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Diffstat (limited to 'os/hal/include/io_channel.h')
| -rw-r--r-- | os/hal/include/io_channel.h | 368 |
1 files changed, 368 insertions, 0 deletions
diff --git a/os/hal/include/io_channel.h b/os/hal/include/io_channel.h new file mode 100644 index 000000000..f6be5dad3 --- /dev/null +++ b/os/hal/include/io_channel.h @@ -0,0 +1,368 @@ +/*
+ ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010,
+ 2011,2012 Giovanni Di Sirio.
+
+ This file is part of ChibiOS/RT.
+
+ ChibiOS/RT 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/RT 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 io_serial.h
+ * @brief I/O serial devices access.
+ * @details This header defines abstract interfaces useful to access generic
+ * I/O serial devices in a standardized way.
+ *
+ * @addtogroup IO_SERIAL
+ * @details This module defines an abstract interface for I/O channels by
+ * extending the @p BaseSequentialStream interface. Note that no code
+ * is present, I/O channels are just abstract interface like
+ * structures, you should look at the systems as to a set of abstract
+ * C++ classes (even if written in C). Specific device drivers can
+ * use/extend the interface and implement them.<br>
+ * This system has the advantage to make the access to channels
+ * independent from the implementation logic.
+ * @{
+ */
+
+#ifndef _IO_SERIAL_H_
+#define _IO_SERIAL_H_
+
+/**
+ * @brief @p BaseChannel specific methods.
+ */
+#define _base_channel_methods \
+ _base_sequential_stream_methods \
+ /* Channel output check.*/ \
+ bool_t (*putwouldblock)(void *instance); \
+ /* Channel input check.*/ \
+ bool_t (*getwouldblock)(void *instance); \
+ /* Channel put method with timeout specification.*/ \
+ msg_t (*put)(void *instance, uint8_t b, systime_t time); \
+ /* Channel get method with timeout specification.*/ \
+ msg_t (*get)(void *instance, systime_t time); \
+ /* Channel write method with timeout specification.*/ \
+ size_t (*writet)(void *instance, const uint8_t *bp, \
+ size_t n, systime_t time); \
+ /* Channel read method with timeout specification.*/ \
+ size_t (*readt)(void *instance, uint8_t *bp, size_t n, systime_t time);
+
+/**
+ * @brief @p BaseChannel specific data.
+ * @note It is empty because @p BaseChannel is only an interface without
+ * implementation.
+ */
+#define _base_channel_data \
+ _base_sequential_stream_data
+
+/**
+ * @extends BaseSequentialStreamVMT
+ *
+ * @brief @p BaseChannel virtual methods table.
+ */
+struct BaseChannelVMT {
+ _base_channel_methods
+};
+
+/**
+ * @extends BaseSequentialStream
+ *
+ * @brief Base channel class.
+ * @details This class represents a generic, byte-wide, I/O channel. This class
+ * introduces generic I/O primitives with timeout specification.
+ */
+typedef struct {
+ /** @brief Virtual Methods Table.*/
+ const struct BaseChannelVMT *vmt;
+ _base_channel_data
+} BaseChannel;
+
+/**
+ * @name Macro Functions (BaseChannel)
+ * @{
+ */
+/**
+ * @brief Channel output check.
+ * @details This function verifies if a subsequent put/write operation would
+ * block.
+ *
+ * @param[in] ip pointer to a @p BaseChannel or derived class
+ * @return The output queue status.
+ * @retval FALSE if the output queue has space and would not block a
+ * write operation.
+ * @retval TRUE if the output queue is full and would block a write
+ * operation.
+ *
+ * @api
+ */
+#define srlPutWouldBlock(ip) ((ip)->vmt->putwouldblock(ip))
+
+/**
+ * @brief Channel input check.
+ * @details This function verifies if a subsequent get/read operation would
+ * block.
+ *
+ * @param[in] ip pointer to a @p BaseChannel or derived class
+ * @return The input queue status.
+ * @retval FALSE if the input queue contains data and would not block a
+ * read operation.
+ * @retval TRUE if the input queue is empty and would block a read
+ * operation.
+ *
+ * @api
+ */
+#define srlGetWouldBlock(ip) ((ip)->vmt->getwouldblock(ip))
+
+/**
+ * @brief Channel blocking byte write.
