Merged in alinjerpelea/nuttx (pull request #1014)

boards: add stub drivers folder for later use

* boards: add stub drivers folder for later use

    The board/drivers folder is added for future use.

    In this folder we should place drives that are platform specific and
    depend on HW that is present only on a specific platform.

    NOTE: All shared drivers should go to the regular driver folder
    Signed-off-by: Alin Jerpelea <alin.jerpelea@sony.com>

* tools: shift BOARD_DIR one level up

    In preparation for drivers and common folders we are moving the
    BOARD_DIR path up one level.

    Signed-off-by: Alin Jerpelea <alin.jerpelea@sony.com>

* tools: add drivers/platform symlink

    Link the boards/<arch>/<chip>/drivers dir to drivers/platform

    Signed-off-by: Alin Jerpelea <alin.jerpelea@sony.com>

* drivers: add platform specifc drivers extension

    There are platforms that use specific drivers and we should be able to
    include those drivers in the build

    Signed-off-by: Alin Jerpelea <alin.jerpelea@sony.com>

* board: cxd56xx: drivers: add AK09912 driver for SCU

    This is a platform specific driver connected on the SCU unit.

    Signed-off-by: Alin Jerpelea <alin.jerpelea@sony.com>

Approved-by: Gregory Nutt <gnutt@nuttx.org>

boards/arm/a1x/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/arm/am335x/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/arm/c5471/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/arm/cxd56xx/drivers/Kconfig

@@ -0,0 +1,6 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#
+
+source "drivers/platform/sensors/Kconfig"

boards/arm/cxd56xx/drivers/Make.defs

@@ -0,0 +1,36 @@
+############################################################################
+# drivers/Makefile
+#
+#   Copyright 2018 Sony Semiconductor Solutions Corporation
+#
+# 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 of Sony Semiconductor Solutions Corporation 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.
+#
+############################################################################
+
+include platform$(DELIM)sensors$(DELIM)Make.defs

boards/arm/cxd56xx/drivers/sensors/Kconfig

@@ -0,0 +1,20 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#
+
+menuconfig SCU_SENSORS
+	bool "SCU Sensor Drivers"
+
+if SCU_SENSORS
+
+config SENSORS_AK09912_SCU
+	bool "Asahi AK09911/AK09912 Compass Sensor"
+	default n
+	select CXD56_I2C
+	select CXD56_SCU
+	---help---
+		Enable driver for AK09911/AK09912 Compass sensor.
+		NOTE: This sensor is connected to the SCU unit
+
+endif # SCU_SENSORS

boards/arm/cxd56xx/drivers/sensors/Make.defs

@@ -0,0 +1,42 @@
+############################################################################
+# drivers/platform/sensors/Make.defs
+#
+#   Copyright 2018 Sony Semiconductor Solutions Corporation
+#
+# 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 of Sony Semiconductor Solutions Corporation 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.
+#
+############################################################################
+
+ifeq ($(CONFIG_SENSORS_AK09912_SCU),y)
+CSRCS += ak09912_scu.c
+endif
+
+DEPPATH += --dep-path platform$(DELIM)sensors
+VPATH += :platform$(DELIM)sensors
+CFLAGS += $(shell $(INCDIR) $(INCDIROPT) "$(CC)" $(TOPDIR)$(DELIM)drivers$(DELIM)platform$(DELIM)sensors)

