Merged in raiden00/nuttx (pull request #214)

Add driver for the ST L3GD20 3 axis gyro

Approved-by: Gregory Nutt

configs/stm32f429i-disco/README.txt

@@ -8,7 +8,7 @@ memory and 256kbytes. The board features:
 
   - On-board ST-LINK/V2 for programming and debugging,
   - On-board 64 Mbits (8 Mbytes) External SDRAM (1 Mbit x 16-bit x 4-bank)
-  - LIS302DL, ST MEMS motion sensor, 3-axis digital output accelerometer,
+  - L3GD20, ST MEMS motion sensor, 3-axis digital output gyroscope,
   - TFT 2.4" LCD, 262K color RGB, 240 x 320 pixels
   - Touchscreen controller
   - Two user LEDs and two push-buttons,

configs/stm32f429i-disco/src/Makefile

@@ -72,6 +72,10 @@ ifeq ($(CONFIG_STM32F429I_DISCO_ILI9341),y)
 CSRCS += stm32_ili93414ws.c
 endif
 
+ifeq ($(CONFIG_SENSORS_L3GD20),y)
+CSRCS += stm32_l3gd20.c
+endif
+
 ifeq ($(and \
       $(CONFIG_STM32F429I_DISCO_ILI9341_LCDIFACE), \
       $(CONFIG_STM32F429I_DISCO_ILI9341_FBIFACE), \

configs/stm32f429i-disco/src/stm32_appinit.c

@@ -165,6 +165,8 @@ int board_app_initialize(uintptr_t arg)
   int ret;
 #elif defined(HAVE_USBHOST) || defined(HAVE_USBMONITOR)
   int ret;
+#elif defined(CONFIG_SENSORS_L3GD20)
+  int ret;
 #endif
 
   /* Configure SPI-based devices */
@@ -378,5 +380,14 @@ int board_app_initialize(uintptr_t arg)
     }
 #endif
 
+#ifdef CONFIG_SENSORS_L3GD20
+  ret = stm32_l3gd20initialize("/dev/gyr0");
+  if (ret != OK)
+    {
+      syslog(LOG_ERR, "ERROR: Failed to initialize l3gd20 sensor: %d\n", ret);
+    }
+
+#endif
+
   return OK;
 }

configs/stm32f429i-disco/src/stm32_l3gd20.c

@@ -0,0 +1,144 @@
+/****************************************************************************
+ * configs/stm32f429i-disco/src/stm32_l3gd20.c
+ *
+ * Authors: Mateusz Szafoni <raiden00@railab.me>
+ *
+ * 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 <errno.h>
+#include <debug.h>
+
+#include <nuttx/spi/spi.h>
+#include <nuttx/sensors/l3gd20.h>
+
+#include "stm32.h"
+#include "stm32_spi.h"
+#include "stm32f429i-disco.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#if defined(CONFIG_SPI) & defined(CONFIG_SENSORS_L3GD20)
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static int l3gd20_attach(FAR struct l3gd20_config_s * cfg, xcpt_t irq);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* Only one L3GD20 device on board */
+
+static struct l3gd20_config_s g_l3gd20_config =
+  {
+    .attach = l3gd20_attach,
+    .irq = L3GD20_IRQ,
+    .spi_devid = SPIDEV_ACCELEROMETER
+  };
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: l3gd20_attach()
+ *
+ * Description: Attach the l3gd20 interrupt handler to the GPIO interrupt
+ *
+ ****************************************************************************/
+
+static int l3gd20_attach(FAR struct l3gd20_config_s * cfg, xcpt_t irq)
+{
+  stm32_gpiosetevent(GPIO_L3GD20_DREADY, true, false, true, irq);
+
+  return OK;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: stm32_l3gd20initialize()
+ *
+ * Description:
+ *   Initialize and register the L3GD20 3 axis gyroscope sensor driver.
+ *
+ * Input parameters:
+ *   devpath - The full path to the driver to register. E.g., "/dev/gyro0"
+ *
+ * Returned Value:
+ *   Zero (OK) on success; a negated errno value on failure.
+ *
+ ****************************************************************************/
+
+int stm32_l3gd20initialize(FAR const char *devpath)
+{
+  int ret = 0;
+  struct spi_dev_s *spi;
+
+  /* Configure DREADY IRQ input */
+
+  stm32_configgpio(GPIO_L3GD20_DREADY);
+
+  /* Initialize SPI */
+
+  spi = stm32_spi5initialize();
+
+  if (!spi)
+    {
+      ret = -ENODEV;
+      goto errout;
+    }
+
+  /* Then register the gyro */
+
+  ret = l3gd20_register(devpath, spi, &g_l3gd20_config);
+  if (ret != OK)
+    {
+      goto errout;
+    }
+
+ errout:
+  return ret;
+}
+
+#endif  /* CONFIG_SPI && CONFIG_SENSORS_L3GD20 */

