This commit addes support for the i.MXRT RTC. This initial commit is code complete (with limited featurs and options) but untested.

Squashed commit of the following:

    arch/arm/src/imxrt:  Fix some first time compile issues.
    arch/arm/src/imxrt:  This brings the RTC implement to code complete but still untested.
    arch/arm/src/imxrt:  Add some RTC initialization logic.
    arch/arm/src/imxrt:  Flesh out most of the RTC driver lower half and LPSRTC support.
    arch/arm/src/imxrt:  Some inital, partial implementation of the HPRTC and LPSRTC.
    arch/arm/src/imxrt:  Add HPSRTC/HPRTC file framework (no logic, just skeleton files).
    arch/arm/src/imxrt:  Add HPRTC header file.
    Some initial configuration logic for SNVS LPRTC and HP RTC.

arch/arm/src/imxrt/Kconfig

@@ -136,6 +136,15 @@ config IMXRT_SEMC
 	bool "Smart External Memory Controller (SEMC)"
 	default n
 
+config IMXRT_SNVS_LPSRTC
+	bool "LP SRTC"
+	default n
+	select IMXRT_SNVS_HPRTC
+
+config IMXRT_SNVS_HPRTC
+	bool "HP RTC"
+	default n
+
 endmenu # i.MX RT Peripheral Selection
 
 menuconfig IMXRT_GPIO_IRQ
@@ -452,4 +461,23 @@ config IMXRT_EDMA_EDBG
 		system exits debug mode or the EDBG bit is cleared
 
 endmenu # eDMA Global Configuration
+
+menu "RTC Configuration"
+	depends on IMXRT_SNVS_HPRTC
+
+config IMXRT_RTC_MAGIC_REG
+	int "RTC SNVS GPR"
+	default 0
+	range  0 3
+	---help---
+		The BKP register used to store/check the Magic value to determine if
+		RTC is already setup
+
+config IMXRT_RTC_MAGIC
+	hex "RTC Magic 1"
+	default 0xfacefeed
+	---help---
+		Value used as Magic to determine if the RTC is already setup
+
+endmenu
 endif # ARCH_CHIP_IMXRT

arch/arm/src/imxrt/Make.defs

@@ -120,6 +120,17 @@ ifeq ($(CONFIG_IMXRT_EDMA),y)
 CHIP_CSRCS += imxrt_edma.c
 endif
 
+ifeq ($(CONFIG_IMXRT_SNVS_LPSRTC),y)
+CHIP_CSRCS += imxrt_lpsrtc.c
+CHIP_CSRCS += imxrt_hprtc.c
+else ifeq ($(CONFIG_IMXRT_SNVS_HPRTC),y)
+CHIP_CSRCS += imxrt_hprtc.c
+endif
+
+ifeq ($(CONFIG_RTC_DRIVER),y)
+CHIP_CSRCS += imxrt_rtc_lowerhalf.c
+endif
+
 ifeq ($(CONFIG_IMXRT_ENET),y)
 CHIP_CSRCS += imxrt_enet.c
 endif

arch/arm/src/imxrt/chip/imxrt_snvs.h

@@ -47,6 +47,8 @@
  * Pre-processor Definitions
  ********************************************************************************************/
 
+#define IMXRT_SNVS_LP_MAXTAMPER       10
+
 /* Register offsets *************************************************************************/
 
 #define IMXRT_SNVS_HPLR_OFFSET        0x0000  /* SNVS_HP Lock Register */
@@ -127,7 +129,9 @@
                                                 /* Bits 0-3: Reserved */
 #define SNVS_HPCOMR_LPSWR             (1 << 4)  /* Bit 4:  LP Software Reset */
 #define SNVS_HPCOMR_LPSWRDIS          (1 << 5)  /* Bit 5:  LP Software Reset Disable */
-                                                /* Bits 6-30: Reserved */
+                                                /* Bits 6-7: Reserved */
+#define SNVS_HPCOMR_SWSV              (1 << 8)  /* Bit 8:  */
+                                                /* Bits 9-30: Reserved */
 #define SNVS_HPCOMR_NPSWAEN           (1 << 31) /* Bit 31: Non-Privileged Software Access Enable */
 