boards/arm/cxd56xx/drivers/sensors/ak09912_scu.c

@@ -0,0 +1,582 @@
+/****************************************************************************
+ * drivers/platform/sensors/ak09912_scu.c
+ *
+ *   Copyright 2018 Sony Semiconductor Solutions Corporation
+ *
+ * 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 of Sony Semiconductor Solutions Corporation 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 <stdlib.h>
+#include <stdio.h>
+#include <fixedmath.h>
+#include <errno.h>
+#include <debug.h>
+#include <semaphore.h>
+#include <arch/types.h>
+#include <nuttx/kmalloc.h>
+#include <nuttx/fs/fs.h>
+#include <nuttx/i2c/i2c_master.h>
+#include <nuttx/sensors/ak09912.h>
+#include <nuttx/irq.h>
+#include <arch/chip/scu.h>
+
+#if defined(CONFIG_I2C) && defined(CONFIG_SENSORS_AK09912_SCU)
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#ifdef CONFIG_CXD56_DECI_AK09912
+#  define MAG_SEQ_TYPE SEQ_TYPE_DECI
+#else
+#  define MAG_SEQ_TYPE SEQ_TYPE_NORMAL
+#endif
+
+#define AK09912_ADDR         0x0C
+#define AK09912_FREQ         400000
+#define AK09912_DEVID        0x0448
+#define AK09911_DEVID        0x0548
+
+/* REGISTER: WIA
+ * Who I am.
+ */
+
+#define AK09912_WIA1       0x00
+#define AK09912_WIA2       0x01
+
+/* REGISTER: CNTL2
+ * Power mode
+ */
+
+#define POWER_MODE_ADDR      0x31
+
+/* REGISTER: ASAX
+ * Sensitivity values
+ */
+
+#define AK09912_ASAX       0x60
+
+/* REGISTER: CNTL1
+ * Enable or disable temparature measure or enable or disable Noise
+ *  suppression filter.
+ */
+
+#define AK09912_CTRL1      0x30
+
+/* REGISTER: HXL
+ * The start address of data registers.
+ */
+
+#define AK09912_HXL        0x11
+
+/* The parameter for compensating. */
+
+#define AK09912_SENSITIVITY               (128)
+#define AK09912_SENSITIVITY_DIV           (256)
+
+/* Noise Suppression Filter */
+
+#define AK09912_NSF_MASK                  (0x3 << 5)
+#define AK09912_NSF_NONE                  (0x0 << 5)
+#define AK09912_NSF_LOW                   (0x1 << 5)
+#define AK09912_NSF_MIDDLE                (0x2 << 5)
+#define AK09912_NSF_HIGH                  (0x3 << 5)
+
+/* Power mode */
+
+#define AKM_POWER_DOWN_MODE                0b0000
+#define AKM_SINGL_MEAS_MODE                0b00001
+#define AKM_CONT_MEAS_1                    0b00010
+#define AKM_CONT_MEAS_2                    0b00100
+#define AKM_CONT_MEAS_3                    0b00110
+#define AKM_CONT_MEAS_4                    0b01000
+#define AKM_EXT_TRIG_MODE                  0b01010
+#define AKM_SELF_TEST_MODE                 0b10000
+#define AKM_FUSE_ROM_MODE                  0b11111
+
+/* REGISTER: ST1
+ * DRDY: Data ready bit. 0: not ready, 1: ready
+ * DOR: Data overrun. 0: Not overrun, 1: overrun
+ */
+
+#define AK09912_ST1 0x10
+
+/* AK09912 is magnetometer */
+
+#define AK09912_BYTESPERSAMPLE  6
+#define AK09912_ELEMENTSIZE     2
+
+#ifndef itemsof
+#  define itemsof(array) (sizeof(array)/sizeof(array[0]))
+#endif
+
+/****************************************************************************
+ * Private Type Definitions
+ ****************************************************************************/
+/**
+ * @brief Structure for ak09912 device
+ */
+
+struct ak09912_dev_s
+{
+  FAR struct i2c_master_s *i2c; /* I2C interface */
+  uint8_t       addr;           /* I2C address */
+  int           freq;           /* Frequency <= 3.4MHz */
+  int           port;           /* I2C port */
+
+  struct seq_s *seq;
+  int           id;
+};
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/* Character driver methods */
+
