/** * \file * * \brief SAM Event System Driver * * Copyright (C) 2012-2016 Atmel Corporation. All rights reserved. * * \asf_license_start * * \page License * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * 1. Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * * 3. The name of Atmel may not be used to endorse or promote products derived * from this software without specific prior written permission. * * 4. This software may only be redistributed and used in connection with an * Atmel microcontroller product. * * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * * \asf_license_stop * */ /* * Support and FAQ: visit Atmel Support */ #ifndef EVENTS_H_INCLUDED #define EVENTS_H_INCLUDED #ifdef __cplusplus extern "C" { #endif /** * \defgroup asfdoc_sam0_events_group SAM Event System (EVENTS) Driver * * This driver for Atmel® | SMART ARM®-based microcontrollers provides * an interface for the configuration and management of the device's peripheral * event resources and users within the device, including enabling and disabling * of peripheral source selection and synchronization of clock domains between * various modules. The following API modes is covered by this manual: * - Polled API * \if EVENTS_INTERRUPT_HOOK_MODE * - Interrupt hook API * \endif * * The following peripheral is used by this module: * - EVSYS (Event System Management) * * The following devices can use this module: * - Atmel | SMART SAM D20/D21 * - Atmel | SMART SAM R21 * - Atmel | SMART SAM D09/D10/D11 * - Atmel | SMART SAM L21/L22 * - Atmel | SMART SAM DA1 * - Atmel | SMART SAM C20/C21 * - Atmel | SMART SAM R30 * * The outline of this documentation is as follows: * - \ref asfdoc_sam0_events_prerequisites * - \ref asfdoc_sam0_events_module_overview * - \ref asfdoc_sam0_events_special_considerations * - \ref asfdoc_sam0_events_extra_info * - \ref asfdoc_sam0_events_examples * - \ref asfdoc_sam0_events_api_overview * * * \section asfdoc_sam0_events_prerequisites Prerequisites * * There are no prerequisites for this module. * * * \section asfdoc_sam0_events_module_overview Module Overview * * Peripherals within the SAM devices are capable of generating two types of * actions in response to given stimulus; set a register flag for later * intervention by the CPU (using interrupt or polling methods), or generate * event signals, which can be internally routed directly to other * peripherals within the device. The use of events allows for direct actions * to be performed in one peripheral in response to a stimulus in another * without CPU intervention. This can lower the overall power consumption of the * system if the CPU is able to remain in sleep modes for longer periods * (SleepWalking), and lowers the latency of the system response. * * The event system is comprised of a number of freely configurable Event * resources, plus a number of fixed Event Users. Each Event resource can be * configured to select the input peripheral that will generate the events * signal, as well as the synchronization path and edge detection mode. * The fixed-function Event Users, connected to peripherals within the device, * can then subscribe to an Event resource in a one-to-many relationship in order * to receive events as they are generated. An overview of the event system * chain is shown in * \ref asfdoc_sam0_events_module_overview_fig "the figure below". * * \anchor asfdoc_sam0_events_module_overview_fig * \dot * digraph overview { * rankdir=LR; * node [label="Source\nPeripheral\n(Generator)" shape=ellipse style=filled fillcolor=lightgray] src_peripheral; * node [label="Event\nResource A" shape=square style=""] event_gen0; * node [label="Event\nUser X" shape=square style=""] event_user0; * node [label="Event\nUser Y" shape=square style=""] event_user1; * node [label="Destination\nPeripheral\n(User)" shape=ellipse style=filled fillcolor=lightgray] dst_peripheral0; * node [label="Destination\nPeripheral\n(User)" shape=ellipse style=filled fillcolor=lightgray] dst_peripheral1; * * src_peripheral -> event_gen0; * event_gen0 -> event_user0; * event_gen0 -> event_user1; * event_user0 -> dst_peripheral0; * event_user1 -> dst_peripheral1; * } * \enddot * * There are many different events that can be routed in the device, which can * then trigger many different actions. For example, an Analog Comparator module * could be configured to generate an event when the input signal rises above * the compare threshold, which then triggers a Timer Counter module to capture * the current count value for later use. * * \subsection asfdoc_sam0_events_module_overview_event_channels Event Channels * The Event module in each device consists of several channels, which can be * freely linked to an event generator (i.e. a peripheral within the device * that is capable of generating events). Each channel can be individually * configured to select the generator peripheral, signal path, and edge detection * applied to the input event signal, before being passed to any event user(s). * * Event channels can support multiple users within the device in a standardized * manner. When an Event User is linked to an Event Channel, the channel will * automatically handshake with all attached users to ensure that all modules * correctly receive and acknowledge the event. * * \subsection asfdoc_sam0_events_module_overview_event_users Event Users * Event Users are able to subscribe to an Event Channel, once it has been * configured. Each Event User consists of a fixed connection to one of the * peripherals within the device (for example, an ADC module, or Timer module) * and is capable of being connected to a single Event Channel. * * \subsection asfdoc_sam0_events_module_overview_edge_detection Edge Detection * For asynchronous events, edge detection on the event input is not possible, * and the event signal must be passed directly between the event generator and * event user. For synchronous and re-synchronous events, the input signal from * the event generator must pass through an edge detection unit, so that only * the rising, falling, or both edges of the event signal triggers an action in * the event user. * * \subsection asfdoc_sam0_events_module_overview_path_selection Path Selection * The event system in the SAM devices supports three signal path types from * the event generator to Event Users: asynchronous, synchronous, and * re-synchronous events. * * \subsubsection asfdoc_sam0_events_module_overview_path_selection_async Asynchronous Paths * Asynchronous event paths allow for an asynchronous connection between the * event generator and Event Users, when the source and destination * peripherals share the same \ref asfdoc_sam0_system_clock_group "Generic Clock" * channel. In this mode the event is propagated between the source and * destination directly to reduce the event latency, thus no edge detection is * possible. The asynchronous event chain is shown in * \ref asfdoc_sam0_events_module_async_path_fig "the figure below". * * \anchor asfdoc_sam0_events_module_async_path_fig * \dot * digraph overview { * rankdir=LR; * node [label="Source\nPeripheral" shape=ellipse style=filled fillcolor=lightgray] src_peripheral; * node [label=" EVSYS | Event\nChannel/User" fillcolor=white style="dashed" shape=record] events_chan; * node [label="Destination\nPeripheral" shape=ellipse style=filled fillcolor=lightgray] dst_peripheral; * * src_peripheral -> events_chan; * events_chan -> dst_peripheral; * * } * \enddot * \note Identically shaped borders in the diagram indicate a shared generic clock channel. * * \subsubsection asfdoc_sam0_events_module_overview_path_selection_sync Synchronous Paths * The Synchronous event path should be used when edge detection or interrupts * from the event channel are required, and the source event generator and the * event channel shares the same Generic Clock channel. The synchronous event * chain is shown in * \ref asfdoc_sam0_events_module_sync_path_fig "the figure below". * * Not all peripherals support Synchronous event paths; refer to the device datasheet. * * \anchor asfdoc_sam0_events_module_sync_path_fig * \dot * digraph overview { * rankdir=LR; * node [label="Source\nPeripheral" shape=ellipse style="filled, dashed" fillcolor=lightgray] src_peripheral; * node [label=" EVSYS | Event\nChannel/User" fillcolor=white shape=record style="dashed"] events_chan; * node [label="Destination\nPeripheral" shape=ellipse style="filled, solid" fillcolor=lightgray] dst_peripheral; * * src_peripheral -> events_chan; * events_chan -> dst_peripheral; * * } * \enddot * \note Identically shaped borders in the diagram indicate a shared generic clock channel. * * \subsubsection asfdoc_sam0_events_module_overview_path_selection_resync Re-synchronous Paths * Re-synchronous event paths are a special form of synchronous events, where * when edge detection or interrupts from the event channel are required, but * the event generator and the event channel use different Generic Clock * channels. The re-synchronous path allows the Event System to synchronize the * incoming event signal from the Event Generator to the clock of the Event * System module to avoid missed events, at the cost of a higher latency due to * the re-synchronization process. The re-synchronous event chain is shown in * \ref asfdoc_sam0_events_module_resync_path_fig "the figure below". * * Not all peripherals support