From 0a428c6cad339261dcb2136362ca0aa790f68be9 Mon Sep 17 00:00:00 2001
From: Adrien Bourmault <neox@os-k.eu>
Date: Thu, 14 Nov 2019 00:54:34 +0100
Subject: [PATCH] PIT is now working !

---
 include/ke/idt.h          |  2 ++
 include/ke/time.h         |  3 +++
 kaleid/kernel/init/init.c |  1 +
 kaleid/kernel/ke/idt.c    | 35 +++++++++++++++++++++++++++++++++++
 kaleid/kernel/ke/pit.c    | 34 +++++++++++++++++++++++++++++++++-
 kaleid/kernel/ke/rtc.c    | 18 +++++++-----------
 6 files changed, 81 insertions(+), 12 deletions(-)

diff --git a/include/ke/idt.h b/include/ke/idt.h
index 80ae7ca..6e705bf 100644
--- a/include/ke/idt.h
+++ b/include/ke/idt.h
@@ -69,6 +69,8 @@ struct ISRList_t
 
 void KeLoadIDT(void);
 void KeSetupIDT(void);
+void KeUnmaskIRQ(uchar IRQline);
+void KeMaskIRQ(uchar IRQline);
 
 void KeSendEOItoPIC(uchar isr);
 void KeSetIDTGate(uchar  rank,
diff --git a/include/ke/time.h b/include/ke/time.h
index 0486dd6..c96c9fc 100644
--- a/include/ke/time.h
+++ b/include/ke/time.h
@@ -58,6 +58,9 @@ void    KeDelayExecution(uint);
 Time_t *KeGetCurTime(void);
 char   *KeFormatCurTime(void);
 
+void KeEnablePIT(void);
+void KeSleep(uint);
+
 
 //----------------------------------------------------------------------------//
 
diff --git a/kaleid/kernel/init/init.c b/kaleid/kernel/init/init.c
index e29259e..cf2f92f 100644
--- a/kaleid/kernel/init/init.c
+++ b/kaleid/kernel/init/init.c
@@ -73,6 +73,7 @@ noreturn void BtStartKern(multiboot_info_t *mbInfo, uint mbMagic, void *codeSeg)
 
     // Start drivers
     KeEnableRTC();
+    KeEnablePIT();
     IoEnableKeyb();
     MmActivatePageHandler();
 
diff --git a/kaleid/kernel/ke/idt.c b/kaleid/kernel/ke/idt.c
index 9a4f63c..d5dc7e2 100644
--- a/kaleid/kernel/ke/idt.c
+++ b/kaleid/kernel/ke/idt.c
@@ -230,6 +230,9 @@ static void EnablePIC(void)
     // Set OCW1 (interrupt masks)
     IoWriteByteOnPort(0x21, 0xff);
     IoWriteByteOnPort(0xa1, 0xff);
+
+    char readIrqs = IoReadByteFromPort(0x21);
+    IoWriteByteOnPort(0x21, 0xFB & readIrqs);     // Enables IRQ forwarding from PIC2 to PIC 1
 }
 
 //
@@ -243,6 +246,38 @@ void KeSendEOItoPIC(uchar isr)
     IoWriteByteOnPort(0x20,0x20);
 }
 
+void KeMaskIRQ(uchar isr)
+{
+    uchar port;
+    uchar value;
+
+    if(isr < 0x8) {
+        port = 0x21;
+    } else {
+        port = 0xA1;
+        isr -= 8;
+    }
+
+    value = IoReadByteFromPort(port) | (1 << isr);
+    IoWriteByteOnPort(port, value);
+}
+
+void KeUnmaskIRQ(uchar isr)
+{
+    uchar port;
+    uchar value;
+
+    if(isr < 0x8) {
+        port = 0x21;
+    } else {
+        port = 0xA1;
+        isr -= 8;
+    }
+
+    value = IoReadByteFromPort(port) & ~(1 << isr);
+    IoWriteByteOnPort(port, value);
+}
+
 void KeEnableNMI(void)
 {
     IoWriteByteOnPort(0x70, IoReadByteFromPort(0x70) & 0x7F);
diff --git a/kaleid/kernel/ke/pit.c b/kaleid/kernel/ke/pit.c
index 7b50c61..3e11afa 100644
--- a/kaleid/kernel/ke/pit.c
+++ b/kaleid/kernel/ke/pit.c
@@ -27,21 +27,30 @@
 #include <ke/idt.h>
 