+static int ak09912_open(FAR struct file *filep);
+static int ak09912_close(FAR struct file *filep);
+static ssize_t ak09912_read(FAR struct file *filep, FAR char *buffer,
+                           size_t buflen);
+static ssize_t ak09912_write(FAR struct file *filep, FAR const char *buffer,
+                            size_t buflen);
+static int ak09912_ioctl(FAR struct file *filep, int cmd, unsigned long arg);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+static const struct file_operations g_ak09912fops =
+{
+  ak09912_open,                  /* open */
+  ak09912_close,                 /* close */
+  ak09912_read,                  /* read */
+  ak09912_write,                 /* write */
+  0,                            /* seek */
+  ak09912_ioctl,                            /* ioctl */
+#ifndef CONFIG_DISABLE_POLL
+  0,                            /* poll */
+#endif
+  0                             /* unlink */
+};
+
+/* Take XYZ data, temperature and Status 2 register.
+ * Status 2 register has a role as data reading end.
+ */
+
+static const uint16_t g_ak09912inst[] =
+{
+  SCU_INST_SEND(AK09912_HXL),
+  SCU_INST_RECV(AK09912_BYTESPERSAMPLE + 2) | SCU_INST_LAST,
+};
+
+static struct ak09912_sensadj_s g_asa;
+
+/* Sequencer instance */
+
+static FAR struct seq_s *g_seq = NULL;
+
+/* Reference count */
+
+static int g_refcnt = 0;
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: ak09912_getreg8
+ *
+ * Description:
+ *   Read from an 8-bit AK09912 register
+ *
+ ****************************************************************************/
+
+static uint8_t ak09912_getreg8(FAR struct ak09912_dev_s *priv,
+                               uint8_t regaddr)
+{
+  uint8_t regval = 0;
+  uint16_t inst[2];
+
+  /* Send register to read and get the next byte */
+
+  inst[0] = SCU_INST_SEND(regaddr);
+  inst[1] = SCU_INST_RECV(1) | SCU_INST_LAST;
+
+  scu_i2ctransfer(priv->port, priv->addr, inst, 2, &regval, 1);
+
+  return regval;
+}
+
+/****************************************************************************
+ * Name: ak09912_putreg8
+ *
+ * Description:
+ *   Write to an 8-bit AK09912 register
+ *
+ ****************************************************************************/
+
+static void ak09912_putreg8(FAR struct ak09912_dev_s *priv, uint8_t regaddr,
+                           uint8_t regval)
+{
+  uint16_t inst[2];
+
+  /* Send register address and set the value */
+
+  inst[0] = SCU_INST_SEND(regaddr);
+  inst[1] = SCU_INST_SEND(regval) | SCU_INST_LAST;
+
+  scu_i2ctransfer(priv->port, priv->addr, inst, 2, NULL, 0);
+}
+
+/****************************************************************************
+ * Name: ak09912_getreg
+ *
+ * Description:
+ *   Read cnt bytes from a ak09912 register
+ *
+ ****************************************************************************/
+
+static int ak09912_getreg(FAR struct ak09912_dev_s *priv, uint8_t regaddr,
+                          uint8_t* buffer, uint32_t cnt)
+{
+  uint16_t inst[2];
+
+  /* Send register to read and get the next byte */
+
+  inst[0] = SCU_INST_SEND(regaddr);
+  inst[1] = SCU_INST_RECV(cnt) | SCU_INST_LAST;
+
+  scu_i2ctransfer(priv->port, priv->addr, inst, 2, buffer, cnt);
+
+  return OK;
+}
+
+/****************************************************************************
+ * Name: ak09912_checkid
+ *
+ * Description:
+ *   Read and verify the AK09911/AK09912 chip ID
+ *
+ ****************************************************************************/
+
+static int ak09912_checkid(FAR struct ak09912_dev_s *priv)
+{
