From f93e69e94e7adb6af68ed7502185dacc743a277a Mon Sep 17 00:00:00 2001 From: Gregory Nutt Date: Mon, 12 Jan 2015 15:52:48 -0600 Subject: [PATCH] Tiva Timer: First cut at timer driver lower half (still incomplete) --- arch/arm/src/tiva/Make.defs | 3 + arch/arm/src/tiva/tiva_timer.c | 306 +++++++++++++++- arch/arm/src/tiva/tiva_timer.h | 100 +++-- arch/arm/src/tiva/tiva_timerlow.c | 583 ++++++++++++++++++++++++++++++ 4 files changed, 958 insertions(+), 34 deletions(-) create mode 100644 arch/arm/src/tiva/tiva_timerlow.c diff --git a/arch/arm/src/tiva/Make.defs b/arch/arm/src/tiva/Make.defs index aa4d9269fc..9851dcbb6f 100644 --- a/arch/arm/src/tiva/Make.defs +++ b/arch/arm/src/tiva/Make.defs @@ -98,6 +98,9 @@ endif ifeq ($(CONFIG_TIVA_TIMER),y) CHIP_CSRCS += tiva_timer.c +ifeq ($(CONFIG_TIMER),y) +CHIP_CSRCS += tiva_timerlow.c +endif endif ifeq ($(CONFIG_NET),y) diff --git a/arch/arm/src/tiva/tiva_timer.c b/arch/arm/src/tiva/tiva_timer.c index 5327c68479..eab2a4ba71 100644 --- a/arch/arm/src/tiva/tiva_timer.c +++ b/arch/arm/src/tiva/tiva_timer.c @@ -820,10 +820,11 @@ static int tiva_oneshot_periodic_mode32(struct tiva_gptmstate_s *priv, #warning Missing Logic /* Enable one-shot/periodic interrupts? Enable interrupts only if an - * interrupt handler was provided. + * non-NULL interrupt handler and non-zero timeout interval were + * provided. */ - if (timer->handler) + if (timer->handler && timer->u.periodic.interval > 0) { /* Select the interrupt mask that will enable the timer interrupt. * Any non-zero value of imr indicates that interrupts are expected. @@ -1527,8 +1528,8 @@ static int tiva_timer16_configure(struct tiva_gptmstate_s *priv, TIMER_HANDLE tiva_gptm_configure(const struct tiva_gptmconfig_s *config) { - static const struct tiva_gptmattr_s *attr; - static struct tiva_gptmstate_s *priv; + const struct tiva_gptmattr_s *attr; + struct tiva_gptmstate_s *priv; uint32_t regval; int ret; @@ -1542,7 +1543,7 @@ TIMER_HANDLE tiva_gptm_configure(const struct tiva_gptmconfig_s *config) case 0: /* Enable GPTM0 clocking and power */ - + attr = &g_gptm0_attr; priv = &g_gptm0_state; break; @@ -1632,7 +1633,7 @@ TIMER_HANDLE tiva_gptm_configure(const struct tiva_gptmconfig_s *config) while (!tiva_gpio_periphrdy(config->gptm)); - /* Reset the time to be certain that it is in the disabled state */ + /* Reset the timer to be certain that it is in the disabled state */ regval = tiva_getreg(priv, TIVA_SYSCON_SRTIMER); regval |= SYSCON_SRTIMER(config->gptm); @@ -1744,6 +1745,64 @@ TIMER_HANDLE tiva_gptm_configure(const struct tiva_gptmconfig_s *config) return ret < 0 ? (TIMER_HANDLE)NULL : (TIMER_HANDLE)priv; } +/**************************************************************************** + * Name: tiva_gptm_release + * + * Description: + * Release resources held by the timer instance. After this function is + * called, the timer handle is invalid and must not be used further. + * + * Input Parameters: + * handle - The handle value returned by tiva_gptm_configure() + * + * Returned Value: + * None. + * + ****************************************************************************/ + +void tiva_gptm_release(TIMER_HANDLE handle) +{ + struct tiva_gptmstate_s *priv = (struct tiva_gptmstate_s *)handle; + const struct tiva_gptmconfig_s *config; + const struct tiva_gptmattr_s *attr; + uint32_t regval; + + DEBUGASSERT(priv && priv->attr && priv->config); + config = priv->config; + attr = priv->attr; + + /* Disable and detach interrupt handlers */ + + up_disable_irq(attr->irq[TIMER16A]); + up_disable_irq(attr->irq[TIMER16B]); + + (void)irq_detach(attr->irq[TIMER16A]); + (void)irq_detach(attr->irq[TIMER16B]); + + /* Reset the time to be certain that it is in the disabled state */ + + regval = tiva_getreg(priv, TIVA_SYSCON_SRTIMER); + regval |= SYSCON_SRTIMER(config->gptm); + tiva_putreg(priv, TIVA_SYSCON_SRTIMER, regval); + + regval &= ~SYSCON_SRTIMER(config->gptm); + tiva_putreg(priv, TIVA_SYSCON_SRTIMER, regval); + + /* Wait for the reset to complete */ + + while (!tiva_emac_periphrdy()); + up_udelay(250); + + /* Disable power and clocking to the GPTM module */ + + tiva_gptm_disableclk(config->gptm); + tiva_gptm_disablepwr(config->gptm); + + /* Un-initialize the state structure */ + + memset(priv, 0, sizeof(struct tiva_gptmstate_s)); +} + /**************************************************************************** * Name: tiva_gptm_putreg * @@ -2083,6 +2142,241 @@ uint32_t tiva_timer16_counter(TIMER_HANDLE handle, int tmndx) return counter; } +/**************************************************************************** + * Name: tiva_timer32_setinterval + * + * Description: + * This function may be called at any time to change the timer interval + * load value of a 32-bit timer. + * + * Input Parameters: + * handle - The handle value returned by tiva_gptm_configure() + * interval - The value to write to the timer interval load register + * + * Returned Value: + * None. + * + ****************************************************************************/ + +void tiva_timer32_setinterval(TIMER_HANDLE handle, uint32_t interval) +{ + struct tiva_gptmstate_s *priv = (struct tiva_gptmstate_s *)handle; + const struct tiva_gptm32config_s *config; + const struct tiva_timer32config_s *timer; + irqstate_t flags; + uintptr_t base; + uintptr_t moder; + uintptr_t loadr; + uintptr_t icrr; + uintptr_t imrr; + uint32_t modev1; + uint32_t modev2; + bool toints; + + DEBUGASSERT(priv && priv->attr && priv->config && + priv->config->mode != TIMER16_MODE); + config = (const struct tiva_gptm32config_s *)priv->config; + timer = &config->config; + + /* Do we need to control timeout interrupts? */ + + base = priv->attr->base; + if (timer->handler && interval > 0 && + (config->cmn.mode == TIMER32_MODE_ONESHOT || + config->cmn.mode == TIMER32_MODE_PERIODIC)) + { + priv->imr |= TIMER_INT_TATO; + toints = true; + } + else + { + priv->imr &= ~TIMER_INT_TATO; + toints = false; + } + + loadr = base + TIVA_TIMER_TAILR_OFFSET; + moder = base + TIVA_TIMER_TAMR_OFFSET; + icrr = base + TIVA_TIMER_ICR_OFFSET; + imrr = base + TIVA_TIMER_IMR_OFFSET; + + /* Make the following atomic */ + + flags = irqsave(); + + /* Set the new timeout interval */ + + putreg32(interval, loadr); + + /* Enable/disable timeout interrupts */ + + if (toints) + { + /* Clearing the TACINTD bit allows the time-out interrupt to be + * generated as normal + */ + + modev1 = tiva_getreg(priv, moder); + modev2 = modev1 & ~TIMER_TnMR_TnCINTD; + putreg32(modev2, moder); + } + else + { + /* Setting the TACINTD bit prevents the time-out interrupt */ + + modev1 = tiva_getreg(priv, moder); + modev2 = modev1 | TIMER_TnMR_TnCINTD; + putreg32(modev2, moder); + + /* Clear any pending timeout interrupts */ + + putreg32(TIMER_INT_TATO, icrr); + } + + /* Set the new interrupt mask */ + + putreg32(priv->imr, imrr); + irqrestore(flags); + +#ifdef CONFIG_TIVA_TIMER_REGDEBUG + /* Generate low-level debug output outside of the critical section */ + + lldbg("%08x<-%08x\n", loadr, interval); + lldbg("%08x->%08x\n", moder, modev1); + lldbg("%08x<-%08x\n", moder, modev2); + if (!toints) + { + lldbg("%08x->%08x\n", icrr, TIMER_INT_TATO); + } + + lldbg("%08x<-%08x\n", imrr, priv->imr); +#endif +} + +/**************************************************************************** + * Name: tiva_timer16_setinterval + * + * Description: + * This function may be called at any time to change the timer interval + * load value of a 16-bit timer. + * + * Input Parameters: + * handle - The handle value returned by tiva_gptm_configure() + * interval - The value to write to the timer interval load register + * tmndx - Either TIMER16A or TIMER16B to select the 16-bit timer + * + * Returned Value: + * None. + * + ****************************************************************************/ + +void tiva_timer16_setinterval(TIMER_HANDLE handle, uint16_t interval, int tmndx) +{ + struct tiva_gptmstate_s *priv = (struct tiva_gptmstate_s *)handle; + const struct tiva_gptm16config_s *config; + const struct tiva_timer16config_s *timer; + irqstate_t flags; + uintptr_t base; + uintptr_t moder; + uintptr_t loadr; + uintptr_t icrr; + uintptr_t imrr; + uint32_t intbit; + uint32_t modev1; + uint32_t modev2; + bool toints; + + DEBUGASSERT(priv && priv->attr && priv->config && + priv->config->mode != TIMER16_MODE); + config = (const struct tiva_gptm16config_s *)priv->config; + timer = &config->config[tmndx]; + + /* Pre-calculate as much as possible outside of the critical section */ + + base = priv->attr->base; + if (tmndx) + { + intbit = TIMER_INT_TBTO; + loadr = base + TIVA_TIMER_TBILR_OFFSET; + moder = base + TIVA_TIMER_TBMR_OFFSET; + } + else + { + intbit = TIMER_INT_TATO; + loadr = base + TIVA_TIMER_TAILR_OFFSET; + moder = base + TIVA_TIMER_TAMR_OFFSET; + } + + icrr = base + TIVA_TIMER_ICR_OFFSET; + imrr = base + TIVA_TIMER_IMR_OFFSET; + + /* Do we need to control timeout interrupts? */ + + if (timer->handler && interval > 0 && + (config->cmn.mode == TIMER16_MODE_ONESHOT || + config->cmn.mode == TIMER16_MODE_PERIODIC)) + { + priv->imr |= intbit; + toints = true; + } + else + { + priv->imr &= ~intbit; + toints = false; + } + + /* Make the following atomic */ + + flags = irqsave(); + + /* Set the new timeout interval */ + + putreg32(interval, loadr); + + /* Enable/disable timeout interrupts */ + + if (toints) + { + /* Clearing the TACINTD bit allows the time-out interrupt to be + * generated as normal + */ + + modev1 = tiva_getreg(priv, moder); + modev2 = modev1 & ~TIMER_TnMR_TnCINTD; + putreg32(modev2, moder); + } + else + { + /* Setting the TACINTD bit prevents the time-out interrupt */ + + modev1 = tiva_getreg(priv, moder); + modev2 = modev1 | TIMER_TnMR_TnCINTD; + putreg32(modev2, moder); + + /* Clear any pending timeout interrupts */ + + putreg32(intbit, icrr); + } + + /* Set the new interrupt mask */ + + putreg32(priv->imr, imrr); + irqrestore(flags); + +#ifdef CONFIG_TIVA_TIMER_REGDEBUG + /* Generate low-level debug output outside of the critical section */ + + lldbg("%08x<-%08x\n", loadr, interval); + lldbg("%08x->%08x\n", moder, modev1); + lldbg("%08x<-%08x\n", moder, modev2); + if (!toints) + { + lldbg("%08x->%08x\n", icrr, intbit); + } + + lldbg("%08x<-%08x\n", imrr, priv->imr); +#endif +} + /**************************************************************************** * Name: tiva_rtc_setalarm * diff --git a/arch/arm/src/tiva/tiva_timer.h b/arch/arm/src/tiva/tiva_timer.h index a7b809c32d..4d5ed1e870 100644 --- a/arch/arm/src/tiva/tiva_timer.h +++ b/arch/arm/src/tiva/tiva_timer.h @@ -47,6 +47,8 @@ #include +#include "up_arch.h" +#include "chip.h" #include "chip/tiva_timer.h" /**************************************************************************** @@ -125,6 +127,20 @@ #define TIMER_ISDMARTCM(c) ((((c)->flags) & TIMER_FLAG_DMARTCM) != 0) #define TIMER_ISDMAMATCH(c) ((((c)->flags) & TIMER_FLAG_DMAMATCH) != 0) +/* Debug ********************************************************************/ +/* Non-standard debug that may be enabled just for testing the timer + * driver. NOTE: that only lldbg types are used so that the output is + * immediately available. + */ + +#ifdef CONFIG_DEBUG_TIMER +# define timdbg lldbg +# define timvdbg llvdbg +#else +# define timdbg(x...) +# define timvdbg(x...) +#endif + /**************************************************************************** * Public Types ****************************************************************************/ @@ -320,6 +336,23 @@ struct tiva_gptm16config_s TIMER_HANDLE tiva_gptm_configure(const struct tiva_gptmconfig_s *gptm); +/**************************************************************************** + * Name: tiva_gptm_release + * + * Description: + * Release resources held by the timer instance. After this function is + * called, the timer handle is invalid and must not be used further. + * + * Input Parameters: + * handle - The handle value returned by tiva_gptm_configure() + * + * Returned Value: + * None. + * + ****************************************************************************/ + +void tiva_gptm_release(TIMER_HANDLE handle); + /**************************************************************************** * Name: tiva_gptm_putreg * @@ -504,61 +537,44 @@ static inline uint32_t tiva_timer32_counter(TIMER_HANDLE handle) uint32_t tiva_timer16_counter(TIMER_HANDLE handle, int tmndx); /**************************************************************************** - * Name: tiva_timer32_setload + * Name: tiva_timer32_setinterval * * Description: * This function may be called at any time to change the timer interval * load value of a 32-bit timer. * * Input Parameters: - * handle - The handle value returned by tiva_gptm_configure() - * load - The value to write to the timer interval load register + * handle - The handle value returned by tiva_gptm_configure() + * interval - The value to write to the timer interval load register * * Returned Value: * None. * ****************************************************************************/ -static inline void tiva_timer32_setload(TIMER_HANDLE handle, uint32_t load) -{ - tiva_gptm_putreg(handle, TIVA_TIMER_TAILR_OFFSET, load); -} +void tiva_timer32_setinterval(TIMER_HANDLE handle, uint32_t interval); /**************************************************************************** - * Name: tiva_timer16_setload + * Name: tiva_timer16_setinterval * * Description: * This function may be called at any time to change the timer interval * load value of a 16-bit timer. * * Input Parameters: - * handle - The handle value returned by tiva_gptm_configure() - * load - The value to write to the timer interval load register - * tmndx - Either TIMER16A or TIMER16B to select the 16-bit timer + * handle - The handle value returned by tiva_gptm_configure() + * interval - The value to write to the timer interval load register + * tmndx - Either TIMER16A or TIMER16B to select the 16-bit timer * * Returned Value: * None. * ****************************************************************************/ -static inline void tiva_timer16_setload(TIMER_HANDLE handle, uint16_t load, - int tmndx) -{ - unsigned int regoffset = - tmndx ? TIVA_TIMER_TBILR_OFFSET : TIVA_TIMER_TAILR_OFFSET; +void tiva_timer16_setinterval(TIMER_HANDLE handle, uint16_t interval, int tmndx); - tiva_gptm_putreg(handle, regoffset, load); -} - -static inline void tiva_timer16a_setload(TIMER_HANDLE handle, uint16_t load) -{ - tiva_gptm_putreg(handle, TIVA_TIMER_TAILR_OFFSET, load); -} - -static inline void tiva_timer16b_setload(TIMER_HANDLE handle, uint16_t load) -{ - tiva_gptm_putreg(handle, TIVA_TIMER_TBILR_OFFSET, load); -} +#define tiva_timer16a_setinterval(h,l) tiva_timer16_setinterval(h,l,TIMER16A) +#define tiva_timer16b_setinterval(h,l) tiva_timer16_setinterval(h,l,TIMER16B) /**************************************************************************** * Name: tiva_timer32_absmatch @@ -768,4 +784,32 @@ static inline void tiva_gptm0_synchronize(uint32_t sync) putreg32(sync, TIVA_TIMER0_SYNC); } +/**************************************************************************** + * Name: tiva_timer_register + * + * Description: + * Bind the configuration timer to a timer lower half instance and + * register the timer drivers at 'devpath' + * + * NOTE: Only 32-bit periodic timers are supported. + * + * Input Parameters: + * devpath - The full path to the timer device. This should be of the form + * /dev/timer0 + * gptm - General purpose timer