include/bsp/dma.h

0001 /* SPDX-License-Identifier: BSD-2-Clause */
0002
0003 /**
0004  * @file
0005  *
0006  * @ingroup RTEMSBSPsARMLPC176X_dma
0007  *
0008  * @brief Direct memory access (DMA) support.
0009  */
0010
0011 /*
0012  * Copyright (C) 2008, 2009 embedded brains GmbH & Co. KG
0013  *
0014  * Redistribution and use in source and binary forms, with or without
0015  * modification, are permitted provided that the following conditions
0016  * are met:
0017  * 1. Redistributions of source code must retain the above copyright
0018  *    notice, this list of conditions and the following disclaimer.
0019  * 2. Redistributions in binary form must reproduce the above copyright
0020  *    notice, this list of conditions and the following disclaimer in the
0021  *    documentation and/or other materials provided with the distribution.
0022  *
0023  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
0024  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
0025  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
0026  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
0027  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
0028  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
0029  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
0030  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
0031  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
0032  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
0033  * POSSIBILITY OF SUCH DAMAGE.
0034  */
0035
0036 #ifndef LIBBSP_ARM_LPC176X_DMA_H
0037 #define LIBBSP_ARM_LPC176X_DMA_H
0038
0039 #include <rtems.h>
0040
0041 #ifdef __cplusplus
0042 extern "C" {
0043 #endif /* __cplusplus */
0044
0045 /**
0046  * @defgroup lpc176x_dma DMA Support
0047  *
0048  * @ingroup RTEMSBSPsARMLPC176X
0049  *
0050  * @brief Direct memory access (DMA) support.
0051  *
0052  * @{
0053  */
0054
0055 /**
0056  * @brief Initializes the general purpose DMA.
0057  */
0058 void lpc176x_dma_initialize( void );
0059
0060 /**
0061  * @brief Tries to obtain the DMA channel @a channel.
0062  *
0063  * @retval RTEMS_SUCCESSFUL Successful operation.
0064  * @retval RTEMS_INVALID_ID Invalid channel number.
0065  * @retval RTEMS_RESOURCE_IN_USE Channel already occupied.
0066  */
0067 rtems_status_code lpc176x_dma_channel_obtain( unsigned channel );
0068
0069 /**
0070  * @brief Releases the DMA channel @a channel.
0071  *
0072  * You must have obtained this channel with lpc176x_dma_channel_obtain()
0073  * previously.
0074  *
0075  * If the channel number @a channel is out of range nothing will happen.
0076  */
0077 void lpc176x_dma_channel_release( unsigned channel );
0078
0079 /**
0080  * @brief Disables the DMA channel @a channel.
0081  *
0082  * If @a force is @c false the channel will be halted and disabled when the
0083  * channel is inactive otherwise it will be disabled immediately.
0084  *
0085  * If the channel number @a channel is out of range nothing will happen.
0086  */
0087 void lpc176x_dma_channel_disable(
0088   unsigned channel,
0089   bool     force
0090 );
0091
0092 rtems_status_code lpc176x_dma_copy_initialize( void );
0093
0094 rtems_status_code lpc176x_dma_copy_release( void );
0095
0096 rtems_status_code lpc176x_dma_copy(
0097   unsigned    channel,
0098   const void *dest,
0099   const void *src,
0100   size_t      n,
0101   size_t      width
0102 );
0103
0104 rtems_status_code lpc176x_dma_copy_wait( unsigned channel );
0105
0106 /** @} */
0107
0108 #ifdef __cplusplus
0109 }
0110 #endif /* __cplusplus */
0111
0112 #endif /* LIBBSP_ARM_LPC176X_DMA_H */