 /* SNVS_HP Control Register */
@@ -143,6 +147,7 @@
                                                 /* Bit 9:  Reserved */
 #define SNVS_HPCR_HPCALBVAL_SHIFT     (10)      /* Bits 10-14: HP Calibration Value */
 #define SNVS_HPCR_HPCALBVAL_MASK      (31 << SNVS_HPCR_HPCALBVAL_SHIFT)
+#  define SNVS_HPCR_HPCALBVAL(n)      ((uint32_t)(n) << SNVS_HPCR_HPCALBVAL_SHIFT)
 #  define SNVS_HPCR_HPCALBVAL_ZERO    (0  << SNVS_HPCR_HPCALBVAL_SHIFT) /* +0  counts per 32768 ticks */
 #  define SNVS_HPCR_HPCALBVAL_P1      (1  << SNVS_HPCR_HPCALBVAL_SHIFT) /* +1  counts per 32768 ticks */
 #  define SNVS_HPCR_HPCALBVAL_P2      (2  << SNVS_HPCR_HPCALBVAL_SHIFT) /* +2  counts per 32768 ticks */
@@ -151,7 +156,9 @@
 #  define SNVS_HPCR_HPCALBVAL_M15     (17 << SNVS_HPCR_HPCALBVAL_SHIFT) /* -15 counts per 32768 ticks */
 #  define SNVS_HPCR_HPCALBVAL_M2      (30 << SNVS_HPCR_HPCALBVAL_SHIFT) /* -2  counts per 32768 ticks */
 #  define SNVS_HPCR_HPCALBVAL_M1      (31 << SNVS_HPCR_HPCALBVAL_SHIFT) /* -1  counts per 32768 ticks */
-                                                /* Bits 15-23: Reserved */
+                                                /* Bits 15: Reserved */
+#define SNVS_HPCR_HPTS                (1 << 16) /* Bit 16: LPSRTC time sychronization */
+                                                /* Bits 17-23: Reserved */
 #define SNVS_HPCR_BTNCONFIG_SHIFT     (24)      /* Bits 24-26: Button Configuration */
 #define SNVS_HPCR_BTNCONFIG_MASK      (7 << SNVS_HPCR_BTNCONFIG_SHIFT)
 #  define SNVS_HPCR_BTNCONFIG_ LOW    (0 << SNVS_HPCR_BTNCONFIG_SHIFT) /* Button signal active low */
@@ -183,8 +190,6 @@
 
 #define SNVS_HPTAMR_MASK              0x00007fff /* Bits 0-14: HP Time Alarm, most-significant 15 bits */
 
-#define SNVS_HPTALR_
-
 /* SNVS_LP Lock Register */
 
                                                 /* Bits 0-3: Reserved */
@@ -203,6 +208,20 @@
 #define SNVS_LPCR_TOP                 (1 << 6)  /* Bit 6:  Turn off System Power */
 #define SNVS_LPCR_PWRGLITCHEN         (1 << 7)  /* Bit 7:  Power Glitch Enable */
                                                 /* Bits 8-15: Reserved */
+#define SNVS_LPCR_LPCALBEN            (1 << 8)  /* Bit 8:  LP Real Time Counter Calibration Enabled */
+                                                /* Bit 9:  Reserved */
+#define SNVS_LPCR_LPCALBVAL_SHIFT     (10)      /* Bits 10-14: LP Calibration Value */
+#define SNVS_LPCR_LPCALBVAL_MASK      (31 << SNVS_LPCR_LPCALBVAL_SHIFT)
+#  define SNVS_LPCR_LPCALBVAL(n)      ((uint32_t)(n) << SNVS_LPCR_LPCALBVAL_SHIFT)
+#  define SNVS_LPCR_LPCALBVAL_ZERO    (0  << SNVS_LPCR_LPCALBVAL_SHIFT) /* +0  counts per 32768 ticks */
+#  define SNVS_LPCR_LPCALBVAL_P1      (1  << SNVS_LPCR_LPCALBVAL_SHIFT) /* +1  counts per 32768 ticks */
+#  define SNVS_LPCR_LPCALBVAL_P2      (2  << SNVS_LPCR_LPCALBVAL_SHIFT) /* +2  counts per 32768 ticks */
+#  define SNVS_LPCR_LPCALBVAL_P15     (15 << SNVS_LPCR_LPCALBVAL_SHIFT) /* +15 counts per 32768 ticks */
+#  define SNVS_LPCR_LPCALBVAL_M16     (16 << SNVS_LPCR_LPCALBVAL_SHIFT) /* -16 counts per 32768 ticks */
+#  define SNVS_LPCR_LPCALBVAL_M15     (17 << SNVS_LPCR_LPCALBVAL_SHIFT) /* -15 counts per 32768 ticks */
+#  define SNVS_LPCR_LPCALBVAL_M2      (30 << SNVS_LPCR_LPCALBVAL_SHIFT) /* -2  counts per 32768 ticks */
+#  define SNVS_LPCR_LPCALBVAL_M1      (31 << SNVS_LPCR_LPCALBVAL_SHIFT) /* -1  counts per 32768 ticks */
+                                                /* Bit 15:  Reserved */
 #define SNVS_LPCR_BTNPRESSTIME_SHIFT  (16)      /* Bits 16-17: PMIC button press time out values */
 #define SNVS_LPCR_BTNPRESSTIME_MASK   (3 << SNVS_LPCR_BTNPRESSTIME_SHIFT)
 #  define SNVS_LPCR_BTNPRESSTIME_5SEC   (0 << SNVS_LPCR_BTNPRESSTIME_SHIFT) /* 5 secs */
@@ -229,7 +248,7 @@
 