 #define COUNTDONE 1
+#define PIT_FREQUENCY 100 // Hz = 10ms
 
 static TimerFilo_t timerFilo[20]; //20 concurrent sleep max
+static ulong Ticks = 0;
 
 //
 // ISR handler for the Programmable Interval Timer
 //
-static void HandleTimer(ISRFrame_t *regs)
+static void HandlePIT(ISRFrame_t *regs)
 {
     for (uchar i = 0; i < 20; i++) {
+
+        // debug
+        //DebugLog("Hello world of PIT ticks !\n");
+        //
+
         if (timerFilo[i].countDown > 0) {
             timerFilo[i].countDown--;
 
             if (timerFilo[i].countDown == 0)
                 i; //XXX SendMessage a message to timerFifo[i].sema that COUNTDONE;
         }
+
+        KeSendEOItoPIC(0x28);
     }
 }
 
@@ -65,3 +74,26 @@ void KeSleep(uint delay)
     timerBlock->countDown = delay;
     // wait for a message on timerFifo[i].sema
 }
+
+
+void KeEnablePIT(void)
+{
+    ulong flags = KePauseIRQs();
+    char readIrqs;
+    uint divisor = 1193180 / PIT_FREQUENCY;
+
+    KeRegisterISR(HandlePIT, 0x20);
+
+    IoWriteByteOnPort(0x43, 0x36);          // 0x34 = 00110100 for rate gen
+
+    IoWriteByteOnPort(0x40, (char)(divisor & 0xFF ));      // low byte of freq
+    IoWriteByteOnPort(0x40, (char)((divisor >> 8)& 0xFF)); // high byte of freq
+
+    // Setting up the IRQs
+    KeUnmaskIRQ(0);
+
+    DebugLog("\tPIT activated with rate generator mode 10ms\n");
+
+    KeRestoreIRQs(flags);
+    KeEnableNMI();
+}
diff --git a/kaleid/kernel/ke/rtc.c b/kaleid/kernel/ke/rtc.c
index b1cd20f..a6f1bdf 100644
--- a/kaleid/kernel/ke/rtc.c
+++ b/kaleid/kernel/ke/rtc.c
@@ -218,9 +218,9 @@ static void UpdateCurTime(void)
     dayRemain =
             (uchar)(((ulong)OriginTime.hour +  hourRemain) / 24);
 
-    if (dayRemain) {
-       KeStartPanic("[RTC] We must shutdown this computer for your safety.\n");
-    }
+    CurTime.day =
+            (uchar)(((ulong)OriginTime.day +  dayRemain) % 30);
+
 }
 
 Time_t* KeGetCurTime(void)
@@ -273,7 +273,6 @@ void KeEnableRTC(void)
     ulong flags = KePauseIRQs();
     char readInterruptConfig;
     char readRegister;
-    char readIrqs;
 
     KeRegisterISR(HandleRTC, 0x28);
 
@@ -294,10 +293,8 @@ void KeEnableRTC(void)
     IoReadByteFromPort(0x71);                       // Flush
 
     // Setting up the IRQs
-    readIrqs = IoReadByteFromPort(0xA1);
-    IoWriteByteOnPort(0xA1, 0xFE & readIrqs);     // Enables IRQ on PIC 2
-    readIrqs = IoReadByteFromPort(0x21);
-    IoWriteByteOnPort(0x21, 0xFB & readIrqs);     // Enables IRQ on PIC 1
+    KeUnmaskIRQ(8);
+
 
     // Clean-up
     IoWriteByteOnPort(0x70, 0x0C);                  // Select status reg C
@@ -306,8 +303,8 @@ void KeEnableRTC(void)
     GetTimeFromRTC();
     KeRestoreIRQs(flags);
     KeEnableNMI();
-    
-    srand(KeGetTimeStamp());
+
+    srand(KeGetTimeStamp());                        // Initializes the kernel number generator
 }
 
 void KeDelayExecution(uint time)
@@ -318,5 +315,4 @@ void KeDelayExecution(uint time)
     while (KeGetClockTicks() < beginTick + (frequency/1000) * time) {
         KeRelaxCPU();
     }
-
 }