re-synchronous event paths; refer to the device datasheet. * \anchor asfdoc_sam0_events_module_resync_path_fig * \dot * digraph overview { * rankdir=LR; * node [label="Source\nPeripheral" shape=ellipse style="filled, dotted" fillcolor=lightgray] src_peripheral; * node [label=" EVSYS | Event\nChannel/User" fillcolor=white shape=record style="dashed"] events_chan; * node [label="Destination\nPeripheral" shape=ellipse style=filled fillcolor=lightgray] dst_peripheral; * * src_peripheral -> events_chan; * events_chan -> dst_peripheral; * * } * \enddot * \note Identically shaped borders in the diagram indicate a shared generic clock channel. * * \subsection asfdoc_sam0_events_module_overview_physical Physical Connection * * \ref asfdoc_sam0_events_module_int_connections_fig "The diagram below" * shows how this module is interconnected within the device. * * \anchor asfdoc_sam0_events_module_int_connections_fig * \dot * digraph overview { * rankdir=LR; * node [label="Source\nPeripherals" shape=ellipse style=filled fillcolor=lightgray] src_peripheral; * * subgraph driver { * node [label=" EVSYS | Event Channels" fillcolor=white shape=record] events_chan; * node [label=" EVSYS | Event Users" fillcolor=white shape=record] events_user; * } * * node [label="Destination\nPeripherals" shape=ellipse style=filled fillcolor=lightgray] dst_peripheral; * * src_peripheral -> events_chan:f1 [label="Source\nMUXs"]; * events_chan:f1 -> events_user:f1 [label="Channel\nMUXs"]; * events_user:f1 -> dst_peripheral; * } * \enddot * * \subsection asfdoc_sam0_events_module_overview_config Configuring Events * For SAM devices, several steps are required to properly configure an * event chain, so that hardware peripherals can respond to events generated by * each other, as listed below. * * \subsubsection asfdoc_sam0_events_module_overview_config_src Source Peripheral * -# The source peripheral (that will generate events) must be configured and * enabled. * -# The source peripheral (that will generate events) must have an output * event enabled. * \subsubsection asfdoc_sam0_events_module_overview_config_evsys Event System * -# An event system channel must be allocated and configured with the * correct source peripheral selected as the channel's event generator. * -# The event system user must be configured and enabled, and attached to # event channel previously allocated. * \subsubsection asfdoc_sam0_events_module_overview_config_dst Destination Peripheral * -# The destination peripheral (that will receive events) must be configured * and enabled. * -# The destination peripheral (that will receive events) must have an input * event enabled. * * * \section asfdoc_sam0_events_special_considerations Special Considerations * * There are no special considerations for this module. * * * \section asfdoc_sam0_events_extra_info Extra Information * * For extra information, see \ref asfdoc_sam0_events_extra. This includes: * - \ref asfdoc_sam0_events_extra_acronyms * - \ref asfdoc_sam0_events_extra_dependencies * - \ref asfdoc_sam0_events_extra_errata * - \ref asfdoc_sam0_events_extra_history * * * \section asfdoc_sam0_events_examples Examples * * For a list of examples related to this driver, see * \ref asfdoc_sam0_events_exqsg. * * * \section asfdoc_sam0_events_api_overview API Overview * @{ */ #include #include "events_common.h" /** * \brief Edge detect enum. * * Event channel edge detect setting. * */ enum events_edge_detect { /** No event output */ EVENTS_EDGE_DETECT_NONE, /** Event on rising edge */ EVENTS_EDGE_DETECT_RISING, /** Event on falling edge */ EVENTS_EDGE_DETECT_FALLING, /** Event on both edges */ EVENTS_EDGE_DETECT_BOTH, }; /** * \brief Path selection enum. * * Event channel path selection. * */ enum events_path_selection { /** Select the synchronous path for this event channel */ EVENTS_PATH_SYNCHRONOUS, /** Select the resynchronizer path for this event channel */ EVENTS_PATH_RESYNCHRONIZED, /** Select the asynchronous path for this event channel */ EVENTS_PATH_ASYNCHRONOUS, }; /** * \brief Events configuration struct. * * This event configuration struct is used to configure each of the channels. * */ struct events_config { /** Select edge detection mode */ enum events_edge_detect edge_detect; /** Select events channel path */ enum events_path_selection path; /** Set event generator for the channel */ uint8_t generator; /** Clock source for the event channel */ uint8_t clock_source; #if (SAML21) || (SAML22) || (SAMC20) || (SAMC21) || (SAMR30) /** Run in standby mode for the channel */ bool run_in_standby; /** Run On Demand */ bool on_demand; #endif }; /** * \brief No event generator definition. * * Use this to disable any peripheral