risc-v/esp32c3: Support ESP32-C3 RTC driver

arch/risc-v/src/esp32c3/Kconfig

@@ -151,6 +151,7 @@ config ESP32C3_CPU_FREQ_MHZ
 config ESP32C3_RT_TIMER
 	bool "Real-time Timer"
 	default n
+	select ESP32C3_TIMER0
 
 config ESP32C3_DISABLE_STDC_ATOMIC
 	bool "Disable standard C atomic"

arch/risc-v/src/esp32c3/Make.defs

@@ -146,6 +146,10 @@ ifeq ($(CONFIG_ARCH_USE_MODULE_TEXT),y)
 CHIP_CSRCS += esp32c3_modtext.c
 endif
 
+ifeq ($(CONFIG_RTC_DRIVER),y)
+CHIP_CSRCS += esp32c3_rtc_lowerhalf.c
+endif
+
 ifeq ($(CONFIG_ESP32C3_WIRELESS),y)
 WIRELESS_DRV_UNPACK  = esp-wireless-drivers-3rdparty
 WIRELESS_DRV_ID      = 2b53111

arch/risc-v/src/esp32c3/esp32c3_rtc.h

@@ -30,6 +30,9 @@
  ****************************************************************************/
 
 #include <nuttx/config.h>
+#include <nuttx/timers/rtc.h>
+#include <sys/types.h>
+#include <time.h>
 #include "hardware/esp32c3_soc.h"
 
 #ifndef __ASSEMBLY__
@@ -137,6 +140,31 @@ struct esp32c3_cpu_freq_config_s
   uint32_t freq_mhz;           /* CPU clock frequency */
 };
 
+#ifdef CONFIG_RTC_ALARM
+
+/* The form of an alarm callback */
+
+typedef CODE void (*alm_callback_t)(FAR void *arg, unsigned int alarmid);
+
+enum alm_id_e
+{
+  RTC_ALARM0 = 0,           /* RTC ALARM 0 */
+  RTC_ALARM1 = 1,           /* RTC ALARM 1 */
+  RTC_ALARM_LAST,
+};
+
+/* Structure used to pass parameters to set an alarm */
+
+struct alm_setalarm_s
+{
+  int               as_id;     /* enum alm_id_e */
+  struct timespec   as_time;   /* Alarm expiration time */
+  alm_callback_t    as_cb;     /* Callback (if non-NULL) */
+  FAR void          *as_arg;   /* Argument for callback */
+};
+
+#endif /* CONFIG_RTC_ALARM */
+
 /****************************************************************************
  * Public Function Prototypes
  ****************************************************************************/
@@ -444,6 +472,187 @@ void esp32c3_rtc_sleep_set_wakeup_time(uint64_t t);
 
 uint64_t esp32c3_rtc_get_time_us(void);
 