                                                 /* Bits 0-1: Reserved */
 #define SNVS_LPSR_MCR                 (1 << 2)  /* Bit 2:  Monotonic Counter Rollover */
-                                                /* Bits 3-16: Reserved */ */
+                                                /* Bits 3-16: Reserved */
 #define SNVS_LPSR_EO                  (1 << 17) /* Bit 17: Emergency Off */
 #define SNVS_LPSR_SPO                 (1 << 18) /* Bit 18: Set Power Off */
                                                 /* Bits 19-31: Reserved */

arch/arm/src/imxrt/imxrt_hprtc.h

@@ -0,0 +1,255 @@
+/****************************************************************************
+ * arch/arm/src/imxrt/imxrt_hprtc.h
+ *
+ *   Copyright (C) 2018 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
+ ****************************************************************************/
+
+#ifndef __ARCH_ARM_SRC_IMXRT_IMXRT_HPRTC_H
+#define __ARCH_ARM_SRC_IMXRT_IMXRT_HPRTC_H
+
+#include <nuttx/config.h>
+
+#include "chip.h"
+
+#ifdef CONFIG_IMXRT_SNVS_HPRTC
+
+/****************************************************************************
+ * Preprocessor Definitions
+ ****************************************************************************/
+
+#ifdef CONFIG_RTC_DATETIME
+#  error CONFIG_RTC_DATETIME should not be selected with this driver
+#endif
+
+#ifdef CONFIG_RTC_PERIODIC
+#  error CONFIG_RTC_PERIODIC should not be selected with this driver
+#endif
+
+/* REVISIT: This is probably supportable.  The 47 bit timer does have
+ * accuracy greater than 1 second.
+ */
+
+#ifdef CONFIG_RTC_HIRES
+#  error CONFIG_RTC_PERIODIC should not be selected with this driver
+#endif
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/* Callback type used by the HPRTC log to notify the RTC driver when the
+ * alarm expires.
+ */
+
+typedef CODE void (*hprtc_alarm_callback_t)(void);
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+#if !defined(CONFIG_IMXRT_SNVS_LPSRTC) && defined(CONFIG_RTC_DRIVER)
+bool g_hprtc_timset;  /* True:  time has been set since power up */
+#endif
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+#ifndef __ASSEMBLY__
+
+#undef EXTERN
+#if defined(__cplusplus)
+#define EXTERN extern "C"
+extern "C"
+{
+#else
+#define EXTERN extern
+#endif
+
+/************************************************************************************
+ * Functions used only for HPRTC
+ ************************************************************************************/
+
+/************************************************************************************
+ * Logic Common to LPSRTC and HPRTC
+ ************************************************************************************/
+
+/****************************************************************************
+ * Name: imxrt_rtc_lowerhalf
+ *
+ * Description:
+ *   Instantiate the RTC lower half driver for the i.MXRT.  General usage:
+ *
+ *     #include <nuttx/timers/rtc.h>
+ *     #include "imxrt_hprtc.h"
+ *
+ *     struct rtc_lowerhalf_s *lower;
+ *     lower = imxrt_hprtc_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_lowerhalf_s;
+FAR struct rtc_lowerhalf_s *imxrt_rtc_lowerhalf(void);
+#endif
+
+/************************************************************************************
+ * Name: imxrt_hprtc_initialize
+ *
+ * Description:
