diff options
Diffstat (limited to 'os/hal/ports/KINETIS/LLD/adc_lld.c')
-rw-r--r-- | os/hal/ports/KINETIS/LLD/adc_lld.c | 258 |
1 files changed, 258 insertions, 0 deletions
diff --git a/os/hal/ports/KINETIS/LLD/adc_lld.c b/os/hal/ports/KINETIS/LLD/adc_lld.c new file mode 100644 index 000000000..d226519ff --- /dev/null +++ b/os/hal/ports/KINETIS/LLD/adc_lld.c @@ -0,0 +1,258 @@ +/* + ChibiOS/HAL - Copyright (C) 2014 Derek Mulcahy + + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this file except in compliance with the License. + You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. +*/ + +/** + * @file KINETIS/LLD/adc_lld.c + * @brief KINETIS ADC subsystem low level driver source. + * + * @addtogroup ADC + * @{ + */ + +#include "hal.h" + +#if HAL_USE_ADC || defined(__DOXYGEN__) + +/*===========================================================================*/ +/* Driver local definitions. */ +/*===========================================================================*/ + +#define ADC_CHANNEL_MASK 0x1f + +/*===========================================================================*/ +/* Driver exported variables. */ +/*===========================================================================*/ + +/** @brief ADC1 driver identifier.*/ +#if KINETIS_ADC_USE_ADC0 || defined(__DOXYGEN__) +ADCDriver ADCD1; +#endif + +/*===========================================================================*/ +/* Driver local variables and types. */ +/*===========================================================================*/ + +/*===========================================================================*/ +/* Driver local functions. */ +/*===========================================================================*/ + +static void calibrate(ADCDriver *adcp) { + + /* Clock Divide by 8, Use Bus Clock Div 2 */ + /* At 48MHz this results in ADCCLK of 48/8/2 == 3MHz */ + adcp->adc->CFG1 = ADCx_CFG1_ADIV(ADCx_CFG1_ADIV_DIV_8) | + ADCx_CFG1_ADICLK(ADCx_CFG1_ADIVCLK_BUS_CLOCK_DIV_2); + + /* Use software trigger and disable DMA etc. */ + adcp->adc->SC2 = 0; + + /* Enable Hardware Average, Average 32 Samples, Calibrate */ + adcp->adc->SC3 = ADCx_SC3_AVGE | + ADCx_SC3_AVGS(ADCx_SC3_AVGS_AVERAGE_32_SAMPLES) | + ADCx_SC3_CAL; + + /* FIXME: May take several ms. Use an interrupt instead of busy wait */ + /* Wait for calibration completion */ + while (!(adcp->adc->SC1A & ADCx_SC1n_COCO)) + ; + + uint16_t gain = ((adcp->adc->CLP0 + adcp->adc->CLP1 + adcp->adc->CLP2 + + adcp->adc->CLP3 + adcp->adc->CLP4 + adcp->adc->CLPS) / 2) | 0x8000; + adcp->adc->PG = gain; + + gain = ((adcp->adc->CLM0 + adcp->adc->CLM1 + adcp->adc->CLM2 + + adcp->adc->CLM3 + adcp->adc->CLM4 + adcp->adc->CLMS) / 2) | 0x8000; + adcp->adc->MG = gain; + +} + +/*===========================================================================*/ +/* Driver interrupt handlers. */ +/*===========================================================================*/ + +#if KINETIS_ADC_USE_ADC0 || defined(__DOXYGEN__) +/** + * @brief ADC interrupt handler. + * + * @isr + */ +OSAL_IRQ_HANDLER(KINETIS_ADC0_IRC_VECTOR) { + OSAL_IRQ_PROLOGUE(); + + ADCDriver *adcp = &ADCD1; + + /* Disable Interrupt, Disable Channel */ + adcp->adc->SC1A = ADCx_SC1n_ADCH(ADCx_SC1n_ADCH_DISABLED); + + /* Read the sample into the buffer */ + adcp->samples[adcp->current_index++] = adcp->adc->RA; + + bool more = true; + + /* At the end of the buffer then we may be finished */ + if (adcp->current_index == adcp->number_of_samples) { + _adc_isr_full_code(&ADCD1); + + adcp->current_index = 0; + + /* We are never finished in circular mode */ + more = ADCD1.grpp->circular; + } + + if (more) { + + /* Signal half completion in circular mode. */ + if (ADCD1.grpp->circular && + (adcp->current_index == (adcp->number_of_samples / 2))) { + + _adc_isr_half_code(&ADCD1); + } + + /* Skip to the next channel */ + do { + adcp->current_channel = (adcp->current_channel + 1) & ADC_CHANNEL_MASK; + } while (((1 << adcp->current_channel) & adcp->grpp->channel_mask) == 0); + + /* Enable Interrupt, Select the Channel */ + adcp->adc->SC1A = ADCx_SC1n_AIEN | ADCx_SC1n_ADCH(adcp->current_channel); + } + + OSAL_IRQ_EPILOGUE(); +} +#endif + +/*===========================================================================*/ +/* Driver exported functions. */ +/*===========================================================================*/ + +/** + * @brief Low level ADC driver initialization. + * + * @notapi + */ +void adc_lld_init(void) { + +#if KINETIS_ADC_USE_ADC0 + /* Driver initialization.*/ + adcObjectInit(&ADCD1); +#endif + + /* The shared vector is initialized on driver initialization and never + disabled.*/ + nvicEnableVector(ADC0_IRQn, KINETIS_ADC_IRQ_PRIORITY); +} + +/** + * @brief Configures and activates the ADC peripheral. + * + * @param[in] adcp pointer to the @p ADCDriver object + * + * @notapi + */ +void adc_lld_start(ADCDriver *adcp) { + + /* If in stopped state then enables the ADC clock.*/ + if (adcp->state == ADC_STOP) { + SIM->SCGC6 |= SIM_SCGC6_ADC0; + +#if KINETIS_ADC_USE_ADC0 + if (&ADCD1 == adcp) { + adcp->adc = ADC0; + if (adcp->config->calibrate) { + calibrate(adcp); + } + } +#endif /* KINETIS_ADC_USE_ADC0 */ + } +} + +/** + * @brief Deactivates the ADC peripheral. + * + * @param[in] adcp pointer to the @p ADCDriver object + * + * @notapi + */ +void adc_lld_stop(ADCDriver *adcp) { + + /* If in ready state then disables the ADC clock.*/ + if (adcp->state == ADC_READY) { + SIM->SCGC6 &= ~SIM_SCGC6_ADC0; + +#if KINETIS_ADC_USE_ADC0 + if (&ADCD1 == adcp) { + /* Disable Interrupt, Disable Channel */ + adcp->adc->SC1A = ADCx_SC1n_ADCH(ADCx_SC1n_ADCH_DISABLED); + } +#endif + } +} + +/** + * @brief Starts an ADC conversion. + * + * @param[in] adcp pointer to the @p ADCDriver object + * + * @notapi + */ +void adc_lld_start_conversion(ADCDriver *adcp) { + const ADCConversionGroup *grpp = adcp->grpp; + + /* Enable the Bandgap Buffer if channel mask includes BANDGAP */ + if (grpp->channel_mask & ADC_BANDGAP) { + PMC->REGSC |= PMC_REGSC_BGBE; + } + + adcp->number_of_samples = adcp->depth * grpp->num_channels; + adcp->current_index = 0; + + /* Skip to the next channel */ + adcp->current_channel = 0; + while (((1 << adcp->current_channel) & grpp->channel_mask) == 0) { + adcp->current_channel = (adcp->current_channel + 1) & ADC_CHANNEL_MASK; + } + + /* Set clock speed and conversion size */ + adcp->adc->CFG1 = grpp->cfg1; + + /* Set averaging */ + adcp->adc->SC3 = grpp->sc3; + + /* Enable Interrupt, Select Channel */ + adcp->adc->SC1A = ADCx_SC1n_AIEN | ADCx_SC1n_ADCH(adcp->current_channel); +} + +/** + * @brief Stops an ongoing conversion. + * + * @param[in] adcp pointer to the @p ADCDriver object + * + * @notapi + */ +void adc_lld_stop_conversion(ADCDriver *adcp) { + const ADCConversionGroup *grpp = adcp->grpp; + + /* Disable the Bandgap buffer if channel mask includes BANDGAP */ + if (grpp->channel_mask & ADC_BANDGAP) { + /* Clear BGBE, ACKISO is w1c, avoid setting */ + PMC->REGSC &= ~(PMC_REGSC_BGBE | PMC_REGSC_ACKISO); + } + +} + +#endif /* HAL_USE_ADC */ + +/** @} */ |