From 9bec5967b293d6c23c9d7e9338d8ece4873f6eac Mon Sep 17 00:00:00 2001 From: Andrew Hannam Date: Mon, 18 Feb 2013 17:33:35 +1000 Subject: GADC implementation with demo program Also includes driver for AT91SAM7 cpu --- include/gadc/lld/gadc_lld.h | 190 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 190 insertions(+) create mode 100644 include/gadc/lld/gadc_lld.h (limited to 'include/gadc/lld') diff --git a/include/gadc/lld/gadc_lld.h b/include/gadc/lld/gadc_lld.h new file mode 100644 index 00000000..f9cc8b47 --- /dev/null +++ b/include/gadc/lld/gadc_lld.h @@ -0,0 +1,190 @@ +/* + ChibiOS/GFX - Copyright (C) 2012, 2013 + Joel Bodenmann aka Tectu + + This file is part of ChibiOS/GFX. + + ChibiOS/GFX 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; either version 3 of the License, or + (at your option) any later version. + + ChibiOS/GFX 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, see . +*/ +/** + * @file include/gadc/lld/gadc_lld.h + * @brief GADC - Periodic ADC driver header file. + * + * @defgroup Driver Driver + * @ingroup GADC + * @{ + */ + +#ifndef _GADC_LLD_H +#define _GADC_LLD_H + +#include "gfx.h" + +#if GFX_USE_GADC || defined(__DOXYGEN__) + +/*===========================================================================*/ +/* Type definitions */ +/*===========================================================================*/ + +/** + * @brief The structure passed to start a timer conversion + * @note We use the structure instead of parameters purely to save + * interrupt stack space which is very limited in some platforms. + * @{ + */ +typedef struct GadcLldTimerData_t { + uint32_t physdev; /* @< A value passed to describe which physical ADC devices/channels to use. */ + adcsample_t *buffer; /* @< The static buffer to put the ADC samples into. */ + size_t count; /* @< The number of conversions to do before doing a callback and stopping the ADC. */ + bool_t now; /* @< Trigger the first conversion now rather than waiting for the first timer interrupt (if possible) */ + } GadcLldTimerData; +/* @} */ + +/** + * @brief The structure passed to start a non-timer conversion + * @note We use the structure instead of parameters purely to save + * interrupt stack space which is very limited in some platforms. + * @{ + */ +typedef struct GadcLldNonTimerData_t { + uint32_t physdev; /* @< A value passed to describe which physical ADC devices/channels to use. */ + adcsample_t *buffer; /* @< The static buffer to put the ADC samples into. */ + } GadcLldNonTimerData; +/* @} */ + +/** + * @brief These routines are the callbacks that the driver uses. + * @details Defined in the high level GADC code. + * + * @notapi + * @{ + */ +extern void GADC_ISR_CompleteI(ADCDriver *adcp, adcsample_t *buffer, size_t n); +extern void GADC_ISR_ErrorI(ADCDriver *adcp, adcerror_t err); +/** + * @} + */ + +/** + * @brief This can be incremented by the low level driver if a timer interrupt is missed. + * @details Defined in the high level GADC code. + * + * @notapi + */ +extern volatile bool_t GADC_Timer_Missed; + +/*===========================================================================*/ +/* External declarations. */ +/*===========================================================================*/ + +#ifdef __cplusplus +extern "C" { +#endif + +/** + * @brief Initialise the driver + * + * @api + */ +void gadc_lld_init(void); + +/** + * @brief Get the number of samples in a conversion. + * @details Calculates and returns the number of samples per conversion for the specified physdev. + * + * @param[in] physdev A value passed to describe which physical ADC devices/channels to use. + * + * @note A physdev describing a mono device would return 1, a stereo device would return 2. + * For most ADC's physdev is a bitmap so it is only a matter of counting the bits. + * + * @api + */ +size_t gadc_lld_samples_per_conversion(uint32_t physdev); + +/** + * @brief Start a periodic timer for high frequency conversions. + * + * @param[in] physdev A value passed to describe which physical ADC devices/channels to use. + * @param[in] frequency The frequency to create ADC conversions + * + * @note The exact meaning of physdev is hardware dependent. It describes the channels + * the will be used later on when a "timer" conversion is actually scheduled. + * @note It is assumed that the timer is capable of free-running even when the ADC + * is stopped or doing something else. + * @details When a timer interrupt occurs a conversion should start if these is a "timer" conversion + * active. + * @note If the ADC is stopped, doesn't have a "timer" conversion active or is currently executing + * a non-timer conversion then the interrupt can be ignored other than (optionally) incrementing + * the GADC_Timer_Missed variable. + * + * @api + */ +void gadc_lld_start_timer(uint32_t physdev, uint32_t frequency); + +/** + * @brief Stop the periodic timer for high frequency conversions. + * @details Also stops any current "timer" conversion (but not a current "non-timer" conversion). + * + * @param[in] physdev A value passed to describe which physical ADC devices/channels in use. + * + * @note The exact meaning of physdev is hardware dependent. + * + * @api + */ +void gadc_lld_stop_timer(uint32_t physdev); + +/** + * @brief Start a "timer" conversion. + * @details Starts a series of conversions triggered by the timer. + * + * @param[in] pgtd Contains the parameters for the timer conversion. + * + * @note The exact meaning of physdev is hardware dependent. It is likely described in the + * drivers gadc_lld_config.h + * @note Some versions of ChibiOS actually call the callback function more than once, once + * at the half-way point and once on completion. The high level code handles this. + * @note The driver should call @p GADC_ISR_CompleteI() when it completes the operation + * (or at the half-way point), or @p GAD_ISR_ErrorI() on an error. + * @note The high level code ensures that this is not called while a non-timer conversion is in + * progress + * + * @iclass + */ +void gadc_lld_adc_timerI(GadcLldTimerData *pgtd); + +/** + * @brief Start a "non-timer" conversion. + * @details Starts a single conversion now. + * + * @param[in] pgntd Contains the parameters for the non-timer conversion. + * + * @note The exact meaning of physdev is hardware dependent. It is likely described in the + * drivers gadc_lld_config.h + * @note The driver should call @p GADC_ISR_CompleteI() when it completes the operation + * or @p GAD_ISR_ErrorI() on an error. + * @note The high level code ensures that this is not called while a timer conversion is in + * progress + * + * @iclass + */ +void gadc_lld_adc_nontimerI(GadcLldNonTimerData *pgntd); + +#ifdef __cplusplus +} +#endif + +#endif /* GFX_USE_GADC */ + +#endif /* _GADC_LLD_H */ +/** @} */ -- cgit v1.2.3