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Diffstat (limited to 'src/gadc/sys_defs.h')
| -rw-r--r-- | src/gadc/sys_defs.h | 270 |
1 files changed, 270 insertions, 0 deletions
diff --git a/src/gadc/sys_defs.h b/src/gadc/sys_defs.h new file mode 100644 index 00000000..f6349dfe --- /dev/null +++ b/src/gadc/sys_defs.h @@ -0,0 +1,270 @@ +/* + * 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 src/gadc/sys_defs.h + * + * @addtogroup GADC + * + * @brief Module to abstract the very variable ADC interfaces of the underlying systems + * + * @details The reason why ChibiOS/GFX has it's own ADC abstraction is because + * the Chibi-OS drivers are very CPU specific and do not + * provide a way across all hardware platforms to create periodic + * ADC conversions. There are also issues with devices with different + * characteristics or periodic requirements on the same ADC + * device (but different channels). This layer attempts to solve these + * problems to provide a architecture neutral API. It also provides extra + * features such as multi-buffer chaining for high speed ADC sources. + * It provides one high speed virtual ADC device (eg a microphone) and + * numerous low speed (less than 100Hz) virtual ADC devices (eg dials, + * temperature sensors etc). The high speed device has timer based polling + * to ensure exact conversion periods and a buffer management system. + * The low speed devices are assumed to be non-critical timing devices + * and do not have any buffer management. + * Note that while only one high speed device has been provided it can + * be used to read multiple physical ADC channels on the one physical + * ADC device. + * All callback routines are thread based unlike the Chibi-OS interrupt based + * routines. + * + * @{ + */ + +#ifndef _GADC_H +#define _GADC_H + +#include "gfx.h" + +#if GFX_USE_GADC || defined(__DOXYGEN__) + +/* Include the driver defines */ +#include "gadc_lld_config.h" + +/*===========================================================================*/ +/* Type definitions */ +/*===========================================================================*/ + +// Event types for GADC +#define GEVENT_ADC (GEVENT_GADC_FIRST+0) + +/** + * @brief The High Speed ADC event structure. + * @{ + */ +typedef struct GEventADC_t { + #if GFX_USE_GEVENT || defined(__DOXYGEN__) + /** + * @brief The type of this event (GEVENT_ADC) + */ + GEventType type; + #endif + + /** + * @brief The event flags + */ + uint16_t flags; + /** + * @brief The event flag values. + * @{ + */ + #define GADC_HSADC_LOSTEVENT 0x0001 /**< @brief The last GEVENT_HSDADC event was lost */ + /** @} */ + /** + * @brief The number of conversions in the buffer + */ + size_t count; + /** + * @brief The buffer containing the conversion samples + */ + adcsample_t *buffer; +} GEventADC; +/** @} */ + +/** + * @brief A callback function (executed in a thread context) for a low speed conversion + */ +typedef void (*GADCCallbackFunction)(adcsample_t *buffer, void *param); + +/** + * @brief A callback function (executed in an ISR context) for a high speed conversion + */ +typedef void (*GADCISRCallbackFunction)(adcsample_t *buffer, size_t size); + +/*===========================================================================*/ +/* External declarations. */ +/*===========================================================================*/ + +#ifdef __cplusplus +extern "C" { +#endif + +/** + * @brief Initialise the high speed ADC. + * @details Initialises but does not start the 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 + * @param[in] buffer The static buffer to put the ADC samples into. + * @param[in] bufcount The total number of conversions that will fit in the buffer. + * @param[in] samplesPerEvent The number of conversions to do before returning an event. + * + * @note If the high speed ADC is running it will be stopped. The Event subsystem is + * disconnected from the high speed ADC and any binary semaphore event is forgotten. + * @note bufcount must be greater than countPerEvent (usually 2 or more times) otherwise + * the buffer will be overwritten with new data while the application is still trying + * to process the old data. + * @note Due to a bug/feature in Chibi-OS countPerEvent must be even. If bufcount is not + * evenly divisable by countPerEvent, the remainder must also be even. + * @note The physdev parameter may be used to turn on more than one ADC channel. + * Each channel is then interleaved into the provided buffer. Note 'bufcount' + * and 'countPerEvent' parameters describe the number of conversions not the + * number of samples. + * As an example, if physdev turns on 2 devices then the buffer contains + * alternate device samples and the buffer must contain 2 * bufcount samples. + * The exact meaning of physdev is hardware dependent. + * @note The buffer is circular. When the end of the buffer is reached it will start + * putting data into the beginning of the buffer again. + * @note The event listener must process the event (and the data in it) before the + * next event occurs. If not, the following event will be lost. + * @note If bufcount is evenly divisable by countPerEvent, then every event will return + * countPerEvent conversions. If bufcount is not evenly divisable, it will return + * a block of samples containing less than countPerEvent samples when it reaches the + * end of