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/*
ChibiOS/RT - Copyright (C) 2006-2013 Giovanni Di Sirio
LPC17xx ADC driver - Copyright (C) 2013 Marcin Jokel
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 LPC17xx/adc_lld.c
* @brief LPC17xx ADC subsystem low level driver source.
* @note Values in samples buffer are from DR register.
* To get ADC values make conversion (DR >> 6) & 0x03FF.
* DMA only support one ADC channel.
* @addtogroup ADC
* @{
*/
#include "ch.h"
#include "hal.h"
#if HAL_USE_ADC || defined(__DOXYGEN__)
/*===========================================================================*/
/* Driver local definitions. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver exported variables. */
/*===========================================================================*/
/** @brief ADC1 driver identifier.*/
ADCDriver ADCD1;
/*===========================================================================*/
/* Driver local variables and types. */
/*===========================================================================*/
static lpc17xx_dma_lli_config_t lpc_adc_lli[2] __attribute__((aligned(0x10)));
/*===========================================================================*/
/* Driver local functions. */
/*===========================================================================*/
#if LPC17xx_ADC_USE_DMA
/**
* @brief Common IRQ handler.
*
* @param[in] adcp pointer to the @p ADCDriver object
*/
static void adc_serve_dma_interrupt(ADCDriver *adcp, uint32_t flags) {
(void) flags;
if ((flags & (1 << LPC17xx_ADC_DMA_CHANNEL)) != 0) {
_adc_isr_error_code(adcp, flags); /* DMA errors handling.*/
}
else if (adcp->half_buffer == false) {
_adc_isr_half_code(adcp);
adcp->half_buffer = true;
}
else {
_adc_isr_full_code(adcp);
adcp->half_buffer = false;
}
}
#endif
/*===========================================================================*/
/* Driver interrupt handlers. */
/*===========================================================================*/
/**
* @brief ADC interrupt handler.
*
* @isr
*/
CH_IRQ_HANDLER(Vector98) {
uint32_t status;
uint32_t n;
uint8_t i;
CH_IRQ_PROLOGUE();
status = LPC_ADC->STAT;
n = ADCD1.num;
/* Note, an overrun may occur only in burst mode, if one or more
conversions was (were) lost. */
if ((status & ADC0STAT_OVERRUN_MASK)) {
if (ADCD1.grpp != NULL)
_adc_isr_error_code(&ADCD1, ADC_ERR_OVERRUN);
}
else {
status = status & ADC0STAT_DONE_MASK;
for (i = 0; i < ADC_MAX_CHANNELS; i++) {
if (status & (0x01 << i)) {
ADCD1.samples[n] = LPC_ADC->DR[i];
n++;
}
}
if (n == (ADCD1.nsamples / 2)) {
_adc_isr_half_code(&ADCD1);
}
if (n == ADCD1.nsamples) {
n = 0;
_adc_isr_full_code(&ADCD1);
}
}
ADCD1.num = n;
CH_IRQ_EPILOGUE();
}
/*===========================================================================*/
/* Driver exported functions. */
/*===========================================================================*/
/**
* @brief Low level ADC driver initialization.
*
* @notapi
*/
void adc_lld_init(void) {
/* Driver initialization.*/
adcObjectInit(&ADCD1);
ADCD1.adc = LPC_ADC;
#if LPC17xx_ADC_USE_DMA
nvicDisableVector(ADC_IRQn);
#else
nvicEnableVector(ADC_IRQn, CORTEX_PRIORITY_MASK(LPC17xx_ADC_IRQ_PRIORITY));
#endif
}
/**
* @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. */
if (adcp->state == ADC_STOP) {
LPC_SC->PCONP |= (1UL << 12); /* Enable ADC power */
#if LPC17xx_ADC_USE_DMA
dmaChannelAllocate(LPC17xx_ADC_DMA_CHANNEL, \
(lpc17xx_dmaisr_t)adc_serve_dma_interrupt, \
(void *)adcp);
#endif
}
}
/**
* @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) {
adcp->adc->CR = 0; /* Clear PDN bit */
LPC_SC->PCONP &= ~(1UL << 12); /* Disable ADC power */
#if LPC17xx_ADC_USE_DMA
dmaChannelRelease(LPC17xx_ADC_DMA_CHANNEL);
#endif
}
}
/**
* @brief Starts an ADC conversion.
