/arm/timer.h
@@ -1,12 +1,14 @@
-#pragma once
-
-#include <types.h>
-
-// The timer interval is calculated using the following equation:
-// T = [(PRESCALER_value + 1) * (Load_value + 1) * 2] / CPU_CLK
-// therefore
-// Load_value = [(CPU_CLK / 2) * (T / (PRESCALER_value + 1))] - 1
-
-#define BASE_CLKRATE	(268111856)
-
-#define CLK_FREQ_TO_INTERVAL(f, p)	((BASE_CLKRATE/2) * ((f) / ((p) + 1)) - 1)
+#pragma once
+
+#include <types.h>
+
+// The timer interval is calculated using the following equation:
+// T = [(PRESCALER_value + 1) * (Load_value + 1) * 2] / CPU_CLK
+// therefore
+// Load_value = [(CPU_CLK / 2) * (T / (PRESCALER_value + 1))] - 1
+
+#define BASE_CLKRATE	(268111856 / 2)
+
+#define CLK_MS_TO_TICKS(m)	(((BASE_CLKRATE / 1000) * (m)) - 1)
+
+void TIMER_WaitTicks(u32 ticks);
diff --git a/arm11/source/system/sys.c b/arm11/source/system/sys.c
index 465ddcf..9869cbb 100755
--- a/arm11/source/system/sys.c
+++ b/arm11/source/system/sys.c
@@ -4,8 +4,9 @@
 #include <pxi.h>
 
 #include "arm/gic.h"
-#include "arm/scu.h"
 #include "arm/mmu.h"
+#include "arm/scu.h"
+#include "arm/timer.h"
 
 #include "hw/gpulcd.h"
 #include "hw/i2c.h"
@@ -93,6 +94,8 @@ void SYS_CoreZeroInit(void)
 
 	GPU_SetFramebufferMode(0, PDC_RGB24);
 	GPU_SetFramebufferMode(1, PDC_RGB24);
+
+	TIMER_WaitTicks(CLK_MS_TO_TICKS(10));
 	MCU_WriteReg(0x22, 0x2A);
 }