From ffae612634548210b4f2facab9ade01bbf8087af Mon Sep 17 00:00:00 2001
From: John Hodge <tpg@mutabah.net>
Date: Sun, 22 Sep 2013 19:22:51 +0800
Subject: [PATCH] Kernel/armv7 - [realview_pb] Implemented basic timekeeping

---
 .../Kernel/arch/armv7/platform_realview_pb.c  | 95 ++++++++++++++++++-
 KernelLand/Kernel/arch/armv7/time.c           |  5 +-
 2 files changed, 97 insertions(+), 3 deletions(-)

diff --git a/KernelLand/Kernel/arch/armv7/platform_realview_pb.c b/KernelLand/Kernel/arch/armv7/platform_realview_pb.c
index 4077f691..b8b6a6f9 100644
--- a/KernelLand/Kernel/arch/armv7/platform_realview_pb.c
+++ b/KernelLand/Kernel/arch/armv7/platform_realview_pb.c
@@ -7,15 +7,106 @@
  */
 #include <acess.h>
 
+// === IMPORTS ===
+extern tTime	giTimestamp;
+
 // === PROTOTYPES ===
-void	Time_Setup(void);
+void	Time_Setup(void);	// TODO: Should be in header
+void	Time_int_RTCIRQHandler(int IRQ, void *unused);
+void	Time_int_TimerIRQHandler(int IRQ, void *unused);
+tTime	Time_GetTickOffset(void);	// TODO: Should be in header
 
 // === GLOBALS ===
+tTime	giTimeBase;
+Uint32	giTime_PartMS;
 tPAddr	gGIC_DistributorAddr = 0x1e001000;
 tPAddr	gGIC_InterfaceAddr = 0x1e000000;
 
+#define DIVISOR_ENC	1
+#define DIVISOR_REAL	(1 << (4*DIVISOR_ENC))
+#define TICKS_PER_SECOND	(1000000/DIVISOR_REAL)
+#define TICKS_PER_IRQ	(TICKS_PER_SECOND/2)	// Tick twice a second
+#define TICKS_PER_MS	(TICKS_PER_SECOND/1000)
+#define MS_PER_IRQ	(TICKS_PER_IRQ*1000/TICKS_PER_SECOND)	// (TICKS_PER_IRQ/(TICKS_PER_SECOND/1000))
+#define PART_PER_IRQ	(TICKS_PER_IRQ%(TICKS_PER_SECOND/1000))	// (TICKS_PER_IRQ%(TICKS_PER_SECOND/1000))
+
+// RTC
+#define PL031_BASE	0x10017000
+#define PL031_IRQ	10
+volatile struct {
+	Uint32	DR;
+	Uint32	MR;
+	Uint32	LR;
+	Uint32	CR;
+	Uint32	IMSC;
+	Uint32	IS;
+	Uint32	MIS;
+	Uint32	ICR;
+} *gTime_PL031;
+// Timer
+#define SP804_BASE	0x10011000
+#define SP805_IRQ	4
+volatile struct {
+	struct {
+		Uint32	Load;
+		Uint32	Value;
+		Uint32	Control;
+		Uint32	CIS;
+		Uint32	RIS;
+		Uint32	MIS;
+		Uint32	BGLoad;
+		Uint32	_unused2;
+	} Timers[2];
+} *gTime_SP804;
+
 // === CODE ===
+void Time_int_RTCIRQHandler(int IRQ, void *unused)
+{
+	if( !(gTime_PL031->IS & 1) ) {
+		return ;
+	}
+	gTime_PL031->ICR = 1;	// Clear interrupt
+//	giTimestamp = (Uint64)gTime_PL031->DR * 1000 - giTimeBase;
+}
+
+void Time_int_TimerIRQHandler(int IRQ, void *unused)
+{
+	if( !(gTime_SP804->Timers[0].RIS) ) {
+		return ;
+	}
+	gTime_SP804->Timers[0].CIS = 1;
+	giTime_PartMS += PART_PER_IRQ;
+	giTimestamp += MS_PER_IRQ;
+	while( giTime_PartMS > TICKS_PER_MS ) {
+		giTime_PartMS -= TICKS_PER_MS;
+		giTimestamp ++;
+	}
+}
+
 void Time_Setup(void)
 {
-	// TODO: 
+	// PL031 RTC
+	gTime_PL031 = MM_MapHWPages(PL031_BASE, 1);
+	//IRQ_AddHandler(PL031_IRQ, Time_int_RTCIRQHandler, NULL);
+	gTime_PL031->IMSC = 1;
+	gTime_PL031->ICR = 1;
+//	giTimestamp = (Uint64)gTime_PL031->DR * 1000;
+	
+	// SP804 Timer (Contains two basic ARM timers, each at 1MHz base)
+	gTime_SP804 = MM_MapHWPages(SP804_BASE, 1);
+	// - Use the first to maintain the system clock
+	gTime_SP804->Timers[0].Load = TICKS_PER_IRQ;
+	//  > Enable,Periodic,IE,Div=1,32bit
+	gTime_SP804->Timers[0].Control = (1<<7)|(1<<6)|(1<<5)|(DIVISOR_ENC<<2)|(1<<1);
+	IRQ_AddHandler(SP805_IRQ, Time_int_TimerIRQHandler, NULL);
+	gTime_SP804->Timers[0].CIS = 1;
+	// - TODO: use the second for short events (and use RTC for long events)
+}
+
+tTime Time_GetTickOffset(void)
+{
+	if( !gTime_SP804 )
+		return 0;
+	// Want count of ms since last tick
+	return (giTime_PartMS + gTime_SP804->Timers[0].Value) / TICKS_PER_MS;
 }
diff --git a/KernelLand/Kernel/arch/armv7/time.c b/KernelLand/Kernel/arch/armv7/time.c
index d4ae4fa6..7be097f4 100644
--- a/KernelLand/Kernel/arch/armv7/time.c
+++ b/KernelLand/Kernel/arch/armv7/time.c
@@ -6,11 +6,14 @@
  */
 #include <acess.h>
 
+// === IMPORTS ===
+extern tTime	Time_GetTickOffset(void);
+
 // === GLOBALS ===
 tTime	giTimestamp;
 
 // === CODE ===
 tTime now(void)
 {
-	return giTimestamp;
+	return giTimestamp + Time_GetTickOffset();
 }
-- 
2.20.1