esp32[s2|s3]: Add SPI bitbang support

Author: eren-terzioglu

arch/xtensa/src/common/espressif/Kconfig

@@ -40,6 +40,22 @@ config ESPRESSIF_I2C_BITBANG
 	---help---
 		Software implemented I2C peripheral with GPIOs. Suggested to use if I2C peripherals are already in use.
 
+config ESPRESSIF_SPI_PERIPH
+	bool
+    depends on (ESP32S3_SPI2 || ESP32S3_SPI3) || (ESP32_SPI2 || ESP32_SPI3) || (ESP32S2_SPI2 || ESP32S2_SPI3)
+	default n
+
+config ESPRESSIF_SPI_BITBANG
+	bool "SPI Bitbang"
+	default n
+	select ESP32_SPI if ARCH_CHIP_ESP32
+	select ESP32S2_SPI if ARCH_CHIP_ESP32S2
+	select ESP32S3_SPI if ARCH_CHIP_ESP32S3
+	select SPI
+	select SPI_BITBANG
+    ---help---
+		Software implemented SPI peripheral with GPIOs. Suggested to use if SPI peripherals are already in use.
+
 config ESPRESSIF_SPIFLASH
 	bool "SPI Flash"
 	depends on ARCH_CHIP_ESP32S2
@@ -104,6 +120,49 @@ config ESPRESSIF_I2C_BITBANG_SDAPIN
 
 endmenu # I2C bitbang configuration
 
+menu "SPI bitbang configuration"
+	depends on 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
+
+endmenu # SPI bitbang configuration
+
 config ESPRESSIF_HAVE_OTA_PARTITION
 	bool
 	default n

arch/xtensa/src/common/espressif/Make.defs

@@ -44,6 +44,10 @@ ifeq ($(CONFIG_ESPRESSIF_I2C_BITBANG),y)
 CHIP_CSRCS += esp_i2c_bitbang.c
 endif
 
+ifeq ($(CONFIG_ESPRESSIF_SPI_BITBANG),y)
+CHIP_CSRCS += esp_spi_bitbang.c
+endif
+
 ifeq ($(CONFIG_ESPRESSIF_SPIFLASH),y)
 CHIP_CSRCS += esp_spiflash.c
 ifeq ($(CONFIG_ESPRESSIF_MTD),y)

arch/xtensa/src/common/espressif/esp_spi_bitbang.c

@@ -0,0 +1,273 @@
+/****************************************************************************
+ * arch/xtensa/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 "esp_spi_bitbang.h"
+#include <nuttx/spi/spi_bitbang.c>
+
+#if defined(CONFIG_ARCH_CHIP_ESP32S3)
+#include "esp32s3_gpio.h"
+#include "hardware/esp32s3_gpio_sigmap.h"
+#elif defined(CONFIG_ARCH_CHIP_ESP32S2)
+#include "esp32s2_gpio.h"
+#include "esp32s2_gpio_sigmap.h"
+#else
+#include "esp32_gpio.h"
+#include "esp32_gpio_sigmap.h"
+#endif
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#if defined(CONFIG_ARCH_CHIP_ESP32S3)
+#define CONFIG_GPIO(pin, attr)                 esp32s3_configgpio(pin, attr)
+#define GPIO_MATRIX_OUT(pin, idx, inv, en_inv) esp32s3_gpio_matrix_out(pin, \
+                                                          idx, inv, en_inv)
+#elif defined(CONFIG_ARCH_CHIP_ESP32S2)
+#define CONFIG_GPIO(pin, attr)                 esp32s2_configgpio(pin, attr)
+#define GPIO_MATRIX_OUT(pin, idx, inv, en_inv) esp32s2_gpio_matrix_out(pin, \
+                                                          idx, inv, en_inv)
+#else
+#define CONFIG_GPIO(pin, attr)                 esp32_configgpio(pin, attr)
+#define GPIO_MATRIX_OUT(pin, idx, inv, en_inv) esp32_gpio_matrix_out(pin,   \
+                                                          idx, inv, en_inv)
+#endif
+
+#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 */
+
+  GPIO_WRITE(CONFIG_ESPRESSIF_SPI_BITBANG_CSPIN, true);
+  GPIO_WRITE(CONFIG_ESPRESSIF_SPI_BITBANG_MOSIPIN, true);
+  GPIO_WRITE(CONFIG_ESPRESSIF_SPI_BITBANG_CLKPIN, true);
+
+#if CONFIG_ESPRESSIF_SPI_SWCS
+  CONFIG_GPIO(CONFIG_ESPRESSIF_SPI_BITBANG_CSPIN, OUTPUT_FUNCTION_1);
+  GPIO_MATRIX_OUT(CONFIG_ESPRESSIF_SPI_BITBANG_CSPIN, SIG_GPIO_OUT_IDX,
+                      0, 0);
+#endif
+  CONFIG_GPIO(CONFIG_ESPRESSIF_SPI_BITBANG_MOSIPIN, OUTPUT_FUNCTION_1);
+  GPIO_MATRIX_OUT(CONFIG_ESPRESSIF_SPI_BITBANG_MOSIPIN, SIG_GPIO_OUT_IDX,
+                      0, 0);
+
+  CONFIG_GPIO(CONFIG_ESPRESSIF_SPI_BITBANG_MISOPIN,
+                 INPUT_FUNCTION_1 | PULLUP);
+  GPIO_MATRIX_OUT(CONFIG_ESPRESSIF_SPI_BITBANG_MISOPIN, SIG_GPIO_OUT_IDX,
+                      0, 0);
+
+  CONFIG_GPIO(CONFIG_ESPRESSIF_SPI_BITBANG_CLKPIN, OUTPUT_FUNCTION_1);
+  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 */