MPC860: quicc_smc_serial_driver change

[nprasad3 at gmu dot edu]

Hi,

I am not sure if this is the correct format for patch submission. If not please let me know and I'll send it in the correct format.

Issue: [BUF_SIZE : 0, *polling* mode]
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1. putc starts filling in the buffer (after the buffer is full,  txbd->length is beyond smc_chan->txsize) and flush routine keeps getting called.
2. txbd->length gets reset only in the interrupt handler (*which was never set because outbound buffer length is 0*) and hence this  never takes place.

The following change allows use of 1 buffer, buffer is marked to be sent and then we just wait and reset the length. 

Nirmal
---------------------------------------------------------------------------------
--- quicc_smc_serial-old.c	2003-03-20 13:48:28.000000000 -0500
+++ quicc_smc_serial.c	2004-01-07 13:52:57.265625000 -0500
@@ -512,38 +512,66 @@ quicc_smc_serial_flush(quicc_smc_serial_
 // Send a character to the device output buffer.
 // Return 'true' if character is sent to device
 static bool
-quicc_smc_serial_putc(serial_channel *chan, unsigned char c)
+quicc_sxx_serial_putc(serial_channel *chan, unsigned char c)
 {
-    quicc_smc_serial_info *smc_chan = (quicc_smc_serial_info *)chan->dev_priv;
+    quicc_sxx_serial_info *smc_chan = (quicc_sxx_serial_info *)chan->dev_priv;
     volatile struct cp_bufdesc *txbd, *txfirst;
+    volatile struct smc_uart_pram *pram = (volatile struct smc_uart_pram *)smc_chan->pram;
     EPPC *eppc = eppc_base();
     bool res;
+
     cyg_drv_dsr_lock();  // Avoid race condition testing pointers
-    txbd = (struct cp_bufdesc *)((char *)eppc + smc_chan->pram->tbptr);
-    txfirst = txbd;
-    // Scan for a non-busy buffer
-    while (txbd->ctrl & QUICC_BD_CTL_Ready) {
-        // This buffer is busy, move to next one
-        if (txbd->ctrl & QUICC_BD_CTL_Wrap) {
-            txbd = smc_chan->tbase;
-        } else {
-            txbd++;
-        }
-        if (txbd == txfirst) break;  // Went all the way around
-    }
-    smc_chan->txbd = txbd;
-    if ((txbd->ctrl & (QUICC_BD_CTL_Ready|QUICC_BD_CTL_Int)) == 0) {
-        // Transmit buffer is not full/busy
-        txbd->buffer[txbd->length++] = c;
-        if (txbd->length == smc_chan->txsize) {
-            // This buffer is now full, tell SMC to start processing it
-            quicc_smc_serial_flush(smc_chan);
-        }
-        res = true;
-    } else {
-        // No space
-        res = false;
-    }
+    txbd = (struct cp_bufdesc *)((char *)eppc + pram->tbptr);
+
+	/*-- NP (Polling) --*/
+	if(chan->out_cbuf.len == 0)	{
+		if(txbd->ctrl & QUICC_BD_CTL_Ready)	{
+			// no space in buffer
+			res = false;
+		} else {
+			 // add character to buffer
+			res = true;
+			txbd->buffer[txbd->length++] = c;
+			if(txbd->length == smc_chan->txsize) {
+				// This buffer is now full, tell SMC to start processing it
+				quicc_sxx_serial_flush(smc_chan);
+				// wait for buffer to be sent
+				while(txbd->ctrl & QUICC_BD_CTL_Ready);
+				// reset interrupt bit
+				txbd->ctrl &= ~QUICC_BD_CTL_Int;
+				// reset length
+				txbd->length = 0;
+			}
+		}
+	} else {
+		txfirst = txbd;
+
+		// Scan for a non-busy buffer
+		while (txbd->ctrl & QUICC_BD_CTL_Ready) {
+			// This buffer is busy, move to next one
+			if (txbd->ctrl & QUICC_BD_CTL_Wrap) {
+				txbd = smc_chan->tbase;
+			} else {
+				txbd++;
+			}
+			if (txbd == txfirst) break;  // Went all the way around
+		}
+		smc_chan->txbd = txbd;
+		if ((txbd->ctrl & (QUICC_BD_CTL_Ready|QUICC_BD_CTL_Int)) == 0) {
+			// Transmit buffer is not full/busy
+			txbd->buffer[txbd->length++] = c;
+			if (txbd->length == smc_chan->txsize) {
+				// This buffer is now full, tell SMC to start processing it
+				quicc_sxx_serial_flush(smc_chan);
+			}
+			res = true;
+		} else {
+			// No space
+			res = false;
+		}
+	}
+	/*-- NP (Polling) --*/
+
     cyg_drv_dsr_unlock();
     return res;
 }