1 files changed, 266 insertions, 0 deletions
diff --git a/nuttx/drivers/input/stmpe811_adc.c b/nuttx/drivers/input/stmpe811_adc.c
new file mode 100644
index 000000000..1ffe987e6
--- /dev/null
+++ b/nuttx/drivers/input/stmpe811_adc.c
@@ -0,0 +1,266 @@
+/****************************************************************************
+ * drivers/input/stmpe811_adc.c
+ *
+ *   Copyright (C) 2012 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * References:
+ *   "STMPE811 S-Touch® advanced resistive touchscreen controller with 8-bit
+ *    GPIO expander," Doc ID 14489 Rev 6, CD00186725, STMicroelectronics"
+ *
+ * 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 <unistd.h>
+#include <assert.h>
+#include <errno.h>
+#include <debug.h>
+
+#include <nuttx/arch.h>
+#include <nuttx/input/stmpe811.h>
+
+#include "stmpe811.h"
+
+#if defined(CONFIG_INPUT) && defined(CONFIG_INPUT_STMPE811) && !defined(CONFIG_STMPE811_ADC_DISABLE)
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: stmpe811_adcinitialize
+ *
+ * Description:
+ *  Configure for ADC mode operation.  Set overall ADC ADC timing that
+ *  applies to all pins.
+ *
+ * Input Parameters:
+ *   handle    - The handle previously returned by stmpe811_instantiate
+ *
+ * Returned Value:
+ *   Zero is returned on success.  Otherwise, a negated errno value is
+ *   returned to indicate the nature of the failure.
+ *
+ ****************************************************************************/
+
+int stmpe811_adcinitialize(STMPE811_HANDLE handle)
+{
+  FAR struct stmpe811_dev_s *priv = (FAR struct stmpe811_dev_s *)handle;
+  uint8_t regval;
+  int ret;
+
+  DEBUGASSERT(handle);
+
+  /* Get exclusive access to the device structure */
+
+  ret = sem_wait(&priv->exclsem);
+  if (ret < 0)
+    {
+      int errval = errno;
+      idbg("sem_wait failed: %d\n", errval);
+      return -errval;
+    }
+
+  /* Enable Clocking for ADC */
+
+  regval = stmpe811_getreg8(priv, STMPE811_SYS_CTRL2);
+  regval &= ~SYS_CTRL2_ADC_OFF;
+  stmpe811_putreg8(priv, STMPE811_SYS_CTRL2, regval);
+
+  /* Select Sample Time, bit number and ADC Reference */
+
+  stmpe811_putreg8(priv, STMPE811_ADC_CTRL1, priv->config->ctrl1);
+
+  /* Wait for 20 ms */
+
+  up_mdelay(20);
+
+  /* Select the ADC clock speed */
+
+  stmpe811_putreg8(priv, STMPE811_ADC_CTRL2, priv->config->ctrl2);
+
+  /* Mark ADC initialized */
+
+  priv->flags |= STMPE811_FLAGS_ADC_INITIALIZED;
+  sem_post(&priv->exclsem);
+  return OK;
+}
+
+/****************************************************************************
+ * Name: stmpe811_adcconfig
+ *
+ * Description:
+ *  Configure a pin for ADC input.
+ *
+ * Input Parameters:
+ *   handle    - The handle previously returned by stmpe811_instantiate
+ *   pin       - The ADC pin number
+ *
+ * Returned Value:
+ *   Zero is returned on success.  Otherwise, a negated errno value is
+ *   returned to indicate the nature of the failure.
+ *
+ ****************************************************************************/
+
+int stmpe811_adcconfig(STMPE811_HANDLE handle, int pin)
+{
+  FAR struct stmpe811_dev_s *priv = (FAR struct stmpe811_dev_s *)handle;
+  uint8_t pinmask = GPIO_PIN(pin);
+  uint8_t regval;
+  int ret;
+
+  DEBUGASSERT(handle && (unsigned)pin < STMPE811_ADC_NPINS);
+
+  /* Get exclusive access to the device structure */
+
+  ret = sem_wait(&priv->exclsem);
+  if (ret < 0)
+    {
+      int errval = errno;
+      idbg("sem_wait failed: %d\n", errval);
+      return -errval;
+    }
+
+  /* Make sure that the pin is not already in use */
+
+  if ((priv->inuse & pinmask) != 0)
+    {
+      idbg("PIN%d is already in-use\n", pin);
+      sem_post(&priv->exclsem);
+      return -EBUSY;
+    }
+
+  /* Clear the alternate function bit for the pin, making it an ADC input
+   * (or perhaps an an external reference, depending on the state of the
+   * ADC_CTRL1_REF_SEL bit).
+   */
+
+  regval  = stmpe811_getreg8(priv, STMPE811_GPIO_AF);
+  regval &= ~pinmask;
+  stmpe811_putreg8(priv, STMPE811_GPIO_AF, regval);
+
+  /* Mark the pin as 'in use' */
+
+  priv->inuse |= pinmask;
+  sem_post(&priv->exclsem);
+  return OK;
+}
+
+/****************************************************************************
+ * Name: stmpe811_adcread
+ *
+ * Description:
+ *  Read the converted analog input value from the select pin.
+ *
+ * Input Parameters:
+ *   handle    - The handle previously returned by stmpe811_instantiate
+ *   pin       - The ADC pin number
+ *
+ * Returned Value:
+ *   The converted value (there is no error reporting mechanism).
+ *
+ ****************************************************************************/
+
+uint16_t stmpe811_adcread(STMPE811_HANDLE handle, int pin)
+{
+  FAR struct stmpe811_dev_s *priv = (FAR struct stmpe811_dev_s *)handle;
+  uint8_t pinmask = GPIO_PIN(pin);
+  uint8_t regval;
+  int i;
+  int ret;
+
+  DEBUGASSERT(handle && (unsigned)pin < 8);
+
+  /* Get exclusive access to the device structure */
+
+  ret = sem_wait(&priv->exclsem);
+  if (ret < 0)
+    {
+      int errval = errno;
+      idbg("sem_wait failed: %d\n", errval);
+      return -errval;
+    }
+
+  /* Request AD conversion by setting the bit corresponding the pin in the
+   * ADC CAPT register.
+   */
+
+  stmpe811_putreg8(priv, STMPE811_ADC_CAPT, pinmask);
+
+  /* Wait for the conversion to complete.  The ADC CAPT register reads '1'
+   * if conversion is completed. Reads '0' if conversion is in progress.
+   * Try three times before giving up.
+   */
+
+  for (i = 0; i < 3; i++)
+    {
+      /* The worst case ADC conversion time is (nominally) 56.4 uS. The
+       * following usleep() looks nice but in reality, the usleep()
+       * does not have that kind of precision (it will probably end up
+       * waiting 10 MS).
+       */
+
+      usleep(57);
+
+      /* Check if the conversion is complete */
+
+      regval = stmpe811_getreg8(priv, STMPE811_ADC_CAPT);
+      if ((regval & pinmask) != 0)
+        {
+          break;
+        }
+    }
+
+  /* At the completion of the conversion, return whatever we read from
+   * from the channel register associated with the pin.
+   */
+ 
+  return stmpe811_getreg16(priv, STMPE811_ADC_DATACH(pin));
+}
+
+#endif /* CONFIG_INPUT && CONFIG_INPUT_STMPE811 && !CONFIG_STMPE811_ADC_DISABLE */
+