esp32[c3|c6|h2]: Add SPI bitbang support

Documentation/platforms/risc-v/esp32c3/boards/esp32c3-generic/index.rst

@@ -248,6 +248,10 @@ by default to each other and running the ``spi`` example::
     Sending:	AB
     Received:	AB
 
+If SPI peripherals are already in use you can also use bitbang driver which is a
+software implemented SPI peripheral by enabling `CONFIG_ESPRESSIF_SPI_BITBANG`
+option.
+
 spiflash
 --------
 

Documentation/platforms/risc-v/esp32c6/boards/esp32c6-devkitc/index.rst

@@ -260,6 +260,10 @@ by default to each other and running the ``spi`` example::
     Sending:	AB
     Received:	AB
 
+If SPI peripherals are already in use you can also use bitbang driver which is a
+software implemented SPI peripheral by enabling `CONFIG_ESPRESSIF_SPI_BITBANG`
+option.
+
 spiflash
 --------
 

Documentation/platforms/risc-v/esp32c6/boards/esp32c6-devkitm/index.rst

@@ -222,6 +222,10 @@ by default to each other and running the ``spi`` example::
     Sending:	AB
     Received:	AB
 
+If SPI peripherals are already in use you can also use bitbang driver which is a
+software implemented SPI peripheral by enabling `CONFIG_ESPRESSIF_SPI_BITBANG`
+option.
+
 spiflash
 --------
 

Documentation/platforms/risc-v/esp32h2/boards/esp32h2-devkit/index.rst

@@ -221,6 +221,10 @@ by default to each other and running the ``spi`` example::
     Sending:	AB
     Received:	AB
 
+If SPI peripherals are already in use you can also use bitbang driver which is a
+software implemented SPI peripheral by enabling `CONFIG_ESPRESSIF_SPI_BITBANG`
+option.
+
 spiflash
 --------
 

arch/risc-v/src/common/espressif/Kconfig

@@ -354,11 +354,26 @@ config ESPRESSIF_SPI
 	bool
 	default n
 
+config ESPRESSIF_SPI_PERIPH
+	bool
+	depends on ESPRESSIF_SPI2
+	default n
+
 config ESPRESSIF_SPI2
 	bool "SPI 2"
 	default n
 	select ESPRESSIF_SPI
 	select SPI
+	select ESPRESSIF_SPI_PERIPH
+
+config ESPRESSIF_SPI_BITBANG
+	bool "SPI Bitbang"
+	default n
+	select ESPRESSIF_SPI
+	select SPI
+	select SPI_BITBANG
+	---help---
+		Software implemented SPI peripheral with GPIOs. Suggested to use if SPI peripheral is already in use.
 
 config ESPRESSIF_SPIFLASH
 	bool "SPI Flash"
@@ -1167,6 +1182,7 @@ menu "SPI configuration"
 
 config ESPRESSIF_SPI_SWCS
 	bool "SPI software CS"
+	depends on ESPRESSIF_SPI_PERIPH
 	default n
 	---help---
 		Use SPI software CS.
@@ -1175,6 +1191,7 @@ config ESPRESSIF_SPI_UDCS
 	bool "User defined CS"
 	default n
 	depends on ESPRESSIF_SPI_SWCS
+	depends on ESPRESSIF_SPI_PERIPH
 	---help---
 		Use user-defined CS.
 
@@ -1245,10 +1262,53 @@ config ESPRESSIF_SPI2_MISOPIN
 
 endif # ESPRESSIF_SPI2
 
+if ESPRESSIF_SPI_BITBANG
+
+config ESPRESSIF_SPI_BITBANG_CSPIN
+	int "SPI Bitbang CS Pin"
+	default 0
+	range 0 21
+
+config ESPRESSIF_SPI_BITBANG_CLKPIN
+	int "SPI Bitbang CLK Pin"
+	default 1
+	range 0 21
+
+config ESPRESSIF_SPI_BITBANG_MOSIPIN
+	int "SPI Bitbang MOSI Pin"
+	default 2
+	range 0 21
+
+config ESPRESSIF_SPI_BITBANG_MISOPIN
+	int "SPI Bitbang MISO Pin"
+	default 3
+	range 0 21
+
+choice ESPRESSIF_SPI_BITBANG_MODE
+	prompt "SPI Bitbang mode"
+	default ESPRESSIF_SPI_BITBANG_MODE0
+
+config ESPRESSIF_SPI_BITBANG_MODE0
+	bool "SPI MODE0"
+
+config ESPRESSIF_SPI_BITBANG_MODE1
+	bool "SPI MODE1"
+
+config ESPRESSIF_SPI_BITBANG_MODE2
+	bool "SPI MODE2"
+
+config ESPRESSIF_SPI_BITBANG_MODE3
+	bool "SPI MODE3"
+
+endchoice # ESPRESSIF_SPI_BITBANG_MODE
+
+endif # ESPRESSIF_SPI_BITBANG
+
 config ESPRESSIF_SPI_TEST_MODE
 	bool "SPI driver loopback test mode (for testing only)"
 	default n
 	depends on SYSTEM_SPITOOL
+	depends on ESPRESSIF_SPI_PERIPH
 	---help---
 		This enables a loopback test mode that attaches the transmitter
 		to the receiver internally, being able to test the SPI

