New Subsystems GADC, GAUDIN, GAUDOUT, GMISC

Subsystem definitions and API (not fully implemented yet)

1 files changed, 250 insertions, 0 deletions

diff --git a/include/gadc/gadc.h b/include/gadc/gadc.h
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+/*

+    ChibiOS/GFX - Copyright (C) 2012

+                 Joel Bodenmann aka Tectu <joel@unormal.org>

+

+    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 <http://www.gnu.org/licenses/>.

+*/

+/**

+ * @file    include/gadc/gadc.h

+ * @brief   GADC - Periodic ADC subsystem header file.

+ *

+ * @addtogroup GADC

+ *

+ * @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 {

+	/**

+	 * @brief The type of this event (GEVENT_ADC)

+	 */

+	GEventType		type;

+	/**

+	 * @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)

+ */

+typedef void (*GADCCallbackFunction)(adcsample_t *buffer, void *param);

+

+/*===========================================================================*/

+/* 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] countPerEvent	The number of conversions to do before returning an event.

+ *

+ * @note				If the high speed ADC is running it will be stopped.

+ * @note				Due to a bug 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 is likely to be 50Hz (although it might be

+ * 						100Hz on some hardware).

+ *

+ * @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 cannot be turned off.

+	 * @note				The high speed ADC is capable of signalling via this method and a binary semaphore

+	 * 						at the same time.

+	 *

+	 * @api

+	 */

+	GSourceHandle gadcHighSpeedGetSource(void);

+#endif

+

+/**

+ * @brief				Allow retrieving of results from the high speed ADC using a Binary Semaphore and a static event buffer.

+ *

+ * @param[in] pbsem			The binary 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.

+ * @note				The high speed ADC is capable of signalling via this method and the GEVENT

+ * 						sub-system at the same time.

+ *

+ * @api

+ */

+void gadcHighSpeedSetBSem(BinarySemaphore *pbsem, GEventADC *pEvent);

+

+/**

+ * @brief   Start the high speed ADC conversions.

+ * @pre		It must have been initialised first with @p gadcHighSpeedInit()

+ *

+ * @api

+ */

+GSourceHandle 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.

+ *

+ * @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 gadcLowSpeedStart(uint32_t physdev, adcsample_t *buffer, GADCCallbackFunction fn, void *param);

+

+#ifdef __cplusplus

+}

+#endif

+

+#endif /* GFX_USE_GADC */

+

+#endif /* _GADC_H */

+/** @} */

+