esp32/rmt: Use the Espressif`s common RMT driver.

This commit implements the common RMT driver (already available for
the other Espressif's xtensa-based devices) for ESP32.
This allows us to have a proper separation between the lower and
upper-half drivers and use the 'ws2812' example to drive WS2812 RGB
LEDs.

arch/xtensa/src/esp32/Kconfig

@@ -213,6 +213,8 @@ config ESP32_EXCEPTION_ENABLE_CACHE
 
 menu "ESP32 Peripheral Selection"
 
+source "arch/xtensa/src/common/espressif/Kconfig"
+
 config ESP32_UART
 	bool
 	default n

arch/xtensa/src/esp32/esp32_gpio.c

@@ -35,6 +35,8 @@
 
 #include "xtensa.h"
 
+#include "soc/soc_caps.h"
+
 #include "hardware/esp32_iomux.h"
 #include "hardware/esp32_gpio.h"
 

arch/xtensa/src/esp32/esp32_gpio.h

@@ -102,6 +102,24 @@
 #define ONLOW_WE          0x0c
 #define ONHIGH_WE         0x0d
 
+/* Check whether it is a valid GPIO number */
+
+#define GPIO_IS_VALID_GPIO(gpio_num)   ((gpio_num >= 0) && \
+                                        (((1ULL << (gpio_num)) & \
+                                         SOC_GPIO_VALID_GPIO_MASK) != 0))
+
+/* Check whether it can be a valid GPIO number of output mode */
+
+#define GPIO_IS_VALID_OUTPUT_GPIO(gpio_num) \
+  ((gpio_num >= 0) && \
+      (((1ULL << (gpio_num)) & SOC_GPIO_VALID_OUTPUT_GPIO_MASK) != 0))
+
+/* Check whether it can be a valid digital I/O pad */
+
+#define GPIO_IS_VALID_DIGITAL_IO_PAD(gpio_num) \
+  ((gpio_num >= 0) && \
+    (((1ULL << (gpio_num)) & SOC_GPIO_VALID_DIGITAL_IO_PAD_MASK) != 0))
+
 /****************************************************************************
  * Public Types
  ****************************************************************************/

boards/xtensa/esp32/common/include/esp32_board_rmt.h

@@ -0,0 +1,97 @@
+/****************************************************************************
+ * boards/xtensa/esp32/common/include/esp32_board_rmt.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.
+ *
+ ****************************************************************************/
+
+#ifndef __BOARDS_XTENSA_ESP32_COMMON_INCLUDE_ESP32_BOARD_RMT_H
+#define __BOARDS_XTENSA_ESP32_COMMON_INCLUDE_ESP32_BOARD_RMT_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#ifndef __ASSEMBLY__
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+#undef EXTERN
+#if defined(__cplusplus)
+#define EXTERN extern "C"
+extern "C"
+{
+#else
+#define EXTERN extern
+#endif
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+#ifdef CONFIG_ESP_RMT
+
+/****************************************************************************
+ * Name: board_rmt_rxinitialize
+ *
+ * Description:
+ *   Initialize the RMT peripheral and register a RX device.
+ *
+ * Input Parameters:
+ *   ch  - the RMT's channel that will be used
+ *   pin - The pin used for the RX channel
+ *
+ * Returned Value:
+ *   Zero (OK) on success; a negated errno value on failure.
+ *
+ ****************************************************************************/
+
+int board_rmt_rxinitialize(int ch, int pin);
+
+/****************************************************************************
+ * Name: board_rmt_txinitialize
+ *
+ * Description:
+ *   Initialize the RMT peripheral and register a TX device.
+ *
+ * Input Parameters:
+ *   ch  - the RMT's channel that will be used
+ *   pin - The pin used for the TX channel
+ *
+ * Returned Value:
+ *   Zero (OK) on success; a negated errno value on failure.
+ *
+ ****************************************************************************/
+
+int board_rmt_txinitialize(int ch, int pin);
+
+#endif /* CONFIG_ESP_RMT */
+
+#undef EXTERN
+#if defined(__cplusplus)
+}
+#endif
+
+#endif /* __ASSEMBLY__ */
+#endif /* __BOARDS_XTENSA_ESP32_COMMON_INCLUDE_ESP32_BOARD_RMT_H */

boards/xtensa/esp32/common/src/Make.defs

@@ -140,8 +140,8 @@ ifeq ($(CONFIG_RGBLED),y)
   CSRCS += esp32_rgbled.c
 endif
 
-ifeq ($(CONFIG_ESP32_RMT),y)
+ifeq ($(CONFIG_ESP_RMT),y)
-  CSRCS += esp32_rmt.c
+  CSRCS += esp32_board_rmt.c
 endif
 