+ *   Initialize the LPSRTC per the selected configuration.  This function is called
+ *   via up_rtc_initialize (see imxrt_hprtc.c).
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value:
+ *   Zero (OK) on success; a negated errno on failure
+ *
+ ************************************************************************************/
+
+int imxrt_hprtc_initialize(void);
+
+/************************************************************************************
+ * Name: imxrt_hprtc_synchronize
+ *
+ * Description:
+ *   Synchronize the HPRTC to the LPSRTC and enable the HPRTC timer.
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value:
+ *   None
+ *
+ ************************************************************************************/
+
+#ifdef CONFIG_IMXRT_SNVS_LPSRTC
+void imxrt_hprtc_synchronize(void);
+#endif
+
+/************************************************************************************
+ * Name: imxrt_hprtc_time
+ *
+ * Description:
+ *   Get the current time in seconds.  This is the underlying implementation of the
+ *   up_rtc_tim() function that is used by the RTOS during initialization to set up
+ *   the system time.
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value:
+ *   The current time in seconds
+ *
+ ************************************************************************************/
+
+uint32_t imxrt_hprtc_time(void);
+
+/************************************************************************************
+ * Name: imxrt_hprtc_getalarm
+ *
+ * Description:
+ *   Get the current alarm setting in seconds.  This is only used by the lower half
+ *   RTC driver.
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value:
+ *   The current alarm setting in seconds
+ *
+ ************************************************************************************/
+
+#if defined(CONFIG_RTC_ALARM) && defined(CONFIG_RTC_DRIVER)
+uint32_t imxrt_hprtc_getalarm(void);
+#endif
+
+/************************************************************************************
+ * Name: imxrt_hprtc_setalarm
+ *
+ * Description:
+ *   Set the alarm (in seconds) and enable alarm interrupts.  This is only used by
+ *   the lower half RTC driver.
+ *
+ * Input Parameters:
+ *   sec - The new alarm setting
+ *
+ * Returned Value:
+ *   The current alarm setting in seconds
+ *
+ ************************************************************************************/
+
+#if defined(CONFIG_RTC_ALARM) && defined(CONFIG_RTC_DRIVER)
+int imxrt_hprtc_setalarm(FAR struct timespec *ts, hprtc_alarm_callback_t cb);
+#endif
+
+/************************************************************************************
+ * Name: imxrt_hprtc_alarmdisable
+ *
+ * Description:
+ *    Disable alarm interrupts.  Used internally after the receipt of the alarm
+ *    interrupt.  Also called by the lower-half RTC driver in order to cancel an
+ *    alarm.
+ *
+ * Input Parameters:
+ *    None
+ *
+ * Returned Value:
+ *    None
+ *
+ ************************************************************************************/
+
+#if defined(CONFIG_RTC_ALARM) && defined(CONFIG_RTC_DRIVER)
+void imxrt_hprtc_alarmdisable(void);
+#endif
+
+#undef EXTERN
+#if defined(__cplusplus)
+}
+#endif
+#endif /* __ASSEMBLY__ */
+
+#endif /* CONFIG_IMXRT_SNVS_HPRTC */
+#endif /* __ARCH_ARM_SRC_IMXRT_IMXRT_HPRTC_H */