configs/stm32f429i-disco/src/stm32f429i-disco.h

@@ -114,6 +114,11 @@
 #define GPIO_CS_SST25   (GPIO_OUTPUT|GPIO_PUSHPULL|GPIO_SPEED_50MHz|\
                          GPIO_OUTPUT_SET|GPIO_PORTE|GPIO_PIN4)
 
+/* L3GD20 MEMS*/
+
+#define GPIO_L3GD20_DREADY (GPIO_INPUT|GPIO_FLOAT|GPIO_EXTI|GPIO_PORTA|GPIO_PIN2)
+#define L3GD20_IRQ  (2 + STM32_IRQ_EXTI0)
+
 /* USB OTG HS
  *
  * PA9  OTG_HS_VBUS VBUS sensing (also connected to the green LED)
@@ -275,6 +280,25 @@ FAR struct ili9341_lcd_s *stm32_ili93414ws_initialize(void);
 FAR struct spi_dev_s *stm32_spi5initialize(void);
 #endif
 
+
+#if defined(CONFIG_SPI) & defined(CONFIG_SENSORS_L3GD20)
+/****************************************************************************
+ * Name: stm32_l3gd20initialize()
+ *
+ * Description:
+ *   Initialize and register the L3GD20 3 axis gyroscope sensor driver.
+ *
+ * Input parameters:
+ *   devpath - The full path to the driver to register. E.g., "/dev/gyro0"
+ *
+ * Returned Value:
+ *   Zero (OK) on success; a negated errno value on failure.
+ *
+ ****************************************************************************/
+
+int stm32_l3gd20initialize(FAR const char *devpath);
+#endif
+
 #endif /* __ASSEMBLY__ */
 #endif /* __CONFIGS_STM32F429I_DISCO_SRC_STM32F429I_DISCO_H */
 

drivers/sensors/Kconfig

@@ -32,6 +32,13 @@ config BMP180
 	---help---
 		Enable driver support for the Bosch BMP180 barometer sensor.
 
+config SENSORS_L3GD20
+	bool "ST L3GD20 Gyroscope Sensor support"
+	default n
+	select SPI
+	---help---
+		Enable driver support for the ST L3GD20 gyroscope sensor.
+
 config SENSOR_KXTJ9
 	bool "Kionix KXTJ9 Accelerometer support"
 	default n

drivers/sensors/Make.defs

@@ -130,6 +130,10 @@ ifeq ($(CONFIG_LIS3MDL),y)
   CSRCS += lis3mdl.c
 endif
 
+ifeq ($(CONFIG_SENSORS_L3GD20),y)
+  CSRCS += l3gd20.c
+endif
+
 endif # CONFIG_SPI
 