 #ifeq ($(CONFIG_DAC),y)

boards/xtensa/esp32/common/src/esp32_board_rmt.c

@@ -0,0 +1,155 @@
+/****************************************************************************
+ * boards/xtensa/esp32/common/src/esp32_board_rmt.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 <errno.h>
+#include <debug.h>
+#include <stdio.h>
+
+#include "xtensa.h"
+
+#include <nuttx/kmalloc.h>
+#include <nuttx/rmt/rmtchar.h>
+#ifdef CONFIG_WS2812_NON_SPI_DRIVER
+#include <nuttx/leds/ws2812.h>
+
+#include "espressif/esp_ws2812.h"
+#endif
+
+#include "espressif/esp_rmt.h"
+
+#ifdef CONFIG_ESP_RMT
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: board_rmt_rxinitialize
+ *
+ * Description:
+ *   Initialize the RMT peripheral and register a RX device.
+ *
+ * Input Parameters:
+ *   ch  - the RMT's channel that will be used
+ *   pin - The pin used for the RX channel
+ *
+ * Returned Value:
+ *   Zero (OK) on success; a negated errno value on failure.
+ *
+ ****************************************************************************/
+
+int board_rmt_rxinitialize(int ch, int pin)
+{
+  int ret;
+
+  struct rmt_dev_s *rmt = esp_rmt_rx_init(ch, pin);
+
+  ret = rmtchar_register(rmt);
+  if (ret < 0)
+    {
+      rmterr("ERROR: rmtchar_register failed: %d\n", ret);
+      return ret;
+    }
+
+  return ret;
+}
+
+/****************************************************************************
+ * Name: board_rmt_txinitialize
+ *
+ * Description:
+ *   Initialize the RMT peripheral and register a TX device.
+ *
+ * Input Parameters:
+ *   ch  - the RMT's channel that will be used
+ *   pin - The pin used for the TX channel
+ *
+ * Returned Value:
+ *   Zero (OK) on success; a negated errno value on failure.
+ *
+ ****************************************************************************/
+
+int board_rmt_txinitialize(int ch, int pin)
+{
+  int ret;
+  struct rmt_dev_s *rmt;
+#ifdef CONFIG_WS2812_NON_SPI_DRIVER
+  struct ws2812_dev_s *led;
+#endif
+
+  rmt = esp_rmt_tx_init(ch, pin);
+
+  if (rmt == NULL)
+    {
+      rmterr("ERROR: esp_rmt_tx_init failed\n");
+      return -ENODEV;
+    }
+
+  ret = rmtchar_register(rmt);
+  if (ret < 0)
+    {
+      rmterr("ERROR: rmtchar_register failed: %d\n", ret);
+      return ret;
+    }
+
+#ifdef CONFIG_WS2812_NON_SPI_DRIVER
+  led = esp_ws2812_setup("/dev/leds0", rmt,
+                           CONFIG_WS2812_LED_COUNT, false);
+
+  if (led == NULL)
+    {
+      rmterr("ERROR: esp_ws2812_setup failed\n");
+      return -ENODEV;
+    }
+#endif
+
+  return ret;
+}
+#endif

