Add support for touchscreen on ITEAD Arduino shield. Untested

6 files changed, 518 insertions, 25 deletions

diff --git a/nuttx/configs/arduino-due/README.txt b/nuttx/configs/arduino-due/README.txt
index 457686da3..24a266956 100644
--- a/nuttx/configs/arduino-due/README.txt
+++ b/nuttx/configs/arduino-due/README.txt
@@ -890,9 +890,24 @@ Configuration sub-directories
     This configuration directory will built the NuttShell.  See NOTES above.
 
     NOTES:
-    1. If the ITEAD TFT shield is connected to the Arduino Due, then
-       support for the SD card slot can be enabled by making the following
-       changes to the configuration:
+    1. NSH built-in applications are supported.  However, there are
+       no built-in applications built with the default configuration.
+
+       Binary Formats:
+         CONFIG_BUILTIN=y                    : Enable support for built-in programs
+
+       Applicaton Configuration:
+         CONFIG_NSH_BUILTIN_APPS=y           : Enable starting apps from NSH command line
+
+    2. By default, this configuration uses UART0 and has support LEDs
+       enabled.  UART0 output is available on the USB debugging port or
+       on pins 0-1 of the PWML connector.
+
+       This configuration can be modified to use peripherals on the ITEAD
+       TFT shield as described below.  However, in that case the UART0 and
+       LED "L" GPIO pins conflict with the pin usage by the ITEAD TFT
+       Shield.  In this case you need to switch to USART0 and disable LEDs
+       by modifying the configuration as follows:
 
        Board Selection -> Peripheral
          CONFIG_SAM34_UART0=n              : Disable UART0.  Can't use with this shield
@@ -915,7 +930,15 @@ Configuration sub-directories
          CONFIG_ARCH_LEDS=n                : Can't support LEDs with this shield installed
          CONFIG_ARDUINO_ITHEAD_TFT=y       : Enable support for the Shield
 
-       NOTE: You cannot use UART0 or LEDs with this ITEAD module.
+    3. If the ITEAD TFT shield is connected to the Arduino Due, then
+       support for the SD card slot can be enabled by making the following
+       changes to the configuration:
+
+       NOTE: You cannot use UART0 or LEDs with this ITEAD module.  You must
+       switch to USART0 and disable LED support as described above.
+
+       Board Selection -> Board-Specific Options:
+         CONFIG_ARDUINO_ITHEAD_TFT=y       : Enable support for the Shield
 
        File Systems:
          CONFIG_DISABLE_MOUNTPOINT=n       : Mountpoint support is needed
@@ -928,9 +951,6 @@ Configuration sub-directories
          file name technologies.  See the top level COPYING file for further
          details.
 
-       System Type -> Peripherals:
-         CONFIG_SAM34_SPI0=y                : Enable the SAM4L SPI peripheral
-
        Device Drivers
          CONFIG_SPI=y                      : Enable SPI support
          CONFIG_SPI_EXCHANGE=y             : The exchange() method is supported
@@ -950,10 +970,46 @@ Configuration sub-directories
          CONFIG_NSH_MMCSDSLOTNO=0          : Only one MMC/SD slot, slot 0
          CONFIG_NSH_MMCSDSPIPORTNO=0       : (does not really matter in this case)
 