arch/risc-v/src/common/espressif/Make.defs

@@ -108,10 +108,15 @@ ifeq ($(CONFIG_ESPRESSIF_I2C),y)
 endif
 
 ifeq ($(CONFIG_ESPRESSIF_SPI),y)
-	CHIP_CSRCS += esp_spi.c
+	ifeq ($(CONFIG_ESPRESSIF_SPI_PERIPH),y)
+		CHIP_CSRCS += esp_spi.c
+	endif
 	ifeq ($(CONFIG_SPI_SLAVE),y)
 		CHIP_CSRCS += esp_spi_slave.c
 	endif
+	ifeq ($(CONFIG_ESPRESSIF_SPI_BITBANG),y)
+		CHIP_CSRCS += esp_spi_bitbang.c
+	endif
 endif
 
 ifeq ($(CONFIG_ESPRESSIF_SPIFLASH),y)

arch/risc-v/src/common/espressif/esp_spi.c

@@ -24,7 +24,7 @@
 
 #include <nuttx/config.h>
 
-#ifdef CONFIG_ESPRESSIF_SPI
+#ifdef CONFIG_ESPRESSIF_SPI_PERIPH
 
 #include <assert.h>
 #include <debug.h>
@@ -1283,4 +1283,4 @@ int esp_spibus_uninitialize(struct spi_dev_s *dev)
   return OK;
 }
 
-#endif /* CONFIG_ESPRESSIF_SPI */
+#endif /* CONFIG_ESPRESSIF_SPI_PERIPH */

arch/risc-v/src/common/espressif/esp_spi.h

@@ -42,13 +42,11 @@ extern "C"
 #define EXTERN extern
 #endif
 
-#ifdef CONFIG_ESPRESSIF_SPI
+#ifdef CONFIG_ESPRESSIF_SPI_PERIPH
 
 #include <nuttx/spi/spi.h>
 
-#ifdef CONFIG_ESPRESSIF_SPI2
+#define ESPRESSIF_SPI2 2
-#  define ESPRESSIF_SPI2 2
-#endif
 
 /****************************************************************************
  * Public Function Prototypes
@@ -159,7 +157,7 @@ struct spi_slave_ctrlr_s *esp_spislave_ctrlr_initialize(int port);
 
 int esp_spislave_ctrlr_uninitialize(struct spi_slave_ctrlr_s *ctrlr);
 
