Diff: targets/hal/TARGET_Freescale/TARGET_KPSDK_MCUS/TARGET_KPSDK_CODE/drivers/pit/src/fsl_pit_driver.c

Revision:

168:cf9372ac0a74

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/hal/TARGET_Freescale/TARGET_KPSDK_MCUS/TARGET_KPSDK_CODE/drivers/pit/src/fsl_pit_driver.c	Thu Apr 24 10:45:06 2014 +0100
@@ -0,0 +1,242 @@
+/*
+ * Copyright (c) 2013 - 2014, Freescale Semiconductor, Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * o Redistributions of source code must retain the above copyright notice, this list
+ *   of conditions and the following disclaimer.
+ *
+ * o 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.
+ *
+ * o Neither the name of Freescale Semiconductor, Inc. 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 HOLDER 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.
+ */
+ 
+#include "fsl_pit_driver.h"
+#include "fsl_clock_manager.h"
+#include "fsl_interrupt_manager.h"
+
+/*******************************************************************************
+ * Variables
+ ******************************************************************************/
+
+/* pit source clock variable which will be updated in pit_init_module. */
+uint64_t pitSourceClock;
+
+/* Table to save PIT IRQ enum numbers defined in CMSIS files. This table is 
+ * defined in fsl_pit_irq.c */
+extern IRQn_Type pit_irq_ids[FSL_FEATURE_PIT_TIMER_COUNT];
+
+/*******************************************************************************
+ * Code
+ ******************************************************************************/
+
+/*FUNCTION**********************************************************************
+ *
+ * Function Name : pit_init_module
+ * Description   : Initialize PIT module.
+ * This function must be called before calling all the other PIT driver functions.
+ * This function un-gates the PIT clock and enables the PIT module. The isRunInDebug
+ * passed into function will affect all timer channels. 
+ *
+ *END**************************************************************************/
+void pit_init_module(bool isRunInDebug)
+{
+    uint32_t busClock;
+
+    /* Un-gate pit clock*/
+    clock_manager_set_gate(kClockModulePIT, 0U, true);
+
+    /* Enable PIT module clock*/
+    pit_hal_enable();
+
+    /* Set timer run or stop in debug mode*/
+    pit_hal_configure_timer_run_in_debug(isRunInDebug);
+   
+    /* Finally, update pit source clock frequency.*/
+    clock_manager_get_frequency(kBusClock, &busClock);    
+    pitSourceClock = (uint64_t)busClock;
+}
+
+/*FUNCTION**********************************************************************
+ *
+ * Function Name : pit_init_channel
+ * Description   : Initialize PIT channel.
+ * This function initialize PIT timers by channel. Pass in timer number and its
+ * config structure. Timers do not start counting by default after calling this
+ * function. Function pit_timer_start must be called to start timer counting. 
+ * Call pit_set_timer_period_us to re-set the period.
+ *
+ *END**************************************************************************/
+void pit_init_channel(uint32_t timer, const pit_user_config_t * config)
+{
+    /* Set timer period.*/
+    pit_set_timer_period_us(timer, config->periodUs);
+
+    #if FSL_FEATURE_PIT_HAS_CHAIN_MODE
+    /* Configure timer chained or not.*/
+    pit_hal_configure_timer_chain(timer, config->isTimerChained);
+    #endif
+
+    /* Enable or disable interrupt.*/
+    pit_hal_configure_interrupt(timer, config->isInterruptEnabled);
+
+    /* Configure NVIC*/
+    if (config->isInterruptEnabled)
+    {
+        /* Enable PIT interrupt.*/
+        interrupt_enable(pit_irq_ids[timer]);
+    }
+}
+
+/*FUNCTION**********************************************************************
+ *
+ * Function Name : pit_shutdown 
+ * Description   : Disable PIT module and gate control
+ * This function will disable all PIT interrupts and PIT clock. Then gate the
+ * PIT clock control. pit_init must be called in order to use PIT again.
+ * 
+ *END**************************************************************************/
+void pit_shutdown(void)
+{
+    uint32_t i;
+
+    /* Disable all PIT interrupts. */
+    for (i=0; i < FSL_FEATURE_PIT_TIMER_COUNT; i++)
+    {
+        pit_hal_configure_interrupt(i, false);
+        interrupt_disable(pit_irq_ids[i]);
+    }
+
+    /* Disable PIT module clock*/
+    pit_hal_disable();
+
+    /* Gate PIT clock control*/
+    clock_manager_set_gate(kClockModulePIT, 0U, false);
+}
+
+/*FUNCTION**********************************************************************
+ *
+ * Function Name : pit_timer_start
+ * Description   : Start timer counting.