*
* @param[in] adcp pointer to the @p ADCDriver object
*
* @notapi
*/
void adc_lld_start_conversion(ADCDriver *adcp) {
uint32_t dummy;
uint32_t cr;
uint8_t i;
#if LPC17xx_ADC_USE_DMA
uint32_t dma_ch_config;
uint8_t ch;
#endif
cr = adcp->grpp->cr0;
adcp->num = 0;
adcp->nsamples = adcp->depth * adcp->grpp->num_channels;
for (i = 0; i < ADC_MAX_CHANNELS; i++) {
dummy = adcp->adc->DR[i]; /* Clear all DONE and OVERRUN flags. */
}
#if LPC17xx_ADC_USE_DMA
adcp->half_buffer = false;
ch = 0;
for (i = 0; i < 8; i++) {
if (cr & (1UL << i)) {
ch = i; /* Get number of first enabled channel. */
break;
}
}
/* DMA configuration */
lpc_adc_lli[0].srcaddr = (uint32_t)&adcp->adc->DR[ch];
lpc_adc_lli[0].dstaddr = (uint32_t)&adcp->samples[0];
lpc_adc_lli[0].lli = (uint32_t) &lpc_adc_lli[1];
lpc_adc_lli[0].control =
DMA_CTRL_TRANSFER_SIZE(adcp->nsamples/2) |
DMA_CTRL_SRC_BSIZE_1 |
DMA_CTRL_DST_BSIZE_1 |
DMA_CTRL_SRC_WIDTH_WORD |
DMA_CTRL_DST_WIDTH_WORD |
DMA_CTRL_SRC_NOINC |
DMA_CTRL_DST_INC |
DMA_CTRL_PROT1_USER |
DMA_CTRL_PROT2_NONBUFF |
DMA_CTRL_PROT3_NONCACHE |
DMA_CTRL_INT;
lpc_adc_lli[1].srcaddr = lpc_adc_lli[0].srcaddr;
lpc_adc_lli[1].dstaddr = (uint32_t)&adcp->samples[adcp->nsamples/2];
lpc_adc_lli[1].control = lpc_adc_lli[0].control;
if (adcp->grpp->circular == true) {
lpc_adc_lli[1].lli = (uint32_t) &lpc_adc_lli[0];
}
else {
lpc_adc_lli[1].lli = 0;
}
dma_ch_config =
DMA_CFG_CH_ENABLE |
DMA_CFG_SRC_PERIPH(DMA_ADC) |
DMA_CFG_TTYPE_P2M |
DMA_CFG_IE |
DMA_CFG_ITC;
dmaChannelSrcAddr(LPC17xx_ADC_DMA_CHANNEL, lpc_adc_lli[0].srcaddr);
dmaChannelDstAddr(LPC17xx_ADC_DMA_CHANNEL, lpc_adc_lli[0].dstaddr);
dmaChannelLinkedList(LPC17xx_ADC_DMA_CHANNEL, lpc_adc_lli[0].lli);
dmaChannelControl(LPC17xx_ADC_DMA_CHANNEL, lpc_adc_lli[0].control);
dmaChannelConfig(LPC17xx_ADC_DMA_CHANNEL, dma_ch_config);
#endif
/* ADC configuration and conversion start. */
adcp->adc->INTEN = adcp->grpp->inten; /* Set ADC interrupt on selected channels */
adcp->adc->CR = (cr & 0x0000FFFF) | ((LPC17xx_ADC_CLKDIV - 1) << 8) | AD0CR_PDN;
adcp->adc->CR |= cr & 0xFFFF0000;
}
/**
* @brief Stops an ongoing conversion.
*
* @param[in] adcp pointer to the @p ADCDriver object
*
* @notapi
*/
void adc_lld_stop_conversion(ADCDriver *adcp) {
#if LPC17xx_ADC_USE_DMA
dmaChannelDisable(LPC17xx_ADC_DMA_CHANNEL);
#endif
adcp->adc->CR &= ~(AD0CR_MODE_BURST | AD0CR_START_MASK); /* Disable ADC conversion. */
adcp->adc->INTEN = 0; /* Mask ADC interrupts. */
}
#endif /* HAL_USE_ADC */
/** @} */
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