SSP driver fixes for the LPC178x; Fixes for Open1788 touchscreen driver

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5812 42af7a65-404d-4744-a932-0658087f49c3

configs/open1788/README.txt

@@ -453,10 +453,11 @@ CONFIGURATION
        following ways:
 
        CONFIG_INPUT=y                      : Enable support for input devices
-       CONFIG_GPIO_IRQ=y                   : GPIO interrupt support
        CONFIG_INPUT_ADS7843E=y             : Enable support for the XPT2048
+       CONFIG_ADS7843E_SPIDEV=1            : Use SSP1 for communication
        CONFIG_SPI=y                        : Enable SPI support
        CONFIG_SPI_EXCHANGE=n               : exchange() method is not supported
+       CONFIG_GPIO_IRQ=y                   : GPIO interrupt support
        CONFIG_LPC17_SSP1=y                 : Enable support for SSP1
        CONFIG_EXAMPLES_TOUCHSCREEN=y       : Enable the touchscreen built-int test
        CONFIG_EXAMPLES_TOUCHSCREEN_BUILTIN=y
@@ -466,7 +467,8 @@ CONFIGURATION
        You will also have to disable SD card support to use this test.  The
        SD card detect (CD) signal is on P0[13].  This signal is shared.  It
        is also used for MOSI1 and USB_UP_LED.  The CD pin may be disconnected.
-       There is a jumper on board that enables the CD pin.
+       There is a jumper on board that enables the CD pin.  OR, you can simply
+       remove the SD module so that it does not drive the CD pin.
 
        CONFIG_LPC17_GPDMA=n                : No DMA
        CONFIG_ARCH_DMA=n

configs/open1788/include/board.h

@@ -407,12 +407,6 @@
 #define GPIO_SSP1_MOSI   GPIO_SSP1_MOSI_2
 #define GPIO_SSP1_SCK    GPIO_SSP1_SCK_2
 
-#define GPIO_SSP1_SSEL_1   (GPIO_ALT2 | GPIO_PULLUP | GPIO_PORT0 | GPIO_PIN6)
-#define GPIO_SSP1_SSEL_2   (GPIO_ALT2 | GPIO_PULLUP | GPIO_PORT0 | GPIO_PIN14)
-#define GPIO_SSP1_SSEL_3   (GPIO_ALT5 | GPIO_PULLUP | GPIO_PORT1 | GPIO_PIN26)
-#define GPIO_SSP1_SSEL_4   (GPIO_ALT3 | GPIO_PULLUP | GPIO_PORT4 | GPIO_PIN21)
-
-
 /************************************************************************************
  * Public Types
  ************************************************************************************/

configs/open1788/src/lpc17_ssp.c

@@ -174,7 +174,7 @@ void  lpc17_ssp1select(FAR struct spi_dev_s *dev, enum spi_dev_e devid, bool sel
   sspdbg("devid: %d CS: %s\n", (int)devid, selected ? "assert" : "de-assert");
   if (devid == SPIDEV_TOUCHSCREEN)
     {
-      /* Assert/de-assert the CS pin to the card */
+      /* Assert/de-assert the CS pin to the touchscreen */
 
       ssp_dumpgpio(GPIO_TC_CS, "lpc17_ssp1select() Entry");
       lpc17_gpiowrite(GPIO_TC_CS, !selected);

configs/open1788/src/lpc17_touchscreen.c

@@ -80,17 +80,27 @@
 #endif
 
 #ifndef CONFIG_ADS7843E_SPIDEV
-#  define CONFIG_ADS7843E_SPIDEV 3
+#  define CONFIG_ADS7843E_SPIDEV 1
 #endif
 
-#if CONFIG_ADS7843E_SPIDEV != 3
+#if CONFIG_ADS7843E_SPIDEV != 1
-#  error "CONFIG_ADS7843E_SPIDEV must be three"
+#  error "CONFIG_ADS7843E_SPIDEV must be one"
 #endif
 
 #ifndef CONFIG_ADS7843E_DEVMINOR
 #  define CONFIG_ADS7843E_DEVMINOR 0
 #endif
 
+/* REVISIT:  Currently, XPT2046 reports BUSY all of the time.  This is
+ * probably GPIO setting issues.  But there is this cryptic statement in
+ * the XPT2046 spec:  "No DCLK delay required with dedicated serial port."
+ *
+ * The busy state is used by the XPT2046 driver to control the delay
+ * between sending the command, then reading the returned data.
+ */
+
+#define XPT2046_NO_BUSY 1
+
 /****************************************************************************
  * Private Types
  ****************************************************************************/
@@ -100,12 +110,12 @@
  ****************************************************************************/
 
 /* IRQ/GPIO access callbacks.  These operations all hidden behind
- * callbacks to isolate the ADS7843E driver from differences in GPIO
+ * callbacks to isolate the XPT2046 driver from differences in GPIO
  * interrupt handling by varying boards and MCUs.  If possible,
  * interrupts should be configured on both rising and falling edges
  * so that contact and loss-of-contact events can be detected.
  *
- * attach  - Attach the ADS7843E interrupt handler to the GPIO interrupt
+ * attach  - Attach the XPT2046 interrupt handler to the GPIO interrupt
  * enable  - Enable or disable the GPIO interrupt
  * clear   - Acknowledge/clear any pending GPIO interrupt
  * pendown - Return the state of the pen down GPIO input
@@ -121,9 +131,9 @@ static bool tsc_pendown(FAR struct ads7843e_config_s *state);
  * Private Data
  ****************************************************************************/
 