-#endif /* CONFIG_ESPRESSIF_SPI */
+#endif /* CONFIG_ESPRESSIF_SPI_PERIPH */
 
 #ifdef __cplusplus
 }

arch/risc-v/src/common/espressif/esp_spi_bitbang.c

@@ -0,0 +1,251 @@
+/****************************************************************************
+ * arch/risc-v/src/common/espressif/esp_spi_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>
+
+#ifdef CONFIG_ESPRESSIF_SPI_BITBANG
+#include <sys/param.h>
+#include <sys/types.h>
+#include <stdint.h>
+#include <string.h>
+#include <assert.h>
+#include <debug.h>
+
+#include <nuttx/arch.h>
+#include <nuttx/irq.h>
+#include <nuttx/mutex.h>
+#include <nuttx/kmalloc.h>
+#include <nuttx/spi/spi.h>
+#include <nuttx/spi/spi_bitbang.h>
+
+#include "riscv_internal.h"
+#include "espressif/esp_gpio.h"
+#include "soc/gpio_sig_map.h"
+#include "esp_spi_bitbang.h"
+#include <nuttx/spi/spi_bitbang.c>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#if defined(CONFIG_ESPRESSIF_SPI_BITBANG_MODE0)
+#undef  SPI_BITBANG_DISABLEMODE0
+#define SPI_BITBANG_DISABLEMODE1 1
+#define SPI_BITBANG_DISABLEMODE2 1
+#define SPI_BITBANG_DISABLEMODE3 1
+#elif defined(CONFIG_ESPRESSIF_SPI_BITBANG_MODE1)
+#undef  SPI_BITBANG_DISABLEMODE1
+#define SPI_BITBANG_DISABLEMODE0 1
+#define SPI_BITBANG_DISABLEMODE2 1
+#define SPI_BITBANG_DISABLEMODE3 1
+#elif defined(CONFIG_ESPRESSIF_SPI_BITBANG_MODE2)
+#undef  SPI_BITBANG_DISABLEMODE2
+#define SPI_BITBANG_DISABLEMODE0 1
+#define SPI_BITBANG_DISABLEMODE1 1
+#define SPI_BITBANG_DISABLEMODE3 1
+#else
+#undef  SPI_BITBANG_DISABLEMODE3
+#define SPI_BITBANG_DISABLEMODE0 1
+#define SPI_BITBANG_DISABLEMODE1 1
+#define SPI_BITBANG_DISABLEMODE2 1
+#endif
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/* Lower-half SPI */
+
+static void spi_select(struct spi_bitbang_s *priv, uint32_t devid,
+                       bool selected);
+static uint8_t spi_status(struct spi_bitbang_s *priv, uint32_t devid);
+#ifdef CONFIG_SPI_CMDDATA
+static int spi_cmddata(struct spi_bitbang_s *priv, uint32_t devid,
+                       bool cmd);
+#endif
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+struct spi_bitbang_ops_s esp_spi_bitbang_ops =
+{
+  .select = spi_select,
+  .status = spi_status,
+#ifdef CONFIG_SPI_CMDDATA
+  .cmddata = spi_cmddata,
+#endif
+  .setfrequency = spi_setfrequency,
+  .setmode = spi_setmode,
+  .exchange = spi_exchange,
+};
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: spi_select
+ *
+ * Description:
+ *   Select or de-selected the SPI device specified by 'devid'
+ *
+ * Input Parameters:
+ *   priv     - An instance of the bit-bang driver structure
+ *   devid    - The device to select or de-select
+ *   selected - True:select false:de-select
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+static void spi_select(struct spi_bitbang_s *priv, uint32_t devid,
+                       bool selected)
+{
+  if (selected)
+    {
+      SPI_CLRCS;
+    }
+  else
+    {
+      SPI_SETCS;
+    }
+}
+
+/****************************************************************************
+ * Name: spi_status
+ *
+ * Description:
+ *   Return status of the SPI device specified by 'devid'
+ *
+ * Input Parameters:
+ *   priv     - An instance of the bit-bang driver structure
+ *   devid    - The device to select or de-select
+ *
+ * Returned Value:
+ *   An 8-bit, bit-encoded status byte
+ *
+ ****************************************************************************/
+
+static uint8_t spi_status(struct spi_bitbang_s *priv, uint32_t devid)
+{
+  if (devid == SPIDEV_MMCSD(0))
+    {
+      return SPI_STATUS_PRESENT;
+    }
+
+  return 0;
+}
+
+/****************************************************************************
+ * Name: spi_cmddata
+ *
+ * Description:
+ *   If there were was a CMD/DATA line, this function would manage it
+ *
+ * Input Parameters:
+ *   priv  - An instance of the bit-bang driver structure
+ *   devid - The device to use
+ *   cmd   - True=MCD false=DATA
+ *
+ * Returned Value:
+ *  OK
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_SPI_CMDDATA
+static int spi_cmddata(struct spi_bitbang_s *priv, uint32_t devid,
+                       bool cmd)
+{
+  return OK;
+}
+#endif
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: esp_spi_bitbang_init
+ *
+ * Description:
+ *   Initialize the SPI bit-bang driver
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value:
+ *   A non-NULL reference to the SPI driver on success
+ *
+ ****************************************************************************/
+
+struct spi_dev_s *esp_spi_bitbang_init(void)
+{
+  /* Configure the SPI bit-bang pins */
+
+  esp_gpiowrite(CONFIG_ESPRESSIF_SPI_BITBANG_CSPIN, true);
+  esp_gpiowrite(CONFIG_ESPRESSIF_SPI_BITBANG_MOSIPIN, true);
+  esp_gpiowrite(CONFIG_ESPRESSIF_SPI_BITBANG_CLKPIN, true);
+
+#if CONFIG_ESPRESSIF_SPI_SWCS
+  esp_configgpio(CONFIG_ESPRESSIF_SPI_BITBANG_CSPIN, OUTPUT_FUNCTION_1);
+  esp_gpio_matrix_out(CONFIG_ESPRESSIF_SPI_BITBANG_CSPIN, SIG_GPIO_OUT_IDX,
+                      0, 0);
+#endif
+  esp_configgpio(CONFIG_ESPRESSIF_SPI_BITBANG_MOSIPIN, OUTPUT_FUNCTION_1);
+  esp_gpio_matrix_out(CONFIG_ESPRESSIF_SPI_BITBANG_MOSIPIN, SIG_GPIO_OUT_IDX,
+                      0, 0);
+
+  esp_configgpio(CONFIG_ESPRESSIF_SPI_BITBANG_MISOPIN,
+                 INPUT_FUNCTION_1 | PULLUP);
+  esp_gpio_matrix_out(CONFIG_ESPRESSIF_SPI_BITBANG_MISOPIN, SIG_GPIO_OUT_IDX,
+                      0, 0);
+
+  esp_configgpio(CONFIG_ESPRESSIF_SPI_BITBANG_CLKPIN, OUTPUT_FUNCTION_1);
+  esp_gpio_matrix_out(CONFIG_ESPRESSIF_SPI_BITBANG_CLKPIN, SIG_GPIO_OUT_IDX,
+                      0, 0);
+
+  /* Create the SPI driver instance */
+
+  return spi_create_bitbang(&esp_spi_bitbang_ops, NULL);
+}
+
+/****************************************************************************
+ * Name:  esp_spi_bitbang_uninitialize
+ *
+ * Description:
+ *   Destroy an instance of the SPI bit-bang driver.
+ *
+ * Input Parameters:
+ *   dev - device instance, target driver to destroy.
+ *
+ ****************************************************************************/
+
+void esp_spi_bitbang_uninitialize(struct spi_dev_s *dev)
+{
+  spi_destroy_bitbang(dev);
+}
+
+#endif /* CONFIG_ESPRESSIF_SPI_BITBANG */

