Break out a new internal interface, stm32_rtc_setdatetime(). This eliminates some un-necessary time conversions. From Freddie Chopin.

Add a skeleton implementation of the RTC lower half interface at arch/arm/src/stm32/stm32_rtc_lowerhalf.c.  This is just the framework for the RTC lower half.  None of the interface methods have yet been implemetned.

arch/arm/src/stm32/Make.defs

@@ -181,6 +181,9 @@ CHIP_CSRCS += stm32_rtc.c
 ifeq ($(CONFIG_RTC_ALARM),y)
 CHIP_CSRCS += stm32_exti_alarm.c
 endif
+ifeq ($(CONFIG_RTC_DRIVER),y)
+CHIP_CSRCS += stm32_rtc_lowerhalf.c
+endif
 endif
 
 ifeq ($(CONFIG_ADC),y)

arch/arm/src/stm32/stm32_rtc.h

@@ -98,6 +98,27 @@ extern "C"
  * Public Functions
  ************************************************************************************/
 
+/************************************************************************************
+ * Name: stm32_rtc_setdatetime
+ *
+ * Description:
+ *   Set the RTC to the provided time. RTC implementations which provide
+ *   up_rtc_getdatetime() (CONFIG_RTC_DATETIME is selected) should provide this
+ *   function.
+ *
+ * Input Parameters:
+ *   tp - the time to use
+ *
+ * Returned Value:
+ *   Zero (OK) on success; a negated errno on failure
+ *
+ ************************************************************************************/
+
+#ifdef CONFIG_RTC_DATETIME
+struct tm;
+int stm32_rtc_setdatetime(FAR const struct tm *tp);
+#endif
+
 /************************************************************************************
  * Name: stm32_rtc_setalarm
  *
@@ -136,6 +157,33 @@ int stm32_rtc_setalarm(FAR const struct timespec *tp, alarmcb_t callback);
 int stm32_rtc_cancelalarm(void);
 #endif
 
+/****************************************************************************
+ * Name: stm32_rtc_lowerhalf
+ *
+ * Description:
+ *   Instantiate the RTC lower half driver for the STM32.  General usage:
+ *
+ *     #include <nuttx/rtc.h>
+ *     #include "stm32_rtc.h>
+ *
+ *     struct rtc_lowerhalf_s *lower;
+ *     lower = stm32_rtc_lowerhalf();
+ *     rtc_initialize(0, lower);
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value:
+ *   On success, a non-NULL RTC lower interface is returned.  NULL is
+ *   returned on any failure.
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_RTC_DRIVER
+struct rtc_lower_half_s;
+struct rtc_lower_half_s *stm32_rtc_lowerhalf(void);
+#endif
+
 #undef EXTERN
 #if defined(__cplusplus)
 }

arch/arm/src/stm32/stm32_rtc_lowerhalf.c

@@ -0,0 +1,147 @@
+/****************************************************************************
+ * arch/arm/src/stm32/stm32_rtc_lowerhalf.c
+ *
+ *   Copyright (C) 2015 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sys/types.h>
+#include <stdbool.h>
+
+#include <nuttx/rtc.h>
+
+#include "chip.h"
+#include "stm32_rtc.h"
+
+#ifdef CONFIG_RTC_DRIVER
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+/* This is the private type for the RTC state.  It must be cast compatible
+ * with struct rtc_lowerhalf_s.
+ */
+
+struct stm32_lowerhalf_s
+{
+  /* This is the contained reference to the read-only, lower-half
+   * operations vtable (which may lie in FLASH or ROM)
+   */
+
+  FAR const struct rtc_ops_s *ops;
+
+  /* Data following is private to this driver and not visible outside of
+   * this file.
+   */
+};
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+/* Prototypes for static methods in struct rtc_ops_s */
+/* To be provided */
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+/* STM32 RTC driver operations */
+
+static const struct rtc_ops_s g_rtc_ops =
+{
+  .rdtime     = NULL,
+  .settime    = NULL,
+  .almread    = NULL,
+  .almset     = NULL,
+  .irqpread   = NULL,
+  .irqpset    = NULL,
+  .aie        = NULL,
+  .uie        = NULL,
+  .pie        = NULL,
+  .rdepoch    = NULL,
+  .setepoch   = NULL,
+  .rdwkalm    = NULL,
+  .setwkalm   = NULL,
+  .destroy    = NULL,
+};
+
+/* STM32 RTC device state */
+
+static struct stm32_lowerhalf_s g_rtc_lowerhalf =
+{
+  .ops        = &g_rtc_ops,
+};
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: stm32_rtc_lowerhalf
+ *
+ * Description:
+ *   Instantiate the RTC lower half driver for the STM32.  General usage:
+ *
+ *     #include <nuttx/rtc.h>
+ *     #include "stm32_rtc.h>
+ *
+ *     struct rtc_lowerhalf_s *lower;
+ *     lower = stm32_rtc_lowerhalf();
+ *     rtc_initialize(0, lower);
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value:
+ *   On success, a non-NULL RTC lower interface is returned.  NULL is
+ *   returned on any failure.
+ *
+ ****************************************************************************/
+
+struct rtc_lower_half_s *stm32_rtc_lowerhalf(void)
+{
+  return (struct rtc_lower_half_s *)&g_rtc_lowerhalf;
+}
+
+#endif /* CONFIG_RTC_DRIVER */

