* Timekeeping
* arch/x86/time.c
*/
-#include <common.h>
+#include <acess.h>
// === MACROS ===
-#define NUM_TIMERS 8
#define TIMER_QUANTUM 100
-#define TIMER_FREQ 1024 //Hz
+// 2^(15-rate), 15: 1HZ, 5: 1024Hz, 2: 8192Hz
+// (Max: 15, Min: 2) - 15 = 1Hz, 13 = 4Hz, 12 = 8Hz, 11 = 16Hz 10 = 32Hz, 2 = 8192Hz
+//#define TIMER_RATE 10 // 32 Hz
+//#define TIMER_RATE 12 // 8 Hz
+#define TIMER_RATE 14 // 2Hz
+//#define TIMER_RATE 15 // 1HZ
+#define TIMER_FREQ (0x8000>>TIMER_RATE) //Hz
#define MS_PER_TICK_WHOLE (1000/(TIMER_FREQ))
-#define MS_PER_TICK_FRACT ((Uint64)(1000*TIMER_FREQ-((Uint64)MS_PER_TICK_WHOLE)*0x80000000/TIMER_FREQ))
+#define MS_PER_TICK_FRACT ((0x80000000*(1000%TIMER_FREQ))/TIMER_FREQ)
-// === TYPEDEFS ===
-typedef struct sTimer {
- int FiresAfter;
- void (*Callback)(void*);
- void *Argument;
-} tTimer;
-
-// === PROTOTYPES ===
-void Time_Interrupt();
-void Timer_CallTimers();
+// === IMPORTS ===
+extern volatile Sint64 giTimestamp;
+extern volatile Uint64 giTicks;
+extern volatile Uint64 giPartMiliseconds;
+extern void Timer_CallTimers(void);
// === GLOBALS ===
-Uint64 giTicks = 0;
-Sint64 giTimestamp = 0;
-Uint64 giPartMiliseconds = 0;
-tTimer gTimers[NUM_TIMERS];
+volatile Uint64 giTime_TSCAtLastTick = 0;
+volatile Uint64 giTime_TSCPerTick = 0;
+
+// === PROTOTYPES ===
+Sint64 now(void);
+ int Time_Setup(void);
+void Time_Interrupt(int);
+Uint64 Time_ReadTSC(void);
// === CODE ===
/**
- * \fn int Time_Setup()
+ * \fn Sint64 now()
+ * \brief Return the current timestamp
+ */
+Sint64 now(void)
+{
+ Uint64 tsc = Time_ReadTSC();
+ tsc -= giTime_TSCAtLastTick;
+ tsc *= MS_PER_TICK_WHOLE;
+ if( giTime_TSCPerTick ) {
+ tsc /= giTime_TSCPerTick;
+ }
+ else
+ tsc = 0;
+ return giTimestamp + tsc;
+}
+
+/**
+ * \fn int Time_Setup(void)
* \brief Sets the system time from the Realtime-Clock
*/
-int Time_Setup()
+int Time_Setup(void)
{
Uint8 val;
+ Log_Log("Timer", "RTC Timer firing at %iHz (%i divisor), %i.0x%08x",
+ TIMER_FREQ, TIMER_RATE, MS_PER_TICK_WHOLE, MS_PER_TICK_FRACT);
+
outb(0x70, inb(0x70)&0x7F); // Disable NMIs
__asm__ __volatile__ ("cli"); // Disable normal interrupts
+ // Set IRQ8 firing rate
+ outb(0x70, 0x0A); // Set the index to register A
+ val = inb(0x71); // Get the current value of register A
+ outb(0x70, 0x0A); // Reset index to A
+ val &= 0xF0;
+ val |= TIMER_RATE;
+ outb(0x71, val); // Update the timer rate
+
// Enable IRQ8
outb(0x70, 0x0B); // Set the index to register B
val = inb(0x71); // Read the current value of register B
outb(0x70, 0x0B); // Set the index again (a read will reset the index to register D)
outb(0x71, val | 0x40); // Write the previous value or'd with 0x40. This turns on bit 6 of register D
- __asm__ __volatile__ ("sti"); // Disable normal interrupts
- outb(0x70, inb(0x70)|0x80); // Disable NMIs
+ __asm__ __volatile__ ("sti"); // Re-enable normal interrupts
+ outb(0x70, inb(0x70)|0x80); // Re-enable NMIs
// Install IRQ Handler
IRQ_AddHandler(8, Time_Interrupt);
+
+ // Make sure the RTC actually fires
+ outb(0x70, 0x0C); // Select register C
+ inb(0x71); // Just throw away contents.