event input to a channel. This can be useful * if you only want to use a channel for software generated events. * */ ///@cond INTERNAL /** * \internal * Status bit offsets in the status register/interrupt register. * * @{ */ #if (SAML21) || (SAML22) || (SAMC20) || (SAMC21) || (SAMR30) # define _EVENTS_START_OFFSET_BUSY_BITS 16 # define _EVENTS_START_OFFSET_USER_READY_BIT 0 # define _EVENTS_START_OFFSET_DETECTION_BIT 16 # define _EVENTS_START_OFFSET_OVERRUN_BIT 0 #else /* SAM D/R */ # define _EVENTS_START_OFFSET_BUSY_BITS 8 # define _EVENTS_START_OFFSET_USER_READY_BIT 0 # define _EVENTS_START_OFFSET_DETECTION_BIT 8 # define _EVENTS_START_OFFSET_OVERRUN_BIT 0 #endif /** @} */ ///@endcond /** * Definition for no generator selection. */ #define EVSYS_ID_GEN_NONE 0 /** * \brief Event channel resource. * * Event resource structure. * * \note The fields in this structure should not be altered by the user application; * they are reserved for driver internals only. */ struct events_resource { #if !defined(__DOXYGEN__) /** Channel allocated for the event resource */ uint8_t channel; /** Channel setting in CHANNEL register */ uint32_t channel_reg; #endif }; #if EVENTS_INTERRUPT_HOOKS_MODE == true typedef void (*events_interrupt_hook)(struct events_resource *resource); /** * \brief Event hook. * * Event hook structure. * */ struct events_hook { /** Event resource */ struct events_resource *resource; /** Event hook function */ events_interrupt_hook hook_func; /** Next event hook */ struct events_hook *next; }; #endif /** * \brief Initializes an event configurations struct to defaults. * * Initailizes an event configuration struct to predefined safe default settings. * * \param[in] config Pointer to an instance of \ref struct events_config * */ void events_get_config_defaults(struct events_config *config); /** * \brief Allocate an event channel and set configuration. * * Allocates an event channel from the event channel pool and sets * the channel configuration. * * \param[out] resource Pointer to a \ref events_resource struct instance * \param[in] config Pointer to a \ref events_config struct * * \return Status of the configuration procedure. * \retval STATUS_OK Allocation and configuration went successful * \retval STATUS_ERR_NOT_FOUND No free event channel found * */ enum status_code events_allocate(struct events_resource *resource, struct events_config *config); /** * \brief Attach user to the event channel. * * Attach a user peripheral to the event channel to receive events. * * \param[in] resource Pointer to an \ref events_resource struct instance * \param[in] user_id A number identifying the user peripheral found in the device header file * * \return Status of the user attach procedure. * \retval STATUS_OK No errors detected when attaching the event user */ enum status_code events_attach_user(struct events_resource *resource, uint8_t user_id); /** * \brief Detach a user peripheral from the event channel. * * Deattach a user peripheral from the event channels so it does not receive any more events. * * \param[in] resource Pointer to an \ref event_resource struct instance * \param[in] user_id A number identifying the user peripheral found in the device header file * * \return Status of the user detach procedure. * \retval STATUS_OK No errors detected when detaching the event user */ enum status_code events_detach_user(struct events_resource *resource, uint8_t user_id); /** * \brief Check if a channel is busy. * * Check if a channel is busy, a channel stays busy until all users connected to the channel * has handled an event. * * \param[in] resource Pointer to a \ref events_resource struct instance * * \return Status of the channels busy state. * \retval true One or more users connected to the channel has not handled the last event * \retval false All users are ready to handle new events */ bool events_is_busy(struct events_resource *resource); /** * \brief Trigger software event. * * Trigger an event by software. * * \note Software event works on either a synchronous path or resynchronized path, and * edge detection must be configured to rising-edge detection. * * \param[in] resource Pointer to an \ref events_resource struct * * \return Status of the event software procedure. * \retval STATUS_OK No error was detected when the software tigger signal was issued * \retval STATUS_ERR_UNSUPPORTED_DEV If the channel path is asynchronous and/or the * edge detection is not set to RISING */ enum status_code events_trigger(struct events_resource *resource); /** * \brief Check if all users connected to the channel are ready. * * Check if all users connected to the channel are ready to handle incoming events. * * \param[in] resource