drivers/sensors: Add driver for the MLX90393 3 axis magnetometer.

drivers/sensors/Kconfig

@@ -75,6 +75,13 @@ config MB7040_I2C_FREQUENCY
 	range 1 400000
 	depends on MB7040
 
+config MLX90393
+	bool "MLX90393 3-Axis Magnetometer"
+	default n
+	select SPI
+	---help---
+		Enable driver support for the Melex MLX90393 3-Axis magnetometer.
+
 config MCP9844
 	bool "MCP9844 Temperature Sensor"
 	default n

drivers/sensors/Make.defs

@@ -89,6 +89,10 @@ ifeq ($(CONFIG_MCP9844),y)
   CSRCS += mcp9844.c
 endif
 
+ifeq ($(CONFIG_MLX90393),y)
+  CSRCS += mlx90393.c
+endif
+
 ifeq ($(CONFIG_MS58XX),y)
   CSRCS += ms58xx.c
 endif

drivers/sensors/lis3mdl.c

@@ -352,10 +352,10 @@ static int lis3mdl_interrupt_handler(int irq, FAR void *context)
 
   DEBUGASSERT(priv->work.worker == NULL);
   ret = work_queue(HPWORK, &priv->work, lis3mdl_worker, priv, 0);
-  if (ret != 0)
+  if (ret < 0)
     {
       snerr("Failed to queue work: %d\n", ret);
-      return ERROR;
+      return ret;
     }
   else
     {
@@ -435,8 +435,9 @@ static int lis3mdl_open(FAR struct file *filep)
   /* Read back the content of all control registers for debug purposes */
 
   reg_content = 0;
-  eg_addr = LIS3MDL_CTRL_REG_1;
+  for (reg_addr = LIS3MDL_CTRL_REG_1;
-  for (; reg_addr <= LIS3MDL_CTRL_REG_5; reg_addr++)
+       reg_addr <= LIS3MDL_CTRL_REG_5;
+       reg_addr++)
     {
       lis3mdl_read_register(priv, reg_addr, &reg_content);
       snerr("R#%04x = %04x\n", reg_addr, reg_content);
@@ -469,6 +470,7 @@ static int lis3mdl_close(FAR struct file *filep)
 /****************************************************************************
  * Name: lis3mdl_read
  ****************************************************************************/
+
 static ssize_t lis3mdl_read(FAR struct file *filep, FAR char *buffer,
                             size_t buflen)
 {
@@ -490,10 +492,10 @@ static ssize_t lis3mdl_read(FAR struct file *filep, FAR char *buffer,
   /* Aquire the semaphore before the data is copied */
 
   ret = sem_wait(&priv->datasem);
-  if (ret != OK)
+  if (ret < 0)
     {
       snerr("Could not aquire priv->datasem: %d\n", ret);
-      return ERROR;
+      return ret;
     }
 
   /* Copy the sensor data into the buffer */
@@ -556,8 +558,10 @@ static int lis3mdl_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
  *
  * Input Parameters:
  *   devpath - The full path to the driver to register. E.g., "/dev/mag0"
- *   spi - An instance of the SPI interface to use to communicate with LIS3MDL
+ *   spi     - An instance of the SPI interface to use to communicate with
- *   config - configuration for the LIS3MDL driver. For details see description above.
+ *             LIS3MDL
+ *   config  - configuration for the LIS3MDL driver. For details see
+ *             description above.
  *
  * Returned Value:
  *   Zero (OK) on success; a negated errno value on failure.

include/nuttx/sensors/lis3mdl.h

@@ -158,8 +158,10 @@ extern "C"
  *
  * Input Parameters:
  *   devpath - The full path to the driver to register. E.g., "/dev/mag0"
- *   spi - An instance of the SPI interface to use to communicate with LIS3MDL
+ *   spi     - An instance of the SPI interface to use to communicate with
- *   config - configuration for the LIS3MDL driver. For details see description above.
+ *             LIS3MDL
+ *   config  - configuration for the LIS3MDL driver. For details see
+ *             description above.
  *
  * Returned Value:
  *   Zero (OK) on success; a negated errno value on failure.