+ * @details This function writes a byte value to a channel. If the channel
+ * is not ready to accept data then the calling thread is suspended.
+ *
+ * @param[in] ip pointer to a @p BaseChannel or derived class
+ * @param[in] b the byte value to be written to the channel
+ * @return The operation status.
+ * @retval Q_OK if the operation succeeded.
+ * @retval Q_RESET if the channel associated queue (if any) was reset.
+ *
+ * @api
+ */
+#define srlPut(ip, b) ((ip)->vmt->put(ip, b, TIME_INFINITE))
+
+/**
+ * @brief Channel blocking byte write with timeout.
+ * @details This function writes a byte value to a channel. If the channel
+ * is not ready to accept data then the calling thread is suspended.
+ *
+ * @param[in] ip pointer to a @p BaseChannel or derived class
+ * @param[in] b the byte value to be written to the channel
+ * @param[in] time the number of ticks before the operation timeouts,
+ * the following special values are allowed:
+ * - @a TIME_IMMEDIATE immediate timeout.
+ * - @a TIME_INFINITE no timeout.
+ * .
+ * @return The operation status.
+ * @retval Q_OK if the operation succeeded.
+ * @retval Q_TIMEOUT if the specified time expired.
+ * @retval Q_RESET if the channel associated queue (if any) was reset.
+ *
+ * @api
+ */
+#define srlPutTimeout(ip, b, time) ((ip)->vmt->put(ip, b, time))
+
+/**
+ * @brief Channel blocking byte read.
+ * @details This function reads a byte value from a channel. If the data
+ * is not available then the calling thread is suspended.
+ *
+ * @param[in] ip pointer to a @p BaseChannel or derived class
+ * @return A byte value from the queue.
+ * @retval Q_RESET if the channel associated queue (if any) has been
+ * reset.
+ *
+ * @api
+ */
+#define srlGet(ip) ((ip)->vmt->get(ip, TIME_INFINITE))
+
+/**
+ * @brief Channel blocking byte read with timeout.
+ * @details This function reads a byte value from a channel. If the data
+ * is not available then the calling thread is suspended.
+ *
+ * @param[in] ip pointer to a @p BaseChannel or derived class
+ * @param[in] time the number of ticks before the operation timeouts,
+ * the following special values are allowed:
+ * - @a TIME_IMMEDIATE immediate timeout.
+ * - @a TIME_INFINITE no timeout.
+ * .
+ * @return A byte value from the queue.
+ * @retval Q_TIMEOUT if the specified time expired.
+ * @retval Q_RESET if the channel associated queue (if any) has been
+ * reset.
+ *
+ * @api
+ */
+#define srlGetTimeout(ip, time) ((ip)->vmt->get(ip, time))
+
+/**
+ * @brief Channel blocking write with timeout.
+ * @details The function writes data from a buffer to a channel. If the channel
+ * is not ready to accept data then the calling thread is suspended.
+ *
+ * @param[in] ip pointer to a @p BaseChannel or derived class
+ * @param[out] bp pointer to the data buffer
+ * @param[in] n the maximum amount of data to be transferred
+ * @param[in] time the number of ticks before the operation timeouts,
+ * the following special values are allowed:
+ * - @a TIME_IMMEDIATE immediate timeout.
+ * - @a TIME_INFINITE no timeout.
+ * .
+ * @return The number of bytes transferred.
+ *
+ * @api
+ */
+#define srlWriteTimeout(ip, bp, n, time) ((ip)->vmt->writet(ip, bp, n, time))
+
+/**
+ * @brief Channel blocking read with timeout.
+ * @details The function reads data from a channel into a buffer. If the data
+ * is not available then the calling thread is suspended.
+ *
+ * @param[in] ip pointer to a @p BaseChannel or derived class
+ * @param[in] bp pointer to the data buffer
+ * @param[in] n the maximum amount of data to be transferred
+ * @param[in] time the number of ticks before the operation timeouts,
+ * the following special values are allowed:
+ * - @a TIME_IMMEDIATE immediate timeout.
+ * - @a TIME_INFINITE no timeout.
+ * .
+ * @return The number of bytes transferred.