arch/risc-v/src/common/espressif/esp_spi_bitbang.h

@@ -0,0 +1,116 @@
+/****************************************************************************
+ * arch/risc-v/src/common/espressif/esp_spi_bitbang.h
+ *
+ * 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
+ ****************************************************************************/
+
+#ifndef __ARCH_RISCV_SRC_COMMON_ESPRESSIF_ESP_SPI_BITBANG_H
+#define __ARCH_RISCV_SRC_COMMON_ESPRESSIF_ESP_SPI_BITBANG_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#ifndef __ASSEMBLY__
+
+#undef EXTERN
+#if defined(__cplusplus)
+#define EXTERN extern "C"
+extern "C"
+{
+#else
+#define EXTERN extern
+#endif
+
+#ifdef CONFIG_ESPRESSIF_SPI_BITBANG
+
+#include <nuttx/spi/spi.h>
+#include <nuttx/spi/spi_bitbang.h>
+#include "espressif/esp_gpio.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Macros needed to include/nuttx/spi/spi_bitbang.c. */
+
+#define SPI_SETSCK  esp_gpiowrite(CONFIG_ESPRESSIF_SPI_BITBANG_CLKPIN, true)
+#define SPI_CLRSCK  esp_gpiowrite(CONFIG_ESPRESSIF_SPI_BITBANG_CLKPIN, false)
+#define SPI_SETMOSI esp_gpiowrite(CONFIG_ESPRESSIF_SPI_BITBANG_MOSIPIN, true)
+#define SPI_CLRMOSI esp_gpiowrite(CONFIG_ESPRESSIF_SPI_BITBANG_MOSIPIN, \
+                                  false)
+#define SPI_GETMISO esp_gpioread(CONFIG_ESPRESSIF_SPI_BITBANG_MISOPIN)
+#define SPI_SETCS   esp_gpiowrite(CONFIG_ESPRESSIF_SPI_BITBANG_CSPIN, true)
+#define SPI_CLRCS   esp_gpiowrite(CONFIG_ESPRESSIF_SPI_BITBANG_CSPIN, false)
+
+/* Calibration value for timing loop */
+
+#define SPI_BITBANG_LOOPSPERMSEC CONFIG_BOARD_LOOPSPERMSEC
+
+/* SPI_PERBIT_NSEC is the minimum time to transfer one bit. This determines
+ * the maximum frequency and is also used to calculate delays to achieve
+ * other SPI frequencies.
+ */
+
+#define SPI_PERBIT_NSEC       100
+
+#define ESPRESSIF_SPI_BITBANG 3
+
+/****************************************************************************
+ * Name: esp_spi_bitbang_init
+ *
+ * Description:
+ *   Initialize the SPI bit-bang driver
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value:
+ *   A non-NULL reference to the SPI driver on success
+ *
+ ****************************************************************************/
+
+struct spi_dev_s *esp_spi_bitbang_init(void);
+
+/****************************************************************************
+ * Name:  esp_spi_bitbang_uninitialize
+ *
+ * Description:
+ *   Destroy an instance of the SPI bit-bang driver.
+ *
+ * Input Parameters:
+ *   dev - device instance, target driver to destroy.
+ *
+ ****************************************************************************/
+
+void esp_spi_bitbang_uninitialize(struct spi_dev_s *dev);
+
+#endif /* CONFIG_ESPRESSIF_SPI_BITBANG */
+
+#ifdef __cplusplus
+}
+#endif
+#undef EXTERN
+
+#endif /* __ASSEMBLY__ */
+#endif /* __ARCH_RISCV_SRC_COMMON_ESPRESSIF_ESP_SPI_BITBANG_H */

boards/risc-v/esp32c3/common/src/esp_board_spidev.c

@@ -30,16 +30,65 @@
 
 #include <nuttx/spi/spi_transfer.h>
 
+#ifdef CONFIG_ESPRESSIF_SPI_PERIPH
 #include "espressif/esp_spi.h"
+#endif
+#ifdef CONFIG_ESPRESSIF_SPI_BITBANG
+#include "espressif/esp_spi_bitbang.h"
+#endif
 
