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Diffstat (limited to 'nuttx/arch/arm/src/stm32/stm32_iwdg.c')
| -rw-r--r-- | nuttx/arch/arm/src/stm32/stm32_iwdg.c | 711 |
1 files changed, 711 insertions, 0 deletions
diff --git a/nuttx/arch/arm/src/stm32/stm32_iwdg.c b/nuttx/arch/arm/src/stm32/stm32_iwdg.c new file mode 100644 index 000000000..fd51ba0fe --- /dev/null +++ b/nuttx/arch/arm/src/stm32/stm32_iwdg.c @@ -0,0 +1,711 @@ +/**************************************************************************** + * arch/arm/src/stm32/stm32_iwdg.c + * + * Copyright (C) 2012 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 <nuttx/arch.h> + +#include <stdint.h> +#include <errno.h> +#include <debug.h> + +#include <nuttx/clock.h> +#include <nuttx/watchdog.h> +#include <arch/board/board.h> + +#include "up_arch.h" +#include "stm32_rcc.h" +#include "chip/stm32_dbgmcu.h" +#include "stm32_wdg.h" + +#if defined(CONFIG_WATCHDOG) && defined(CONFIG_STM32_IWDG) + +/**************************************************************************** + * Pre-Processor Definitions + ****************************************************************************/ +/* Clocking *****************************************************************/ +/* The minimum frequency of the IWDG clock is: + * + * Fmin = Flsi / 256 + * + * So the maximum delay (in milliseconds) is then: + * + * 1000 * IWDG_RLR_MAX / Fmin + * + * For example, if Flsi = 30Khz (the nominal, uncalibrathed value), then the + * maximum delay is: + * + * Fmin = 117.1875 + * 1000 * 4095 / Fmin = 34,944 MSec + */ + +#define IWDG_FMIN (STM32_LSI_FREQUENCY / 256) +#define IWDG_MAXTIMEOUT (1000 * IWDG_RLR_MAX / IWDG_FMIN) + +/* Configuration ************************************************************/ + +#ifndef CONFIG_STM32_IWDG_DEFTIMOUT +# define CONFIG_STM32_IWDG_DEFTIMOUT IWDG_MAXTIMEOUT +#endif + +/* REVISIT: It appears that you can only setup the prescaler and reload + * registers once. After that, the SR register's PVU and RVU bits never go + * to zero. So we defer setting up these registers until the watchdog + * is started, then refuse any further attempts to change timeout. + */ + +#define CONFIG_STM32_IWDG_ONETIMESETUP 1 + +/* REVISIT: Another possibility is that we CAN change the prescaler and + * reload values after starting the timer. This option is untested but the + * implementation place conditioned on the following: + */ + +#undef CONFIG_STM32_IWDG_DEFERREDSETUP + +/* But you can only try one at a time */ + +#if defined(CONFIG_STM32_IWDG_ONETIMESETUP) && defined(CONFIG_STM32_IWDG_DEFERREDSETUP) +# error "Both CONFIG_STM32_IWDG_ONETIMESETUP and CONFIG_STM32_IWDG_DEFERREDSETUP are defined" +#endif + +/* Debug ********************************************************************/ +/* Non-standard debug that may be enabled just for testing the watchdog + * driver. NOTE: that only lldbg types are used so that the output is + * immediately available. + */ + +#ifdef CONFIG_DEBUG_WATCHDOG +# define wddbg lldbg +# define wdvdbg llvdbg +#else +# define wddbg(x...) +# define wdvdbg(x...) +#endif + +/**************************************************************************** + * Private Types + ****************************************************************************/ +/* This structure provides the private representation of the "lower-half" + * driver state structure. This structure must be cast-compatible with the + * well-known watchdog_lowerhalf_s structure. + */ + +struct stm32_lowerhalf_s +{ + FAR const struct watchdog_ops_s *ops; /* Lower half operations */ + uint32_t lsifreq; /* The calibrated frequency of the LSI oscillator */ + uint32_t timeout; /* The (actual) selected timeout */ + uint32_t lastreset; /* The last reset time */ + bool started; /* true: The watchdog timer has been started */ + uint8_t prescaler; /* Clock prescaler value */ + uint16_t reload; /* Timer reload value */ +}; + +/**************************************************************************** + * Private Function Prototypes + ****************************************************************************/ +/* Register operations ******************************************************/ + +#if defined(CONFIG_STM32_IWDG_REGDEBUG) && defined(CONFIG_DEBUG) +static uint16_t stm32_getreg(uint32_t addr); +static void stm32_putreg(uint16_t val, uint32_t addr); +#else +# define stm32_getreg(addr) getreg16(addr) +# define stm32_putreg(val,addr) putreg16(val,addr) +#endif + +static inline void stm32_setprescaler(FAR struct stm32_lowerhalf_s *priv); + +/* "Lower half" driver methods **********************************************/ + +static int stm32_start(FAR struct watchdog_lowerhalf_s *lower); +static int stm32_stop(FAR struct watchdog_lowerhalf_s *lower); +static int stm32_keepalive(FAR struct watchdog_lowerhalf_s *lower); +static int stm32_getstatus(FAR struct watchdog_lowerhalf_s *lower, + FAR struct watchdog_status_s *status); +static int stm32_settimeout(FAR struct watchdog_lowerhalf_s *lower, + uint32_t timeout); + +/**************************************************************************** + * Private Data + ****************************************************************************/ +/* "Lower half" driver methods */ + +static const struct watchdog_ops_s g_wdgops = +{ + .start = stm32_start, + .stop = stm32_stop, + .keepalive = stm32_keepalive, + .getstatus = stm32_getstatus, + .settimeout = stm32_settimeout, + .capture = NULL, + .ioctl = NULL, +}; + +/* "Lower half" driver state */ + +static struct stm32_lowerhalf_s g_wdgdev; + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: stm32_getreg + * + * Description: + * Get the contents of an STM32 IWDG register + * + ****************************************************************************/ + +#if defined(CONFIG_STM32_IWDG_REGDEBUG) && defined(CONFIG_DEBUG) +static uint16_t stm32_getreg(uint32_t addr) +{ + static uint32_t prevaddr = 0; + static uint32_t count = 0; + static uint16_t preval = 0; + + /* Read the value from the register */ + + uint16_t val = getreg16(addr); + + /* Is this the same value that we read from the same registe last time? Are + * we polling the register? If so, suppress some of the output. + */ + + if (addr == prevaddr && val == preval) + { + if (count == 0xffffffff || ++count > 3) + { + if (count == 4) + { + lldbg("...\n"); + } + return val; + } + } + + /* No this is a new address or value */ + + else + { + /* Did we print "..." for the previous value? */ + + if (count > 3) + { + /* Yes.. then show how many times the value repeated */ + + lldbg("[repeats %d more times]\n", count-3); + } + + /* Save the new address, value, and count */ + + prevaddr = addr; + preval = val; + count = 1; + } + + /* Show the register value read */ + + lldbg("%08x->%04x\n", addr, val); + return val; +} +#endif + +/**************************************************************************** + * Name: stm32_putreg + * + * Description: + * Set the contents of an STM32 register to a value + * + ****************************************************************************/ + +#if defined(CONFIG_STM32_IWDG_REGDEBUG) && defined(CONFIG_DEBUG) +static void stm32_putreg(uint16_t val, uint32_t addr) +{ + /* Show the register value being written */ + + lldbg("%08x<-%04x\n", addr, val); + + /* Write the value */ + + putreg16(val, addr); +} +#endif + +/**************************************************************************** + * Name: stm32_setprescaler + * + * Description: + * Set up the prescaler and reload values. This seems to be something + * that can only be done one time. + * + * Input Parameters: + * priv - A pointer the internal representation of the "lower-half" + * driver state structure. + * timeout - The new timeout value in millisecnds. + * + * Returned Values: + * Zero on success; a negated errno value on failure. + * + ****************************************************************************/ + +static inline void stm32_setprescaler(FAR struct stm32_lowerhalf_s *priv) +{ + /* Enable write access to IWDG_PR and IWDG_RLR registers */ + + stm32_putreg(IWDG_KR_KEY_ENABLE, STM32_IWDG_KR); + + /* Wait for the PVU and RVU bits to be reset be hardware. These bits + * were set the last time that the PR register was written and may not + * yet be cleared. + * + * If the setup is only permitted one time, then this wait should not + * be necessary. + */ + +#ifndef CONFIG_STM32_IWDG_ONETIMESETUP + while ((stm32_getreg(STM32_IWDG_SR) & (IWDG_SR_PVU|IWDG_SR_RVU)) != 0); +#endif + + /* Set the prescaler */ + + stm32_putreg((uint16_t)priv->prescaler << IWDG_PR_SHIFT, STM32_IWDG_PR); + + /* Set the reload value */ + + stm32_putreg((uint16_t)priv->reload, STM32_IWDG_RLR); + + /* Reload the counter (and disable write access) */ + + stm32_putreg(IWDG_KR_KEY_RELOAD, STM32_IWDG_KR); +} + +/**************************************************************************** + * Name: stm32_start + * + * Description: + * Start the watchdog timer, resetting the time to the current timeout, + * + * Input Parameters: + * lower - A pointer the publicly visible representation of the "lower-half" + * driver state structure. + * + * Returned Values: + * Zero on success; a negated errno value on failure. + * + ****************************************************************************/ + +static int stm32_start(FAR struct watchdog_lowerhalf_s *lower) +{ + FAR struct stm32_lowerhalf_s *priv = (FAR struct stm32_lowerhalf_s *)lower; + irqstate_t flags; + + wdvdbg("Entry: started=%d\n"); + DEBUGASSERT(priv); + + /* Have we already been started? */ + + if (!priv->started) + { + /* REVISIT: It appears that you can only setup the prescaler and reload + * registers once. After that, the SR register's PVU and RVU bits never go + * to zero. So we defer setting up these registers until the watchdog + * is started, then refuse any further attempts to change timeout. + */ + + /* Set up prescaler and reload value for the selected timeout before + * starting the watchdog timer. + */ + +#if defined(CONFIG_STM32_IWDG_ONETIMESETUP) || defined(CONFIG_STM32_IWDG_DEFERREDSETUP) + stm32_setprescaler(priv); +#endif + + /* Enable IWDG (the LSI oscillator will be enabled by hardware). NOTE: + * If the "Hardware watchdog" feature is enabled through the device option + * bits, the watchdog is automatically enabled at power-on. + */ + + flags = irqsave(); + stm32_putreg(IWDG_KR_KEY_START, STM32_IWDG_KR); + priv->lastreset = clock_systimer(); + priv->started = true; + irqrestore(flags); + } + return OK; +} + +/**************************************************************************** + * Name: stm32_stop + * + * Description: + * Stop the watchdog timer + * + * Input Parameters: + * lower - A pointer the publicly visible representation of the "lower-half" + * driver state structure. + * + * Returned Values: + * Zero on success; a negated errno value on failure. + * + ****************************************************************************/ + +static int stm32_stop(FAR struct watchdog_lowerhalf_s *lower) +{ + /* There is no way to disable the IDWG timer once it has been started */ + + wdvdbg("Entry\n"); + return -ENOSYS; +} + +/**************************************************************************** + * Name: stm32_keepalive + * + * Description: + * Reset the watchdog timer to the current timeout value, prevent any + * imminent watchdog timeouts. This is sometimes referred as "pinging" + * the atchdog timer or "petting the dog". + * + * Input Parameters: + * lower - A pointer the publicly visible representation of the "lower-half" + * driver state structure. + * + * Returned Values: + * Zero on success; a negated errno value on failure. + * + ****************************************************************************/ + +static int stm32_keepalive(FAR struct