arch/arm/src/imxrt/imxrt_lpsrtc.c

@@ -0,0 +1,258 @@
+/************************************************************************************
+ * arch/arm/src/imxrt/imxrt_lpsrtc.c
+ *
+ *   Copyright (C) 2018 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 <stdlib.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <errno.h>
+#include <debug.h>
+
+#include <nuttx/arch.h>
+#include <nuttx/irq.h>
+#include <nuttx/timers/rtc.h>
+
+#include <arch/board/board.h>
+
+#include "up_arch.h"
+
+#include "chip/imxrt_snvs.h"
+#include "imxrt_periphclks.h"
+#include "imxrt_hprtc.h"
+#include "imxrt_lpsrtc.h"
+
+#ifdef CONFIG_IMXRT_SNVS_LPSRTC
+
+/************************************************************************************
+ * Private Functions
+ ************************************************************************************/
+
+/************************************************************************************
+ * Name: imxrt_lpsrtc_enable
+ *
+ * Description:
+ *   Enable/start the LPRTC time counter.
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value:
+ *   None
+ *
+ ************************************************************************************/
+
+static void imxrt_lpsrtc_enable(void)
+{
+  uint32_t regval;
+
+  /* Enable the LPSRTC */
+
+  regval  = getreg32(IMXRT_SNVS_LPCR);
+  regval |= SNVS_LPCR_MCENV;
+  putreg32(regval, IMXRT_SNVS_LPCR);
+
+  while ((getreg32(IMXRT_SNVS_LPCR) & SNVS_LPCR_MCENV) == 0)
+    {
+    }
+}
+
+/************************************************************************************
+ * Public Functions
+ ************************************************************************************/
+
+/************************************************************************************
+ * Name: imxrt_lpsrtc_initialize
+ *
+ * Description:
+ *   Initialize the LPSRTC per the selected configuration.  This function is called
+ *   via up_rtc_initialize (see imxrt_hprtc.c).
+ *
+ *   NOTE that the LPSRTC is always configured synchronized with the HPRTC.  This
+ *   means that the time is set via the LPSRTC but read via the HPRTC.  Also, only
+ *   the alarms from the HPRTC are used.
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value:
+ *   Zero (OK) on success; a negated errno on failure
+ *
+ ************************************************************************************/
+
+int imxrt_lpsrtc_initialize(void)
+{
+#ifdef CONFIG_IMXRTC_LPSRTC_CALENABLE
+  uint32_t regval;
+#endif
+
+  /* Initialize the HPRTC */
+
+  imxrt_hprtc_initialize();
+
+  /* Enable clocking to the the SNVS LP module.
+   * Clock is on during all modes, except STOP mode.
+   */
+
+   imxrt_clockall_snvs_lp();
+
+#ifdef CONFIG_IMXRTC_LPSRTC_CALENABLE
+  /* Set the LPSRTC calibration value */
+
+  regval  = getreg32(IMXRT_SNVS_LPCR);
+  regval &= ~SNVS_LPCR_LPCALBVAL_MASK;
+  regval |= SNVS_LPCR_LPCALBVAL(CONFIG_IMXRTC_LPSRTC_CALVALUE);
+  regval |= SNVS_LPCR_LPCALBEN;
+  putreg32(regval, IMXRT_SNVS_LPCR);
+#endif
+
+  /* Disable tamper pins.
+   * TODO:  I don't think this applies the currently supported device.
+   */
+
+  /* Enable the LPSRTC */
+
+  imxrt_lpsrtc_enable();
+ 
+  /* Synchronize HPRTC time with the LPSRTC and enable HPRTC */
+
+  imxrt_hprtc_synchronize();
+  return OK;
+}
+
+/************************************************************************************
+ * 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)
+{
+  /* Delegate to imxrt_hprtc_time() */
+
+  return imxrt_hprtc_time();
+}
+#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)
+{
+  uint32_t regval;
+
+  DEBUGASSERT(ts != NULL);
+
+  /* Disable the LPSRTC */
+
+  regval  = getreg32(IMXRT_SNVS_LPCR);
+  regval &= ~SNVS_LPCR_MCENV;
+  putreg32(regval, IMXRT_SNVS_LPCR);
+
+  while ((getreg32(IMXRT_SNVS_LPCR) & SNVS_LPCR_MCENV) != 0)
+    {
+    }
+
+  /* Set LPSRTC time in seconds.  We could do better by accounting for the
+   * ts->tv_nsec unused residual.
+   *
+   * IMXRT_SNVS_LPSMCMR Bits 9-14 = 15-bit MSB of alarm setting.
+   * IMXRT_SNVS_LPSMCLR 32-bit LSB of alarm setting.
+   */
+
+  putreg32((uint32_t)ts->tv_sec >> 17, IMXRT_SNVS_LPSMCMR);
+  putreg32((uint32_t)ts->tv_sec << 15, IMXRT_SNVS_LPSMCLR);
+
+  /* The time has been set */
+
+  putreg32(CONFIG_IMXRT_RTC_MAGIC,
+           IMXRT_SNVS_LPGPR(CONFIG_IMXRT_RTC_MAGIC_REG));
+
+  /* Unconditionally re-enable the LPSRTC */
+
+  imxrt_lpsrtc_enable();
+  return OK;
+}
+
+/****************************************************************************
+ * Name: imxrt_lpsrtc_havesettime
+ *
+ * Description:
+ *   Check if the LPSRTC time has been set
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value:
+ *   Returns true if RTC date-time have been previously set.
+ *
+ ****************************************************************************/
+
+bool imxrt_lpsrtc_havesettime(void)
+{
+  return (getreg32(IMXRT_SNVS_LPGPR(CONFIG_IMXRT_RTC_MAGIC_REG)) ==
+          CONFIG_IMXRT_RTC_MAGIC);
+}
+#endif /* CONFIG_IMXRT_SNVS_LPSRTC */