 #include "esp_board_spidev.h"
 
 /****************************************************************************
- * Public Functions
+ * Private Functions
  ****************************************************************************/
 
 /****************************************************************************
- * Name: board_spidev_initialize
+ * Name: spi_bitbang_driver_init
+ *
+ * Description:
+ *   Initialize SPI bitbang driver and register the /dev/spi device.
+ *
+ * Input Parameters:
+ *   port - The SPI bus number, used to build the device path as /dev/spiN
+ *
+ * Returned Value:
+ *   Zero (OK) is returned on success; A negated errno value is returned
+ *   to indicate the nature of any failure.
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_ESPRESSIF_SPI_BITBANG
+static int spi_bitbang_driver_init(int port)
+{
+  int ret;
+  struct spi_dev_s *spi;
+
+  syslog(LOG_INFO, "Initializing /dev/spi%d...\n", port);
+
+  /* Initialize SPI device */
+
+  spi = esp_spi_bitbang_init();
+
+  if (spi == NULL)
+    {
+      syslog(LOG_ERR, "Failed to initialize SPI%d.\n", port);
+      return -ENODEV;
+    }
+
+  ret = spi_register(spi, port);
+  if (ret < 0)
+    {
+      syslog(LOG_ERR, "Failed to register /dev/spi%d: %d\n", port, ret);
+      esp_spi_bitbang_uninitialize(spi);
+    }
+
+  return ret;
+}
+#endif
+
+/****************************************************************************
+ * Name: spi_driver_init
  *
  * Description:
  *   Initialize SPI driver and register the /dev/spi device.
@@ -53,9 +102,10 @@
  *
  ****************************************************************************/
 
-int board_spidev_initialize(int port)
+#ifdef CONFIG_ESPRESSIF_SPI_PERIPH
+static int spi_driver_init(int port)
 {
-  int ret;
+  int ret = OK;
   struct spi_dev_s *spi;
 
   syslog(LOG_INFO, "Initializing /dev/spi%d...\n", port);
@@ -63,6 +113,7 @@ int board_spidev_initialize(int port)
   /* Initialize SPI device */
 
   spi = esp_spibus_initialize(port);
+
   if (spi == NULL)
     {
       syslog(LOG_ERR, "Failed to initialize SPI%d.\n", port);
@@ -73,9 +124,68 @@ int board_spidev_initialize(int port)
   if (ret < 0)
     {
       syslog(LOG_ERR, "Failed to register /dev/spi%d: %d\n", port, ret);
-
       esp_spibus_uninitialize(spi);
     }
 
   return ret;
 }
+#endif
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: board_spidev_initialize
+ *
+ * Description:
+ *   Configure the SPI drivers.
+ *
+ * Input Parameters:
+ *   port - The SPI bus number, used to build the device path as /dev/spiN
+ *
+ * Returned Value:
+ *   Zero (OK) is returned on success; A negated errno value is returned
+ *   to indicate the nature of any failure.
+ *
+ ****************************************************************************/
+
+int board_spidev_initialize(int port)
+{
+  int ret = OK;
+
+  switch (port)
+    {
+#ifdef CONFIG_ESPRESSIF_SPI2
+      case ESPRESSIF_SPI2:
+        {
+          ret = spi_driver_init(ESPRESSIF_SPI2);
+          if (ret != OK)
+            {
+              return ret;
+            }
+          break;
+        }
+#endif
+
+#ifdef CONFIG_ESPRESSIF_SPI_BITBANG
+      case ESPRESSIF_SPI_BITBANG:
+        {
+          ret = spi_bitbang_driver_init(ESPRESSIF_SPI_BITBANG);
+          if (ret != OK)
+            {
+              return ret;
+            }
+          break;
+        }
+#endif
+
+    default:
+      {
+        wderr("ERROR: unsupported SPI %d\n", port);
+        return ERROR;
+      }
+    }
+
+  return ret;
+}

boards/risc-v/esp32c3/esp32c3-generic/src/esp32c3_bringup.c

@@ -70,6 +70,9 @@
 #ifdef CONFIG_ESPRESSIF_SPI
 #  include "espressif/esp_spi.h"
 #  include "esp_board_spidev.h"
+#  ifdef CONFIG_ESPRESSIF_SPI_BITBANG
+#    include "espressif/esp_spi_bitbang.h"
+#  endif
 #endif
 