arch/arm/src/stm32/stm32_rtcc.c

@@ -821,11 +821,12 @@ int up_rtc_getdatetime(FAR struct tm *tp)
 }
 
 /************************************************************************************
- * Name: up_rtc_settime
+ * Name: stm32_rtc_setdatetime
  *
  * Description:
- *   Set the RTC to the provided time.  All RTC implementations must be able to
+ *   Set the RTC to the provided time. RTC implementations which provide
- *   set their time based on a standard timespec.
+ *   up_rtc_getdatetime() (CONFIG_RTC_DATETIME is selected) should provide this
+ *   function.
  *
  * Input Parameters:
  *   tp - the time to use
@@ -835,17 +836,13 @@ int up_rtc_getdatetime(FAR struct tm *tp)
  *
  ************************************************************************************/
 
-int up_rtc_settime(FAR const struct timespec *tp)
+int stm32_rtc_setdatetime(FAR const struct tm *tp)
 {
-  FAR struct tm newtime;
   uint32_t tr;
   uint32_t dr;
   int ret;
 
-  /* Break out the time values (not that the time is set only to units of seconds) */
+  rtc_dumptime(tp, "Setting time");
-
-  (void)gmtime_r(&tp->tv_sec, &newtime);
-  rtc_dumptime(&newtime, "Setting time");
 
   /* Then write the broken out values to the RTC */
 
@@ -854,9 +851,9 @@ int up_rtc_settime(FAR const struct timespec *tp)
    * register.
    */
 
-  tr = (rtc_bin2bcd(newtime.tm_sec)  << RTC_TR_SU_SHIFT) |
+  tr = (rtc_bin2bcd(tp->tm_sec)  << RTC_TR_SU_SHIFT) |
-       (rtc_bin2bcd(newtime.tm_min)  << RTC_TR_MNU_SHIFT) |
+       (rtc_bin2bcd(tp->tm_min)  << RTC_TR_MNU_SHIFT) |
-       (rtc_bin2bcd(newtime.tm_hour) << RTC_TR_HU_SHIFT);
+       (rtc_bin2bcd(tp->tm_hour) << RTC_TR_HU_SHIFT);
   tr &= ~RTC_TR_RESERVED_BITS;
 
   /* Now convert the fields in struct tm format to the RTC date register fields:
@@ -868,9 +865,9 @@ int up_rtc_settime(FAR const struct timespec *tp)
    * years 2000-2099?  I'll assume so.
    */
 
-  dr = (rtc_bin2bcd(newtime.tm_mday) << RTC_DR_DU_SHIFT) |
+  dr = (rtc_bin2bcd(tp->tm_mday) << RTC_DR_DU_SHIFT) |
-       ((rtc_bin2bcd(newtime.tm_mon + 1))  << RTC_DR_MU_SHIFT) |
+       ((rtc_bin2bcd(tp->tm_mon + 1))  << RTC_DR_MU_SHIFT) |
-       ((rtc_bin2bcd(newtime.tm_year - 100)) << RTC_DR_YU_SHIFT);
+       ((rtc_bin2bcd(tp->tm_year - 100)) << RTC_DR_YU_SHIFT);
   dr &= ~RTC_DR_RESERVED_BITS;
 
   /* Disable the write protection for RTC registers */
@@ -902,6 +899,31 @@ int up_rtc_settime(FAR const struct timespec *tp)
   return ret;
 }
 
+/************************************************************************************
+ * 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 *tp)
+{
+  FAR struct tm newtime;
+
+  /* Break out the time values (not that the time is set only to units of seconds) */
+
+  (void)gmtime_r(&tp->tv_sec, &newtime);
+  return stm32_rtc_setdatetime(&newtime);
+}
+
 /************************************************************************************
  * Name: stm32_rtc_setalarm
  *
@@ -939,6 +961,7 @@ int stm32_rtc_setalarm(FAR const struct timespec *tp, alarmcb_t callback)
 
       ret = OK;
     }
+
   return ret;
 }
 #endif

include/nuttx/rtc.h

@@ -47,6 +47,9 @@
 
 #include <nuttx/config.h>
 #include <nuttx/compiler.h>
+
+#include <stdbool.h>
+
 #include <nuttx/fs/ioctl.h>
 
 #ifdef CONFIG_RTC
@@ -314,7 +317,6 @@ struct rtc_wkalrm
 struct rtc_lowerhalf_s;
 struct rtc_ops_s
 {
-  
   /* rdtime() returns the current RTC time. */
 
   CODE int (*rdtime)(FAR struct rtc_lowerhalf_s *lower,