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Diffstat (limited to 'nuttx/arch/arm/src/stm32/stm32f10xxx_rtc.c')
| -rw-r--r-- | nuttx/arch/arm/src/stm32/stm32f10xxx_rtc.c | 685 |
1 files changed, 685 insertions, 0 deletions
diff --git a/nuttx/arch/arm/src/stm32/stm32f10xxx_rtc.c b/nuttx/arch/arm/src/stm32/stm32f10xxx_rtc.c new file mode 100644 index 000000000..df8ad9dd5 --- /dev/null +++ b/nuttx/arch/arm/src/stm32/stm32f10xxx_rtc.c @@ -0,0 +1,685 @@ +/************************************************************************************ + * arch/arm/src/stm32/stm32f10xxx_rtc.c + * + * Copyright (C) 2011 Uros Platise. All rights reserved. + * Author: Uros Platise <uros.platise@isotel.eu> + * + * With extensions, modifications by: + * + * Copyright (C) 2011-2012 Gregory Nutt. All rights reserved. + * Author: Gregroy 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. + * + ************************************************************************************/ + +/* The STM32 RTC Driver offers standard precision of 1 Hz or High Resolution + * operating at rate up to 16384 Hz. It provides UTC time and alarm interface + * with external output pin (for wake-up). + * + * RTC is based on hardware RTC module which is located in a separate power + * domain. The 32-bit counter is extended by 16-bit registers in BKP domain + * STM32_BKP_DR1 to provide system equiv. function to the: time_t time(time_t *). + * + * Notation: + * - clock refers to 32-bit hardware counter + * - time is a combination of clock and upper bits stored in backuped domain + * with unit of 1 [s] + * + * TODO: Error Handling in case LSE fails during start-up or during operation. + */ + +/************************************************************************************ + * Included Files + ************************************************************************************/ + +#include <nuttx/config.h> +#include <nuttx/arch.h> +#include <nuttx/irq.h> +#include <nuttx/rtc.h> +#include <arch/board/board.h> + +#include <stdlib.h> +#include <stdint.h> +#include <stdbool.h> +#include <stdio.h> +#include <errno.h> + +#include "up_arch.h" + +#include "stm32_pwr.h" +#include "stm32_rcc.h" +#include "stm32_rtc.h" +#include "stm32_waste.h" + +/************************************************************************************ + * Pre-processor Definitions + ************************************************************************************/ +/* Configuration ********************************************************************/ +/* In hi-res mode, the RTC operates at 16384Hz. Overflow interrupts are handled + * when the 32-bit RTC counter overflows every 3 days and 43 minutes. A BKP register + * is incremented on each overflow interrupt creating, effectively, a 48-bit RTC + * counter. + * + * In the lo-res mode, the RTC operates at 1Hz. Overflow interrupts are not handled + * (because the next overflow is not expected until the year 2106. + * + * WARNING: Overflow interrupts are lost whenever the STM32 is powered down. The + * overflow interrupt may be lost even if the STM32 is powered down only momentarily. + * Therefor hi-res solution is only useful in systems where the power is always on. + */ + +#ifdef CONFIG_RTC_HIRES +# ifndef CONFIG_RTC_FREQUENCY +# error "CONFIG_RTC_FREQUENCY is required for CONFIG_RTC_HIRES" +# elif CONFIG_RTC_FREQUENCY != 16384 +# error "Only hi-res CONFIG_RTC_FREQUENCY of 16384Hz is supported" +# endif +#else +# ifndef CONFIG_RTC_FREQUENCY +# define CONFIG_RTC_FREQUENCY 1 +# endif +# if CONFIG_RTC_FREQUENCY != 1 +# error "Only lo-res CONFIG_RTC_FREQUENCY of 1Hz is supported" +# endif +#endif + +#ifndef CONFIG_STM32_BKP +# error "CONFIG_STM32_BKP is required for CONFIG_RTC" +#endif + +/* RTC/BKP Definitions *************************************************************/ +/* STM32_RTC_PRESCALAR_VALUE + * RTC pre-scalar value. The RTC is driven by a 32,768Hz input clock. This input + * value is divided by this value (plus one) to generate the RTC frequency. + * RTC_TIMEMSB_REG + * The BKP module register used to hold the RTC overflow value. Overflows are + * only handled in hi-res mode. + * RTC_CLOCKS_SHIFT + * The shift used to convert the hi-res timer LSB to one second. Not used with + * the lo-res timer. + */ + +#ifdef CONFIG_RTC_HIRES +# define STM32_RTC_PRESCALAR_VALUE STM32_RTC_PRESCALER_MIN +# define RTC_TIMEMSB_REG STM32_BKP_DR1 +# define RTC_CLOCKS_SHIFT 14 +#else +# define STM32_RTC_PRESCALAR_VALUE STM32_RTC_PRESCALER_SECOND +#endif + +/************************************************************************************ + * Private Types + ************************************************************************************/ + +struct rtc_regvals_s +{ + uint16_t cntl; + uint16_t cnth; +#ifdef CONFIG_RTC_HIRES + uint16_t ovf; +#endif +}; + +/************************************************************************************ + * Private Data + ************************************************************************************/ + +/* Callback to use when the alarm expires */ + +#ifdef CONFIG_RTC_ALARM +static alarmcb_t g_alarmcb; +#endif + +/************************************************************************************ + * Public Data + ************************************************************************************/ + +/* Variable determines the state of the LSE oscilator. + * Possible errors: + * - on start-up + * - during operation, reported by LSE interrupt + */ + +volatile bool g_rtc_enabled = false; + +/************************************************************************************ + * Private Functions + ************************************************************************************/ + +/************************************************************************************ + * Name: stm32_rtc_beginwr + * + * Description: + * Enter configuration mode + * + * Input Parameters: + * None + * + * Returned Value: + * None + * + ************************************************************************************/ + +static inline void stm32_rtc_beginwr(void) +{ + /* Previous write is done? */ + + while ((getreg16(STM32_RTC_CRL) & RTC_CRL_RTOFF) == 0) + { + up_waste(); + } + + /* Enter Config mode, Set Value and Exit */ + + modifyreg16(STM32_RTC_CRL, 0, RTC_CRL_CNF); +} + +/************************************************************************************ + * Name: stm32_rtc_endwr + * + * Description: + * Exit configuration mode + * + * Input Parameters: + * None + * + * Returned Value: + * None + * + ************************************************************************************/ + +static inline void stm32_rtc_endwr(void) +{ + modifyreg16(STM32_RTC_CRL, RTC_CRL_CNF, 0); +} + +/************************************************************************************ + * Name: stm32_rtc_wait4rsf + * + * Description: + * Wait for registers to synchronise with RTC module, call after power-up only + * + * Input Parameters: + * None + * + * Returned Value: + * None + * + ************************************************************************************/ + +static inline void stm32_rtc_wait4rsf(void) +{ + modifyreg16(STM32_RTC_CRL, RTC_CRL_RSF, 0); + while ((getreg16(STM32_RTC_CRL) & RTC_CRL_RSF) == 0) + { + up_waste(); + } +} + +/************************************************************************************ + * Name: up_rtc_breakout + * + * Description: + * Set the RTC to the provided time. + * + * Input Parameters: + * tp - the time to use + * + * Returned Value: + * None + * + ************************************************************************************/ + +#ifdef CONFIG_RTC_HIRES +static void up_rtc_breakout(FAR const struct timespec *tp, + FAR struct rtc_regvals_s *regvals) +{ + uint64_t frac; + uint32_t cnt; + uint16_t ovf; + + /* Break up the time in seconds + milleconds into the correct values for our use */ + + frac = ((uint64_t)tp->tv_nsec * CONFIG_RTC_FREQUENCY) / 1000000000; + cnt = (tp->tv_sec << RTC_CLOCKS_SHIFT) | ((uint32_t)frac & (CONFIG_RTC_FREQUENCY-1)); + ovf = (tp->tv_sec >> (32 - RTC_CLOCKS_SHIFT)); + + /* Then return the broken out time */ + + regvals->cnth = cnt >> 16; + regvals->cntl = cnt & 0xffff; + regvals->ovf = ovf; +} +#else +static inline void up_rtc_breakout(FAR const struct timespec *tp, + FAR struct rtc_regvals_s *regvals) +{ + /* The low-res timer is easy... tv_sec holds exactly the value needed by the + * CNTH/CNTL registers. + */ + + regvals->cnth = (uint16_t)((uint32_t)tp->tv_sec >> 16); + regvals->cntl = (uint16_t)((uint32_t)tp->tv_sec & 0xffff); +} +#endif + +/************************************************************************************ + * Name: stm32_rtc_interrupt + * + * Description: + * RTC