Changeset eff217e in rtems

Timestamp:

Sep 10, 1998, 12:16:39 PM (21 years ago)

Author:

Joel Sherrill <joel.sherrill@…>

Branches:

4.10, 4.11, 4.8, 4.9, master

Children:

109b17f4

Parents:

c7cb6bbb

Message:

Patch from Emmanuel Raguet <raguet@…>:

After some good comments from Eric Norum [thanks, Eric !],
I have added some modifications to my previous driver patch :

• wait for transmitter ready before sending a packet,

• new delay management in case of ring-overwritting.

Location:

c/src/lib/libbsp/i386/pc386

Files:

• network/network.c (modified) (4 diffs)
• startup/bspstart.c (modified) (1 diff)
• timer/timer.c (modified) (3 diffs)

c/src/lib/libbsp/i386/pc386/network/network.c

@@ -130 +130 @@
 wd8003Enet_interrupt_handler (rtems_vector_number v)
 {
-  unsigned int tport, nowTicks, bootTicks;
+  unsigned int tport;
   unsigned char status, status2;
 
@@ -147 +147 @@
   if (status & MSK_OVW){
     outport_byte(tport+CMDR, MSK_STP + MSK_RD2);        /* stop 8390 */
-    rtems_clock_get(RTEMS_CLOCK_GET_TICKS_SINCE_BOOT, &bootTicks );
-    while(nowTicks < bootTicks+loopc)               /* 2ms delay */
-      rtems_clock_get(RTEMS_CLOCK_GET_TICKS_SINCE_BOOT, &nowTicks );
+    Wait_X_ms(2);
     outport_byte(tport+RBCR0, 0);                       /* clear byte count */
     outport_byte(tport+RBCR1, 0);
@@ -362 +360 @@
         struct mbuf *n;
         unsigned int len, tport;
-        char *shp;
+        char *shp, txReady;
 
         tport = dp->port;
 
-
+  /*
+   * Waiting for Transmitter ready
+   */   
+  inport_byte(tport+CMDR, txReady); 
+  while(txReady & MSK_TXP)
+    inport_byte(tport+CMDR, txReady); 
 
   len = 0;
@@ -640 +643 @@
                 ifp->if_snd.ifq_maxlen = ifqmaxlen;
 
-        /* calibrate a delay loop for 2 milliseconds */
-        rtems_clock_get(RTEMS_CLOCK_GET_TICKS_PER_SECOND, &loopc );
-        loopc /= 500;
-
         /*
          * init some variables

c/src/lib/libbsp/i386/pc386/startup/bspstart.c

@@ -147 +147 @@
 void bsp_start( void )
 {
+
+  /*
+   * Calibrate variable for 1ms-loop (see timer.c)
+   */
+  Calibrate_loop_1ms();
+
   rtemsFreeMemStart = (rtems_unsigned32)&_end + _stack_size;
                                     /* set the value of start of free memory. */

c/src/lib/libbsp/i386/pc386/timer/timer.c

@@ -46 +46 @@
 #define AVG_OVERHEAD  0              /* 0.1 microseconds to start/stop timer. */
 #define LEAST_VALID   1              /* Don't trust a value lower than this.  */
-
+#define SLOW_DOWN_IO  0x80      /* io which does nothing */
+
+#define TWO_MS  (rtems_unsigned32)(2000)     /* TWO_MS = 2000us (sic!) */
+
+#define MSK_NULL_COUNT 0x40     /* bit counter available for reading */
+
+#define CMD_READ_BACK_STATUS 0xE2   /* command read back status */
 /*-------------------------------------------------------------------------+
 | Global Variables
@@ -52 +58 @@
 volatile rtems_unsigned32 Ttimer_val;
          rtems_boolean    Timer_driver_Find_average_overhead = TRUE;
+         unsigned int     loop1ms;
 