-       Board Selection -> SAM4L Xplained Pro Modules
-         CONFIG_SAM4L_XPLAINED_IOMODULE=y      : I/O1 module is connected
-         CONFIG_SAM4L_XPLAINED_IOMODULE_EXT1=y : In EXT1, or EXT2
-         CONFIG_SAM4L_XPLAINED_IOMODULE_EXT2=y
-
        Application Configuration -> NSH Library
          CONFIG_NSH_ARCHINIT=y             : Board has architecture-specific initialization
+
+    3. This configuration has been used for verifying the touchscreen on
+       on the ITEAD TFT Shield.  With the modifications below, you can
+       include the touchscreen test program at apps/examples/touchscreen as
+       an NSH built-in application.  You can enable the touchscreen and test
+       by modifying the  default configuration in the following ways:
+
+       NOTE: You cannot use UART0 or LEDs with this ITEAD module.  You must
+       switch to USART0 and disable LED support as described above.
+
+       Board Selection -> Board-Specific Options:
+         CONFIG_ARDUINO_ITHEAD_TFT=y       : Enable support for the Shield
+
+       Device Drivers
+         CONFIG_SPI=y                      : Enable SPI support
+         CONFIG_SPI_EXCHANGE=y             : The exchange() method is supported
+         CONFIG_SPI_OWNBUS=y               : Smaller code if this is the only SPI device
+         CONFIG_SPI_BITBANG=y              : Enable SPI bit-bang support
+
+         CONFIG_INPUT=y                    : Enable support for input devices
+
+       System Type:
+         CONFIG_GPIO_IRQ=y                 : GPIO interrupt support
+         CONFIG_GPIOACIRQ=y                : Enable GPIO interrupts from port C
+
+       RTOS Features:
+         CONFIG_DISABLE_SIGNALS=n          : Signals are required
+
+       Library Support:
+         CONFIG_SCHED_WORKQUEUE=y          : Work queue support required
+
+       Applicaton Configuration:
+         CONFIG_EXAMPLES_TOUCHSCREEN=y     : Enable the touchscreen built-int test
+
+       Defaults should be okay for related touchscreen settings.  Touchscreen
+       debug output on USART0 can be enabled with:
+
+       Build Setup:
+         CONFIG_DEBUG=y                    : Enable debug features
+         CONFIG_DEBUG_VERBOSE=y            : Enable verbose debug output
+         CONFIG_DEBUG_INPUT=y              : Enable debug output from input devices
diff --git a/nuttx/configs/arduino-due/src/Makefile b/nuttx/configs/arduino-due/src/Makefile
index 1ea60b65a..7f7844c8c 100644
--- a/nuttx/configs/arduino-due/src/Makefile
+++ b/nuttx/configs/arduino-due/src/Makefile
@@ -59,7 +59,7 @@ ifeq ($(CONFIG_MMCSD_SPI),y)
 CSRCS += sam_mmcsd.c
 endif
 
-ifeq ($(CONFIG_INPUT),y)
+ifeq ($(CONFIG_INPUT_ADS7843E),y)
 CSRCS += sam_touchscreen.c
 endif
 endif
diff --git a/nuttx/configs/arduino-due/src/arduino-due.h b/nuttx/configs/arduino-due/src/arduino-due.h
index 6233b3d12..47a506cce 100644
--- a/nuttx/configs/arduino-due/src/arduino-due.h
+++ b/nuttx/configs/arduino-due/src/arduino-due.h
@@ -194,10 +194,10 @@
 #  endif
 
   /* In order to use the touchscreen on the ITEAD shield, you must enable the
-   * SPI bit-bang driver and INPUT device support.
+   * SPI bit-bang driver and ADS7843E/XPT2046 device support.
    */
 
-#  if defined(CONFIG_SPI_BITBANG) && defined(CONFIG_INPUT)
+#  if defined(CONFIG_SPI_BITBANG) && defined(CONFIG_INPUT_ADS7843E)
 #    define GPIO_TSC_SCK  (GPIO_OUTPUT | GPIO_CFG_DEFAULT | GPIO_OUTPUT_CLEAR | \
                            GPIO_PORT_PIOA | GPIO_PIN24)
 #    define GPIO_TSC_MISO (GPIO_OUTPUT | GPIO_CFG_DEFAULT | GPIO_OUTPUT_CLEAR | \
diff --git a/nuttx/configs/arduino-due/src/sam_mmcsd.c b/nuttx/configs/arduino-due/src/sam_mmcsd.c
index 765523fed..42c03989f 100644
--- a/nuttx/configs/arduino-due/src/sam_mmcsd.c
+++ b/nuttx/configs/arduino-due/src/sam_mmcsd.c
@@ -125,16 +125,18 @@ static int spi_cmddata(FAR struct spi_bitbang_s *priv, enum spi_dev_e devid,
 #include <nuttx/spi/spi_bitbang.c>
 
 /****************************************************************************
- * Name: sam_mmcsd_spiinitialize
+ * Name: spi_select
  *
  * Description:
- *   Initialize the SPI bitband driver
+ *   Select or de-selected the SPI device specified by 'devid'
  *
  * Input Parameters:
- *   None
+ *   priv     - An instance of the bit-bang driver structure
+ *   devid    - The device to select or de-select
+ *   selected - True:select false:de-select
  *
  * Returned Value:
- *   A non-NULL reference to the SPI driver on success
+ *   None
  *
  ****************************************************************************/
 
@@ -145,16 +147,17 @@ static void spi_select(FAR struct spi_bitbang_s *priv, enum spi_dev_e devid,
 }
 
 /****************************************************************************
- * Name: sam_mmcsd_spiinitialize
+ * Name: spi_status
  *
  * Description:
- *   Initialize the SPI bitband driver
+ *   Return status of the SPI device specified by 'devid'
  *
  * Input Parameters:
- *   None
+ *   priv     - An instance of the bit-bang driver structure
+ *   devid    - The device to select or de-select
  *
  * Returned Value:
- *   A non-NULL reference to the SPI driver on success
+ *   An 8-bit, bit-encoded status byte
  *
  ****************************************************************************/
 