number + * timeout - Timeout interval in milliseconds. Set to a non-zero value + * to enable timeout interrupts + * altlck - True: Use alternate clock source. + * + * Returned Values: + * Zero (OK) is returned on success; A negated errno value is returned + * to indicate the nature of any failure. + * + ****************************************************************************/ + +#ifdef CONFIG_TIMER +int tiva_timer_register(FAR const char *devpath, int gptm, uint32_t timeout, + bool altclk); +#endif + #endif /* __ARCH_ARM_SRC_TIVA_TIVA_TIMER_H */ diff --git a/arch/arm/src/tiva/tiva_timerlow.c b/arch/arm/src/tiva/tiva_timerlow.c new file mode 100644 index 0000000000..9959d80fee --- /dev/null +++ b/arch/arm/src/tiva/tiva_timerlow.c @@ -0,0 +1,583 @@ +/**************************************************************************** + * arch/arm/src/tiva/tiva_timerlow.c + * + * Copyright (C) 2015 Gregory Nutt. All rights reserved. + * Authors: Gregory Nutt + * + * 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 + +#include + +#include +#include +#include +#include + +#include +#include + +#include + +#include "tiva_timer.h" + +#if defined(CONFIG_TIMER) && defined(CONFIG_TIVA_TIMER) + +/**************************************************************************** + * Pre-Processor Definitions + ****************************************************************************/ + +/**************************************************************************** + * Private Types + ****************************************************************************/ +/* This structure provides the private representation of the "lower-half" + * driver state structure. This structure must be cast-compatible with the + * timer_lowerhalf_s structure. + */ + +struct tiva_lowerhalf_s +{ + const struct timer_ops_s *ops; /* Lower half operations */ + struct tiva_gptm32config_s config; /* Persistent timer configuration */ + TIMER_HANDLE handle; /* Contained timer handle */ + tccb_t handler; /* Current user interrupt handler */ + uint32_t clkin; /* Input clock frequency */ + uint32_t timeout; /* The current timeout value (us) */ + uint32_t clkticks; /* Actual clock ticks for current interval */ + uint32_t adjustment; /* Time lost due to clock resolution truncation (us) */ + bool started; /* True: Timer has been started */ +}; + +/**************************************************************************** + * Private Function Prototypes + ****************************************************************************/ +/* Helper functions *********************************************************/ + +static uint32_t tiva_usec2ticks(struct tiva_lowerhalf_s *priv, uint32_t usecs); +static uint32_t tiva_ticks2usec(struct tiva_lowerhalf_s *priv, uint32_t ticks); + +/* Interrupt handling *******************************************************/ + +static void tiva_handler(TIMER_HANDLE handle, + const struct tiva_gptm32config_s *config, uint32_t status); + +/* "Lower half" driver methods **********************************************/ + +static int tiva_start(struct timer_lowerhalf_s *lower); +static int tiva_stop(struct timer_lowerhalf_s *lower); +static int tiva_getstatus(struct timer_lowerhalf_s *lower, + struct timer_status_s *status); +static int tiva_settimeout(struct timer_lowerhalf_s *lower, + uint32_t timeout); +static tccb_t tiva_sethandler(struct timer_lowerhalf_s *lower, + tccb_t handler); +static int tiva_ioctl(struct timer_lowerhalf_s *lower, int cmd, + unsigned long arg); + +/**************************************************************************** + * Private Data + ****************************************************************************/ +/* "Lower half" driver methods */ + +static const struct timer_ops_s g_timer_ops = +{ + .start = tiva_start, + .stop = tiva_stop, + .getstatus = tiva_getstatus, + .settimeout = tiva_settimeout, + .sethandler = tiva_sethandler, + .ioctl = tiva_ioctl, +}; + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: tiva_usec2ticks + * + * Description: + * Convert microseconds to timer clock ticks. + * + * Input Parameters: + * priv - A pointer to a private timer driver lower half instance + * usecs - The number of usecs to convert + * + * Returned Values: + * The time converted to clock ticks. + * + ****************************************************************************/ + +static uint32_t tiva_usec2ticks(struct tiva_lowerhalf_s *priv, uint32_t usecs) +{ + uint64_t bigticks; + + bigticks = ((uint64_t)usecs * (uint64_t)priv->clkin) / 1000000; + if (bigticks > UINT32_MAX) + { + return UINT32_MAX; + } + + return (uint32_t)bigticks; +} + +/**************************************************************************** + * Name: tiva_ticks2usec + * + * Description: + * Convert timer clock ticks to microseconds. + * + * Input Parameters: + * priv - A pointer to a private timer driver lower half instance + * usecs - The number of ticks to convert + * + * Returned Values: + * The time converted to microseconds. + * + ****************************************************************************/ + +static uint32_t tiva_ticks2usec(struct tiva_lowerhalf_s *priv, uint32_t ticks) +{ + uint64_t bigusec; + + bigusec = (1000000ull * (uint64_t)ticks) / priv->clkin; + if (bigusec > UINT32_MAX) + { + return UINT32_MAX; + } + + return (uint32_t)bigusec; +} + +/**************************************************************************** + * Name: tiva_handler + * + * Description: + * 32-bit timer interrupt handler + * + * Input Parameters: + * Usual 32-bit timer interrupt handler arguments. + * + * Returned Values: + * None + * + ****************************************************************************/ + +static void tiva_handler(TIMER_HANDLE handle, + const struct tiva_gptm32config_s *config, + uint32_t status) +{ + struct tiva_lowerhalf_s *priv; + + timvdbg("Entry\n"); + + /* Check if the timeout interrupt is pending */ +#warning Missing logic + { + uint32_t timeout; + + /* Is there a registered handler? */ + + if (priv->handler && priv->handler(&priv->timeout)) + { + /* Calculate new ticks / dither adjustment */ + + priv->clkticks = tiva_usec2ticks(priv, priv->adjustment + priv->timeout); + + /* Set next interval interval. TODO: make sure the interval is not + * so soon it will be missed! + */ +#warning Missing logic + + /* Calculate the next adjustment */ + + timeout = tiva_ticks2usec(priv, priv->clkticks); + priv->adjustment = (priv->adjustment + priv->timeout) - timeout; + } + else /* stop */ + { + tiva_timer32_stop(priv->handle); + } + } +} + +/**************************************************************************** + * Name: tiva_start + * + * Description: + * Start the 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 tiva_start(struct timer_lowerhalf_s *lower) +{ + struct tiva_lowerhalf_s *priv = (struct tiva_lowerhalf_s *)lower; + + timvdbg("Entry: started %d\n", priv->started); + + /* Has the timer already been started? */ + + if (!priv->started) + { + /* Start the timer */ + + tiva_timer32_start(priv->handle); + priv->started = true; + return OK; + } + + /* Return EBUSY to indicate that the timer was already running */ + + return -EBUSY; +} + +/**************************************************************************** + * Name: tiva_stop + * + * Description: + * Stop the 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 tiva_stop(struct timer_lowerhalf_s *lower) +{ + struct tiva_lowerhalf_s *priv = (struct tiva_lowerhalf_s *)lower; + + timvdbg("Entry: started %d\n", priv->started); + + /* Has the timer already been started? */ + + if (priv->started) + { + /* Stop the timer */ + + tiva_timer32_stop(priv->handle); + priv->started = false; + return OK; + } + + /* Return