nuttx/configs/arduino-due/src/sam_touchscreen.c

/************************************************************************************
 * 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/board.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_SAM34_GPIOC_IRQ
#  error "Touchscreen support requires CONFIG_SAM34_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) >> 22) & 1)

/* 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 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 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
 */

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 XPT2046
 * driver.  This structure provides information about the configuration
 * 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. 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)
{
  /* The touchscreen controller is always selected */
}

/****************************************************************************
 * 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 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 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
 *
 ****************************************************************************/

static int tsc_attach(FAR struct ads7843e_config_s *state, xcpt_t isr)
{
  /* Attach the XPT2046 interrupt */

  ivdbg("Attaching %p to IRQ %d\n", isr, SAM_TSC_IRQ);
  return irq_attach(SAM_TSC_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_TSC_IRQ, enable);
  if (enable)
    {
      sam_gpioirqenable(SAM_TSC_IRQ);
    }
  else
    {
      sam_gpioirqdisable(SAM_TSC_IRQ);
    }
}

static void tsc_clear(FAR struct ads7843e_config_s *state)
{
  /* Does nothing */
}

static bool tsc_busy(FAR struct ads7843e_config_s *state)
{
  return false; /* The BUSY signal is not connected */
}

static bool tsc_pendown(FAR struct ads7843e_config_s *state)
{
  /* The /PENIRQ value is active low */

  bool pendown = !sam_gpioread(GPIO_TSC_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);

  /* Create the SPI driver instance */

  return spi_create_bitbang(&g_spiops);
}

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/****************************************************************************
 * Name: board_tsc_setup
 *
 * 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 board_tsc_setup(int minor)
{
  FAR struct spi_dev_s *dev;
  static bool initialized = false;
  int ret;

  idbg("minor %d\n", minor);
  DEBUGASSERT(minor == 0);

  /* Have we already initialized?  Since we never uninitialize we must prevent
   * multiple initializations.  This is necessary, for example, when the
   * touchscreen example is used as a built-in application in NSH and can be
   * called numerous time.  It will attempt to initialize each time.
   */

  if (!initialized)
    {
      /* Configure and enable the XPT2046 interrupt pin as an input */

      (void)sam_configgpio(GPIO_TSC_IRQ);

      /* Configure the PIO interrupt */

      sam_gpioirq(SAM_TSC_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;
        }

      /* Now we are initialized */

      initialized = true;
    }

  return OK;
}

/****************************************************************************
 * Name: board_tsc_teardown
 *
 * 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 board_tsc_teardown(void)
{
  /* No support for un-initializing the touchscreen XPT2046 device.  It will
   * continue to run and process touch interrupts in the background.
   */
}

#endif /* CONFIG_ARDUINO_ITHEAD_TFT && CONFIG_SPI_BITBANG && CONFIG_INPUT_ADS7843E */