Add files missed in previous commit

ChangeLog

@@ -11033,3 +11033,8 @@
 	* configs/stm32f4discovery/src/stm32_zerocross.c: Add low level support
 	  for the Zero Cross driver for the STM32F4-Discovery.  From Alan
 	  Carvalho de Assis (2015-10-13).
+	* drivers/sensors/max6675.c and include/nuttx/sensors/max6675.h:  Add
+	  support to Thermocouple-to-Digital converter MAX6675.  From Alan
+	  Carvalho de Assis (2015-10-18).
+	* configs/stm32f4discovery/src: Add board config to support MAX6675.
+	  From Alan Carvalho de Assis (2015-10-18).

configs

@@ -1 +1 @@
-Subproject commit 47c4c967a3dd1c9de5fa41ba587468f744f1ca36
+Subproject commit d459d2d3160b0947ed87f8ebd6a0bf7ad04ebd05

drivers/sensors/max6675.c

@@ -0,0 +1,278 @@
+/****************************************************************************
+ * drivers/sensors/max6675.c
+ * Character driver for the Maxim MAX6675 Thermocouple-to-Digital Converter
+ *
+ *   Copyright (C) 2015 Alan Carvalho de Assis. All rights reserved.
+ *   Author: Alan Carvalho de Assis <acassis@extern.io>
+ *
+ * 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.
+ *
+ ****************************************************************************/
+
+/* NOTE: Some Maxim MAX6675 chips have an issue it report value 25% lower
+ * of real temperature, for more info read this thread:
+ * http://www.eevblog.com/forum/projects/max6675-temperature-error/
+*/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <stdlib.h>
+#include <fixedmath.h>
+#include <errno.h>
+#include <debug.h>
+
+#include <nuttx/kmalloc.h>
+#include <nuttx/fs/fs.h>
+#include <nuttx/spi/spi.h>
+#include <nuttx/sensors/max6675.h>
+
+#if defined(CONFIG_SPI) && defined(CONFIG_MAX6675)
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private
+ ****************************************************************************/
+
+#define MAX6675_THREE_STATE   (1 << 0)
+#define MAX6675_DEV_ID        (1 << 1)
+#define MAX6675_OPEN_CIRCUIT  (1 << 2)
+#define MAX6675_TEMP_COUPLE   0x7ff8
+
+struct max6675_dev_s
+{
+  FAR struct spi_dev_s *spi;           /* Saved SPI driver instance */
+  int16_t temp;
+};
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/* Character driver methods */
+
+static int     max6675_open(FAR struct file *filep);
+static int     max6675_close(FAR struct file *filep);
+static ssize_t max6675_read(FAR struct file *, FAR char *, size_t);
+static ssize_t max6675_write(FAR struct file *filep, FAR const char *buffer,
+                             size_t buflen);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+static const struct file_operations g_max6675fops =
+{
+  max6675_open,
+  max6675_close,
+  max6675_read,
+  max6675_write,
+  NULL,
+  NULL
+#ifndef CONFIG_DISABLE_POLL
+  , NULL
+#endif
+};
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+/****************************************************************************
+ * Name: max6675_open
+ *
+ * Description:
+ *   This function is called whenever the MAX6675 device is opened.
+ *
+ ****************************************************************************/
+
+static int max6675_open(FAR struct file *filep)
+{
+  return OK;
+}
+
+/****************************************************************************
+ * Name: max6675_close
+ *
+ * Description:
+ *   This routine is called when the MAX6675 device is closed.
+ *
+ ****************************************************************************/
+
+static int max6675_close(FAR struct file *filep)
+{
+  return OK;
+}
+
+/****************************************************************************
+ * Name: max6675_read
+ ****************************************************************************/
+
+static ssize_t max6675_read(FAR struct file *filep, FAR char *buffer, size_t buflen)
+{
+  FAR struct inode         *inode = filep->f_inode;
+  FAR struct max6675_dev_s *priv  = inode->i_private;
+  FAR uint16_t             *temp  = (FAR uint16_t *) buffer;
+  int                       ret   = 2;
+  int16_t                   regmsb;
+  int16_t                   regval;
+
+  /* Check for issues */
+
+  if (!buffer)
+    {
+      sndbg("Buffer is null\n");
+      return -EINVAL;
+    }
+
+  if (buflen != 2)
+    {
+      sndbg("You can't read something other than 16 bits (2 bytes)\n");
+      return -EINVAL;
+    }
+
+  /* Enable MAX6675's chip select */
+
+  SPI_SELECT(priv->spi, SPIDEV_TEMPERATURE, true);
+
+  /* Read temperature */
+
+  SPI_RECVBLOCK(priv->spi, &regmsb, 2);
+
+  /* Disable MAX6675's chip select */
+
+  SPI_SELECT(priv->spi, SPIDEV_TEMPERATURE, false);
+
+  regval  = (regmsb & 0xFF00) >> 8;
+  regval |= (regmsb & 0xFF) << 8;
+
+  sndbg("Read from MAX6675 = 0x%04X\n", regval);
+
+  /* Verify if the device ID bit is really zero */
+
+  if (regval & MAX6675_DEV_ID)
+    {
+      sndbg("ERROR: The Device ID bit needs to be 0 !\n");
+      ret = -EINVAL;
+    }
+
+  /* Detect if termocople input is open */
+
+  if (regval & MAX6675_OPEN_CIRCUIT)
+    {
+      sndbg("The thermocouple input is not connected!\n");
+      ret = -EINVAL;
+    }
+
+  /* Get the temperature */
+
+  *temp = (regval & MAX6675_TEMP_COUPLE) >> 3;
+
+  /* Return two bytes, the temperature is fixed point Q10.2, then divide by 4
+   * in your application in order to get real temperature in Celsius degrees.
+   */
+
+  return ret;
+}
+
+/****************************************************************************
+ * Name: max6675_write
+ ****************************************************************************/
+
+static ssize_t max6675_write(FAR struct file *filep, FAR const char *buffer,
+                             size_t buflen)
+{
+  return -ENOSYS;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: max6675_register
+ *
+ * Description:
+ *   Register the MAX6675 character device as 'devpath'
+ *
+ * Input Parameters:
+ *   devpath - The full path to the driver to register. E.g., "/dev/temp0"
+ *   spi - An instance of the SPU interface to use to communicate with
+ *   MAX6675.
+ *
+ * Returned Value:
+ *   Zero (OK) on success; a negated errno value on failure.
+ *
+ ****************************************************************************/
+
+int max6675_register(FAR const char *devpath, FAR struct spi_dev_s *spi)
+{
+  FAR struct max6675_dev_s *priv;
+  int ret;
+
+  /* Sanity check */
+
+  DEBUGASSERT(spi != NULL);
+
+  /* Initialize the MAX6675 device structure */
+
+  priv = (FAR struct max6675_dev_s *)kmm_malloc(sizeof(struct max6675_dev_s));
+  if (priv == NULL)
+    {
+      sndbg("Failed to allocate instance\n");
+      return -ENOMEM;
+    }
+
+  priv->spi        = spi;
+  priv->temp       = 0;
+
+#ifdef CONFIG_SPI_OWNBUS
+  /* Configure SPI for the MAX6675 */
+
+  SPI_SETMODE(priv->spi, SPIDEV_MODE1);
+  SPI_SETBITS(priv->spi, 8);
+  SPI_SETFREQUENCY(priv->spi, MAX6675_SPI_MAXFREQ);
+#endif
+
+  /* Register the character driver */
+
+  ret = register_driver(devpath, &g_max6675fops, 0666, priv);
+  if (ret < 0)
+    {
+      sndbg("Failed to register driver: %d\n", ret);
+      kmm_free(priv);
+    }
+
+  return ret;
+}
+#endif /* CONFIG_SPI && CONFIG_MAX6675 */