+  uint16_t devid = 0;
+
+  /* Read device ID */
+
+  devid = ak09912_getreg8(priv, AK09912_WIA1);
+  devid += ak09912_getreg8(priv, AK09912_WIA2) << 8;
+  sninfo("devid: 0x%04x\n", devid);
+
+  if (devid != AK09911_DEVID && devid != AK09912_DEVID)
+    {
+      /* ID is not Correct */
+
+      snerr("Wrong Device ID! %02x\n", devid);
+      return -ENODEV;
+    }
+
+  return OK;
+}
+
+static int ak09912_seqinit(FAR struct ak09912_dev_s *priv)
+{
+  DEBUGASSERT(g_seq == NULL);
+
+  /* Open sequencer */
+
+  g_seq = seq_open(MAG_SEQ_TYPE, SCU_BUS_I2C0);
+  if (!g_seq)
+    {
+      return -ENOENT;
+    }
+  priv->seq = g_seq;
+
+  seq_setaddress(priv->seq, priv->addr);
+
+  /* Set instruction and sample data information to sequencer */
+
+  seq_setinstruction(priv->seq, g_ak09912inst, itemsof(g_ak09912inst));
+  seq_setsample(priv->seq, AK09912_BYTESPERSAMPLE, 0,
+                AK09912_ELEMENTSIZE, false);
+
+  return OK;
+}
+
+/****************************************************************************
+ * Name: ak09912_open
+ *
+ * Description:
+ *   This function is called whenever the AK09912 device is opened.
+ *
+ ****************************************************************************/
+
+static int ak09912_open(FAR struct file *filep)
+{
+  FAR struct inode        *inode = filep->f_inode;
+  FAR struct ak09912_dev_s *priv  = inode->i_private;
+
+  if (g_refcnt == 0)
+    {
+      int ret;
+
+      ret = ak09912_seqinit(priv);
+      if (ret < 0)
+        {
+          return ret;
+        }
+
+      ak09912_putreg8(priv, POWER_MODE_ADDR, AKM_CONT_MEAS_4);
+      up_mdelay(1);
+    }
+  else
+    {
+      /* Set existing sequencer */
+
+      priv->seq = g_seq;
+    }
+
+  g_refcnt++;
+
+  return OK;
+}
+
+/****************************************************************************
+ * Name: ak09912_close
+ *
+ * Description:
+ *   This routine is called when the AK09912 device is closed.
+ *
+ ****************************************************************************/
+
+static int ak09912_close(FAR struct file *filep)
+{
+  FAR struct inode        *inode = filep->f_inode;
+  FAR struct ak09912_dev_s *priv  = inode->i_private;
+
+  g_refcnt--;
+
+  (void) seq_ioctl(priv->seq, priv->id, SCUIOC_STOP, 0);
+
+  if (g_refcnt == 0)
+    {
+      DEBUGASSERT(g_seq);
+
+      ak09912_putreg8(priv, POWER_MODE_ADDR, AKM_POWER_DOWN_MODE);
+      up_mdelay(1);
+
+      seq_close(g_seq);
+      g_seq = NULL;
+    }
+  else
+    {
+      (void) seq_ioctl(priv->seq, priv->id, SCUIOC_FREEFIFO, 0);
+    }
+
+  return OK;
+}
+
+/****************************************************************************
+ * Name: ak09912_read
+ ****************************************************************************/
+
+static ssize_t ak09912_read(FAR struct file *filep, FAR char *buffer,
+                            size_t len)
+{
+  FAR struct inode        *inode = filep->f_inode;
+  FAR struct ak09912_dev_s *priv  = inode->i_private;
+
+  len = len / AK09912_BYTESPERSAMPLE * AK09912_BYTESPERSAMPLE;
+  len = seq_read(priv->seq, priv->id, buffer, len);
+
+  return len;
+}
+
+/****************************************************************************
+ * Name: ak09912_write
+ ****************************************************************************/
+
+static ssize_t ak09912_write(FAR struct file *filep, FAR const char *buffer,
+                            size_t buflen)
+{
+  return -ENOSYS;
+}
+
+/****************************************************************************
+ * Name: ak09912_write