 #ifdef CONFIG_ESPRESSIF_TEMP
@@ -197,12 +200,22 @@ int esp_bringup(void)
 #endif
 
 #if defined(CONFIG_ESPRESSIF_SPI) && defined(CONFIG_SPI_DRIVER)
+#  ifdef CONFIG_ESPRESSIF_SPI2
   ret = board_spidev_initialize(ESPRESSIF_SPI2);
   if (ret < 0)
     {
       syslog(LOG_ERR, "ERROR: Failed to init spidev 2: %d\n", ret);
     }
-#endif
+#  endif /* CONFIG_ESPRESSIF_SPI2 */
+
+#  ifdef CONFIG_ESPRESSIF_SPI_BITBANG
+  ret = board_spidev_initialize(ESPRESSIF_SPI_BITBANG);
+  if (ret < 0)
+    {
+      syslog(LOG_ERR, "ERROR: Failed to init spidev 3: %d\n", ret);
+    }
+#  endif /* CONFIG_ESPRESSIF_SPI_BITBANG */
+#endif /* CONFIG_ESPRESSIF_SPI && CONFIG_SPI_DRIVER*/
 
 #ifdef CONFIG_ESPRESSIF_SPIFLASH
   ret = board_spiflash_init();

boards/risc-v/esp32c6/common/src/esp_board_spidev.c

@@ -30,16 +30,65 @@
 
 #include <nuttx/spi/spi_transfer.h>
 
+#ifdef CONFIG_ESPRESSIF_SPI_PERIPH
 #include "espressif/esp_spi.h"
+#endif
+#ifdef CONFIG_ESPRESSIF_SPI_BITBANG
+#include "espressif/esp_spi_bitbang.h"
+#endif
 
 #include "esp_board_spidev.h"
 
 /****************************************************************************
- * Public Functions
+ * Private Functions
  ****************************************************************************/
 
 /****************************************************************************
- * Name: board_spidev_initialize
+ * Name: spi_bitbang_driver_init
+ *
+ * Description:
+ *   Initialize SPI bitbang driver and register the /dev/spi device.
+ *
+ * Input Parameters:
+ *   port - The SPI bus number, used to build the device path as /dev/spiN
+ *
+ * Returned Value:
+ *   Zero (OK) is returned on success; A negated errno value is returned
+ *   to indicate the nature of any failure.
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_ESPRESSIF_SPI_BITBANG
+static int spi_bitbang_driver_init(int port)
+{
+  int ret;
+  struct spi_dev_s *spi;
+
+  syslog(LOG_INFO, "Initializing /dev/spi%d...\n", port);
+
+  /* Initialize SPI device */
+
+  spi = esp_spi_bitbang_init();
+
+  if (spi == NULL)
+    {
+      syslog(LOG_ERR, "Failed to initialize SPI%d.\n", port);
+      return -ENODEV;
+    }
+
+  ret = spi_register(spi, port);
+  if (ret < 0)
+    {
+      syslog(LOG_ERR, "Failed to register /dev/spi%d: %d\n", port, ret);
+      esp_spi_bitbang_uninitialize(spi);
+    }
+
+  return ret;
+}
+#endif
+
+/****************************************************************************
+ * Name: spi_driver_init
  *
  * Description:
  *   Initialize SPI driver and register the /dev/spi device.
@@ -53,9 +102,10 @@
  *
  ****************************************************************************/
 
-int board_spidev_initialize(int port)
+#ifdef CONFIG_ESPRESSIF_SPI_PERIPH
+static int spi_driver_init(int port)
 {
-  int ret;
+  int ret = OK;
   struct spi_dev_s *spi;
 
   syslog(LOG_INFO, "Initializing /dev/spi%d...\n", port);
@@ -63,6 +113,7 @@ int board_spidev_initialize(int port)
   /* Initialize SPI device */
 
   spi = esp_spibus_initialize(port);
+
   if (spi == NULL)
     {
       syslog(LOG_ERR, "Failed to initialize SPI%d.\n", port);
@@ -73,9 +124,68 @@ int board_spidev_initialize(int port)
   if (ret < 0)
     {
       syslog(LOG_ERR, "Failed to register /dev/spi%d: %d\n", port, ret);
-
       esp_spibus_uninitialize(spi);
     }
 
   return ret;
 }
+#endif
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: board_spidev_initialize
+ *
+ * Description:
+ *   Configure the SPI drivers.
+ *
+ * Input Parameters:
+ *   port - The SPI bus number, used to build the device path as /dev/spiN
+ *
+ * Returned Value:
+ *   Zero (OK) is returned on success; A negated errno value is returned
+ *   to indicate the nature of any failure.
+ *
+ ****************************************************************************/
+
+int board_spidev_initialize(int port)
+{
+  int ret = OK;
+
+  switch (port)
+    {
+#ifdef CONFIG_ESPRESSIF_SPI2
+      case ESPRESSIF_SPI2:
+        {
+          ret = spi_driver_init(ESPRESSIF_SPI2);
+          if (ret != OK)
+            {
+              return ret;
+            }
+          break;
+        }
+#endif
+
+#ifdef CONFIG_ESPRESSIF_SPI_BITBANG
+      case ESPRESSIF_SPI_BITBANG:
+        {
+          ret = spi_bitbang_driver_init(ESPRESSIF_SPI_BITBANG);
+          if (ret != OK)
+            {
+              return ret;
+            }
+          break;
+        }
+#endif
+
+    default:
+      {
+        wderr("ERROR: unsupported SPI %d\n", port);
+        return ERROR;
+      }
+    }
+
+  return ret;
+}

boards/risc-v/esp32c6/esp32c6-devkitc/src/esp32c6_bringup.c

@@ -70,6 +70,9 @@
 #ifdef CONFIG_ESPRESSIF_SPI
 #  include "espressif/esp_spi.h"
 #  include "esp_board_spidev.h"
+#  ifdef CONFIG_ESPRESSIF_SPI_BITBANG
+#    include "espressif/esp_spi_bitbang.h"
+#  endif
 #endif
 