ENODEV to indicate that the timer was not running */ + + return -ENODEV; +} + +/**************************************************************************** + * Name: tiva_getstatus + * + * Description: + * Get the current timer status + * + * Input Parameters: + * lower - A pointer the publicly visible representation of the "lower-half" + * driver state structure. + * status - The location to return the status information. + * + * Returned Values: + * Zero on success; a negated errno value on failure. + * + ****************************************************************************/ + +static int tiva_getstatus(struct timer_lowerhalf_s *lower, + struct timer_status_s *status) +{ + struct tiva_lowerhalf_s *priv = (struct tiva_lowerhalf_s *)lower; + uint32_t elapsed; + + timvdbg("Entry\n"); + DEBUGASSERT(priv); + + /* Return the status bit */ + + status->flags = 0; + if (priv->started) + { + status->flags |= TCFLAGS_ACTIVE; + } + + if (priv->handler) + { + status->flags |= TCFLAGS_HANDLER; + } + + /* Return the actual timeout in microseconds */ + + status->timeout = priv->timeout; + + /* Get the time remaining until the timer expires (in microseconds) */ + + //elapsed = ; + status->timeleft = ((uint64_t)priv->timeout * elapsed) / (priv->clkticks + 1); /* TODO - check on this +1 */ + + timvdbg(" flags : %08x\n", status->flags); + timvdbg(" timeout : %d\n", status->timeout); + timvdbg(" timeleft : %d\n", status->timeleft); + return OK; +} + +/**************************************************************************** + * Name: tiva_settimeout + * + * Description: + * Set a new timeout value (and reset the timer) + * + * Input Parameters: + * lower - A pointer the publicly visible representation of the "lower-half" + * driver state structure. + * timeout - The new timeout value in microseconds. + * + * Returned Values: + * Zero on success; a negated errno value on failure. + * + ****************************************************************************/ + +static int tiva_settimeout(struct timer_lowerhalf_s *lower, + uint32_t timeout) +{ + struct tiva_lowerhalf_s *priv = (struct tiva_lowerhalf_s *)lower; + + DEBUGASSERT(priv); + + if (priv->started) + { + return -EPERM; + } + + timvdbg("Entry: timeout=%d\n", timeout); + + /* Save the desired timeout value */ + + priv->timeout = timeout; + + /* Calculate the actual timeout value in clock ticks */ + + priv->clkticks = tiva_usec2ticks(priv, timeout); + + /* Calculate an adjustment due to truncation in timer resolution */ + + timeout = tiva_ticks2usec(priv, priv->clkticks); + priv->adjustment = priv->timeout - timeout; + + timvdbg("clkin=%d clkticks=%d timout=%d, adjustment=%d\n", + priv->clkin, priv->clkticks, priv->timeout, priv->adjustment); + + /* Reset the timer interval */ + + tiva_timer32_setinterval(priv->handle, priv->clkticks); + return OK; +} + +/**************************************************************************** + * Name: tiva_sethandler + * + * Description: + * Call this user provided timeout handler. + * + * Input Parameters: + * lower - A pointer the publicly visible representation of the "lower-half" + * driver state structure. + * newhandler - The new timer expiration function pointer. If this + * function pointer is NULL, then the reset-on-expiration + * behavior is restored, + * + * Returned Values: + * The previous timer expiration function pointer or NULL is there was + * no previous function pointer. + * + ****************************************************************************/ + +static tccb_t tiva_sethandler(struct timer_lowerhalf_s *lower, + tccb_t handler) +{ + struct tiva_lowerhalf_s *priv = (struct tiva_lowerhalf_s *)lower; + irqstate_t flags; + tccb_t oldhandler; + + flags = irqsave(); + + DEBUGASSERT(priv); + timvdbg("Entry: handler=%p\n", handler); + + /* Get the old handler return value */ + + oldhandler = priv->handler; + + /* Save the new handler */ + + priv->handler = handler; + + irqrestore(flags); + return oldhandler; +} + +/**************************************************************************** + * Name: tiva_ioctl + * + * Description: + * Any ioctl commands that are not recognized by the "upper-half" driver + * are forwarded to the lower half driver through this method. + * + * Input Parameters: + * lower - A pointer the publicly visible representation of the "lower-half" + * driver state structure. + * cmd - The ioctl command value + * arg - The optional argument that accompanies the 'cmd'. The + * interpretation of this argument depends on the particular + * command. + * + * Returned Values: + * Zero on success; a negated errno value on failure. + * + ****************************************************************************/ + +static int tiva_ioctl(struct timer_lowerhalf_s *lower, int cmd, + unsigned long arg) +{ + struct tiva_lowerhalf_s *priv = (struct tiva_lowerhalf_s *)lower; + int ret = -ENOTTY; + + DEBUGASSERT(priv); + timvdbg("Entry: cmd=%d arg=%ld\n", cmd, arg); + + return ret; +} + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: tiva_timer_register + * + * Description: + * Bind the configuration timer to a timer lower half instance and + * register the timer drivers at 'devpath' + * + * NOTE: Only 32-bit periodic timers are supported. + * + * Input Parameters: + * devpath - The full path to the timer device. This should be of the form + * /dev/timer0 + * gptm - General purpose timer number + * timeout - Timeout interval in microseconds. Set to a non-zero value + * to enable timeout interrupts + * altlck - True: Use alternate clock source. + * + * Returned Values: + * Zero (OK) is returned on success; A negated errno value is returned + * to indicate the nature of any failure. + * + ****************************************************************************/ + +int tiva_timer_register(const char *devpath, int gptm, uint32_t timeout, + bool altclk) +{ + struct tiva_lowerhalf_s *priv; + struct tiva_gptm32config_s *config; + void *rethandle; + + DEBUGASSERT(devpath); + timvdbg("Entry: devpath=%s\n", devpath); + + /* Allocate an instance of the lower half state structure */ + + priv = (struct tiva_lowerhalf_s *)kmm_zalloc(sizeof(struct tiva_lowerhalf_s)); + if (!priv) + { + timdbg("ERROR: Failed to allocate driver structure\n"); + return -ENOMEM; + } + + /* Initialize the non-zero elements of lower half state structure */ + + priv->ops = &g_timer_ops; + priv->clkin = altclk ? ALTCLK_FREQUENCY : SYSCLK_FREQUENCY; + priv->timeout = timeout; + + config = &priv->config; + config->cmn.gptm = gptm; + config->cmn.mode = TIMER32_MODE_PERIODIC; + config->cmn.alternate = altclk; + config->config.flags = TIMER_FLAG_COUNTUP; + config->config.handler = tiva_handler; + config->config.u.periodic.interval = tiva_usec2ticks(priv, timeout); + + /* Create the timer handle */ + + priv->handle = tiva_gptm_configure((const struct tiva_gptmconfig_s *)&priv->config); + if (!priv->handle) + { + timdbg("ERROR: Failed to create timer handle\n"); + return -EINVAL; + } + + /* Register the timer driver as /dev/timerX. The returned value from + * timer_register is a handle that could be used with timer_unregister(). + * REVISIT: The returned handle is discard here. + */ + + rethandle = timer_register(devpath, (struct timer_lowerhalf_s *)priv); + if (!rethandle) + { + /* Free the allocated state structure */ + + kmm_free(priv); + + /* The actual cause of the failure may have been a failure to allocate + * perhaps a failure to register the timer driver (such as if the + * 'depath' were not unique). We know here but we return EEXIST to + * indicate the failure (implying the non-unique devpath). + */ + + return -EEXIST; + } + + return OK; +} + +#endif /* CONFIG_TIMER && CONFIG_TIVA_TIMER */