+ ****************************************************************************/
+
+static int ak09912_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
+{
+  FAR struct inode *inode = filep->f_inode;
+  FAR struct ak09912_dev_s *priv  = inode->i_private;
+  int ret = OK;
+
+  switch (cmd)
+    {
+      /* Get sensitivity adjustment value
+       * Arg: Pointer to struct ak09912_sensadj_s
+       */
+
+      case SNIOC_GETADJ:
+        {
+          struct ak09912_sensadj_s *user = (struct ak09912_sensadj_s *)(uintptr_t)arg;
+
+          user->x = g_asa.x;
+          user->y = g_asa.y;
+          user->z = g_asa.z;
+        }
+        break;
+
+      default:
+        {
+          if (_SCUIOCVALID(cmd))
+            {
+              /* Redirect SCU commands */
+
+              ret = seq_ioctl(priv->seq, priv->id, cmd, arg);
+            }
+          else
+            {
+              snerr("Unrecognized cmd: %d\n", cmd);
+              ret = - ENOTTY;
+            }
+        }
+        break;
+    }
+
+  return ret;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+int ak09912_init(FAR struct i2c_master_s *i2c, int port)
+{
+  FAR struct ak09912_dev_s tmp, *priv = &tmp;
+  uint8_t val;
+  int ret;
+
+  /* Setup temporary device structure for initialization */
+
+  priv->i2c = i2c;
+  priv->addr = AK09912_ADDR;
+  priv->freq = AK09912_FREQ;
+  priv->port = port;
+
+  /* Check Device ID */
+
+  ret = ak09912_checkid(priv);
+  if (ret < 0)
+    {
+      snerr("Failed to register driver: %d\n", ret);
+      return ret;
+    }
+
+  ak09912_putreg8(priv, POWER_MODE_ADDR, AKM_FUSE_ROM_MODE);
+  up_mdelay(1);
+
+  ak09912_getreg(priv, AK09912_ASAX, (uint8_t *)&g_asa,
+                 sizeof(struct ak09912_sensadj_s));
+
+  ak09912_putreg8(priv, POWER_MODE_ADDR, AKM_POWER_DOWN_MODE);
+  up_mdelay(1);
+
+  /* Set noise suppression filter to LOW */
+
+  val = ak09912_getreg8(priv, AK09912_CTRL1);
+  val = (val & ~AK09912_NSF_MASK) | AK09912_NSF_LOW;
+  ak09912_putreg8(priv, AK09912_CTRL1, val);
+
+  return OK;
+}
+
+/****************************************************************************
+ * Name: ak09912_register
+ *
+ * Description:
+ *   Register the AK09912 character device as 'devpath'
+ *
+ * Input Parameters:
+ *   devpath - The full path to the driver to register. E.g., "/dev/mag"
+ *   i2c     - An instance of the I2C interface to use to communicate with
+ *             AK09912
+ *
+ * Returned Value:
+ *   Zero (OK) on success; a negated errno value on failure.
+ *
+ ****************************************************************************/
+
+int ak09912_register(FAR const char *devpath, int minor,
+                     FAR struct i2c_master_s *i2c, int port)
+{
+  FAR struct ak09912_dev_s *priv;
+  char path[16];
+  int ret;
+
+  /* Initialize the AK09912 device structure */
+
+  priv = (FAR struct ak09912_dev_s *)kmm_malloc(sizeof(struct ak09912_dev_s));
+  if (!priv)
+    {
+      snerr("Failed to allocate instance\n");
+      return -ENOMEM;
+    }
+
+  priv->i2c = i2c;
+  priv->id = minor;
+  priv->addr = AK09912_ADDR;
+  priv->freq = AK09912_FREQ;
+  priv->port = port;
+
+  /* Register the character driver */
+
+  (void) snprintf(path, sizeof(path), "%s%d", devpath, minor);
+  ret = register_driver(path, &g_ak09912fops, 0666, priv);
+  if (ret < 0)
+    {
+      snerr("Failed to register driver: %d\n", ret);
+      kmm_free(priv);
+    }
+
+  sninfo("AK09912 driver loaded successfully!\n");
+  return ret;
+}
+
+#endif /* CONFIG_I2C && CONFIG_SENSORS_AK09912_SCU */