 #ifdef CONFIG_ESPRESSIF_TEMP
@@ -225,12 +228,22 @@ int esp_bringup(void)
 #endif
 
 #if defined(CONFIG_ESPRESSIF_SPI) && defined(CONFIG_SPI_DRIVER)
+#  ifdef CONFIG_ESPRESSIF_SPI2
   ret = board_spidev_initialize(ESPRESSIF_SPI2);
   if (ret < 0)
     {
       syslog(LOG_ERR, "ERROR: Failed to init spidev 2: %d\n", ret);
     }
-#endif
+#  endif /* CONFIG_ESPRESSIF_SPI2 */
+
+#  ifdef CONFIG_ESPRESSIF_SPI_BITBANG
+  ret = board_spidev_initialize(ESPRESSIF_SPI_BITBANG);
+  if (ret < 0)
+    {
+      syslog(LOG_ERR, "ERROR: Failed to init spidev 3: %d\n", ret);
+    }
+#  endif /* CONFIG_ESPRESSIF_SPI_BITBANG */
+#endif /* CONFIG_ESPRESSIF_SPI && CONFIG_SPI_DRIVER*/
 
 #ifdef CONFIG_ESPRESSIF_SPIFLASH
   ret = board_spiflash_init();

boards/risc-v/esp32c6/esp32c6-devkitm/src/esp32c6_bringup.c

@@ -70,6 +70,9 @@
 #ifdef CONFIG_ESPRESSIF_SPI
 #  include "espressif/esp_spi.h"
 #  include "esp_board_spidev.h"
+#  ifdef CONFIG_ESPRESSIF_SPI_BITBANG
+#    include "espressif/esp_spi_bitbang.h"
+#  endif
 #endif
 
 #ifdef CONFIG_ESPRESSIF_TEMP
@@ -221,12 +224,22 @@ int esp_bringup(void)
 #endif
 
 #if defined(CONFIG_ESPRESSIF_SPI) && defined(CONFIG_SPI_DRIVER)
+#  ifdef CONFIG_ESPRESSIF_SPI2
   ret = board_spidev_initialize(ESPRESSIF_SPI2);
   if (ret < 0)
     {
       syslog(LOG_ERR, "ERROR: Failed to init spidev 2: %d\n", ret);
     }
-#endif
+#  endif /* CONFIG_ESPRESSIF_SPI2 */
+
+#  ifdef CONFIG_ESPRESSIF_SPI_BITBANG
+  ret = board_spidev_initialize(ESPRESSIF_SPI_BITBANG);
+  if (ret < 0)
+    {
+      syslog(LOG_ERR, "ERROR: Failed to init spidev 3: %d\n", ret);
+    }
+#  endif /* CONFIG_ESPRESSIF_SPI_BITBANG */
+#endif /* CONFIG_ESPRESSIF_SPI && CONFIG_SPI_DRIVER*/
 
 #ifdef CONFIG_ESPRESSIF_SPIFLASH
   ret = board_spiflash_init();

boards/risc-v/esp32h2/common/src/esp_board_spidev.c

@@ -30,16 +30,65 @@
 
 #include <nuttx/spi/spi_transfer.h>
 
+#ifdef CONFIG_ESPRESSIF_SPI_PERIPH
 #include "espressif/esp_spi.h"
+#endif
+#ifdef CONFIG_ESPRESSIF_SPI_BITBANG
+#include "espressif/esp_spi_bitbang.h"
+#endif
 
 #include "esp_board_spidev.h"
 
 /****************************************************************************
- * Public Functions
+ * Private Functions
  ****************************************************************************/
 