boards/xtensa/esp32/esp32-devkitc/configs/rmt/defconfig

@@ -0,0 +1,57 @@
+#
+# This file is autogenerated: PLEASE DO NOT EDIT IT.
+#
+# You can use "make menuconfig" to make any modifications to the installed .config file.
+# You can then do "make savedefconfig" to generate a new defconfig file that includes your
+# modifications.
+#
+# CONFIG_ARCH_LEDS is not set
+# CONFIG_NSH_ARGCAT is not set
+# CONFIG_NSH_CMDOPT_HEXDUMP is not set
+CONFIG_ARCH="xtensa"
+CONFIG_ARCH_BOARD="esp32-devkitc"
+CONFIG_ARCH_BOARD_COMMON=y
+CONFIG_ARCH_BOARD_ESP32_DEVKITC=y
+CONFIG_ARCH_CHIP="esp32"
+CONFIG_ARCH_CHIP_ESP32=y
+CONFIG_ARCH_CHIP_ESP32WROVER=y
+CONFIG_ARCH_STACKDUMP=y
+CONFIG_ARCH_XTENSA=y
+CONFIG_BOARD_LOOPSPERMSEC=16717
+CONFIG_BUILTIN=y
+CONFIG_ESP32_UART0=y
+CONFIG_ESP_RMT=y
+CONFIG_EXAMPLES_RMTCHAR=y
+CONFIG_EXAMPLES_RMTCHAR_RX=y
+CONFIG_EXAMPLES_RMTCHAR_TX=y
+CONFIG_EXAMPLES_WS2812=y
+CONFIG_FS_PROCFS=y
+CONFIG_HAVE_CXX=y
+CONFIG_HAVE_CXXINITIALIZE=y
+CONFIG_IDLETHREAD_STACKSIZE=3072
+CONFIG_INIT_ENTRYPOINT="nsh_main"
+CONFIG_INIT_STACKSIZE=3072
+CONFIG_INTELHEX_BINARY=y
+CONFIG_MM_REGIONS=3
+CONFIG_NSH_ARCHINIT=y
+CONFIG_NSH_BUILTIN_APPS=y
+CONFIG_NSH_FILEIOSIZE=512
+CONFIG_NSH_LINELEN=64
+CONFIG_NSH_READLINE=y
+CONFIG_PREALLOC_TIMERS=4
+CONFIG_RAM_SIZE=114688
+CONFIG_RAM_START=0x20000000
+CONFIG_RMT=y
+CONFIG_RMTCHAR=y
+CONFIG_RMT_DEFAULT_RX_BUFFER_SIZE=256
+CONFIG_RR_INTERVAL=200
+CONFIG_SCHED_WAITPID=y
+CONFIG_START_DAY=6
+CONFIG_START_MONTH=12
+CONFIG_START_YEAR=2011
+CONFIG_SYSLOG_BUFFER=y
+CONFIG_SYSTEM_NSH=y
+CONFIG_UART0_SERIAL_CONSOLE=y
+CONFIG_WS2812=y
+CONFIG_WS2812_LED_COUNT=100
+CONFIG_WS2812_NON_SPI_DRIVER=y

boards/xtensa/esp32/esp32-devkitc/src/esp32-devkitc.h

@@ -68,8 +68,16 @@
 
 /* RMT gpio */
 
-#define RMT_OUTPUT_PIN 4
+#define RMT_RXCHANNEL       1
-#define RMT_CHANNEL    0
+#define RMT_TXCHANNEL       0
+
+#ifdef CONFIG_RMT_LOOP_TEST_MODE
+#  define RMT_INPUT_PIN     0
+#  define RMT_OUTPUT_PIN    0
+#else
+#  define RMT_INPUT_PIN     2
+#  define RMT_OUTPUT_PIN    4
+#endif
 
 /****************************************************************************
  * Public Types

boards/xtensa/esp32/esp32-devkitc/src/esp32_bringup.c

@@ -165,6 +165,10 @@
 #  include "esp32_board_dac.h"
 #endif
 
+#ifdef CONFIG_ESP_RMT
+#  include "esp32_board_rmt.h"
+#endif
+
 #include "esp32-devkitc.h"
 
 /****************************************************************************
@@ -653,6 +657,20 @@ int esp32_bringup(void)
     }
 #endif
 
+#ifdef CONFIG_ESP_RMT
+  ret = board_rmt_txinitialize(RMT_TXCHANNEL, RMT_OUTPUT_PIN);
+  if (ret < 0)
+    {
+      syslog(LOG_ERR, "ERROR: board_rmt_txinitialize() failed: %d\n", ret);
+    }
+
+  ret = board_rmt_rxinitialize(RMT_RXCHANNEL, RMT_INPUT_PIN);
+  if (ret < 0)
+    {
+      syslog(LOG_ERR, "ERROR: board_rmt_txinitialize() failed: %d\n", ret);
+    }
+#endif
+
 #ifdef CONFIG_RTC_DRIVER
   /* Instantiate the ESP32 RTC driver */
 
@@ -676,7 +694,7 @@ int esp32_bringup(void)
 #endif
 
 #ifdef CONFIG_WS2812
-#  ifndef CONFIG_WS2812_NON_SPI_DRIVER 
+#  ifndef CONFIG_WS2812_NON_SPI_DRIVER
   ret = board_ws2812_initialize(0, ESP32_SPI3, CONFIG_WS2812_LED_COUNT);
   if (ret < 0)
     {