# HG changeset patch
# User Mychaela Falconia <falcon@freecalypso.org>
# Date 1593139982 0
# Node ID 17b7b92e7dba46399258d28fc2776e9414da92f0
# Parent  140a0d24a64ceef14b73cb8e7f7b2ae8ecc570d2
uartfax.c: fix for old Openmoko bug with Auto-CTS

Openmoko made the change of enabling hardware assisted CTS flow control
in the UART when RTS/CTS flow control is used - it is a change which we
have retained in FreeCalypso - but they forgot to turn this hw mode off
if RTS/CTS flow control is deselected at the application level.  We
(FreeCalypso) are now fixing the latter defect ourselves.

diff -r 140a0d24a64c -r 17b7b92e7dba src/cs/drivers/drv_app/uart/uartfax.c
--- a/src/cs/drivers/drv_app/uart/uartfax.c	Thu Jun 25 05:36:24 2020 +0000
+++ b/src/cs/drivers/drv_app/uart/uartfax.c	Fri Jun 26 02:53:02 2020 +0000
@@ -3623,25 +3623,49 @@
             uart, IER, READ_UART_REGISTER (uart, IER) | IER_SLEEP);
             */
 #endif
-        
+
+        /*
+         * Openmoko made the change of enabling hardware assisted CTS
+         * flow control in the UART when RTS/CTS flow control is used -
+         * it is a change which we have retained in FreeCalypso -
+         * but they forgot to turn this hw mode off if RTS/CTS flow control
+         * is deselected at the application level.  We (FreeCalypso)
+         * are now fixing the latter defect ourselves.
+         */
         if (fcMode == fc_rts) {
-#if 1 // Dmitriy: enable hardware assisted CTS 
-            volatile SYS_UWORD8 oldValue;
+            /* begin Openmoko change */
+            SYS_UWORD8 oldValue;
 
             oldValue = READ_UART_REGISTER (uart, LCR);
-            
+
             // LCR value to allow acces to EFR
-     
+
             WRITE_UART_REGISTER (uart, LCR, 0xBF);
-            
+
             // enable hardware assisted CTS
-            
+
             SET_BIT (uart, EFR, AUTO_CTS_BIT);
-            
-            WRITE_UART_REGISTER (uart, LCR, oldValue);    
-#endif
+
+            WRITE_UART_REGISTER (uart, LCR, oldValue);
+            /* end Openmoko change */
+
             if (uart->rts_level)
                 uart->tx_stopped_by_driver = 1;
+        } else {
+            /* FreeCalypso addition: turn off OM-added Auto-CTS */
+            SYS_UWORD8 oldValue;
+
+            oldValue = READ_UART_REGISTER (uart, LCR);
+
+            // LCR value to allow acces to EFR
+
+            WRITE_UART_REGISTER (uart, LCR, 0xBF);
+
+            // disable hardware assisted CTS
+
+            RESET_BIT (uart, EFR, AUTO_CTS_BIT);
+
+            WRITE_UART_REGISTER (uart, LCR, oldValue);
         }
 
         /*