+/****************************************************************************
+ * Name: esp32c3_rtc_set_boot_time
+ *
+ * Description:
+ *   Set time to RTC register to replace the original boot time.
+ *
+ * Input Parameters:
+ *   time_us - set time in microseconds.
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+void esp32c3_rtc_set_boot_time(uint64_t time_us);
+
+/****************************************************************************
+ * Name: esp32c3_rtc_get_boot_time
+ *
+ * Description:
+ *   Get time of RTC register to indicate the original boot time.
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value:
+ *   time_us - get time in microseconds.
+ *
+ ****************************************************************************/
+
+uint64_t esp32c3_rtc_get_boot_time(void);
+
+#ifdef CONFIG_RTC_DRIVER
+
+/****************************************************************************
+ * Name: up_rtc_time
+ *
+ * Description:
+ *   Get the current time in seconds.  This is similar to the standard time()
+ *   function.  This interface is only required if the low-resolution
+ *   RTC/counter hardware implementation selected.  It is only used by the
+ *   RTOS during initialization to set up the system time when CONFIG_RTC is
+ *   set but neither CONFIG_RTC_HIRES nor CONFIG_RTC_DATETIME are set.
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value:
+ *   The current time in seconds
+ *
+ ****************************************************************************/
+
+#ifndef CONFIG_RTC_HIRES
+time_t up_rtc_time(void);
+#endif
+
+/****************************************************************************
+ * Name: up_rtc_settime
+ *
+ * Description:
+ *   Set the RTC to the provided time.  All RTC implementations must be
+ *   able to set their time based on a standard timespec.
+ *
+ * Input Parameters:
+ *   tp - the time to use
+ *
+ * Returned Value:
+ *   Zero (OK) on success; a negated errno on failure
+ *
+ ****************************************************************************/
+
+int up_rtc_settime(FAR const struct timespec *ts);
+
+/****************************************************************************
+ * Name: up_rtc_initialize
+ *
+ * Description:
+ *   Initialize the hardware RTC per the selected configuration.
+ *   This function is called once during the OS initialization sequence
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value:
+ *   Zero (OK) on success; a negated errno on failure
+ *
+ ****************************************************************************/
+
+int up_rtc_initialize(void);
+
+/****************************************************************************
+ * Name: up_rtc_gettime
+ *
+ * Description:
+ *   Get the current time from the high resolution RTC clock/counter.  This
+ *   interface is only supported by the high-resolution RTC/counter hardware
+ *   implementation.  It is used to replace the system timer.
+ *
+ * Input Parameters:
+ *   tp - The location to return the high resolution time value.
+ *
+ * Returned Value:
+ *   Zero (OK) on success; a negated errno on failure
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_RTC_HIRES
+int up_rtc_gettime(FAR struct timespec *tp);
+#endif
+
+#ifdef CONFIG_RTC_ALARM
+
+/****************************************************************************
+ * Name: up_rtc_setalarm
+ *
+ * Description:
+ *   Set up an alarm.
+ *
+ * Input Parameters:
+ *   alminfo - Information about the alarm configuration.
+ *
+ * Returned Value:
+ *   Zero (OK) on success; a negated errno on failure
+ *
+ ****************************************************************************/
+
+int up_rtc_setalarm(FAR struct alm_setalarm_s *alminfo);
+
+/****************************************************************************
+ * Name: up_rtc_cancelalarm
+ *
+ * Description:
+ *   Cancel an alaram.
+ *
+ * Input Parameters:
+ *  alarmid - Identifies the alarm to be cancelled
+ *
+ * Returned Value:
+ *   Zero (OK) on success; a negated errno on failure
+ *
+ ****************************************************************************/
+
+int up_rtc_cancelalarm(enum alm_id_e alarmid);
+
+/****************************************************************************
+ * Name: up_rtc_rdalarm
+ *
+ * Description:
+ *   Query an alarm configured in hardware.
+ *
+ * Input Parameters:
+ *  tp      - Location to return the timer match register.
+ *  alarmid - Identifies the alarm to be cancelled
+ *
+ * Returned Value:
+ *   Zero (OK) on success; a negated errno on failure
+ *
+ ****************************************************************************/
+
+int up_rtc_rdalarm(FAR struct timespec *tp, uint32_t alarmid);
+
+#endif /* CONFIG_RTC_ALARM */
+
+/****************************************************************************
+ * Name: up_rtc_timer_init
+ *
+ * Description:
+ *   Init RTC timer.
+ *
+ * Input Parameters:
+ *  None
+ *
+ * Returned Value:
+ *   Zero (OK) on success; a negated errno on failure
+ *
+ ****************************************************************************/
+
+int up_rtc_timer_init(void);
+
+#endif /* CONFIG_RTC_DRIVER */
+
 #ifdef __cplusplus
 }
 #endif

