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/**
* \file
*
* \brief SAM Frequency Meter (FREQM) Driver
*
* Copyright (C) 2015-2016 Atmel Corporation. All rights reserved.
*
* \asf_license_start
*
* \page License
*
* 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. The name of Atmel may not be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* 4. This software may only be redistributed and used in connection with an
* Atmel microcontroller product.
*
* THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
* EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL 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.
*
* \asf_license_stop
*
*/
/*
* Support and FAQ: visit <a href="http://www.atmel.com/design-support/">Atmel Support</a>
*/
#include "freqm.h"
#include <gclk.h>
#ifndef FREQM_GCLK_ID_REF
#define FREQM_GCLK_ID_REF (FREQM_GCLK_ID_MSR + 1)
#endif
/**
* \brief Initializes a hardware FREQM module instance.
*
* Enables the clock and initializes the FREQM module, based on the given
* configuration values.
*
* \param[in,out] module_inst Pointer to the software module instance struct
* \param[in] hw Pointer to the FREQM hardware module
* \param[in] config Pointer to the FREQM configuration options struct
*
* \return Status of the initialization procedure.
*
* \retval STATUS_OK The module was initialized successfully
*/
enum status_code freqm_init(
struct freqm_module *const module_inst,
Freqm *const hw,
struct freqm_config *const config)
{
/* Sanity check arguments */
Assert(module_inst);
Assert(hw);
Assert(config);
Assert(config->ref_clock_circles);
/* Initialize device instance */
module_inst->hw = hw;
/* Turn on the digital interface clock */
system_apb_clock_set_mask(SYSTEM_CLOCK_APB_APBA, MCLK_APBAMASK_FREQM);
/* Set up the GCLK for the module */
struct system_gclk_chan_config gclk_chan_conf;
system_gclk_chan_get_config_defaults(&gclk_chan_conf);
gclk_chan_conf.source_generator = config->msr_clock_source;
system_gclk_chan_set_config(FREQM_GCLK_ID_MSR, &gclk_chan_conf);
system_gclk_chan_enable(FREQM_GCLK_ID_MSR);
gclk_chan_conf.source_generator = config->ref_clock_source;
system_gclk_chan_set_config(FREQM_GCLK_ID_REF, &gclk_chan_conf);
system_gclk_chan_enable(FREQM_GCLK_ID_REF);
module_inst->ref_clock_freq = system_gclk_gen_get_hz(config->ref_clock_source);
/* Perform a software reset */
hw->CTRLA.reg = FREQM_CTRLA_SWRST;
while (freqm_is_syncing()) {
/* Wait for all hardware modules to complete synchronization */
}
/* Initialize the FREQM with new configurations */
hw->CFGA.reg = config->ref_clock_circles;
#if FREQM_CALLBACK_MODE == true
/* Initialize parameters */
for (uint8_t i = 0; i < FREQM_CALLBACK_N; i++) {
module_inst->callback[i] = NULL;
}
/* Register this instance for callbacks*/
_freqm_instance = module_inst;
#endif
return STATUS_OK;
}
/**
* \brief Read the measurement data result
*
* Reads the measurement data result.
*
* \param[in] module_inst Pointer to the FREQM software instance struct
* \param[out] result Pointer to store the result value in
*
* \return Status of the FREQM read request.
* \retval FREQM_STATUS_MEASURE_DONE Measurement result was retrieved successfully
* \retval FREQM_STATUS_MEASURE_BUSY Measurement result was not ready
* \retval FREQM_STATUS_CNT_OVERFLOW Measurement result was overflow
*
* \note If overflow occurred, configure faster reference clock or reduce reference clock cycles.
*/
enum freqm_status freqm_get_result_value(
struct freqm_module *const module_inst, uint32_t *result)
{
/* Sanity check arguments */
Assert(module_inst);
Assert(module_inst->hw);
Assert(result);
Freqm *const freqm_hw = module_inst->hw;
uint32_t result_cal;
*result = result_cal= 0;
if (freqm_hw->STATUS.reg & FREQM_STATUS_BUSY) {
/* Result not ready */
return FREQM_STATUS_MEASURE_BUSY;
} else {
if (freqm_hw->STATUS.reg & FREQM_STATUS_OVF) {
/* Overflow */
return FREQM_STATUS_CNT_OVERFLOW;
} else {
/* Get measurement output data (it will clear data done flag) */
result_cal = freqm_hw->VALUE.reg;
freqm_hw->INTFLAG.reg = FREQM_INTFLAG_DONE;
*result = result_cal * module_inst->ref_clock_freq / freqm_hw->CFGA.reg;
return FREQM_STATUS_MEASURE_DONE;
}
}
}
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