interrupt service routine + * + * Input Parameters: + * irq - The IRQ number that generated the interrupt + * context - Architecture specific register save information. + * + * Returned Value: + * Zero (OK) on success; A negated errno value on failure. + * + ************************************************************************************/ + +#if defined(CONFIG_RTC_HIRES) || defined(CONFIG_RTC_ALARM) +static int stm32_rtc_interrupt(int irq, void *context) +{ + uint16_t source = getreg16(STM32_RTC_CRL); + +#ifdef CONFIG_RTC_HIRES + if ((source & RTC_CRL_OWF) != 0) + { + putreg16(getreg16(RTC_TIMEMSB_REG) + 1, RTC_TIMEMSB_REG); + } +#endif + +#ifdef CONFIG_RTC_ALARM + if ((source & RTC_CRL_ALRF) != 0 && g_alarmcb != NULL) + { + /* Alarm callback */ + + g_alarmcb(); + g_alarmcb = NULL; + } +#endif + + /* Clear pending flags, leave RSF high */ + + putreg16(RTC_CRL_RSF, STM32_RTC_CRL); + return 0; +} +#endif + +/************************************************************************************ + * Public Functions + ************************************************************************************/ + +/************************************************************************************ + * Name: up_rtcinitialize + * + * 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_rtcinitialize(void) +{ + /* Set access to the peripheral, enable the backup domain (BKP) and the lower power + * extern 32,768Hz (Low-Speed External, LSE) oscillator. Configure the LSE to + * drive the RTC. + */ + + stm32_pwr_enablebkp(); + stm32_rcc_enablelse(); + + /* TODO: Get state from this function, if everything is + * okay and whether it is already enabled (if it was disabled + * reset upper time register) + */ + + g_rtc_enabled = true; + + /* TODO: Possible stall? should we set the timeout period? and return with -1 */ + + stm32_rtc_wait4rsf(); + + /* Configure prescaler, note that these are write-only registers */ + + stm32_rtc_beginwr(); + putreg16(STM32_RTC_PRESCALAR_VALUE >> 16, STM32_RTC_PRLH); + putreg16(STM32_RTC_PRESCALAR_VALUE & 0xffff, STM32_RTC_PRLL); + stm32_rtc_endwr(); + + /* Configure RTC interrupt to catch overflow and alarm interrupts. */ + +#if defined(CONFIG_RTC_HIRES) || defined(CONFIG_RTC_ALARM) + irq_attach(STM32_IRQ_RTC, stm32_rtc_interrupt); + up_enable_irq(STM32_IRQ_RTC); +#endif + + /* Previous write is done? This is required prior writing into CRH */ + + while ((getreg16(STM32_RTC_CRL) & RTC_CRL_RTOFF) == 0) + { + up_waste(); + } + modifyreg16(STM32_RTC_CRH, 0, RTC_CRH_OWIE); + + /* Alarm Int via EXTI Line */ + + /* STM32_IRQ_RTCALRM 41: RTC alarm through EXTI line interrupt */ + + 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 + * intialization 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) +{ + irqstate_t flags; + uint16_t cnth; + uint16_t cntl; + uint16_t tmp; + + /* The RTC counter is read from two 16-bit registers to form one 32-bit + * value. Because these are non-atomic operations, many things can happen + * between the two reads: This thread could get suspended or interrrupted + * or the lower 16-bit counter could rollover between reads. Disabling + * interrupts will prevent suspensions and interruptions: + */ + + flags = irqsave(); + + /* And the following loop will handle any clock rollover events that may + * happen between samples. Most of the time (like 99.9%), the following + * loop will execute only once. In the rare rollover case, it should + * execute no more than 2 times. + */ + + do + { + tmp = getreg16(STM32_RTC_CNTL); + cnth = getreg16(STM32_RTC_CNTH); + cntl = getreg16(STM32_RTC_CNTL); + } + + /* The second sample of CNTL could be less than the first sample of CNTL + * only if rollover occurred. In that case, CNTH may or may not be out + * of sync. The best thing to do is try again until we know that no + * rollover occurred. + */ + + while (cntl < tmp); + irqrestore(flags); + + /* Okay.. the samples should be as close together in time as possible and + * we can be assured that no clock rollover occurred between the samples. + * + * Return the time in seconds. + */ + + return (time_t)cnth << 16 | (time_t)cntl; +} +#endif + +/************************************************************************************ + * 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) +{ + irqstate_t flags; + uint32_t ls; + uint32_t ms; + uint16_t ovf; + uint16_t