arch/risc-v/src/esp32c3/esp32c3_rtc_lowerhalf.h

@@ -0,0 +1,56 @@
+/****************************************************************************
+ * arch/risc-v/src/esp32c3/esp32c3_rtc_lowerhalf.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 __ARCH_RISCV_SRC_ESP32C3_ESP32C3_RTC_LOWERHALF_H
+#define __ARCH_RISCV_SRC_ESP32C3_ESP32C3_RTC_LOWERHALF_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#ifdef CONFIG_RTC_DRIVER
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: esp32c3_rtc_driverinit
+ *
+ * Description:
+ *   Bind the configuration timer to a timer lower half instance and
+ *   register the timer drivers at 'devpath'
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value:
+ *   Zero (OK) is returned on success; A negated errno value is returned
+ *   to indicate the nature of any failure.
+ *
+ ****************************************************************************/
+
+int esp32c3_rtc_driverinit(void);
+
+#endif /* CONFIG_RTC_DRIVER */
+
+#endif /* __ARCH_RISCV_SRC_ESP32C3_ESP32C3_RTC_LOWERHALF_H */

boards/risc-v/esp32c3/esp32c3-devkit/configs/rtc/defconfig

@@ -0,0 +1,50 @@
+#
+# 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_NSH_ARGCAT is not set
+# CONFIG_NSH_CMDOPT_HEXDUMP is not set
+# CONFIG_NSH_CMDPARMS is not set
+CONFIG_ARCH="risc-v"
+CONFIG_ARCH_BOARD="esp32c3-devkit"
+CONFIG_ARCH_BOARD_ESP32C3_DEVKIT=y
+CONFIG_ARCH_CHIP="esp32c3"
+CONFIG_ARCH_CHIP_ESP32C3=y
+CONFIG_ARCH_CHIP_ESP32C3WROOM02=y
+CONFIG_ARCH_INTERRUPTSTACK=1536
+CONFIG_ARCH_RISCV=y
+CONFIG_ARCH_STACKDUMP=y
+CONFIG_BOARD_LOOPSPERMSEC=15000
+CONFIG_BUILTIN=y
+CONFIG_DEV_ZERO=y
+CONFIG_ESP32C3_RT_TIMER=y
+CONFIG_EXAMPLES_ALARM=y
+CONFIG_FS_PROCFS=y
+CONFIG_IDLETHREAD_STACKSIZE=2048
+CONFIG_INTELHEX_BINARY=y
+CONFIG_LIBC_PERROR_STDOUT=y
+CONFIG_LIBC_STRERROR=y
+CONFIG_MAX_TASKS=16
+CONFIG_NFILE_DESCRIPTORS_PER_BLOCK=6
+CONFIG_NSH_ARCHINIT=y
+CONFIG_NSH_BUILTIN_APPS=y
+CONFIG_NSH_FILEIOSIZE=512
+CONFIG_NSH_READLINE=y
+CONFIG_NSH_STRERROR=y
+CONFIG_PREALLOC_TIMERS=0
+CONFIG_RAW_BINARY=y
+CONFIG_RR_INTERVAL=200
+CONFIG_RTC=y
+CONFIG_RTC_ALARM=y
+CONFIG_RTC_DRIVER=y
+CONFIG_RTC_NALARMS=2
+CONFIG_SCHED_WAITPID=y
+CONFIG_START_DAY=29
+CONFIG_START_MONTH=11
+CONFIG_START_YEAR=2019
+CONFIG_SYSTEM_NSH=y
+CONFIG_UART0_SERIAL_CONSOLE=y
+CONFIG_USER_ENTRYPOINT="nsh_main"

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

@@ -56,6 +56,10 @@
 
 #include "esp32c3_rtc.h"
 
+#ifdef CONFIG_RTC_DRIVER
+#  include "esp32c3_rtc_lowerhalf.h"
+#endif
+
 /****************************************************************************
  * Pre-processor Definitions
  ****************************************************************************/
@@ -328,6 +332,17 @@ int esp32c3_bringup(void)
     }
 #endif /* CONFIG_ESP32C3_ADC */
 
+#ifdef CONFIG_RTC_DRIVER
+  /* Instantiate the ESP32-C3 RTC driver */
+
+  ret = esp32c3_rtc_driverinit();
+  if (ret < 0)
+    {
+      syslog(LOG_ERR,
+             "ERROR: Failed to Instantiate the RTC driver: %d\n", ret);
+    }
+#endif
+
   /* If we got here then perhaps not all initialization was successful, but
    * at least enough succeeded to bring-up NSH with perhaps reduced
    * capabilities.