@@ -196,7 +199,7 @@ static int spi_cmddata(FAR struct spi_bitbang_s *priv, enum spi_dev_e devid,
  * Name: sam_mmcsd_spiinitialize
  *
  * Description:
- *   Initialize the SPI bitband driver
+ *   Initialize the SPI bit-bang driver
  *
  * Input Parameters:
  *   None
diff --git a/nuttx/configs/arduino-due/src/sam_touchscreen.c b/nuttx/configs/arduino-due/src/sam_touchscreen.c
new file mode 100644
index 000000000..cad3d3cda
--- /dev/null
+++ b/nuttx/configs/arduino-due/src/sam_touchscreen.c
@@ -0,0 +1,434 @@
+/************************************************************************************
+ * configs/sam3u-ek/src/up_touchscreen.c
+ *
+ *   Copyright (C) 2011-2013 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ************************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <stdbool.h>
+#include <stdio.h>
+#include <debug.h>
+#include <assert.h>
+#include <errno.h>
+
+#include <nuttx/spi/spi.h>
+#include <nuttx/spi/spi_bitbang.h>
+#include <nuttx/input/touchscreen.h>
+#include <nuttx/input/ads7843e.h>
+
+#include "up_arch.h"
+#include "sam_gpio.h"
+#include "chip/sam3u_pio.h"
+
+#include "arduino-due.h"
+
+/* In order to use the SD card on the ITEAD shield, you must enable the SPI
+ * bit-bang driver as well as support for SPI-based ADS7843E/XPT2046
+ * touchscreen controller.
+ */
+
+#if defined(CONFIG_ARDUINO_ITHEAD_TFT) && defined(CONFIG_SPI_BITBANG) && \
+    defined(CONFIG_INPUT_ADS7843E)
+
+/****************************************************************************
+ * Pre-Processor Definitions
+ ****************************************************************************/
+/* Configuration ************************************************************/
+
+#ifndef CONFIG_GPIOC_IRQ
+#  error "Touchscreen support requires CONFIG_GPIOC_IRQ"
+#endif
+
+#ifndef CONFIG_ADS7843E_FREQUENCY
+#  define CONFIG_ADS7843E_FREQUENCY 500000
+#endif
+
+#ifndef CONFIG_ADS7843E_SPIDEV
+#  define CONFIG_ADS7843E_SPIDEV 0
+#endif
+
+#ifndef CONFIG_ADS7843E_DEVMINOR
+#  define CONFIG_ADS7843E_DEVMINOR 0
+#endif
+
+/* Definitions for include/nuttx/spi/spi_bitbang.c. */
+
+#define SPI_SETSCK  putreg32(1 << 24, SAM_PIOA_SODR)
+#define SPI_CLRSCK  putreg32(1 << 24, SAM_PIOA_CODR)
+#define SPI_SETMOSI putreg32(1 << 16, SAM_PIOA_SODR)
+#define SPI_CLRMOSI putreg32(1 << 16, SAM_PIOA_CODR)
+#define SPI_GETMISO ((getreg32(SAM_PIOC_PDSR) >> 21) & 1)
+#define SPI_SETCS   putreg32(1 << ?, SAM_PIO?_SODR)
+#define SPI_CLRCS   putreg32(1 << ?, SAM_PIO?_CODR)
+
+/* Only mode 0 */
+
+#undef  SPI_BITBANG_DISABLEMODE0
+#define SPI_BITBANG_DISABLEMODE1 1
+#define SPI_BITBANG_DISABLEMODE2 1
+#define SPI_BITBANG_DISABLEMODE3 1
+
+/* Only 8-bit data width */
+
+#undef SPI_BITBANG_VARWIDTH
+
+/* Calibration value for timing loop */
+
+#define SPI_BITBAND_LOOPSPERMSEC CONFIG_BOARD_LOOPSPERMSEC
+
+/* SPI_PERBIT_NSEC is the minimum time to transfer one bit.  This determines
+ * the maximum frequency and is also used to calculate delays to achieve
+ * other SPI frequencies.
+ */
+
+#define SPI_PERBIT_NSEC      100
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+/* Lower-half SPI */
+
+static void spi_select(FAR struct spi_bitbang_s *priv, enum spi_dev_e devid,
+                       bool selected);
+static uint8_t spi_status(FAR struct spi_bitbang_s *priv, enum spi_dev_e devid);
+#ifdef CONFIG_SPI_CMDDATA
+static int spi_cmddata(FAR struct spi_bitbang_s *priv, enum spi_dev_e devid,
+                       bool cmd);
+#endif
+
+/* IRQ/GPIO access callbacks.  These operations all hidden behind
+ * callbacks to isolate the ADS7843E 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
+ * enable  - Enable or disable the GPIO interrupt
+ * clear   - Acknowledge/clear any pending GPIO interrupt
+ * pendown - Return the state of the pen down GPIO input
+ */
+
+static int  tsc_attach(FAR struct ads7843e_config_s *state, xcpt_t isr);
+static void tsc_enable(FAR struct ads7843e_config_s *state, bool enable);