boards/arm/dm320/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/arm/efm32/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/arm/imx6/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/arm/imxrt/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/arm/kinetis/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/arm/kl/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/arm/lc823450/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/arm/lpc17xx_40xx/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/arm/lpc214x/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/arm/lpc2378/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/arm/lpc31xx/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/arm/lpc43xx/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/arm/lpc54xx/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/arm/max326xx/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/arm/moxart/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/arm/nrf52/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/arm/nuc1xx/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/arm/s32k1xx/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/arm/sam34/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/arm/sama5/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/arm/samd2l2/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/arm/samd5e5/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/arm/samv7/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/arm/stm32/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/arm/stm32f0l0g0/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/arm/stm32f7/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/arm/stm32h7/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/arm/stm32l4/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/arm/str71x/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/arm/tiva/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/arm/tms570/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/arm/xmc4/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/avr/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/hc/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/mips/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/misoc/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/or1k/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/renesas/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/risc-v/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/sim/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/x86/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/xtensa/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/z16/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

boards/z80/drivers/Kconfig

@@ -0,0 +1,4 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#

drivers/Kconfig

@@ -407,3 +407,13 @@ menuconfig 1WIRE
 source drivers/1wire/Kconfig
 
 source drivers/syslog/Kconfig
+
+menuconfig SPECIFIC_DRIVERS
+	bool "Board specific drivers"
+	default n
+	---help---
+		Board specific drivers located in each board/driver folder.
+
+if SPECIFIC_DRIVERS
+source drivers/platform/Kconfig
+endif # SPECIFIC_DRIVERS

drivers/Makefile

@@ -83,6 +83,10 @@ include wireless$(DELIM)Make.defs
 include contactless$(DELIM)Make.defs
 include 1wire$(DELIM)Make.defs
 
+ifeq ($(CONFIG_SPECIFIC_DRIVERS),y)
+include platform$(DELIM)Make.defs
+endif
+
 CSRCS += dev_null.c dev_zero.c
 
 ifneq ($(CONFIG_DISABLE_MOUNTPOINT),y)

include/nuttx/sensors/ak09912.h

@@ -38,7 +38,8 @@
 
 #include <nuttx/config.h>
 
-#if defined(CONFIG_I2C) && defined(CONFIG_SENSORS_AK09912)
+#if defined(CONFIG_I2C) && (defined(CONFIG_SENSORS_AK09912) || defined (CONFIG_SENSORS_AK09912_SCU))
+
 
 /****************************************************************************
  * Pre-processor Definitions
@@ -75,7 +76,6 @@ extern "C"
 /* Arg: 0: Disable compensated
  *      1: Enable compensated
  */
-
 #define ENABLE_COMPENSATED (1)
 #define DISABLE_COMPENSATED (0)
 #define SNIOC_ENABLE_COMPENSATED   _SNIOC(0x0001)
@@ -96,6 +96,25 @@ struct ak09912_sensadj_s
   uint8_t z;
 };
 
+#ifdef CONFIG_SENSORS_AK09912_SCU
+/****************************************************************************
+ * Name: ak09912_init
+ *
+ * Description:
+ *   Initialize AK09912 magnetometer device
+ *
+ * Input Parameters:
+ *   i2c     - An instance of the I2C interface to use to communicate with
+ *             AK09912
+ *
+ * Returned Value:
+ *   Zero (OK) on success; a negated errno value on failure.
+ *
+ ****************************************************************************/
+
+int ak09912_init(FAR struct i2c_master_s *i2c, int port);
+#endif
+
 /****************************************************************************
  * Name: ak09912_register
  *
@@ -111,7 +130,12 @@ struct ak09912_sensadj_s
  *   Zero (OK) on success; a negated errno value on failure.
  *
  ****************************************************************************/
+#ifdef CONFIG_SENSORS_AK09912_SCU
+int ak09912_register(FAR const char *devpath, int minor,
+                     FAR struct i2c_master_s *i2c, int port);
+#else
 int ak09912_register(FAR const char *devpath, FAR struct i2c_master_s *i2c);
+#endif
 
 #undef EXTERN
 #ifdef __cplusplus
@@ -119,4 +143,4 @@ int ak09912_register(FAR const char *devpath, FAR struct i2c_master_s *i2c);
 #endif
 
 #endif /* CONFIG_I2C && CONFIG_AK09912 */
-#endif /* __DRIVERS_AK09912_H */
+#endif /* __INCLUDE_NUTTX_SENSORS_AK09912_H */

tools/Makefile.unix

@@ -78,7 +78,7 @@ else
 BOARD_DIR = $(CONFIG_ARCH_BOARD_CUSTOM_DIR)
 endif
 else
-BOARD_DIR = $(TOPDIR)$(DELIM)boards$(DELIM)$(CONFIG_ARCH)$(DELIM)$(CONFIG_ARCH_CHIP)$(DELIM)$(CONFIG_ARCH_BOARD)
+BOARD_DIR = $(TOPDIR)$(DELIM)boards$(DELIM)$(CONFIG_ARCH)$(DELIM)$(CONFIG_ARCH_CHIP)
 endif
 