+ * After calling this function, timers load period value, count down to 0 and
+ * then load the respective start value again. Each time a timer reaches 0,
+ * it will generate a trigger pulse and set the timeout interrupt flag.
+ * 
+ *END**************************************************************************/
+void pit_timer_start(uint32_t timer)
+{
+    pit_hal_timer_start(timer);
+}
+
+/*FUNCTION**********************************************************************
+ *
+ * Function Name : pit_timer_stop
+ * Description   : Stop timer counting.
+ * This function will stop every timer counting. Timers will reload their periods
+ * respectively after calling pit_timer_start next time.
+ *
+ *END**************************************************************************/
+void pit_timer_stop(uint32_t timer)
+{
+    pit_hal_timer_stop(timer);
+}
+
+/*FUNCTION**********************************************************************
+ *
+ * Function Name : pit_set_timer_period_us
+ * Description   : Set timer period in microseconds unit.
+ * The period range depends on the frequency of PIT source clock. If required
+ * period is out the range, try to use lifetime timer if applicable. 
+ *
+ *END**************************************************************************/
+void pit_set_timer_period_us(uint32_t timer, uint32_t us)
+{
+    /* Calculate the count value, assign it to timer counter register.*/
+    uint32_t count = (uint32_t)(us * pitSourceClock / 1000000U - 1U);
+    pit_hal_set_timer_period_count(timer, count);
+}
+
+/*FUNCTION**********************************************************************
+ *
+ * Function Name : pit_read_timer_us
+ * Description   : Read current timer value in microseconds unit.
+ * This function will return an absolute time stamp in the unit of microseconds.
+ * One common use of this function is to measure the running time of part of
+ * code. Just call this function at both the beginning and end of code, the time
+ * difference between these two time stamp will be the running time (Need to 
+ * make sure the running time will not exceed the timer period). Also, the time
+ * stamp returned is up-counting.
+ *
+ *END**************************************************************************/
+uint32_t pit_read_timer_us(uint32_t timer)
+{
+    /* Get current timer count, and reverse it to up-counting.*/
+    uint64_t currentTime = (~pit_hal_read_timer_count(timer));
+
+    /* Convert count numbers to microseconds unit.*/
+    currentTime = (currentTime * 1000000U) / pitSourceClock;
+    return (uint32_t)currentTime;
+}
+
+#if FSL_FEATURE_PIT_HAS_LIFETIME_TIMER
+/*FUNCTION**********************************************************************
+ *
+ * Function Name : pit_set_lifetime_timer_period_us
+ * Description   : Set lifetime timer period (Timers must be chained).
+ * Timer 1 must be chained with timer 0 before using lifetime timer. The period
+ * range is restricted by "period * pitSourceClock < max of an uint64_t integer",
+ * or it may cause a overflow and is not able to set correct period.
+ *
+ *END**************************************************************************/
+void pit_set_lifetime_timer_period_us(uint64_t us)
+{
+    uint64_t lifeTimeCount;
+    
+    /* Calculate the counter value.*/
+    lifeTimeCount = us * pitSourceClock / 1000000U - 1U;
+
+    /* Assign to timers.*/
+    pit_hal_set_timer_period_count(0U, (uint32_t)lifeTimeCount);
+    pit_hal_set_timer_period_count(1U, (uint32_t)(lifeTimeCount >> 32U));
+}
+
+/*FUNCTION**********************************************************************
+ *
+ * Function Name : pit_read_lifetime_timer_us
+ * Description   : Read current lifetime value in microseconds unit.
+ * Return an absolute time stamp in the unit of microseconds. The time stamp 
+ * value will not exceed the timer period. Also, the timer is up-counting.
+ *
+ *END**************************************************************************/
+uint64_t pit_read_lifetime_timer_us(void)
+{
+    /* Get current lifetime timer count, and reverse it to up-counting.*/
+    uint64_t currentTime = (~pit_hal_read_lifetime_timer_count());
+
+    /* Convert count numbers to microseconds unit.*/
+    /* Note: using currentTime * 1000 rather than 1000000 to avoid short time overflow. */
+    return currentTime = (currentTime * 1000U) / (pitSourceClock / 1000U);
+}
+#endif /* FSL_FEATURE_PIT_HAS_LIFETIME_TIMER*/
+
+/*******************************************************************************
+ * EOF
+ ******************************************************************************/
+