/**************************************************************************** * arch/arm/src/sam34/sam_tc.c * * Copyright (C) 2014 Gregory Nutt. All rights reserved. * Authors: Gregory Nutt * Bob Dioron * * 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 "up_arch.h" #include "sam_tc.h" #include "sam_periphclks.h" #if defined(CONFIG_TIMER) && (defined(CONFIG_SAM34_TC0) || \ defined(CONFIG_SAM34_TC1) || defined(CONFIG_SAM34_TC2) || \ defined(CONFIG_SAM34_TC3) || defined(CONFIG_SAM34_TC4) || \ defined(CONFIG_SAM34_TC5)) /**************************************************************************** * Pre-Processor Definitions ****************************************************************************/ /* Clocking *****************************************************************/ /* TODO: Allow selection of any of the input clocks */ #define TC_FCLK (BOARD_SCLK_FREQUENCY) #define TC_MAXTIMEOUT ((1000000ULL * (1ULL + TC_RVALUE_MASK)) / TC_FCLK) /* Configuration ************************************************************/ /* 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 tcdbg lldbg # define tcvdbg llvdbg #else # define tcdbg(x...) # define tcvdbg(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 * timer_lowerhalf_s structure. */ struct sam34_lowerhalf_s { FAR const struct timer_ops_s *ops; /* Lower half operations */ /* Private data */ uint32_t base; /* Base address of the timer */ tccb_t handler; /* Current user interrupt handler */ uint32_t timeout; /* The current timeout value (us) */ uint32_t adjustment; /* time lost due to clock resolution truncation (us) */ uint32_t clkticks; /* actual clock ticks for current interval */ bool started; /* The timer has been started */ uint16_t periphid; /* peripheral id */ }; /**************************************************************************** * Private Function Prototypes ****************************************************************************/ /* Register operations ******************************************************/ #if defined(CONFIG_SAM34_TC_REGDEBUG) && defined(CONFIG_DEBUG) static uint32_t sam34_getreg(uint32_t addr); static void sam34_putreg(uint32_t val, uint32_t addr); #else # define sam34_getreg(addr) getreg32(addr) # define sam34_putreg(val,addr) putreg32(val,addr) #endif /* Interrupt handling *******************************************************/ static int sam34_interrupt(int irq, FAR void *context); /* "Lower half" driver methods **********************************************/ static int sam34_start(FAR struct timer_lowerhalf_s *lower); static int sam34_stop(FAR struct timer_lowerhalf_s *lower); static int sam34_getstatus(FAR struct timer_lowerhalf_s *lower, FAR struct timer_status_s *status); static int sam34_settimeout(FAR struct timer_lowerhalf_s *lower, uint32_t timeout); static tccb_t sam34_sethandler(FAR struct timer_lowerhalf_s *lower, tccb_t handler); static int sam34_ioctl(FAR struct timer_lowerhalf_s *lower, int cmd, unsigned long arg); /**************************************************************************** * Private Data ****************************************************************************/ /* "Lower half" driver methods */ static const struct timer_ops_s g_tcops = { .start = sam34_start, .stop = sam34_stop, .getstatus = sam34_getstatus, .settimeout = sam34_settimeout, .sethandler = sam34_sethandler, .ioctl = sam34_ioctl, }; /* "Lower half" driver state */ /* TODO - allocating all 6 now, even though we might not need them. * May want to allocate the right number to not be wasteful. */ static struct sam34_lowerhalf_s g_tcdevs[6]; /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: sam34_getreg * * Description: * Get the contents of a register * ****************************************************************************/ #if defined(CONFIG_SAM34_TC_REGDEBUG) && defined(CONFIG_DEBUG) static uint32_t sam34_getreg(uint32_t addr) { static uint32_t prevaddr = 0; static uint32_t count = 0; static uint32_t preval = 0; /* Read the value from the register */ uint32_t val = getreg32(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("%08lx->%08lx\n", addr, val); return val; } #endif /**************************************************************************** * Name: sam34_putreg * * Description: * Set the contents of an SAM34 register to a value * ****************************************************************************/ #if defined(CONFIG_SAM34_TC_REGDEBUG) && defined(CONFIG_DEBUG) static void sam34_putreg(uint32_t val, uint32_t addr) { /* Show the register value being written */ lldbg("%08lx<-%08lx\n", addr, val); /* Write the value */ putreg32(val, addr); } #endif /**************************************************************************** * Name: sam34_interrupt * * Description: * TC interrupt * * Input Parameters: * Usual interrupt handler arguments. * * Returned Values: * Always returns OK. * ****************************************************************************/ static int sam34_interrupt(int irq, FAR void *context) { FAR struct sam34_lowerhalf_s *priv = &g_tcdevs[irq-SAM_IRQ_TC0]; tcvdbg("Entry\n"); DEBUGASSERT((irq >= SAM_IRQ_TC0) && (irq <= SAM_IRQ_TC5)); /* Check if the interrupt is really pending */ if ((sam34_getreg(priv->base + SAM_TC_SR_OFFSET) & TC_INT_CPCS) != 0) { uint32_t timeout; /* Is there a registered handler? */ if (priv->handler && priv->handler(&priv->timeout)) { /* Calculate new ticks / dither adjustment */ priv->clkticks = ((uint64_t)(priv->adjustment + priv->timeout))*TC_FCLK / 1000000; /* Set next interval interval. TODO: make sure the interval is not so soon it will be missed! */ sam34_putreg(priv->clkticks, priv->base + SAM_TC_RC_OFFSET); timeout = (1000000ULL * priv->clkticks) / TC_FCLK; /* trucated timeout */ priv->adjustment = (priv->adjustment + priv->timeout) - timeout; /* truncated time to be added to next interval (dither) */ } else /* stop */ { sam34_stop((FAR struct timer_lowerhalf_s *)priv); } /* TC_INT_CPCS is cleared by reading SAM_TCx_SR */ } return OK; } /**************************************************************************** * Name: sam34_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 sam34_start(FAR struct timer_lowerhalf_s *lower) { FAR struct sam34_lowerhalf_s *priv = (FAR struct sam34_lowerhalf_s *)lower; uint32_t mr_val; tcvdbg("Entry\n"); DEBUGASSERT(priv); if (priv->started) { return -EINVAL; } sam_enableperiph0(priv->periphid); /* Enable peripheral clock */ sam34_putreg(TC_CCR_CLKDIS, priv->base + SAM_TC_CCR_OFFSET); /* Disable counter */ sam34_putreg(0, priv->base + SAM_TC_CV_OFFSET); /* clear counter */ /* TC_CMR_WAVE - waveform mode * TC_CMR_WAVSEL_UPAUTO - reset on RC compare (interval timer) * TC_CMR_TCCLKS_TIMERCLOCK5 = SCLK */ mr_val = (TC_CMR_WAVE + TC_CMR_WAVSEL_UPAUTO + TC_CMR_TCCLKS_TIMERCLOCK5); sam34_putreg(mr_val, priv->base + SAM_TC_CMR_OFFSET); sam34_putreg(priv->clkticks, priv->base + SAM_TC_RC_OFFSET); /* Set interval */ if (priv->handler) { /* Clear status and enable interrupt */ sam34_getreg(priv->base + SAM_TC_SR_OFFSET); /* Clear status */ sam34_putreg(TC_INT_CPCS, priv->base + SAM_TC_IER_OFFSET); /* Enable interrupt */ } sam34_putreg(TC_CCR_SWTRG + TC_CCR_CLKEN, priv->base + SAM_TC_CCR_OFFSET); /* Start counter */ priv->started = true; return OK; } /**************************************************************************** * Name: sam34_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 sam34_stop(FAR struct timer_lowerhalf_s *lower) { FAR struct sam34_lowerhalf_s *priv = (FAR struct sam34_lowerhalf_s *)lower; tcvdbg("Entry\n"); DEBUGASSERT(priv); if (!priv->started) { return -EINVAL; } sam34_putreg(TC_CCR_CLKDIS, priv->base + SAM_TC_CCR_OFFSET); /* Disable counter */ sam34_putreg(TC_INT_ALL, priv->base + SAM_TC_IDR_OFFSET); /* Disable all ints */ sam_disableperiph0(priv->periphid); /* Disable peripheral clock */ priv->started = false; return OK; } /**************************************************************************** * Name: sam34_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 sam34_getstatus(FAR struct timer_lowerhalf_s *lower, FAR struct timer_status_s *status) { FAR struct sam34_lowerhalf_s *priv = (FAR struct sam34_lowerhalf_s *)lower; uint32_t elapsed; tcvdbg("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 is milliseconds */ status->timeout = priv->timeout; /* Get the time remaining until the timer expires (in microseconds) */ elapsed = sam34_getreg(priv->base + SAM_TC_CV_OFFSET); status->timeleft = ((uint64_t)priv->timeout * elapsed) / (priv->clkticks + 1); /* TODO - check on this +1 */ tcvdbg(" flags : %08x\n", status->flags); tcvdbg(" timeout : %d\n", status->timeout); tcvdbg(" timeleft : %d\n", status->timeleft); return OK; } /**************************************************************************** * Name: sam34_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 milliseconds. * * Returned Values: * Zero on success; a negated errno value on failure. * ****************************************************************************/ static int sam34_settimeout(FAR struct timer_lowerhalf_s *lower, uint32_t timeout) { FAR struct sam34_lowerhalf_s *priv = (FAR struct sam34_lowerhalf_s *)lower; DEBUGASSERT(priv); if (priv->started) { return -EPERM; } tcvdbg("Entry: timeout=%d\n", timeout); /* Can this timeout be represented? */ if (timeout < 1 || timeout > TC_MAXTIMEOUT) { tcdbg("Cannot represent timeout=%lu > %lu\n", timeout, TC_MAXTIMEOUT); return -ERANGE; } priv->timeout = timeout; /* Intended timeout */ priv->clkticks = (((uint64_t)timeout * TC_FCLK) / 1000000); /* Actual clock ticks */ timeout = (1000000ULL * priv->clkticks) / TC_FCLK; /* Truncated timeout */ priv->adjustment = priv->timeout - timeout; /* Truncated time to be added to next interval (dither) */ tcvdbg("fclk=%d clkticks=%d timout=%d, adjustment=%d\n", TC_FCLK, priv->clkticks, priv->timeout, priv->adjustment); return OK; } /**************************************************************************** * Name: sam34_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 sam34_sethandler(FAR struct timer_lowerhalf_s *lower, tccb_t handler) { FAR struct sam34_lowerhalf_s *priv = (FAR struct sam34_lowerhalf_s *)lower; irqstate_t flags; tccb_t oldhandler; flags = irqsave(); DEBUGASSERT(priv); tcvdbg("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: sam34_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 sam34_ioctl(FAR struct timer_lowerhalf_s *lower, int cmd, unsigned long arg) { FAR struct sam34_lowerhalf_s *priv = (FAR struct sam34_lowerhalf_s *)lower; int ret = -ENOTTY; DEBUGASSERT(priv); tcvdbg("Entry: cmd=%d arg=%ld\n", cmd, arg); return ret; } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: sam_tcinitialize * * Description: * Initialize the timer. The timer is initialized and * registers as 'devpath'. * * Input Parameters: * devpath - The full path to the timer. This should be of the form * /dev/tc0 * * Returned Values: * None * ****************************************************************************/ void sam_tcinitialize(FAR const char *devpath, int irq) { FAR struct sam34_lowerhalf_s *priv = &g_tcdevs[irq-SAM_IRQ_TC0]; tcvdbg("Entry: devpath=%s\n", devpath); DEBUGASSERT((irq >= SAM_IRQ_TC0) && (irq <= SAM_IRQ_TC5)); /* Initialize the driver state structure. Here we assume: (1) the state * structure lies in .bss and was zeroed at reset time. (2) This function * is only called once so it is never necessary to re-zero the structure. */ switch(irq) { #if defined(CONFIG_SAM34_TC0) case SAM_IRQ_TC0: priv->base = SAM_TC0_BASE; priv->periphid = SAM_PID_TC0; break; #endif #if defined(CONFIG_SAM34_TC1) case SAM_IRQ_TC1: priv->base = SAM_TC1_BASE; priv->periphid = SAM_PID_TC1; break; #endif #if defined(CONFIG_SAM34_TC2) case SAM_IRQ_TC2: priv->base = SAM_TC2_BASE; priv->periphid = SAM_PID_TC2; break; #endif #if defined(CONFIG_SAM34_TC3) case SAM_IRQ_TC3: priv->base = SAM_TC3_BASE; priv->periphid = SAM_PID_TC3; break; #endif #if defined(CONFIG_SAM34_TC4) case SAM_IRQ_TC4: priv->base = SAM_TC4_BASE; priv->periphid = SAM_PID_TC4; break; #endif #if defined(CONFIG_SAM34_TC5) case SAM_IRQ_TC5: priv->base = SAM_TC5_BASE; priv->periphid = SAM_PID_TC5; break; #endif default: ASSERT(0); } priv->ops = &g_tcops; (void)irq_attach(irq, sam34_interrupt); /* Enable NVIC interrupt. */ up_enable_irq(irq); /* Register the timer driver as /dev/timerX */ (void)timer_register(devpath, (FAR struct timer_lowerhalf_s *)priv); } #endif /* CONFIG_TIMER && CONFIG_SAM34_TCx */