 /****************************************************************************
- * Name: board_spidev_initialize
+ * Name: spi_bitbang_driver_init
+ *
+ * Description:
+ *   Initialize SPI bitbang driver and register the /dev/spi device.
+ *
+ * Input Parameters:
+ *   port - The SPI bus number, used to build the device path as /dev/spiN
+ *
+ * Returned Value:
+ *   Zero (OK) is returned on success; A negated errno value is returned
+ *   to indicate the nature of any failure.
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_ESPRESSIF_SPI_BITBANG
+static int spi_bitbang_driver_init(int port)
+{
+  int ret;
+  struct spi_dev_s *spi;
+
+  syslog(LOG_INFO, "Initializing /dev/spi%d...\n", port);
+
+  /* Initialize SPI device */
+
+  spi = esp_spi_bitbang_init();
+
+  if (spi == NULL)
+    {
+      syslog(LOG_ERR, "Failed to initialize SPI%d.\n", port);
+      return -ENODEV;
+    }
+
+  ret = spi_register(spi, port);
+  if (ret < 0)
+    {
+      syslog(LOG_ERR, "Failed to register /dev/spi%d: %d\n", port, ret);
+      esp_spi_bitbang_uninitialize(spi);
+    }
+
+  return ret;
+}
+#endif
+
+/****************************************************************************
+ * Name: spi_driver_init
  *
  * Description:
  *   Initialize SPI driver and register the /dev/spi device.
@@ -53,9 +102,10 @@
  *
  ****************************************************************************/
 
-int board_spidev_initialize(int port)
+#ifdef CONFIG_ESPRESSIF_SPI_PERIPH
+static int spi_driver_init(int port)
 {
-  int ret;
+  int ret = OK;
   struct spi_dev_s *spi;
 
   syslog(LOG_INFO, "Initializing /dev/spi%d...\n", port);
@@ -63,6 +113,7 @@ int board_spidev_initialize(int port)
   /* Initialize SPI device */
 
   spi = esp_spibus_initialize(port);
+
   if (spi == NULL)
     {
       syslog(LOG_ERR, "Failed to initialize SPI%d.\n", port);
@@ -73,9 +124,68 @@ int board_spidev_initialize(int port)
   if (ret < 0)
     {
       syslog(LOG_ERR, "Failed to register /dev/spi%d: %d\n", port, ret);
-
       esp_spibus_uninitialize(spi);
     }
 
   return ret;
 }
+#endif
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: board_spidev_initialize
+ *
+ * Description:
+ *   Configure the SPI drivers.
+ *
+ * Input Parameters:
+ *   port - The SPI bus number, used to build the device path as /dev/spiN
+ *
+ * Returned Value:
+ *   Zero (OK) is returned on success; A negated errno value is returned
+ *   to indicate the nature of any failure.
+ *
+ ****************************************************************************/
+
+int board_spidev_initialize(int port)
+{
+  int ret = OK;
+
+  switch (port)
+    {
+#ifdef CONFIG_ESPRESSIF_SPI2
+      case ESPRESSIF_SPI2:
+        {
+          ret = spi_driver_init(ESPRESSIF_SPI2);
+          if (ret != OK)
+            {
+              return ret;
+            }
+          break;
+        }
+#endif
+
+#ifdef CONFIG_ESPRESSIF_SPI_BITBANG
+      case ESPRESSIF_SPI_BITBANG:
+        {
+          ret = spi_bitbang_driver_init(ESPRESSIF_SPI_BITBANG);
+          if (ret != OK)
+            {
+              return ret;
+            }
+          break;
+        }
+#endif
+
+    default:
+      {
+        wderr("ERROR: unsupported SPI %d\n", port);
+        return ERROR;
+      }
+    }
+
+  return ret;
+}

boards/risc-v/esp32h2/esp32h2-devkit/src/esp32h2_bringup.c

@@ -70,6 +70,9 @@
 #ifdef CONFIG_ESPRESSIF_SPI
 #  include "espressif/esp_spi.h"
 #  include "esp_board_spidev.h"
+#  ifdef CONFIG_ESPRESSIF_SPI_BITBANG
+#    include "espressif/esp_spi_bitbang.h"
+#  endif
 #endif
 
 #ifdef CONFIG_SPI_SLAVE_DRIVER
@@ -213,12 +216,22 @@ int esp_bringup(void)
 #endif
 
 #if defined(CONFIG_ESPRESSIF_SPI) && defined(CONFIG_SPI_DRIVER)
+#  ifdef CONFIG_ESPRESSIF_SPI2
   ret = board_spidev_initialize(ESPRESSIF_SPI2);
   if (ret < 0)
     {
       syslog(LOG_ERR, "ERROR: Failed to init spidev 2: %d\n", ret);
     }
-#endif
+#  endif /* CONFIG_ESPRESSIF_SPI2 */
+
+#  ifdef CONFIG_ESPRESSIF_SPI_BITBANG
+  ret = board_spidev_initialize(ESPRESSIF_SPI_BITBANG);
+  if (ret < 0)
+    {
+      syslog(LOG_ERR, "ERROR: Failed to init spidev 3: %d\n", ret);
+    }
+#  endif /* CONFIG_ESPRESSIF_SPI_BITBANG */
+#endif /* CONFIG_ESPRESSIF_SPI && CONFIG_SPI_DRIVER*/
 
 #ifdef CONFIG_ESPRESSIF_SPIFLASH
   ret = board_spiflash_init();