Correct port direction for Arduino MISO signal

configs/arduino-due/README.txt

@@ -122,6 +122,11 @@ ITEAD 2.4" TFT with Touch
   The Arduino 2.4" TFT Touch shield uses the S6D1121 controller , it
   supports 8-bit data interface. The touch IC is XPT2046.
 
+  NOTE:  When used with the ITEAD shield, the power from the USB connector
+  seems to be inefficient (for example, I lose the USB connection when I
+  insert an SD card).  I recommends using a 7-12V power supply with the
+  Arduino in this case.
+
   Connector:
 
   ---------- --------------------------- ----------- --------------------------- ------------------
@@ -863,25 +868,28 @@ Configurations
        reconfiguration process.
 
   2. Unless stated otherwise, all configurations generate console
-     output on UART1 which is available on J1 or J4 (see the
-     section "Serial Consoles" above).  USART1 or the virtual COM
-     port on UART0 are options. The virtual COM port could
-     be used, for example, by reconfiguring to use UART0 like:
-
-       System Type -> AT91SAM3/4 Peripheral Support
-         CONFIG_SAM_UART0=y
-         CONFIG_SAM_UART1=n
-
-       Device Drivers -> Serial Driver Support -> Serial Console
-         CONFIG_UART0_SERIAL_CONSOLE=y
-
-       Device Drivers -> Serial Driver Support -> UART0 Configuration
-         CONFIG_UART0_2STOP=0
-         CONFIG_UART0_BAUD=115200
-         CONFIG_UART0_BITS=8
-         CONFIG_UART0_PARITY=0
-         CONFIG_UART0_RXBUFSIZE=256
-         CONFIG_UART0_TXBUFSIZE=256
+     output on UART0 which is available both on the USB virtual COM port
+     and on the PWML connector (see the section "Serial Consoles" above).
+
+     However, the pin usage by the ITEAD TFT shield conflict with the pin
+     usage for UART0.  In this case you need to switch to USART0 by
+     modifying the configuration as follows:
+
+       Board Selection -> Peripheral
+         CONFIG_SAM34_UART0=n              : Disable UART0.  Can't use with this shield
+         CONFIG_SAM34_USART0=y             : Enable USART0
+         CONFIG_USART0_ISUART=y
+
+       Device Drivers -> Serial
+         CONFIG_USART0_SERIAL_CONSOLE=y    : Configure the console on USART0
+         CONFIG_USART0_RXBUFSIZE=256
+         CONFIG_USART0_TXBUFSIZE=256
+         CONFIG_USART0_BAUD=115200
+         CONFIG_USART0_BITS=8
+         CONFIG_USART0_PARITY=0
+         CONFIG_USART0_2STOP=0
+
+     NOTE: USART0 TTL levels are available on COMM 5 (TXD0) and COMM 6 (RXD0).
 
   3. Unless otherwise stated, the configurations are setup for
      Linux (or any other POSIX environment like Cygwin under Windows):

configs/arduino-due/src/arduino-due.h

@@ -205,8 +205,8 @@
 
 #    define GPIO_SD_SCK   (GPIO_OUTPUT | GPIO_CFG_DEFAULT | GPIO_OUTPUT_CLEAR | \
                            GPIO_PORT_PIOB | GPIO_PIN27)
-#    define GPIO_SD_MISO  (GPIO_OUTPUT | GPIO_CFG_DEFAULT | GPIO_OUTPUT_CLEAR | \
-                           GPIO_PORT_PIOD | GPIO_PIN8)
+#    define GPIO_SD_MISO  (GPIO_INPUT | GPIO_CFG_PULLUP | GPIO_PORT_PIOD | \
+                           GPIO_PIN8)
 #    define GPIO_SD_MOSI  (GPIO_OUTPUT | GPIO_CFG_DEFAULT | GPIO_OUTPUT_CLEAR | \
                            GPIO_PORT_PIOD | GPIO_PIN7)
 
@@ -241,8 +241,8 @@
 
 #    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 | \
-                           GPIO_PORT_PIOC | GPIO_PIN22)
+#    define GPIO_TSC_MISO (GPIO_INPUT | GPIO_CFG_PULLUP | GPIO_PORT_PIOC | \
+                           GPIO_PIN22)
 #    define GPIO_TSC_MOSI (GPIO_OUTPUT | GPIO_CFG_DEFAULT | GPIO_OUTPUT_CLEAR | \
                            GPIO_PORT_PIOA | GPIO_PIN16)
 

drivers/spi/spi_bitbang.c

@@ -238,6 +238,8 @@ static void spi_select(FAR struct spi_dev_s *dev, enum spi_dev_e devid,
                        bool selected)
 {
   FAR struct spi_bitbang_s *priv = (FAR struct spi_bitbang_s *)dev;
+
+  spivdbg("devid=%d selected=%d\n", devid, selected);
   DEBUGASSERT(priv && priv->low->select);
   priv->low->select(priv, devid, selected);
 }
@@ -287,6 +289,7 @@ static uint32_t spi_setfrequency(FAR struct spi_dev_s *dev, uint32_t frequency)
 static void spi_setmode(FAR struct spi_dev_s *dev, enum spi_mode_e mode)
 {
   FAR struct spi_bitbang_s *priv = (FAR struct spi_bitbang_s *)dev;
+
   DEBUGASSERT(priv && priv->low->setmode);
   priv->low->setmode(priv, mode);
   spivdbg("mode=%d exchange=%p\n", mode, priv->exchange);