boards: cxd56xx: Add I2C bitbang driver registration

Add board API to register i2c bitbang driver as i2c device.

boards/arm/cxd56xx/common/src/Make.defs

@@ -136,6 +136,10 @@ ifeq ($(CONFIG_CXD56_I2C_DRIVER),y)
 CSRCS += cxd56_i2cdev.c
 endif
 
+ifeq ($(CONFIG_I2C_BITBANG),y)
+CSRCS += cxd56_i2cdev_bitbang.c
+endif
+
 ifeq ($(CONFIG_CXD56_SPI_DRIVER),y)
 CSRCS += cxd56_spidev.c
 endif

boards/arm/cxd56xx/common/src/cxd56_i2cdev_bitbang.c

@@ -0,0 +1,83 @@
+/****************************************************************************
+ * boards/arm/cxd56xx/common/src/cxd56_i2cdev_bitbang.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <nuttx/i2c/i2c_master.h>
+
+#include <stdio.h>
+#include <debug.h>
+#include <errno.h>
+
+#include "cxd56_i2c_bitbang.h"
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: board_i2cdev_bitbang_initialize
+ *
+ * Description:
+ *   Initialize i2c bitbang driver and register as the /dev/i2c device.
+ *
+ * Input Parameters:
+ *   sda_pin - The pin number used as I2C SDA signal
+ *   scl_pin - The pin number used as I2C SCL signal
+ *
+ * Returned Value:
+ *   OK on success; Negated errno on failure.
+ *
+ ****************************************************************************/
+
+int board_i2cdev_bitbang_initialize(uint32_t sda_pin, uint32_t scl_pin)
+{
+  int ret = 0;
+  FAR struct i2c_master_s *i2c;
+  int port;
+
+  /* Use a sda pin number as port number */
+
+  port = sda_pin;
+
+  _info("Initializing /dev/i2c%d..\n", port);
+
+  /* Initialize i2c bitbang device */
+
+  i2c = cxd56_i2c_bitbang_initialize(sda_pin, scl_pin);
+  if (!i2c)
+    {
+      _err("ERROR: Failed to initialize i2c%d.\n", port);
+      return -ENODEV;
+    }
+
+#ifdef CONFIG_I2C_DRIVER
+  ret = i2c_register(i2c, port);
+  if (ret < 0)
+    {
+      _err("ERROR: Failed to register i2c%d: %d\n", port, ret);
+    }
+#endif
+
+  return ret;
+}

boards/arm/cxd56xx/spresense/include/cxd56_i2cdev.h

@@ -26,6 +26,7 @@
  ****************************************************************************/
 
 #include <nuttx/config.h>
+#include <stdint.h>
 
 /****************************************************************************
  * Public Types
@@ -62,6 +63,25 @@ extern "C"
 int board_i2cdev_initialize(int bus);
 #endif
 
+/****************************************************************************
+ * Name: board_i2cdev_bitbang_initialize
+ *
+ * Description:
+ *   Initialize i2c bitbang driver and register as the /dev/i2c device.
+ *
+ * Input Parameters:
+ *   sda_pin - The pin number used as I2C SDA signal
+ *   scl_pin - The pin number used as I2C SCL signal
+ *
+ * Returned Value:
+ *   OK on success; Negated errno on failure.
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_I2C_BITBANG
+int board_i2cdev_bitbang_initialize(uint32_t sda_pin, uint32_t scl_pin);
+#endif
+
 #undef EXTERN
 #if defined(__cplusplus)
 }