+
return 0;
}
/**
- * \fn void Time_Interrupt()
* \brief Called on the timekeeping IRQ
+ * \param irq IRQ number (unused)
*/
-void Time_Interrupt()
+void Time_Interrupt(int irq)
{
+ //Log("RTC Tick");
+ Uint64 curTSC = Time_ReadTSC();
+
+ if( giTime_TSCAtLastTick )
+ {
+ giTime_TSCPerTick = curTSC - giTime_TSCAtLastTick;
+ //Log("curTSC = %lli, giTime_TSCPerTick = %lli", curTSC, giTime_TSCPerTick);
+ }
+ giTime_TSCAtLastTick = curTSC;
+
giTicks ++;
giTimestamp += MS_PER_TICK_WHOLE;
giPartMiliseconds += MS_PER_TICK_FRACT;
giPartMiliseconds -= 0x80000000;
}
- Log("giTimestamp = %lli", giTimestamp);
-
Timer_CallTimers();
+
+ // Make sure the RTC Fires again
+ outb(0x70, 0x0C); // Select register C
+ inb(0x71); // Just throw away contents.
}
+#if 0
/**
- * \fn void Time_TimerThread()
+ * \fn void Time_TimerThread(void)
*/
-#if 0
-void Time_TimerThread()
+void Time_TimerThread(void)
{
Sint64 next;
Threads_SetName("TIMER");
}
#endif
-/**
- * \fn Sint64 now()
- * \brief Return the current timestamp
- */
-Sint64 now()
-{
- return giTimestamp;
-}
-
-/**
- * \fn void Timer_CallTimers()
- */
-void Timer_CallTimers()
-{
- int i;
- void (*callback)(void *);
-
- for(i = 0;
- i < NUM_TIMERS;
- i ++)
- {
- Log("%i", i);
- if(gTimers[i].Callback == NULL) continue;
- Log("%i - %lli < %lli", i, giTimestamp, gTimers[i].FiresAfter);
- if(giTimestamp < gTimers[i].FiresAfter) continue;
- callback = gTimers[i].Callback;
- gTimers[i].Callback = NULL;
- callback(gTimers[i].Argument);
- }
-}
-
-/**
- * \fn int Time_CreateTimer(int Delta, void *Callback, void *Argument)
- */
-int Time_CreateTimer(int Delta, void *Callback, void *Argument)
-{
- int ret;
-
- if(Callback == NULL) return -1;
-
- for(ret = 0;
- ret < NUM_TIMERS;
- ret++)
- {
- if(gTimers[ret].Callback != NULL) continue;
- gTimers[ret].Callback = Callback;
- gTimers[ret].FiresAfter = giTimestamp + Delta;
- gTimers[ret].Argument = Argument;
- Log("Callback = %p", Callback);
- Log("Timer %i fires at %lli", ret, gTimers[ret].FiresAfter);
- return ret;
- }
- return -1;
-}
-
-/**
- * \fn void Time_RemoveTimer(int ID)
- */
-void Time_RemoveTimer(int ID)
-{
- if(ID < 0 || ID >= NUM_TIMERS) return;
- gTimers[ID].Callback = NULL;
-}
-
-/**
- * \fn void Time_Delay(int Delay)
- * \brief Delay for a small ammount of time
- */
-void Time_Delay(int Delay)
+Uint64 Time_ReadTSC(void)
{
- Sint64 dest = giTimestamp + Delay;
- while(dest < giTimestamp) Threads_Yield();
+ Uint32 a, d;
+ __asm__ __volatile__ ("rdtsc" : "=a" (a), "=d" (d));
+ return ((Uint64)d << 32) | a;
}