Fixes mostly related to touchscreen on Shenzhou board (still does not work)

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5196 42af7a65-404d-4744-a932-0658087f49c3

configs/shenzhou/README.txt

@@ -696,3 +696,61 @@ Where <subdir> is one of the following:
        delay (maybe 30 seconds?) before anything happens.  That is the timeout
        before the networking finally gives up and decides that no network is
        available.
+
+  nxwm
+  ----
+    This is a special configuration setup for the NxWM window manager
+    UnitTest.  The NxWM window manager can be found here:
+
+      trunk/NxWidgets/nxwm
+
+    The NxWM unit test can be found at:
+
+      trunk/NxWidgets/UnitTests/nxwm
+
+    NOTE:  JP6 selects between the touchscreen interrupt and the MII
+    interrupt.  It should be positioned 1-2 to enable the touchscreen
+    interrupt.
+
+    Documentation for installing the NxWM unit test can be found here:
+
+      trunk/NxWidgets/UnitTests/README.txt
+
+    Here is the quick summary of the build steps:
+
+    1. Intall the nxwm configuration
+
+       $ cd ~/nuttx/trunk/nuttx/tools
+       $ ./configure.sh shenzhou/nxwm
+
+    2. Make the build context (only)
+
+       $ cd ..
+       $ . ./setenv.sh
+       $ make context
+       ...
+
+    3. Install the nxwm unit test
+
+       $ cd ~/nuttx/trunk/NxWidgets
+       $ tools/install.sh ~/nuttx/trunk/apps nxwm
+       Creating symbolic link
+        - To ~/nuttx/trunk/NxWidgets/UnitTests/nxwm
+        - At ~/nuttx/trunk/apps/external
+
+    4. Build the NxWidgets library
+
+       $ cd ~/nuttx/trunk/NxWidgets/libnxwidgets
+       $ make TOPDIR=~/nuttx/trunk/nuttx
+       ...
+
+    5. Build the NxWM library
+
+       $ cd ~/nuttx/trunk/NxWidgets/nxwm
+       $ make TOPDIR=~//nuttx/trunk/nuttx
+       ...
+
+    6. Built NuttX with the installed unit test as the application
+
+       $ cd ~/nuttx/trunk/nuttx
+       $ make

configs/shenzhou/src/up_touchscreen.c

@@ -173,19 +173,23 @@ static void tsc_enable(FAR struct ads7843e_config_s *state, bool enable)
 {
   FAR struct stm32_config_s *priv = (FAR struct stm32_config_s *)state;
 
-  DEBUGASSERT(priv->handler);
+  /* The caller should not attempt to enable interrupts if the handler
+   * has not yet been 'attached'
+   */
+
+  DEBUGASSERT(priv->handler || !enable);
 
   /* Attach and enable, or detach and disable */
 
   ivdbg("enable:%d\n", enable);
   if (enable)
     {
-      (void)stm32_gpiosetevent(GPIO_TP_INT, false, true, true,
+      (void)stm32_gpiosetevent(GPIO_TP_INT, true, true, false,
                                priv->handler);
     }
   else
     {
-      (void)stm32_gpiosetevent(GPIO_TP_INT, false, true, true, NULL);
+      (void)stm32_gpiosetevent(GPIO_TP_INT, false, false, false, NULL);
     }
 }
 
@@ -205,9 +209,12 @@ static bool tsc_busy(FAR struct ads7843e_config_s *state)
 
 static bool tsc_pendown(FAR struct ads7843e_config_s *state)
 {
-  /* REVISIT:  This might need to be inverted */
+  /* XPT2046 uses an an internal pullup resistor.  The PENIRQ output goes low
+   * due to the current path through the touch screen to ground, which
+   * initiates an interrupt to the processor via TP_INT.
+   */
 
-  bool pendown = stm32_gpioread(GPIO_TP_INT);
+  bool pendown = !stm32_gpioread(GPIO_TP_INT);
   ivdbg("pendown:%d\n", pendown);
   return pendown;
 }