 # Quadrature encoder upper half

include/nuttx/sensors/l3gd20.h

@@ -0,0 +1,296 @@
+/****************************************************************************
+ * drivers/sensors/l3gd20.c
+ *
+ * Authors: Mateusz Szafoni <raiden00@railab.me>
+ *
+ * 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_L3GD20_H
+#define __INCLUDE_NUTTX_SENSORS_L3GD20_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_SENSORS_L3GD20)
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* SPI BUS PARAMETERS ********************************************************/
+
+#define L3GD20_SPI_FREQUENCY  (4000000)        /* 4 MHz */
+#define L3GD20_SPI_MODE       (SPIDEV_MODE3)   /* Device uses SPI Mode 3: CPOL=1, CPHA=1 *
+
+/* Register Addresses *******************************************************/
+/* Gyroscope registers */
+
+#define L3GD20_WHO_AM_I                0x0F /* Accelerometer and gyroscope device identification */
+#define L3GD20_CTRL_REG_1              0x20 /* Gyroscope control register 1 */
+#define L3GD20_CTRL_REG_2              0x21 /* Gyroscope control register 2 */
+#define L3GD20_CTRL_REG_3              0x22 /* Gyroscope control register 3 */
+#define L3GD20_CTRL_REG_4              0x23 /* Gyroscope control register 4 */
+#define L3GD20_CTRL_REG_5              0x24 /* Gyroscope control register 5 */
+#define L3GD20_REF_REG                 0x25 /* Gyroscope reference value for interrupt generation */
+#define L3GD20_OUT_TEMP_REG            0x26 /* Temperature data */
+#define L3GD20_STATUS_REG              0x27 /* Status register */
+#define L3GD20_OUT_X_L_REG             0x28 /* Gyroscope pitch (X) low byte */
+#define L3GD20_OUT_X_H_REG             0x29 /* Gyroscope pitch (X) high byte */
+#define L3GD20_OUT_Y_L_REG             0x2A /* Gyroscope roll (Y) low byte */
+#define L3GD20_OUT_Y_H_REG             0x2B /* Gyroscope roll (Y) high byte */
+#define L3GD20_OUT_Z_L_REG             0x2C /* Gyroscope yaw (Z) low byte */
+#define L3GD20_OUT_Z_H_REG             0x2D /* Gyroscope yaw (Z) high byte */
+#define L3GD20_FIFO_CTRL_REG           0x2E /* FIFO control register */
+#define L3GD20_FIFO_SRC_REG            0x2f /* FIFO status control register */
+#define L3GD20_INT_GEN_CFG_REG         0x30 /* Gyroscope interrupt configuration */
+#define L3GD20_INT_GEN_SRC_REG         0x31 /* Gyroscope interrupt source */
+#define L3GD20_INT_GEN_THS_X_H_REG     0x32 /* Gyroscope pitch (X) interrupt threshold high byte */
+#define L3GD20_INT_GEN_THS_X_L_REG     0x33 /* Gyroscope pitch (X) interrupt threshold low byte */
+#define L3GD20_INT_GEN_THS_Y_H_REG     0x34 /* Gyroscope roll (Y) interrupt threshold high byte */
+#define L3GD20_INT_GEN_THS_Y_L_REG     0x35 /* Gyroscope roll (Y) interrupt threshold low byte */
+#define L3GD20_INT_GEN_THS_Z_H_REG     0x36 /* Gyroscope yaw (Z) interrupt threshold high byte */
+#define L3GD20_INT_GEN_THS_Z_L_REG     0x37 /* Gyroscope yaw (Z) interrupt threshold low byte */
+#define L3GD20_INT_GEN_DUR_REG         0x38 /* Gyroscope interrupt duration */
+
+
+/* Register Bit Definitions *************************************************/
+
+/* Device identification register */
+
+#define L3GD20_WHO_AM_I_VALUE       0xD4
+
+/* Gyroscope control register 1 */
+
+#define L3GD20_CTRL_REG_1_X_EN_bm         (1 << 0)
+#define L3GD20_CTRL_REG_1_Y_EN_bm         (1 << 1)
+#define L3GD20_CTRL_REG_1_Z_EN_bm         (1 << 2)
+#define L3GD20_CTRL_REG_1_POWERDOWN_bm    (1 << 3)