arch/arm/src/imxrt/imxrt_lpsrtc.h

@@ -0,0 +1,127 @@
+/****************************************************************************
+ * arch/arm/src/imxrt/imxrt_lpsrtc.h
+ *
+ *   Copyright (C) 2018 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
+ ****************************************************************************/
+
+#ifndef __ARCH_ARM_SRC_IMXRT_IMXRT_LPSRTC_H
+#define __ARCH_ARM_SRC_IMXRT_IMXRT_LPSRTC_H
+
+#include <nuttx/config.h>
+
+#include "chip.h"
+
+#ifdef CONFIG_IMXRT_SNVS_LPSRTC
+
+/****************************************************************************
+ * Preprocessor Definitions
+ ****************************************************************************/
+
+#  ifdef CONFIG_RTC_DATETIME
+#    error CONFIG_RTC_DATETIME should not be selected with this driver
+#  endif
+
+#  ifdef CONFIG_RTC_PERIODIC
+#    error CONFIG_RTC_PERIODIC should not be selected with this driver
+#  endif
+
+/* REVISIT: This is probably supportable.  The 47 bit timer does have
+ * accuracy greater than 1 second.
+ */
+
+#  ifdef CONFIG_RTC_HIRES
+#    error CONFIG_RTC_PERIODIC should not be selected with this driver
+#  endif
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+#ifndef __ASSEMBLY__
+
+#undef EXTERN
+#if defined(__cplusplus)
+#define EXTERN extern "C"
+extern "C"
+{
+#else
+#define EXTERN extern
+#endif
+
+/************************************************************************************
+ * Name: imxrt_lpsrtc_initialize
+ *
+ * Description:
+ *   Initialize the LPSRTC per the selected configuration.  This function is called
+ *   via up_rtc_initialize (see imxrt_hprtc.c).
+ *
+ *   NOTE that the LPSRTC is always configured synchronized with the HPRTC.  This
+ *   means that the time is set via the LPSRTC but read via the HPRTC.  Also, only
+ *   the alarms from the HPRTC are used.
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value:
+ *   Zero (OK) on success; a negated errno on failure
+ *
+ ************************************************************************************/
+
+int imxrt_lpsrtc_initialize(void);
+
+/****************************************************************************
+ * Name: imxrt_lpsrtc_havesettime
+ *
+ * Description:
+ *   Check if the LPSRTC time has been set
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value:
+ *   Returns true if RTC date-time have been previously set.
+ *
+ ****************************************************************************/
+
+bool imxrt_lpsrtc_havesettime(void);
+
+#undef EXTERN
+#if defined(__cplusplus)
+}
+#endif
+#endif /* __ASSEMBLY__ */
+#endif /* CONFIG_IMXRT_SNVS_LPSRTC */
+#endif /* __ARCH_ARM_SRC_IMXRT_IMXRT_LPSRTC_H */

configs/imxrt1050-evk/README.txt

@@ -289,10 +289,6 @@ Configuration sub-directories
          CONFIG_NSH_NETINIT_THREAD_PRIORITY=80
          CONFIG_NSH_NETINIT_THREAD_STACKSIZE=1568
 
-       STATUS: As of this writing, I get a hardfault when I enable the PHY
-       interrupt so I suspect that there is something incorrect in that
-       pin configuration.
-
   nsh:
 
     Configures the NuttShell (nsh) located at examples/nsh.  This NSH