/*
 * Copyright © 2012 Keith Packard <keithp@keithp.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
 */

#ifndef _AO_ADC_H_
#define _AO_ADC_H_



/*
 * One set of samples read from the A/D converter or telemetry
 */


/*
 * ao_adc.c
 */

#define ao_adc_ring_next(n)	(((n) + 1) & (AO_ADC_RING - 1))
#define ao_adc_ring_prev(n)	(((n) - 1) & (AO_ADC_RING - 1))


/*
 * A/D data is stored in a ring, with the next sample to be written
 * at ao_adc_head
 */
extern volatile __xdata struct ao_adc	ao_adc_ring[AO_ADC_RING];
extern volatile __data uint8_t		ao_adc_head;
#if HAS_ACCEL_REF
extern volatile __xdata uint16_t	ao_accel_ref[AO_ADC_RING];
#endif

/* Trigger a conversion sequence (called from the timer interrupt) */
void
ao_adc_poll(void);

/* Suspend the current task until another A/D sample is converted */
void
ao_adc_sleep(void);

/* Get a copy of the last complete A/D sample set */
void
ao_adc_get(__xdata struct ao_adc *packet);

/* Initialize the A/D converter */
void
ao_adc_init(void);

#endif /* _AO_ADC_H_ */