include/nuttx/sensors/mlx90393.h

@@ -0,0 +1,153 @@
+/****************************************************************************
+ * include/nuttx/sensors/mlx90393.h
+ *
+ *   Copyright (C) 2016 DS-Automotion GmbH. All rights reserved.
+ *   Author: Alexander Entinger <a.entinger@ds-automotion.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 NUTTX_INCLUDE_NUTTX_SENSORS_MLX90393_H_
+#define NUTTX_INCLUDE_NUTTX_SENSORS_MLX90393_H_
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/irq.h>
+#include <nuttx/config.h>
+#include <nuttx/fs/ioctl.h>
+#include <nuttx/spi/spi.h>
+
+#if defined(CONFIG_SPI) && defined(CONFIG_MLX90393)
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* MLX90393 Command Definitions *********************************************/
+
+#define MLX90393_SB               (0x10)          /* SB = Start Burst Mode */
+#define MLX90393_SW               (0x20)          /* SW = Start Wake-up on Change Mode */
+#define MLX90393_SM               (0x30)          /* SB = Start Single Measurement Mode */
+#define MLX90393_RM               (0x40)          /* RM = Read Measurement */
+#define MLX90393_RR               (0x50)          /* RR = Read Register */
+#define MLX90393_WR               (0x60)          /* WR = Write Register */
+#define MLX90393_EX               (0x80)          /* EX = Exit Mode */
+#define MLX90393_HR               (0xD0)          /* HR = Memory Recall */
+#define MLX90393_HS               (0xE0)          /* HS = Memory Store */
+#define MLX90393_RT               (0xF0)          /* RT = Reset */
+
+/* MLX90393 Sensor Selection Bit Definitions ********************************/
+
+#define MLX90393_T_bm             (1<<0)          /* Temperature Sensor Bitmask  */
+#define MLX90393_X_bm             (1<<1)          /* Magnetometer X-Axis Bitmask */
+#define MLX90393_Y_bm             (1<<2)          /* Magnetometer Y-Axis Bitmask */
+#define MLX90393_Z_bm             (1<<3)          /* Magnetometer Z-Axis Bitmask */
+#define MLX90393_ZYXT_bm          (MLX90393_Z_bm | MLX90393_Y_bm | MLX90393_X_bm | MLX90393_T_bm)
+
+/* SPI BUS PARAMETERS *******************************************************/
+
+#define MLX90393_SPI_FREQUENCY    (1000000)        /* 1 MHz */
+#define MLX90393_SPI_MODE         (SPIDEV_MODE3)   /* Device uses SPI Mode 3: CPOL=1, CPHA=1 */
+
+/****************************************************************************
+ * Public Types
+ ****************************************************************************/
+
+/* A reference to a structure of this type must be passed to the MLX90393
+ * driver. This structure provides information about the configuration
+ * of the sensor 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.
+ */
+
+struct mlx90393_config_s
+{
+  /* Since multiple MLX90393 can be connected to the same SPI bus we need
+   * to use multiple spi device ids which are employed by NuttX to select/
+   * deselect the desired MLX90393 chip via their chip select inputs.
+   */
+
+  int spi_devid;
+
+  /* The IRQ number must be provided for each so MLX90393 device so that
+   * their interrupts can be distinguished.
+   */
+
+  int irq;
+
+  /* Attach the MLX90393 interrupt handler to the GPIO interrupt of the
+   * concrete MLX90393 instance.
+   */
+
+  int (*attach)(FAR struct mlx90393_config_s *, xcpt_t);
+};
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+#ifdef __cplusplus
+#define EXTERN extern "C"
+extern "C"
+{
+#else
+#define EXTERN extern
+#endif
+
+/****************************************************************************
+ * Name: mlx90393_register
+ *
+ * Description:
+ *   Register the MLX90393 character device as 'devpath'
+ *
+ * Input Parameters:
+ *   devpath - The full path to the driver to register. E.g., "/dev/mag0"
+ *   spi     - An instance of the SPI interface to use to communicate with
+ *             MLX90393
+ *   config  - Describes the configuration of the MLX90393 part.
+ *
+ * Returned Value:
+ *   Zero (OK) on success; a negated errno value on failure.
+ *
+ ****************************************************************************/
+
+int mlx90393_register(FAR const char *devpath, FAR struct spi_dev_s *spi,
+                      FAR struct mlx90393_config_s *config);
+
+#undef EXTERN
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* CONFIG_SPI && CONFIG_MLX90393 */
+
+#endif /* NUTTX_INCLUDE_NUTTX_SENSORS_MLX90393_H_ */