*** empty log message ***

[palacios.git] / palacios / src / devices / 8254.c

diff --git a/palacios/src/devices/8254.c b/palacios/src/devices/8254.c
index 8dbe05e..7c0de12 100644 (file)
--- a/palacios/src/devices/8254.c
+++ b/palacios/src/devices/8254.c
@@ -2,6 +2,7 @@
 #include <palacios/vmm.h>
 #include <palacios/vmm_time.h>
 #include <palacios/vmm_util.h>
+#include <palacios/vmm_intr.h>
 
 
 
@@ -44,6 +45,12 @@ struct channel {
   ushort_t counter;
   ushort_t reload_value;
 
+  ushort_t latched_value;
+  
+  enum {NOTLATCHED, LATCHED} latch_state;
+
+  enum {LSB, MSB} read_state;
+
   uint_t output_pin : 1;
   uint_t gate_input_pin : 1;
 };
@@ -96,37 +103,50 @@ static int handle_crystal_tics(struct vm_device * dev, struct channel * ch, uint
   uint_t channel_cycles = 0;
   uint_t output_changed = 0;
   
-  PrintDebug("8254 PIT: %d crystal tics\n", oscillations);
+  // PrintDebug("8254 PIT: %d crystal tics\n", oscillations);
   if (ch->run_state == PENDING) {
     oscillations--;
     ch->counter = ch->reload_value;
+
+    if (ch->op_mode == SQR_WAVE) {
+      ch->counter -= ch->counter % 2;
+    }
+
     ch->run_state = RUNNING;
   } else if (ch->run_state != RUNNING) {
     return output_changed;
   }
 
-
+  /*
   PrintDebug("8254 PIT: Channel Run State = %d, counter=", ch->run_state);
   PrintTraceLL(ch->counter);
   PrintDebug("\n");
-
+  */
+  if (ch->op_mode == SQR_WAVE) {
+    oscillations *= 2;
+  }
 
   if (ch->counter > oscillations) {
     ch->counter -= oscillations;
     return output_changed;
   } else {
+    ushort_t reload_val = ch->reload_value; 
     oscillations -= ch->counter;
     ch->counter = 0;
     channel_cycles = 1;
 
     
-    channel_cycles += oscillations / ch->reload_value;
-    oscillations = oscillations % ch->reload_value;
+    if (ch->op_mode == SQR_WAVE) {
+      reload_val -= reload_val % 2;
+    }
+    
+    channel_cycles += oscillations / reload_val;
+    oscillations = oscillations % reload_val;
 
-    ch->counter = ch->reload_value - oscillations;
+    ch->counter = reload_val - oscillations;
   }
 
-  PrintDebug("8254 PIT: Channel Cycles: %d\n", channel_cycles);
+  //  PrintDebug("8254 PIT: Channel Cycles: %d\n", channel_cycles);
   
 
 
@@ -150,10 +170,18 @@ static int handle_crystal_tics(struct vm_device * dev, struct channel * ch, uint
     }
     break;
   case SQR_WAVE:
+    ch->output_pin = (ch->output_pin + 1) % 2;
+
+    if (ch->output_pin == 1) {
+      output_changed = 1;
+    }
+
     break;
   case SW_STROBE:
+    return -1;
     break;
   case HW_STROBE:
+    return -1;
     break;
   default:
     break;
@@ -212,7 +240,7 @@ static void pit_update_time(ullong_t cpu_cycles, ullong_t cpu_freq, void * priva
     if (handle_crystal_tics(dev, &(state->ch_0), oscillations) == 1) {
       // raise interrupt
       PrintDebug("8254 PIT: Injecting Timer interrupt to guest\n");
-      dev->vm->vm_ops.raise_irq(dev->vm, 0);
+      v3_raise_irq(dev->vm, 0);
     }
 
     //handle_crystal_tics(dev, &(state->ch_1), oscillations);
@@ -254,20 +282,20 @@ static int handle_channel_write(struct channel * ch, char val) {
     case WAITING_LOBYTE:
       ch->reload_value &= 0xff00;
       ch->reload_value |= val;
-
+      
       if (ch->access_mode == LOBYTE_HIBYTE) {
        ch->access_state = WAITING_HIBYTE;
       } else if ((ch->op_mode != RATE_GEN) || (ch->run_state != RUNNING)) {
        ch->run_state = PENDING;
       }
-
+      
       PrintDebug("8254 PIT: updated channel counter: %d\n", ch->reload_value);
       PrintDebug("8254 PIT: Channel Run State=%d\n", ch->run_state);
       break;
     default:
       return -1;
-  }
-
+    }
+    
 
     switch (ch->op_mode) {
     case IRQ_ON_TERM_CNT:
@@ -279,8 +307,9 @@ static int handle_channel_write(struct channel * ch, char val) {
     case RATE_GEN:
       ch->output_pin = 1;
       break;
-
-
+    case SQR_WAVE:
+      ch->output_pin = 1;
+      break;
     default:
       return -1;
       break;
@@ -292,7 +321,28 @@ static int handle_channel_write(struct channel * ch, char val) {
 
 
 static int handle_channel_read(struct channel * ch, char * val) {
-  return -1;
+
+  ushort_t * myval;
+
+  if (ch->latch_state == NOTLATCHED) { 
+    myval = &(ch->counter);
+  } else {
+    myval = &(ch->latched_value);
+  }
+
+  if (ch->read_state == LSB) { 
+    *val = ((char*)myval)[0];  // little endian
+    ch->read_state = MSB;
+  } else {
+    *val = ((char*)myval)[1];
+    ch->read_state = LSB;
+    if (ch->latch_state == LATCHED) { 
+      ch->latch_state = NOTLATCHED;
+    }
+  }
+
+  return 0;
+
 }
 
 
@@ -308,7 +358,10 @@ static int handle_channel_cmd(struct channel * ch, struct pit_cmd_word cmd) {
 
   switch (cmd.access_mode) {
   case LATCH_COUNT:
-    return -1;
+    if (ch->latch_state == NOTLATCHED) { 
+      ch->latched_value = ch->counter;
+      ch->latch_state = LATCHED;
+    }
     break;
   case HIBYTE_ONLY:
     ch->access_state = WAITING_HIBYTE;
@@ -478,6 +531,10 @@ static void init_channel(struct channel * ch) {
   ch->output_pin = 0;
   ch->gate_input_pin = 0;
 
+  ch->latched_value = 0;
+  ch->latch_state = NOTLATCHED;
+  ch->read_state = LSB;
+
   return;
 }