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/*
* This file is subject to the terms of the GFX License. If a copy of
* the license was not distributed with this file, you can obtain one at:
*
* http://ugfx.org/license.html
*/
/**
* @file drivers/gadc/AT91SAM7/gadc_lld.c
* @brief GADC - Periodic ADC driver source file for the AT91SAM7 cpu.
*/
#include "gfx.h"
#if GFX_USE_GADC
#include "src/gadc/driver.h"
static GDataBuffer *pData;
static size_t bytesperconversion;
static void ISR_CompleteI(ADCDriver *adcp, adcsample_t *buffer, size_t n);
static void ISR_ErrorI(ADCDriver *adcp, adcerror_t err);
static ADCConversionGroup acg = {
FALSE, // circular
1, // num_channels
ISR_CompleteI, // end_cb
ISR_ErrorI, // error_cb
0, // channelselects
0, // trigger
0, // frequency
};
static void ISR_CompleteI(ADCDriver *adcp, adcsample_t *buffer, size_t n) {
(void) adcp;
(void) buffer;
if (pData) {
// A set of timer base conversions is complete
pData->len += n * bytesperconversion;
// Are we finished yet?
// In ChibiOS we (may) get a half-buffer complete. In this situation the conversions
// are really not complete and so we just wait for the next lot of data.
if (pData->len + bytesperconversion > pData->size)
gadcDataReadyI();
} else {
// A single non-timer conversion is complete
gadcDataReadyI();
}
}
static void ISR_ErrorI(ADCDriver *adcp, adcerror_t err) {
(void) adcp;
(void) err;
gadcDataFailI();
}
void gadc_lld_init(void) {
adcStart(&ADCD1, 0);
}
void gadc_lld_start_timer(GadcLldTimerData *pgtd) {
int phys;
/* Calculate the bytes per conversion from physdev */
/* The AT91SAM7 has AD0..7 - physdev is a bitmap of those channels */
phys = pgtd->physdev;
for(bytesperconversion = 0; phys; phys >>= 1)
if (phys & 0x01)
bytesperconversion++;
bytesperconversion *= (gfxSampleFormatBits(GADC_SAMPLE_FORMAT)+7)/8;
/**
* The AT91SAM7 ADC driver supports triggering the ADC using a timer without having to implement
* an interrupt handler for the timer. The driver also initialises the timer correctly for us.
* Because we aren't trapping the interrupt ourselves we can't increment GADC_Timer_Missed if an
* interrupt is missed.
*/
acg.frequency = pgtd->frequency;
}
void gadc_lld_stop_timer(GadcLldTimerData *pgtd) {
(void) pgtd;
if ((acg.trigger & ~ADC_TRIGGER_SOFTWARE) == ADC_TRIGGER_TIMER)
adcStop(&ADCD1);
}
void gadc_lld_adc_timerI(GadcLldTimerData *pgtd) {
/**
* We don't need to calculate num_channels because the AT91SAM7 ADC does this for us.
*/
acg.channelselects = pgtd->physdev;
acg.trigger = pgtd->now ? (ADC_TRIGGER_TIMER|ADC_TRIGGER_SOFTWARE) : ADC_TRIGGER_TIMER;
pData = pgtd->pdata;
adcStartConversionI(&ADCD1, &acg, (adcsample_t *)(pgtd->pdata+1), pData->size/bytesperconversion);
/* Next time assume the same (still running) timer */
acg.frequency = 0;
}
void gadc_lld_adc_nontimerI(GadcLldNonTimerData *pgntd) {
/**
* We don't need to calculate num_channels because the AT91SAM7 ADC does this for us.
*/
acg.channelselects = pgntd->physdev;
acg.trigger = ADC_TRIGGER_SOFTWARE;
pData = 0;
adcStartConversionI(&ADCD1, &acg, pgntd->buffer, 1);
}
#endif /* GFX_USE_GADC */
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