+static void tsc_clear(FAR struct ads7843e_config_s *state);
+static bool tsc_busy(FAR struct ads7843e_config_s *state);
+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
+ * driver.  This structure provides information about the configuration
+ * of the ADS7843E 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. The
+ * memory must be writable because, under certain circumstances, the driver
+ * may modify frequency or X plate resistance values.
+ */
+
+static struct ads7843e_config_s g_tscinfo =
+{
+  .frequency = CONFIG_ADS7843E_FREQUENCY,
+
+  .attach    = tsc_attach,
+  .enable    = tsc_enable,
+  .clear     = tsc_clear,
+  .busy      = tsc_busy,
+  .pendown   = tsc_pendown,
+};
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+/****************************************************************************
+ * Include the bit-band skeleton logic
+ ****************************************************************************/
+
+#include <nuttx/spi/spi_bitbang.c>
+
+/****************************************************************************
+ * Name: spi_select
+ *
+ * Description:
+ *   Select or de-selected the SPI device specified by 'devid'
+ *
+ * Input Parameters:
+ *   priv     - An instance of the bit-bang driver structure
+ *   devid    - The device to select or de-select
+ *   selected - True:select false:de-select
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+static void spi_select(FAR struct spi_bitbang_s *priv, enum spi_dev_e devid,
+                       bool selected)
+{
+# warning Still need CS GPIO pin
+}
+
+/****************************************************************************
+ * Name: spi_status
+ *
+ * Description:
+ *   Return status of the SPI device specified by 'devid'
+ *
+ * Input Parameters:
+ *   priv     - An instance of the bit-bang driver structure
+ *   devid    - The device to select or de-select
+ *
+ * Returned Value:
+ *   An 8-bit, bit-encoded status byte
+ *
+ ****************************************************************************/
+
+static uint8_t spi_status(FAR struct spi_bitbang_s *priv, enum spi_dev_e devid)
+{
+  return 0;
+}
+
+/****************************************************************************
+ * Name: spi_cmddata
+ *
+ * Description:
+ *   If there were was a CMD/DATA line, this function would manage it
+ *
+ * Input Parameters:
+ *   priv  - An instance of the bit-bang driver structure
+ *   devid - The device to use
+ *   cmd   - True=MCD false=DATA
+ *
+ * Returned Value:
+ *  OK
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_SPI_CMDDATA
+static int spi_cmddata(FAR struct spi_bitbang_s *priv, enum spi_dev_e devid,
+                       bool cmd)
+{
+  return OK;
+}
+#endif
+
+/****************************************************************************
+ * IRQ/GPIO access callbacks.  These operations all hidden behind
+ * callbacks to isolate the ADS7843E 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
+ *   enable  - Enable or disable the GPIO interrupt
+ *   clear   - Acknowledge/clear any pending GPIO interrupt
+ *   pendown - Return the state of the pen down GPIO input
+ *
+ ****************************************************************************/
+
+static int tsc_attach(FAR struct ads7843e_config_s *state, xcpt_t isr)
+{
+  /* Attach the ADS7843E interrupt */
+
+  ivdbg("Attaching %p to IRQ %d\n", isr, SAM_TCS_IRQ);
+  return irq_attach(SAM_TCS_IRQ, isr);
+}
+
+static void tsc_enable(FAR struct ads7843e_config_s *state, bool enable)
+{
+  /* Attach and enable, or detach and disable */
+
+  ivdbg("IRQ:%d enable:%d\n", SAM_TCS_IRQ, enable);
+  if (enable)
+    {
+      sam_gpioirqenable(SAM_TCS_IRQ);
+    }
+  else
+    {
+      sam_gpioirqdisable(SAM_TCS_IRQ);
+    }
+}
+
+static void tsc_clear(FAR struct ads7843e_config_s *state)
+{
+  /* Does nothing */
+}
+
+static bool tsc_busy(FAR struct ads7843e_config_s *state)
+{
+#if defined(CONFIG_DEBUG_INPUT) && defined(CONFIG_DEBUG_VERBOSE)
+  static bool last = (bool)-1;
