spi.dox
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/*
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/>.
---
A special exception to the GPL can be applied should you wish to distribute
a combined work that includes ChibiOS/RT, without being obliged to provide
the source code for any proprietary components. See the file exception.txt
for full details of how and when the exception can be applied.
*/
/**
* @defgroup SPI SPI Driver
* @brief Generic SPI Driver.
* @details This module implements a generic SPI (Serial Peripheral Interface)
* driver allowing bidirectional and monodirectional transfers,
* complex atomic transactions are supported as well.
* @pre In order to use the SPI driver the @p HAL_USE_SPI option
* must be enabled in @p halconf.h.
*
* @section spi_1 Driver State Machine
* The driver implements a state machine internally, not all the driver
* functionalities can be used in any moment, any transition not explicitly
* shown in the following diagram has to be considered an error and shall
* be captured by an assertion (if enabled).
* @if LATEX_PDF
* @dot
digraph example {
size="5, 7";
rankdir="LR";
node [shape=circle, fontname=Helvetica, fontsize=8, fixedsize="true",
width="0.9", height="0.9"];
edge [fontname=Helvetica, fontsize=8];
stop [label="SPI_STOP\nLow Power"];
uninit [label="SPI_UNINIT", style="bold"];
ready [label="SPI_READY\nClock Enabled"];
active [label="SPI_ACTIVE\nBus Active"];
complete [label="SPI_COMPLETE\nComplete"];
uninit -> stop [label="\n spiInit()", constraint=false];
stop -> ready [label="\nspiStart()"];
ready -> ready [label="\nspiSelect()\nspiUnselect()\nspiStart()"];
ready -> stop [label="\nspiStop()"];
stop -> stop [label="\nspiStop()"];
ready -> active [label="\nspiStartXXXI() (async)\nspiXXX() (sync)"];
active -> ready [label="\nsync return"];
active -> complete [label="\nasync callback\n>spc_endcb<"];
complete -> active [label="\nspiStartXXXI() (async)\nthen\ncallback return"];
complete -> ready [label="\ncallback return"];
}
* @enddot
* @else
* @dot
digraph example {
rankdir="LR";
node [shape=circle, fontname=Helvetica, fontsize=8, fixedsize="true", width="0.9", height="0.9"];
edge [fontname=Helvetica, fontsize=8];
stop [label="SPI_STOP\nLow Power"];
uninit [label="SPI_UNINIT", style="bold"];
ready [label="SPI_READY\nClock Enabled"];
active [label="SPI_ACTIVE\nBus Active"];
complete [label="SPI_COMPLETE\nComplete"];
uninit -> stop [label="\n spiInit()", constraint=false];
stop -> ready [label="\nspiStart()"];
ready -> ready [label="\nspiSelect()\nspiUnselect()\nspiStart()"];
ready -> stop [label="\nspiStop()"];
stop -> stop [label="\nspiStop()"];
ready -> active [label="\nspiStartXXX() (async)\nspiXXX() (sync)"];
active -> ready [label="\nsync return"];
active -> complete [label="\nasync callback\n>spc_endcb<"];
complete -> active [label="\nspiStartXXXI() (async)\nthen\ncallback return"];
complete -> ready [label="\ncallback return"];
}
* @enddot
* @endif
*
* The driver is not thread safe for performance reasons, if you need to access
* the SPI bus from multiple threads then use the @p spiAcquireBus() and
* @p spiReleaseBus() APIs in order to gain exclusive access.
*
* @ingroup IO
*/