+ *
+ * @api
+ */
+#define srlReadTimeout(ip, bp, n, time) ((ip)->vmt->readt(ip, bp, n, time))
+/** @} */
+
+#if CH_USE_EVENTS || defined(__DOXYGEN__)
+/**
+ * @name I/O status flags
+ * @{
+ */
+/** @brief No pending conditions.*/
+#define IO_NO_ERROR 0
+/** @brief Connection happened.*/
+#define IO_CONNECTED 1
+/** @brief Disconnection happened.*/
+#define IO_DISCONNECTED 2
+/** @brief Data available in the input queue.*/
+#define IO_INPUT_AVAILABLE 4
+/** @brief Output queue empty.*/
+#define IO_OUTPUT_EMPTY 8
+/** @brief Transmission end.*/
+#define IO_TRANSMISSION_END 16
+/** @} */
+
+/**
+ * @brief Type of an I/O condition flags mask.
+ */
+typedef uint_fast16_t ioflags_t;
+
+/**
+ * @brief @p BaseAsynchronousChannel specific methods.
+ */
+#define _base_asynchronous_channel_methods \
+ _base_channel_methods \
+ /* Channel read method with timeout specification.*/ \
+ ioflags_t (*getflags)(void *instance);
+
+/**
+ * @brief @p BaseAsynchronousChannel specific data.
+ */
+#define _base_asynchronous_channel_data \
+ _base_channel_data \
+ /* I/O condition event source.*/ \
+ EventSource event; \
+ /* I/O condition flags.*/ \
+ ioflags_t flags;
+
+/**
+ * @extends BaseChannelVMT
+ *
+ * @brief @p BaseAsynchronousChannel virtual methods table.
+ */
+struct BaseAsynchronousChannelVMT {
+ _base_asynchronous_channel_methods
+};
+
+/**
+ * @extends BaseChannel
+ *
+ * @brief Base asynchronous channel class.
+ * @details This class extends @p BaseChannel by adding event sources fields
+ * for asynchronous I/O for use in an event-driven environment.
+ */
+typedef struct {
+ /** @brief Virtual Methods Table.*/
+ const struct BaseAsynchronousChannelVMT *vmt;
+ _base_asynchronous_channel_data
+} BaseAsynchronousChannel;
+
+/**
+ * @name Macro Functions (BaseAsynchronousChannel)
+ * @{
+ */
+/**
+ * @brief Returns the I/O condition event source.
+ * @details The event source is broadcasted when an I/O condition happens.
+ *
+ * @param[in] ip pointer to a @p BaseAsynchronousChannel or derived
+ * class
+ * @return A pointer to an @p EventSource object.
+ *
+ * @api
+ */
+#define srlGetEventSource(ip) (&((ip)->event))
+
+/**
+ * @brief Adds status flags to the channel's mask.
+ * @details This function is usually called from the I/O ISRs in order to
+ * notify I/O conditions such as data events, errors, signal
+ * changes etc.
+ *
+ * @param[in] ip pointer to a @p BaseAsynchronousChannel or derived
+ * class
+ * @param[in] mask condition flags to be added to the mask
+ *
+ * @iclass
+ */
+#define srlAddFlagsI(ip, mask) { \
+ (ip)->flags |= (mask); \
+ chEvtBroadcastI(&(ip)->event); \
+}
+
+/**
+ * @brief Returns and clears the status flags associated to the channel.
+ *
+ * @param[in] ip pointer to a @p BaseAsynchronousChannel or derived
+ * class
+ * @return The condition flags modified since last time this
+ * function was invoked.
+ *
+ * @api
+ */
+#define srlGetAndClearFlags(ip) ((ip)->vmt->getflags(ip))
+/** @} */
+
+/**
+ * @brief Default implementation of the @p getflags virtual method.
+ *
+ * @param[in] ip pointer to a @p BaseAsynchronousChannel or derived
+ * class
+ * @return The condition flags modified since last time this
+ * function was invoked.
+ *
+ * @notapi
+ */
+#define _ser_get_and_clear_flags_impl(ip) \
+ ioflags_t mask; \
+ chSysLock(); \
+ mask = ((BaseAsynchronousChannel *)(ip))->flags; \
+ ((BaseAsynchronousChannel *)(ip))->flags = IO_NO_ERROR; \
+ chSysUnlock(); \
+ return mask
+
+#endif /* CH_USE_EVENTS */
+
+#endif /* _IO_SERIAL_H_ */
+
+/** @} */
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