+#endif
+
+  /* BUSY is high impedance when CS is high (not selected).  When CS is
+   * is low, BUSY is active high.
+   */
+
+  bool busy = sam_gpioread(GPIO_TCS_BUSY);
+#if defined(CONFIG_DEBUG_INPUT) && defined(CONFIG_DEBUG_VERBOSE)
+  if (busy != last)
+    {
+      ivdbg("busy:%d\n", busy);
+      last = busy;
+    }
+#endif
+
+  return busy;
+}
+
+static bool tsc_pendown(FAR struct ads7843e_config_s *state)
+{
+  /* The /PENIRQ value is active low */
+
+  bool pendown = !sam_gpioread(GPIO_TCS_IRQ);
+  ivdbg("pendown:%d\n", pendown);
+  return pendown;
+}
+
+/****************************************************************************
+ * Name: sam_tsc_spiinitialize
+ *
+ * Description:
+ *   Initialize the SPI bit-bang driver
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value:
+ *   A non-NULL reference to the SPI driver on success
+ *
+ ****************************************************************************/
+
+static FAR struct spi_dev_s *sam_tsc_spiinitialize(void)
+{
+  /* Configure the SPI bit-bang pins */
+
+  sam_configgpio(GPIO_TSC_SCK);
+  sam_configgpio(GPIO_TSC_MISO);
+  sam_configgpio(GPIO_TSC_MOSI);
+  sam_configgpio(GPIO_TSC_CS);
+
+  /* Create the SPI driver instance */
+
+  return spi_create_bitbang(&g_spiops);
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: arch_tcinitialize
+ *
+ * Description:
+ *   Each board that supports a touchscreen device must provide this function.
+ *   This function is called by application-specific, setup logic to
+ *   configure the touchscreen device.  This function will register the driver
+ *   as /dev/inputN where N is the minor device number.
+ *
+ * Input Parameters:
+ *   minor   - The input device minor number
+ *
+ * Returned Value:
+ *   Zero is returned on success.  Otherwise, a negated errno value is
+ *   returned to indicate the nature of the failure.
+ *
+ ****************************************************************************/
+
+int arch_tcinitialize(int minor)
+{
+  FAR struct spi_dev_s *dev;
+  int ret;
+
+  idbg("minor %d\n", minor);
+  DEBUGASSERT(minor == 0);
+
+  /* Configure and enable the ADS7843E interrupt pin as an input */
+
+  (void)sam_configgpio(GPIO_TSC_IRQ);
+  (void)sam_configgpio(GPIO_TCS_IRQ);
+
+  /* Configure the PIO interrupt */
+
+  sam_gpioirq(SAM_TCS_IRQ);
+
+  /* Get an instance of the SPI interface for the touchscreen chip select */
+
+  dev = sam_tsc_spiinitialize();
+  if (!dev)
+    {
+      idbg("Failed to initialize bit bang SPI\n");
+      return -ENODEV;
+    }
+
+  /* Initialize and register the SPI touschscreen device */
+
+  ret = ads7843e_register(dev, &g_tscinfo, CONFIG_ADS7843E_DEVMINOR);
+  if (ret < 0)
+    {
+      idbg("Failed to register touchscreen device\n");
+      /* up_spiuninitialize(dev); */
+      return -ENODEV;
+    }
+
+  return OK;
+}
+
+/****************************************************************************
+ * Name: arch_tcuninitialize
+ *
+ * Description:
+ *   Each board that supports a touchscreen device must provide this function.
+ *   This function is called by application-specific, setup logic to
+ *   uninitialize the touchscreen device.
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value:
+ *   None.
+ *
+ ****************************************************************************/
+
+void arch_tcuninitialize(void)
+{
+  /* No support for un-initializing the touchscreen ADS7843E device yet */
+}
+
+#endif /* CONFIG_ARDUINO_ITHEAD_TFT && CONFIG_SPI_BITBANG && CONFIG_INPUT_ADS7843E */
diff --git a/nuttx/drivers/spi/Kconfig b/nuttx/drivers/spi/Kconfig
index 2dd09bd5b..b7a59a865 100644
--- a/nuttx/drivers/spi/Kconfig
+++ b/nuttx/drivers/spi/Kconfig
@@ -42,7 +42,7 @@ config SPI_BITBANG_VARWIDTH
 	bool "SPI bit-bang variable width transfers"
 	default n
 	---help---
-		Enable support for a variable dat width transfers.  Default: 8-bit
+		Enable support for a variable data width transfers.  Default: 8-bit
 		only.
 
 endif