cnth; + uint16_t cntl; + uint16_t tmp; + + /* The RTC counter is read from two 16-bit registers to form one 32-bit + * value. Because these are non-atomic operations, many things can happen + * between the two reads: This thread could get suspended or interrrupted + * or the lower 16-bit counter could rollover between reads. Disabling + * interrupts will prevent suspensions and interruptions: + */ + + flags = irqsave(); + + /* And the following loop will handle any clock rollover events that may + * happen between samples. Most of the time (like 99.9%), the following + * loop will execute only once. In the rare rollover case, it should + * execute no more than 2 times. + */ + + do + { + tmp = getreg16(STM32_RTC_CNTL); + cnth = getreg16(STM32_RTC_CNTH); + ovf = getreg16(RTC_TIMEMSB_REG); + cntl = getreg16(STM32_RTC_CNTL); + } + + /* The second sample of CNTL could be less than the first sample of CNTL + * only if rollover occurred. In that case, CNTH may or may not be out + * of sync. The best thing to do is try again until we know that no + * rollover occurred. + */ + + while (cntl < tmp); + irqrestore(flags); + + /* Okay.. the samples should be as close together in time as possible and + * we can be assured that no clock rollover occurred between the samples. + * + * Create a 32-bit value from the LS and MS 16-bit RTC counter values and + * from the MS and overflow 16-bit counter values. + */ + + ls = (uint32_t)cnth << 16 | (uint32_t)cntl; + ms = (uint32_t)ovf << 16 | (uint32_t)cnth; + + /* Then we can save the time in seconds and fractional seconds. */ + + tp->tv_sec = (ms << (32-RTC_CLOCKS_SHIFT-16)) | (ls >> (RTC_CLOCKS_SHIFT+16)); + tp->tv_nsec = (ls & (CONFIG_RTC_FREQUENCY-1)) * (1000000000/CONFIG_RTC_FREQUENCY); + return OK; +} +#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 *tp) +{ + struct rtc_regvals_s regvals; + irqstate_t flags; + + /* Break out the time values */ + + up_rtc_breakout(tp, ®vals); + + /* Then write the broken out values to the RTC counter and BKP overflow register + * (hi-res mode only) + */ + + flags = irqsave(); + stm32_rtc_beginwr(); + putreg16(regvals.cnth, STM32_RTC_CNTH); + putreg16(regvals.cntl, STM32_RTC_CNTL); + stm32_rtc_endwr(); + +#ifdef CONFIG_RTC_HIRES + putreg16(regvals.ovf, RTC_TIMEMSB_REG); +#endif + irqrestore(flags); + return OK; +} + +/************************************************************************************ + * Name: up_rtc_setalarm + * + * Description: + * Set up an alarm. + * + * Input Parameters: + * tp - the time to set the alarm + * callback - the function to call when the alarm expires. + * + * Returned Value: + * Zero (OK) on success; a negated errno on failure + * + ************************************************************************************/ + +#ifdef CONFIG_RTC_ALARM +int up_rtc_setalarm(FAR const struct timespec *tp, alarmcb_t callback) +{ + struct rtc_regvals_s regvals; + irqstate_t flags; + uint16_t cr; + int ret = -EBUSY; + + /* Is there already something waiting on the ALARM? */ + + if (g_alarmcb == NULL) + { + /* No.. Save the callback function pointer */ + + g_alarmcb = callback; + + /* Break out the time values */ + + up_rtc_breakout(tp, ®vals); + + /* Enable RTC alarm */ + + cr = getreg16(STM32_RTC_CRH); + cr |= RTC_CRH_ALRIE; + putreg16(cr, STM32_RTC_CRH); + + /* The set the alarm */ + + flags = irqsave(); + stm32_rtc_beginwr(); + putreg16(regvals.cnth, STM32_RTC_ALRH); + putreg16(regvals.cntl, STM32_RTC_ALRL); + stm32_rtc_endwr(); + irqrestore(flags); + + ret = OK; + } + return ret; +} +#endif + +/************************************************************************************ + * Name: up_rtc_cancelalarm + * + * Description: + * Cancel a pending alarm alarm + * + * Input Parameters: + * none + * + * Returned Value: + * Zero (OK) on success; a negated errno on failure + * + ************************************************************************************/ + +#ifdef CONFIG_RTC_ALARM +int up_rtc_cancelalarm(void) +{ + irqstate_t flags; + int ret = -ENODATA; + + if (g_alarmcb != NULL) + { + /* Cancel the global callback function */ + + g_alarmcb = NULL; + + /* Unset the alarm */ + + flags = irqsave(); + stm32_rtc_beginwr(); + putreg16(0xffff, STM32_RTC_ALRH); + putreg16(0xffff, STM32_RTC_ALRL); + stm32_rtc_endwr(); + irqrestore(flags); + + ret = OK; + } + return ret; +} +#endif |