 # CONFIG_APPS_DIR can be over-ridden from the command line or in the .config file.
@@ -314,17 +314,23 @@ include/arch: .config
 	@echo "LN: include/arch to $(ARCH_DIR)/include"
 	$(Q) $(DIRLINK) $(TOPDIR)/$(ARCH_DIR)/include include/arch
 
-# Link the boards/<arch>/<chip><board>/include directory to include/arch/board
+# Link the boards/<arch>/<chip>/<board>/include directory to include/arch/board
 
 include/arch/board: include/arch
-	@echo "LN: include/arch/board to $(BOARD_DIR)/include"
-	$(Q) $(DIRLINK) $(BOARD_DIR)/include include/arch/board
+	@echo "LN: include/arch/board to $(BOARD_DIR)/$(CONFIG_ARCH_BOARD)/include"
+	$(Q) $(DIRLINK) $(BOARD_DIR)/$(CONFIG_ARCH_BOARD)/include include/arch/board
 
-# Link the boards/<arch>/<chip><board>/src dir to arch/<arch-name>/src/board
+# Link the boards/<arch>/<chip>/<board>/src dir to arch/<arch-name>/src/board
 
 $(ARCH_SRC)/board: .config
-	@echo "LN: $(ARCH_SRC)/board to $(BOARD_DIR)/src"
-	$(Q) $(DIRLINK) $(BOARD_DIR)/src $(ARCH_SRC)/board
+	@echo "LN: $(ARCH_SRC)/board to $(BOARD_DIR)/$(CONFIG_ARCH_BOARD)/src"
+	$(Q) $(DIRLINK) $(BOARD_DIR)/$(CONFIG_ARCH_BOARD)/src $(ARCH_SRC)/board
+
+# Link the boards/<arch>/<chip>/drivers dir to drivers/platform
+
+$(ARCH_SRC)/drivers: .config
+	@echo "LN: $(ARCH_SRC)/drivers to $(BOARD_DIR)/drivers/platform"
+	$(Q) $(DIRLINK) $(BOARD_DIR)/drivers $(TOPDIR)/drivers/platform
 
 # Link arch/<arch-name>/include/<chip-name> to arch/<arch-name>/include/chip
 
@@ -342,7 +348,7 @@ ifneq ($(CONFIG_ARCH_CHIP),)
 	$(Q) $(DIRLINK) $(TOPDIR)/$(ARCH_INC)/$(CONFIG_ARCH_CHIP) include/arch/chip
 endif
 
-dirlinks: include/arch include/arch/board include/arch/chip $(ARCH_SRC)/board $(ARCH_SRC)/chip
+dirlinks: include/arch include/arch/board include/arch/chip $(ARCH_SRC)/board $(ARCH_SRC)/chip $(ARCH_SRC)/drivers
 	$(Q) $(MAKE) -C boards dirlinks TOPDIR="$(TOPDIR)"
 	$(Q) $(MAKE) -C $(CONFIG_APPS_DIR) dirlinks TOPDIR="$(TOPDIR)"
 
@@ -376,6 +382,7 @@ clean_context:
 	$(Q) $(DIRUNLINK) include/arch
 	$(Q) $(DIRUNLINK) $(ARCH_SRC)/board
 	$(Q) $(DIRUNLINK) $(ARCH_SRC)/chip
+	$(Q) $(DIRUNLINK) $(TOPDIR)/drivers/platform
 
 # check_context
 #

tools/Makefile.win

@@ -73,7 +73,7 @@ else
 BOARD_DIR = $(CONFIG_ARCH_BOARD_CUSTOM_DIR)
 endif
 else
-BOARD_DIR = $(TOPDIR)$(DELIM)boards$(DELIM)$(CONFIG_ARCH)$(DELIM)$(CONFIG_ARCH_CHIP)$(DELIM)$(CONFIG_ARCH_BOARD)
+BOARD_DIR = $(TOPDIR)$(DELIM)boards$(DELIM)$(CONFIG_ARCH)$(DELIM)$(CONFIG_ARCH_CHIP)
 endif
 