-/* A reference to a structure of this type must be passed to the ADS7843E
+/* A reference to a structure of this type must be passed to the XPT2046
  * driver.  This structure provides information about the configuration
- * of the ADS7843E and provides some board-specific hooks.
+ * of the XPT2046 and provides some board-specific hooks.
  *
  * Memory for this structure is provided by the caller.  It is not copied
  * by the driver and is presumed to persist while the driver is active.
@@ -144,12 +154,12 @@ static struct ads7843e_config_s g_tscinfo =
  ****************************************************************************/
 
 /* IRQ/GPIO access callbacks.  These operations all hidden behind
- * callbacks to isolate the ADS7843E driver from differences in GPIO
+ * callbacks to isolate the XPT2046 driver from differences in GPIO
  * interrupt handling by varying boards and MCUs.  If possible,
  * interrupts should be configured on both rising and falling edges
  * so that contact and loss-of-contact events can be detected.
  *
- * attach  - Attach the ADS7843E interrupt handler to the GPIO interrupt
+ * attach  - Attach the XPT2046 interrupt handler to the GPIO interrupt
  * enable  - Enable or disable the GPIO interrupt
  * clear   - Acknowledge/clear any pending GPIO interrupt
  * pendown - Return the state of the pen down GPIO input
@@ -183,6 +193,20 @@ static void tsc_clear(FAR struct ads7843e_config_s *state)
 
 static bool tsc_busy(FAR struct ads7843e_config_s *state)
 {
+/* The busy state is used by the XPT2046 driver to control the delay
+ * between sending the command, then reading the returned data.
+ */
+
+#ifdef XPT2046_NO_BUSY
+/* REVISIT:  Currently, XPT2046 reports BUSY all of the time.  This is
+ * probably GPIO setting issues.  But there is this cryptic statement in
+ * the XPT2046 spec:  "No DCLK delay required with dedicated serial port."
+ */
+
+  return false;
+
+#else /* XPT2046_NO_BUSY */
+
 #if defined(CONFIG_DEBUG_INPUT) && defined(CONFIG_DEBUG_VERBOSE)
   static bool last = (bool)-1;
 #endif
@@ -199,6 +223,8 @@ static bool tsc_busy(FAR struct ads7843e_config_s *state)
 #endif
 
   return busy;
+
+#endif /* XPT2046_NO_BUSY */
 }
 
 static bool tsc_pendown(FAR struct ads7843e_config_s *state)
@@ -237,37 +263,50 @@ static bool tsc_pendown(FAR struct ads7843e_config_s *state)
 
 int arch_tcinitialize(int minor)
 {
+  static bool initialized = false;
   FAR struct spi_dev_s *dev;
   int ret;
 
-  idbg("minor %d\n", minor);
+  idbg("initialized:%d minor:%d\n", initialized, minor);
   DEBUGASSERT(minor == 0);
 
-  /* Configure and enable the ADS7843E PENIRQ pin as an interrupting input. */
+  /* Since there is no uninitialized logic, this initialization can be
+   * performed only one time.
+   */
 
-  (void)lpc17_configgpio(GPIO_TC_PENIRQ);
+  if (!initialized)
-
-  /* Configure the ADS7843E BUSY pin as a normal input. */
-
-  (void)lpc17_configgpio(GPIO_TC_BUSY);
-
-  /* Get an instance of the SPI interface */
-
-  dev = lpc17_sspinitialize(CONFIG_ADS7843E_SPIDEV);
-  if (!dev)
     {
-      idbg("Failed to initialize SPI bus %d\n", CONFIG_ADS7843E_SPIDEV);
+      /* Configure and enable the XPT2046 PENIRQ pin as an interrupting input. */
-      return -ENODEV;
-    }
 
-  /* Initialize and register the SPI touschscreen device */
+      (void)lpc17_configgpio(GPIO_TC_PENIRQ);
 
-  ret = ads7843e_register(dev, &g_tscinfo, CONFIG_ADS7843E_DEVMINOR);
+      /* Configure the XPT2046 BUSY pin as a normal input. */
-  if (ret < 0)
+
-    {
+#ifndef XPT2046_NO_BUSY
-      idbg("Failed to initialize SPI bus %d\n", CONFIG_ADS7843E_SPIDEV);
+      (void)lpc17_configgpio(GPIO_TC_BUSY);
-      /* up_spiuninitialize(dev); */
+#endif
-      return -ENODEV;
+
+      /* Get an instance of the SPI interface */
+
+      dev = lpc17_sspinitialize(CONFIG_ADS7843E_SPIDEV);
+      if (!dev)
+        {
+          idbg("Failed to initialize SPI bus %d\n", CONFIG_ADS7843E_SPIDEV);
+          return -ENODEV;
+        }
+
+      /* Initialize and register the SPI touchscreen device */
+
+      ret = ads7843e_register(dev, &g_tscinfo, CONFIG_ADS7843E_DEVMINOR);
+      if (ret < 0)
+        {
+          idbg("Failed to register touchscreen device minor=%d\n",
+               CONFIG_ADS7843E_DEVMINOR);
+          /* up_spiuninitialize(dev); */
+          return -ENODEV;
+        }
+
+      initialized = true;
     }
 
   return OK;
@@ -291,7 +330,7 @@ int arch_tcinitialize(int minor)
 
 void arch_tcuninitialize(void)
 {
-  /* No support for un-initializing the touchscreen ADS7843E device yet */
+  /* No support for un-initializing the touchscreen XPT2046 device yet */
 }
 
 #endif /* CONFIG_INPUT_ADS7843E */