include/nuttx/sensors/max6675.h

@@ -0,0 +1,98 @@
+/****************************************************************************
+ * include/nuttx/input/max6675.h
+ *
+ *   Copyright (C) 2015 Gregory Nutt. All rights reserved.
+ *   Author: Alan Carvalho de Assis <acassis@gmail.com>
+ *
+ * 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.
+ *
+ ****************************************************************************/
+
+#ifndef __INCLUDE_NUTTX_SENSORS_MAX6675_H
+#define __INCLUDE_NUTTX_SENSORS_MAX6675_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <nuttx/irq.h>
+
+#if defined(CONFIG_MAX6675)
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Types
+ ****************************************************************************/
+
+#define MAX6675_SPI_MAXFREQ 4000000
+
+struct spi_dev_s;
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+#ifdef __cplusplus
+#define EXTERN extern "C"
+extern "C"
+{
+#else
+#define EXTERN extern
+#endif
+
+/****************************************************************************
+ * Name: max6675_register
+ *
+ * Description:
+ *  This function will register the max6675 driver as /dev/tempN
+ *  where N is the minor device number
+ *
+ * Input Parameters:
+ *   devpath - The full path to the driver to register. E.g., "/dev/temp0"
+ *   spi     - An instance of the SPI interface to use to communicate with
+ *             MAX6675
+ *
+ * Returned Value:
+ *   Zero is returned on success.  Otherwise, a negated errno value is
+ *   returned to indicate the nature of the failure.
+ *
+ ****************************************************************************/
+
+int max6675_register(FAR const char *devpath, FAR struct spi_dev_s *spi);
+
+#undef EXTERN
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* CONFIG_MAX6675 */
+#endif /* __INCLUDE_NUTTX_SENSORS_MAX6675_H */