 /*-------------------------------------------------------------------------+
@@ -294 +301 @@
   Timer_driver_Find_average_overhead = find_flag;
 } /* Set_find_average_overhead */
+
+/*-------------------------------------------------------------------------+
+|         Function: Calibrate_loop_1ms
+|      Description: Set loop variable to calibrate a 1ms loop
+| Global Variables: loop1ms
+|        Arguments: none
+|          Returns: Nothing. 
++--------------------------------------------------------------------------*/
+void
+Calibrate_loop_1ms(void){
+  unsigned int i;
+  unsigned short loadedValue, offset;
+  unsigned int timerValue;
+  rtems_interrupt_level  level;
+  unsigned short lsb, msb;
+  unsigned char status;
+  
+  
+  loop1ms = 100 ;
+  timerValue = 2000;
+  loadedValue = US_TO_TICK(2000);
+  
+  rtems_interrupt_disable(level);
+
+  /*
+   * Compute the offset to apply due to read counter register
+   */
+  outport_byte(TIMER_MODE, TIMER_SEL0|TIMER_16BIT|TIMER_RATEGEN);
+  outport_byte(TIMER_CNTR0, loadedValue >> 0 & 0xff);
+  outport_byte(TIMER_CNTR0, loadedValue >> 8 & 0xff);
+
+  outport_byte(TIMER_MODE, CMD_READ_BACK_STATUS); /* read Status counter 0 */
+  inport_byte(TIMER_CNTR0, status);
+  while (status & MSK_NULL_COUNT){      /* wait for counter ready */    
+    outport_byte(TIMER_MODE, CMD_READ_BACK_STATUS);
+    inport_byte(TIMER_CNTR0, status);
+  }
+  
+  outport_byte(TIMER_MODE, TIMER_SEL0|TIMER_LATCH);
+  inport_byte(TIMER_CNTR0, lsb);
+  inport_byte(TIMER_CNTR0, msb);
+  offset = loadedValue - (unsigned short)((msb << 8) | lsb);
+
+  while (timerValue > 1000){
+    loop1ms++;
+
+    /* load timer for 2ms+offset period */
+    outport_byte(TIMER_MODE, TIMER_SEL0|TIMER_16BIT|TIMER_RATEGEN);
+    outport_byte(TIMER_CNTR0, (loadedValue+offset) >> 0 & 0xff);
+    outport_byte(TIMER_CNTR0, (loadedValue+offset) >> 8 & 0xff);
+
+    outport_byte(TIMER_MODE, CMD_READ_BACK_STATUS); /* read Status counter 0 */
+    inport_byte(TIMER_CNTR0, status);
+    while (status & MSK_NULL_COUNT) {   /* wait for counter ready */ 
+      outport_byte(TIMER_MODE, CMD_READ_BACK_STATUS);
+      inport_byte(TIMER_CNTR0, status);
+    }
+    
+    for (i=0; i<loop1ms; i++)
+      outport_byte(SLOW_DOWN_IO, 0);    /* write is # 1us */
+
+    outport_byte(TIMER_MODE, TIMER_SEL0|TIMER_LATCH);
+    inport_byte(TIMER_CNTR0, lsb);
+    inport_byte(TIMER_CNTR0, msb);
+    timerValue = TICK_TO_US((msb << 8) | lsb);
+  }
+
+  rtems_interrupt_enable(level);
+}
+
+/*-------------------------------------------------------------------------+
+|         Function: Wait_X_1ms
+|      Description: loop which waits at least timeToWait ms
+| Global Variables: loop1ms
+|        Arguments: timeToWait
+|          Returns: Nothing. 
++--------------------------------------------------------------------------*/
+void
+Wait_X_ms( unsigned int timeToWait){
+
+  unsigned int i, j;
+
+  for (j=0; j<timeToWait ; j++)
+    for (i=0; i<loop1ms; i++)
+      outport_byte(SLOW_DOWN_IO, 0);    /* write is # 1us */
+}
+
+
+
+
+
+