+#define L3GD20_CTRL_REG_1_BW_0_bm         (1 << 4)
+#define L3GD20_CTRL_REG_1_BW_1_bm         (1 << 5)
+#define L3GD20_CTRL_REG_1_DR_0_bm         (1 << 6)
+#define L3GD20_CTRL_REG_1_DR_1_bm         (1 << 7)
+
+/* Gyroscope control register 2 */
+
+#define L3GD20_CTRL_REG_2_HPCF_0_bm        (1 << 0)
+#define L3GD20_CTRL_REG_2_HPCF_1_bm        (1 << 1)
+#define L3GD20_CTRL_REG_2_HPCF_2_bm        (1 << 2)
+#define L3GD20_CTRL_REG_2_HPCF_3_bm        (1 << 3)
+#define L3GD20_CTRL_REG_2_HPM_0_bm         (1 << 4)
+#define L3GD20_CTRL_REG_2_HPM_1_bm         (1 << 5)
+#define L3GD20_CTRL_REG_2_RES6_            (1 << 6)
+#define L3GD20_CTRL_REG_2_RES7_            (1 << 7)
+
+/* Gyroscope control register 3 */
+
+#define L3GD20_CTRL_REG_3_I2_EMPTY_bm      (1 << 0)
+#define L3GD20_CTRL_REG_3_I2_ORUN_bm       (1 << 1)
+#define L3GD20_CTRL_REG_3_I2_WTM_bm        (1 << 2)
+#define L3GD20_CTRL_REG_3_I2_DRDY_bm       (1 << 3)
+#define L3GD20_CTRL_REG_3_PP_OD_bm         (1 << 4)
+#define L3GD20_CTRL_REG_3_H_LACTIVE_bm     (1 << 5)
+#define L3GD20_CTRL_REG_3_I1_BOOT_bm       (1 << 6)
+#define L3GD20_CTRL_REG_3_I1_INT1_bm       (1 << 7)
+
+
+/* Gyroscope control register 4 */
+
+#define L3GD20_CTRL_REG_4_SIM_bm           (1 << 0)
+#define L3GD20_CTRL_REG_4_RES1_            (1 << 1)
+#define L3GD20_CTRL_REG_4_RES2_            (1 << 2)
+#define L3GD20_CTRL_REG_4_RES3_            (1 << 3)
+#define L3GD20_CTRL_REG_4_FS_0_bm          (1 << 4)
+#define L3GD20_CTRL_REG_4_FS_1_bm          (1 << 5)
+#define L3GD20_CTRL_REG_4_BLE_bm           (1 << 6)
+#define L3GD20_CTRL_REG_4_BDU_bm           (1 << 7)
+
+/* Gyroscope control register 5 */
+
+#define L3GD20_CTRL_REG_5_OUT_SEL_0_bm     (1 << 0)
+#define L3GD20_CTRL_REG_5_OUT_SEL_1_bm     (1 << 1)
+#define L3GD20_CTRL_REG_5_INT1_SEL_0_bm    (1 << 2)
+#define L3GD20_CTRL_REG_5_INT1_SEL_1_bm    (1 << 3)
+#define L3GD20_CTRL_REG_5_HP_EN_bm         (1 << 4)
+#define L3GD20_CTRL_REG_5_RES5_            (1 << 5)
+#define L3GD20_CTRL_REG_5_FIFO_EN_bm       (1 << 6)
+#define L3GD20_CTRL_REG_5_BOOT_bm          (1 << 7)
+
+/* Status register */
+
+#define L3GD20_STATUS_REG_X_DA_bm          (1 << 0)
+#define L3GD20_STATUS_REG_Y_DA_bm          (1 << 1)
+#define L3GD20_STATUS_REG_Z_DA_bm          (1 << 2)
+#define L3GD20_STATUS_REG_ZYX_DA_bm        (1 << 3)
+#define L3GD20_STATUS_REG_X_OR_bm          (1 << 4)
+#define L3GD20_STATUS_REG_Y_OR_bm          (1 << 5)
+#define L3GD20_STATUS_REG_Z_OR_bm          (1 << 6)
+#define L3GD20_STATUS_REG_ZYX_OR_bm        (1 << 7)
+
+/* FIFO control register */
+
+#define L3GD20_FIFO_CTRL_WTM_0_bm          (1 << 0)
+#define L3GD20_FIFO_CTRL_WTM_1_bm          (1 << 1)
+#define L3GD20_FIFO_CTRL_WTM_2_bm          (1 << 2)
+#define L3GD20_FIFO_CTRL_WTM_3_bm          (1 << 3)
+#define L3GD20_FIFO_CTRL_WTM_4_bm          (1 << 4)
+#define L3GD20_FIFO_CTRL_FM_0_bm           (1 << 5)
+#define L3GD20_FIFO_CTRL_FM_1_bm           (1 << 6)
+#define L3GD20_FIFO_CTRL_FM_2_bm           (1 << 7)
+#define L3GD20_FIFO_CTRL_FMODE_BYPASS      (0)
+#define L3GD20_FIFO_CTRL_FMODE_FIFO        (L3GD20_FIFO_CTRL_FM0)
+#define L3GD20_FIFO_CTRL_FMODE_CONT        (L3GD20_FIFO_CTRL_FM1)
+#define L3GD20_FIFO_CTRL_FMODE_CONT_FIFO   (L3GD20_FIFO_CTRL_FM1 | L3GD20_FIFO_CTRL_FM0)
+#define L3GD20_FIFO_CTRL_FMODE_BYPASS_CONT (L3GD20_FIFO_CTRL_FM2 | L3GD20_FIFO_CTRL_FM1)
+
+/* FIFO status control register */
+
+#define L3GD20_FIFO_SRC_FSS_0_bm          (1 << 0)
+#define L3GD20_FIFO_SRC_FSS_1_bm          (1 << 1)