Pointer to an \ref events_resource struct * * \return The ready status of users connected to an event channel. * \retval true All the users connected to the event channel are ready to handle incoming events * \retval false One or more users connected to the event channel are not ready to handle incoming events */ bool events_is_users_ready(struct events_resource *resource); /** * \brief Check if an event is detected on the event channel. * * Check if an event has been detected on the channel. * * \note This function will clear the event detected interrupt flag. * * \param[in] resource Pointer to an \ref events_resource struct * * \return Status of the event detection interrupt flag. * \retval true Event has been detected * \retval false Event has not been detected */ bool events_is_detected(struct events_resource *resource); /** * \brief Check if there has been an overrun situation on this channel. * * \note This function will clear the event overrun detected interrupt flag. * * \param[in] resource Pointer to an \ref events_resource struct * * \return Status of the event overrun interrupt flag. * \retval true Event overrun has been detected * \retval false Event overrun has not been detected */ bool events_is_overrun(struct events_resource *resource); /** * \brief Release allocated channel back the the resource pool. * * Release an allocated channel back to the resource pool to make it available for other purposes. * * \param[in] resource Pointer to an \ref events_resource struct * * \return Status of the channel release procedure. * \retval STATUS_OK No error was detected when the channel was released * \retval STATUS_BUSY One or more event users have not processed the last event * \retval STATUS_ERR_NOT_INITIALIZED Channel not allocated, and can therefore not be released */ enum status_code events_release(struct events_resource *resource); /** * \brief Get the number of free channels. * * Get the number of allocatable channels in the events system resource pool. * * \return The number of free channels in the event system. * */ uint8_t events_get_free_channels(void); ///@cond INTERNAL /** * \internal * Function to find bit position in the CHSTATUS and INTFLAG register, * and return bit mask of this position. * * @{ */ uint32_t _events_find_bit_position(uint8_t channel, uint8_t start_offset); /** @} */ ///@endcond /** @} */ /** * \page asfdoc_sam0_events_extra Extra Information for EVENTS Driver * * \section asfdoc_sam0_events_extra_acronyms Acronyms * Below is a table listing the acronyms used in this module, along with their * intended meanings. * * * * * * * * * * * * * * *
AcronymDescription
CPUCentral Processing Unit
MUXMultiplexer
* * * \section asfdoc_sam0_events_extra_dependencies Dependencies * This driver has the following dependencies: * * - \ref asfdoc_sam0_system_clock_group "System Clock Driver" * * * \section asfdoc_sam0_events_extra_errata Errata * There are no errata related to this driver. * * * \section asfdoc_sam0_events_extra_history Module History * An overview of the module history is presented in the table below, with * details on the enhancements and fixes made to the module since its first * release. The current version of this corresponds to the newest version in * the table. * * * * * * * * * * * * * * *
Changelog
Fix a bug in internal function _events_find_bit_position()
Rewrite of events driver
Initial Release
*/ /** * \page asfdoc_sam0_events_exqsg Examples for EVENTS Driver * * This is a list of the available Quick Start guides (QSGs) and example * applications for \ref asfdoc_sam0_events_group. QSGs are simple examples with * step-by-step instructions to configure and use this driver in a selection of * use cases. Note that a QSG can be compiled as a standalone application or be * added to the user application. * * - \subpage asfdoc_sam0_events_basic_use_case * \if EVENTS_INTERRUPT_HOOK_MODE * - \subpage asfdoc_sam0_events_interrupt_hook_use_case * \endif * * \page asfdoc_sam0_events_document_revision_history Document Revision History * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Doc. Rev. * Date * Comments *
42108G12/2015Added support for SAM D09 and SAM L22
42108F08/2015Added support for SAM L21, SAM DA1, SAMR30 and SAM C20/C21
42108E12/2014Added support for interrupt hook mode. * Added support for SAM R21 and SAM D10/D11.
42108D01/2014Update to support SAM D21 and corrected documentation typos
42108C11/2013Fixed incorrect documentation for the event signal paths. Added * configuration steps overview to the documentation.
42108B06/2013Corrected documentation typos
42108A06/2013Initial release
*/ #ifdef __cplusplus } #endif #endif /* EVENTS_H_INCLUDED */