the buffer. + * @note While the high speed ADC is running, low speed conversions can only occur at + * the frequency of the high speed events. Thus if high speed events are + * being created at 50Hz (eg countPerEvent = 100, frequency = 5kHz) then the maximum + * frequency for low speed conversions will be 50Hz. + * + * @api + */ +void gadcHighSpeedInit(uint32_t physdev, uint32_t frequency, adcsample_t *buffer, size_t bufcount, size_t samplesPerEvent); + +#if GFX_USE_GEVENT || defined(__DOXYGEN__) + /** + * @brief Turn on sending results to the GEVENT sub-system. + * @details Returns a GSourceHandle to listen for GEVENT_ADC events. + * + * @note The high speed ADC will not use the GEVENT system unless this is + * called first. This saves processing time if the application does + * not want to use the GEVENT sub-system for the high speed ADC. + * Once turned on it can only be turned off by calling @p gadcHighSpeedInit() again. + * @note The high speed ADC is capable of signalling via this method, an ISR callback and a + * binary semaphore at the same time. + * + * @return The GSourceHandle + * + * @api + */ + GSourceHandle gadcHighSpeedGetSource(void); +#endif + +/** + * @brief Allow retrieving of results from the high speed ADC using an ISR callback. + * + * @param[in] isrfn The callback function (called in an ISR context). + * + * @note Passing a NULL for isrfn will turn off signalling via this method as will calling + * @p gadcHighSpeedInit(). + * @note The high speed ADC is capable of signalling via this method, a binary semaphore and the GEVENT + * sub-system at the same time. + * + * @api + */ +void gadcHighSpeedSetISRCallback(GADCISRCallbackFunction isrfn); + +/** + * @brief Allow retrieving of results from the high speed ADC using a Binary Semaphore and a static event buffer. + * + * @param[in] pbsem The semaphore is signaled when data is available. + * @param[in] pEvent The static event buffer to place the result information. + * + * @note Passing a NULL for pbsem or pEvent will turn off signalling via this method as will calling + * @p gadcHighSpeedInit(). + * @note The high speed ADC is capable of signalling via this method, an ISR callback and the GEVENT + * sub-system at the same time. + * + * @api + */ +void gadcHighSpeedSetBSem(gfxSem *pbsem, GEventADC *pEvent); + +/** + * @brief Start the high speed ADC conversions. + * @pre It must have been initialised first with @p gadcHighSpeedInit() + * + * @api + */ +void gadcHighSpeedStart(void); + +/** + * @brief Stop the high speed ADC conversions. + * + * @api + */ +void gadcHighSpeedStop(void); + +/** + * @brief Perform a single low speed ADC conversion + * @details Blocks until the conversion is complete + * @pre This should not be called from within a GTimer callback as this routine + * blocks until the conversion is ready. + * + * @param[in] physdev A value passed to describe which physical ADC devices/channels to use. + * @param[in] buffer The static buffer to put the ADC samples into. + * + * @note This may take a while to complete if the high speed ADC is running as the + * conversion is interleaved with the high speed ADC conversions on a buffer + * completion. + * @note The result buffer must be large enough to store one sample per device + * described by the 'physdev' parameter. + * @note If calling this routine would exceed @p GADC_MAX_LOWSPEED_DEVICES simultaneous low + * speed devices, the routine will wait for an available slot to complete the + * conversion. + * @note Specifying more than one device in physdev is possible but discouraged as the + * calculations to ensure the high speed ADC correctness will be incorrect. Symptoms + * from over-running the high speed ADC include high speed samples being lost. + * + * @api + */ +void gadcLowSpeedGet(uint32_t physdev, adcsample_t *buffer); + +/** + * @brief Perform a low speed ADC conversion with callback (in a thread context) + * @details Returns FALSE if there are no free low speed ADC slots. See @p GADC_MAX_LOWSPEED_DEVICES for details. + * + * @param[in] physdev A value passed to describe which physical ADC devices/channels to use. + * @param[in] buffer The static buffer to put the ADC samples into. + * @param[in] fn The callback function to call when the conversion is complete. + * @param[in] param A parameter to pass to the callback function. + * + * @return FALSE if no free low speed ADC slots. + * + * @note This may be safely called from within a GTimer callback. + * @note The callback may take a while to occur if the high speed ADC is running as the + * conversion is interleaved with the high speed ADC conversions on a buffer + * completion. + * @note The result buffer must be large enough to store one sample per device + * described by the 'physdev' parameter. + * @note As this routine uses a low speed ADC, it asserts if you try to run more than @p GADC_MAX_LOWSPEED_DEVICES + * at the same time. + * @note Specifying more than one device in physdev is possible but discouraged as the + * calculations to ensure the high speed ADC correctness will be incorrect. Symptoms + * from over-running the high speed ADC include high speed samples being lost. + * + * @api + */ +bool_t gadcLowSpeedStart(uint32_t physdev, adcsample_t *buffer, GADCCallbackFunction fn, void *param); + +#ifdef __cplusplus +} +#endif + +#endif /* GFX_USE_GADC */ + +#endif /* _GADC_H */ +/** @} */ + |