 # CONFIG_APPS_DIR can be over-ridden from the command line or in the .config file.
@@ -316,25 +316,36 @@ else
 	$(Q) echo FAKELNK > include\arch\.fakelnk
 endif
 
-# Link the boards\<arch>\<chip><board>\include directory to include\arch\board
+# Link the boards\<arch>\<chip>\<board>\include directory to include\arch\board
 
 include\arch\board: include\arch
-	@echo LN: include\arch\board to $(BOARD_DIR)\include
+	@echo LN: include\arch\board to $(BOARD_DIR)\$(CONFIG_ARCH_BOARD)\include
 ifeq ($(CONFIG_WINDOWS_MKLINK),y)
-	$(Q) /user:administrator mklink /d include\arch\board $(BOARD_DIR)\include
+	$(Q) /user:administrator mklink /d include\arch\board $(BOARD_DIR)\$(CONFIG_ARCH_BOARD)\include
 else
-	$(Q) xcopy $(BOARD_DIR)\include include\arch\board /c /q /s /e /y /i
+	$(Q) xcopy $(BOARD_DIR)\$(CONFIG_ARCH_BOARD)\include include\arch\board /c /q /s /e /y /i
 	$(Q) echo FAKELNK > include\arch\board\.fakelnk
 endif
 
-# Link the boards\<arch>\<chip><board>\src dir to arch\<arch-name>\src\board
+# Link the boards\<arch>\<chip>\drivers dir to drivers\platform
+
+$(ARCH_SRC)\drivers: .config
+	@echo LN: drivers\platform to $(BOARD_DIR)\drivers
+ifeq ($(CONFIG_WINDOWS_MKLINK),y)
+	$(Q) /user:administrator mklink /d $(TOPDIR)\drivers\platform $(BOARD_DIR)\drivers
+else
+	$(Q) xcopy $(BOARD_DIR)\drivers $(TOPDIR)\drivers\platform /c /q /s /e /y /i
+	$(Q) echo FAKELNK > $(TOPDIR)\drivers\platform .fakelnk
+endif
+
+# Link the boards\<arch>\<chip>\<board>\src dir to arch\<arch-name>\src\board
 
 $(ARCH_SRC)\board: .config
-	@echo LN: $(ARCH_SRC)\board to $(BOARD_DIR)\src
+	@echo LN: $(ARCH_SRC)\board to $(BOARD_DIR)\$(CONFIG_ARCH_BOARD)\src
 ifeq ($(CONFIG_WINDOWS_MKLINK),y)
-	$(Q) /user:administrator mklink /d $(ARCH_SRC)\board $(BOARD_DIR)\src
+	$(Q) /user:administrator mklink /d $(ARCH_SRC)\board $(BOARD_DIR)\$(CONFIG_ARCH_BOARD)\src
 else
-	$(Q) xcopy $(BOARD_DIR)\src $(ARCH_SRC)\board /c /q /s /e /y /i
+	$(Q) xcopy $(BOARD_DIR)\$(CONFIG_ARCH_BOARD)\src $(ARCH_SRC)\board /c /q /s /e /y /i
 	$(Q) echo FAKELNK > $(ARCH_SRC)\board\.fakelnk
 endif
 
@@ -364,7 +375,7 @@ else
 endif
 endif
 
-dirlinks: include\arch include\arch\board include\arch\chip $(ARCH_SRC)\board $(ARCH_SRC)\chip
+dirlinks: include\arch include\arch\board include\arch\chip $(ARCH_SRC)\board $(ARCH_SRC)\chip $(ARCH_SRC)\drivers
 	$(Q) $(MAKE) -C boards dirlinks TOPDIR="$(TOPDIR)"
 	$(Q) $(MAKE) -C $(CONFIG_APPS_DIR) dirlinks TOPDIR="$(TOPDIR)"
 
@@ -396,6 +407,7 @@ clean_context:
 	$(call DELDIR, include\arch)
 	$(call DELDIR, $(ARCH_SRC)\board)
 	$(call DELDIR, $(ARCH_SRC)\chip)
+	$(call DELDIR, $(TOPDIR)\drivers\platform)
 
 # check_context
 #