+#define L3GD20_FIFO_SRC_FSS_2_bm          (1 << 2)
+#define L3GD20_FIFO_SRC_FSS_3_bm          (1 << 3)
+#define L3GD20_FIFO_SRC_FSS_4_bm          (1 << 4)
+#define L3GD20_FIFO_SRC_EMPTY_bm          (1 << 5)
+#define L3GD20_FIFO_SRC_OVRUN_bm          (1 << 6)
+#define L3GD20_FIFO_SRC_WTM_bm            (1 << 7)
+
+/* Gyroscope interrupt configuration */
+
+#define L3GD20_INT_GEN_CFG_X_L_IE_bm       (1 << 0)
+#define L3GD20_INT_GEN_CFG_X_H_IE_bm       (1 << 1)
+#define L3GD20_INT_GEN_CFG_Y_L_IE_bm       (1 << 2)
+#define L3GD20_INT_GEN_CFG_Y_H_IE_bm       (1 << 3)
+#define L3GD20_INT_GEN_CFG_Z_L_IE_bm       (1 << 4)
+#define L3GD20_INT_GEN_CFG_Z_H_IE_bm       (1 << 5)
+#define L3GD20_INT_GEN_CFG_LIR_bm          (1 << 6)
+#define L3GD20_INT_GEN_CFG_AOI_bm          (1 << 7)
+
+
+/* Gyroscope interrupt source */
+
+#define L3GD20_INT_GEN_SRC_X_L_bm        (1 << 0)
+#define L3GD20_INT_GEN_SRC_X_H_bm        (1 << 1)
+#define L3GD20_INT_GEN_SRC_Y_L_bm        (1 << 2)
+#define L3GD20_INT_GEN_SRC_Y_H_bm        (1 << 3)
+#define L3GD20_INT_GEN_SRC_Z_L_bm        (1 << 4)
+#define L3GD20_INT_GEN_SRC_Z_H_bm        (1 << 5)
+#define L3GD20_INT_GEN_SRC_I_A_bm        (1 << 6)
+#define L3GD20_INT_GEN_SRC_RES7_         (1 << 7)
+
+/****************************************************************************
+ * Public Types
+ ****************************************************************************/
+
+/* A reference to a structure of this type must be passed to the L3GD20
+ * 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 l3gd20_config_s
+{
+  /* Since multiple L3GD20 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 L3GD20 chip via their chip select inputs.
+   */
+
+  int spi_devid;
+
+  /* The IRQ number must be provided for each L3GD20 device so that
+   * their interrupts can be distinguished.
+   */
+
+  int irq;
+
+  /* Attach the L3GD20 interrupt handler to the GPIO interrupt of the
+   * concrete L3GD20 instance.
+   */
+
+  int (*attach)(FAR struct l3gd20_config_s *, xcpt_t);
+};
+
+/* Data returned by reading from the L3GD20 is returned in this format. */
+
+struct l3gd20_sensor_data_s
+{
+  int16_t x_gyr;              /* Measurement result for x axis */
+  int16_t y_gyr;              /* Measurement result for y axis */
+  int16_t z_gyr;              /* Measurement result for z axis */
+  int8_t temperature;         /* Measurement result for temperature sensor */
+};
+
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+#ifdef __cplusplus
+#define EXTERN extern "C"
+extern "C"
+{
+#else
+#define EXTERN extern
+#endif
+
+
+/****************************************************************************
+ * Name: l3gd20_register
+ *
+ * Description:
+ *   Register the L3DF20 character device as 'devpath'.
+ *
+ * Input Parameters:
+ *   devpath - The full path to the driver to register, e.g., "/dev/gyr0".
+ *   i2c     - An SPI driver instance.
+ *   config  - configuration for the L3GD20 driver. For details see
+ *             description above.
+ *
+ * Returned Value:
+ *   Zero (OK) on success; a negated errno value on failure.
+ *
+ ****************************************************************************/
+
+int l3gd20_register(FAR const char *devpath, FAR struct spi_dev_s *spi,
+                    FAR struct l3gd20_config_s *config);
+
+#undef EXTERN
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* CONFIG_SPI && CONFIG_SENSORS_L3GD20 */
+#endif /* __INCLUDE_NUTTX_SENSORS_L3GD20_H */