watchdog_lowerhalf_s *lower) +{ + FAR struct stm32_lowerhalf_s *priv = (FAR struct stm32_lowerhalf_s *)lower; + irqstate_t flags; + + wdvdbg("Entry\n"); + + /* Reload the IWDG timer */ + + flags = irqsave(); + stm32_putreg(IWDG_KR_KEY_RELOAD, STM32_IWDG_KR); + priv->lastreset = clock_systimer(); + irqrestore(flags); + + return OK; +} + +/**************************************************************************** + * Name: stm32_getstatus + * + * Description: + * Get the current watchdog timer status + * + * Input Parameters: + * lower - A pointer the publicly visible representation of the "lower-half" + * driver state structure. + * stawtus - The location to return the watchdog status information. + * + * Returned Values: + * Zero on success; a negated errno value on failure. + * + ****************************************************************************/ + +static int stm32_getstatus(FAR struct watchdog_lowerhalf_s *lower, + FAR struct watchdog_status_s *status) +{ + FAR struct stm32_lowerhalf_s *priv = (FAR struct stm32_lowerhalf_s *)lower; + uint32_t ticks; + uint32_t elapsed; + + wdvdbg("Entry\n"); + DEBUGASSERT(priv); + + /* Return the status bit */ + + status->flags = WDFLAGS_RESET; + if (priv->started) + { + status->flags |= WDFLAGS_ACTIVE; + } + + /* Return the actual timeout in milliseconds */ + + status->timeout = priv->timeout; + + /* Get the elapsed time since the last ping */ + + ticks = clock_systimer() - priv->lastreset; + elapsed = (int32_t)TICK2MSEC(ticks); + + if (elapsed > priv->timeout) + { + elapsed = priv->timeout; + } + + /* Return the approximate time until the watchdog timer expiration */ + + status->timeleft = priv->timeout - elapsed; + + wdvdbg("Status :\n"); + wdvdbg(" flags : %08x\n", status->flags); + wdvdbg(" timeout : %d\n", status->timeout); + wdvdbg(" timeleft : %d\n", status->timeleft); + return OK; +} + +/**************************************************************************** + * Name: stm32_settimeout + * + * Description: + * Set a new timeout value (and reset the watchdog timer) + * + * Input Parameters: + * lower - A pointer the publicly visible representation of the "lower-half" + * driver state structure. + * timeout - The new timeout value in millisecnds. + * + * Returned Values: + * Zero on success; a negated errno value on failure. + * + ****************************************************************************/ + +static int stm32_settimeout(FAR struct watchdog_lowerhalf_s *lower, + uint32_t timeout) +{ + FAR struct stm32_lowerhalf_s *priv = (FAR struct stm32_lowerhalf_s *)lower; + uint32_t fiwdg; + uint64_t reload; + int prescaler; + int shift; + + wdvdbg("Entry: timeout=%d\n", timeout); + DEBUGASSERT(priv); + + /* Can this timeout be represented? */ + + if (timeout < 1 || timeout > IWDG_MAXTIMEOUT) + { + wddbg("Cannot represent timeout=%d > %d\n", + timeout, IWDG_MAXTIMEOUT); + return -ERANGE; + } + + /* REVISIT: It appears that you can only setup the prescaler and reload + * registers once. After that, the SR register's PVU and RVU bits never go + * to zero. + */ + +#ifdef CONFIG_STM32_IWDG_ONETIMESETUP + if (priv->started) + { + wddbg("Timer is already started\n"); + return -EBUSY; + } +#endif + + /* Select the smallest prescaler that will result in a reload value that is + * less than the maximum. + */ + + for (prescaler = 0; ; prescaler++) + { + /* PR = 0 -> Divider = 4 = 1 << 2 + * PR = 1 -> Divider = 8 = 1 << 3 + * PR = 2 -> Divider = 16 = 1 << 4 + * PR = 3 -> Divider = 32 = 1 << 5 + * PR = 4 -> Divider = 64 = 1 << 6 + * PR = 5 -> Divider = 128 = 1 << 7 + * PR = 6 -> Divider = 256 = 1 << 8 + * PR = n -> Divider = 1 << (n+2) + */ + + shift = prescaler + 2; + + /* Get the IWDG counter frequency in Hz. For a nominal 32Khz LSI clock, + * this is value in the range of 7500 and 125. + */ + + fiwdg = priv->lsifreq >> shift; + + /* We want: + * 1000 * reload / Fiwdg = timeout + * Or: + * reload = Fiwdg * timeout / 1000 + */ + + reload = (uint64_t)fiwdg * (uint64_t)timeout / 1000; + + /* If this reload valid is less than the maximum or we are not ready + * at the prescaler value, then break out of the loop to use these + * settings. + */ + + if (reload <= IWDG_RLR_MAX || prescaler == 6) + { + /* Note that we explicity break out of the loop rather than using + * the 'for' loop termination logic because we do not want the + * value of prescaler to be incremented. + */ + + break; + } + } + + /* Make sure that the final reload value is within range */ + + if (reload > IWDG_RLR_MAX) + { + reload = IWDG_RLR_MAX; + } + + /* Get the actual timeout value in milliseconds. + * + * We have: + * reload = Fiwdg * timeout / 1000 + * So we want: + * timeout = 1000 * reload / Fiwdg + */ + + priv->timeout = (1000 * (uint32_t)reload) / fiwdg; + + /* Save setup values for later use */ + + priv->prescaler = prescaler; + priv->reload = reload; + + /* Write the prescaler and reload values to the IWDG registers. + * + * REVISIT: It appears that you can only setup the prescaler and reload + * registers once. After that, the SR register's PVU and RVU bits never go + * to zero. + */ + +#ifndef CONFIG_STM32_IWDG_ONETIMESETUP + /* If CONFIG_STM32_IWDG_DEFERREDSETUP is selected, then perform the register + * configuration only if the timer has been started. + */ + +#ifdef CONFIG_STM32_IWDG_DEFERREDSETUP + if (priv->started) +#endif + { + stm32_setprescaler(priv); + } +#endif + + wdvdbg("prescaler=%d fiwdg=%d reload=%d\n", prescaler, fiwdg, reload); + + return OK; +} + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: stm32_iwdginitialize + * + * Description: + * Initialize the IWDG watchdog time. The watchdog timer is intialized and + * registers as 'devpath. The initial state of the watchdog time is + * disabled. + * + * Input Parameters: + * devpath - The full path to the watchdog. This should be of the form + * /dev/watchdog0 + * lsifreq - The calibrated LSI clock frequency + * + * Returned Values: + * None + * + ****************************************************************************/ + +void stm32_iwdginitialize(FAR const char *devpath, uint32_t lsifreq) +{ + FAR struct stm32_lowerhalf_s *priv = &g_wdgdev; + + wdvdbg("Entry: devpath=%s lsifreq=%d\n", devpath, lsifreq); + + /* NOTE we assume that clocking to the IWDG has already been provided by + * the RCC initialization logic. + */ + + /* Initialize the driver state structure. */ + + priv->ops = &g_wdgops; + priv->lsifreq = lsifreq; + priv->started = false; + + /* Make sure that the LSI ocsillator is enabled. NOTE: The LSI oscillator + * is enabled here but is not disabled by this file (because this file does + * not know the the global usage of the oscillator. Any clock management + * logic (say, as part of a power management scheme) needs handle other + * LSI controls outside of this file. + */ + + stm32_rcc_enablelsi(); + wdvdbg("RCC CSR: %08x\n", getreg32(STM32_RCC_CSR)); + + /* Select an arbitrary initial timeout value. But don't start the watchdog + * yet. NOTE: If the "Hardware watchdog" feature is enabled through the + * device option bits, the watchdog is automatically enabled at power-on. + */ + + stm32_settimeout((FAR struct watchdog_lowerhalf_s *)priv, CONFIG_STM32_IWDG_DEFTIMOUT); + + /* Register the watchdog driver as /dev/watchdog0 */ + + (void)watchdog_register(devpath, (FAR struct watchdog_lowerhalf_s *)priv); + + /* When the microcontroller enters debug mode (Cortex™-M4F core halted), + * the IWDG counter either continues to work normally or stops, depending + * on DBG_WIDG_STOP configuration bit in DBG module. + */ + +#if defined(CONFIG_STM32_JTAG_FULL_ENABLE) || \ + defined(CONFIG_STM32_JTAG_NOJNTRST_ENABLE) || \ + defined(CONFIG_STM32_JTAG_SW_ENABLE) + { + uint32_t cr = getreg32(STM32_DBGMCU_CR); + cr |= DBGMCU_CR_IWDGSTOP; + putreg32(cr, STM32_DBGMCU_CR); + } +#endif +} + +#endif /* CONFIG_WATCHDOG && CONFIG_STM32_IWDG */ |