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Diffstat (limited to 'libmaple/dma.h')
-rw-r--r-- | libmaple/dma.h | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/libmaple/dma.h b/libmaple/dma.h new file mode 100644 index 0000000..3417f02 --- /dev/null +++ b/libmaple/dma.h @@ -0,0 +1,122 @@ +/****************************************************************************** + * The MIT License + * + * Copyright (c) 2010 Michael Hope. + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + *****************************************************************************/ + +/** + * @file dma.h + * + * @brief Direct Memory Access peripheral support + * + * TODO: add DMA2 support for high-density devices. + */ + +#ifndef _DMA_H_ +#define _DMA_H_ + +#include "libmaple_types.h" + +#ifdef __cplusplus +extern "C"{ +#endif + +/** Base address of the DMA1 peripheral */ +#define DMA1_BASE 0x40020000 +/** DMA Interrupt Status Register */ +#define DMA1_ISR (DMA1_BASE + 0x00) +/** DMA Interrupt Flag Clear Register */ +#define DMA1_IFCR (DMA1_BASE + 0x04) +/** DMA Channel Configuration Register */ +#define DMA1_CCR1 (DMA1_BASE + 0x08) +/** DMA Channel Number of Data Register */ +#define DMA1_CNDTR1 (DMA1_BASE + 0x0C) +/** DMA Channel Peripheral Address Register */ +#define DMA1_CPAR1 (DMA1_BASE + 0x10) +/** DMA Channel Memory Address Register */ +#define DMA1_CMAR1 (DMA1_BASE + 0x14) +/** Spacing between channel registers */ +#define DMA_CHANNEL_STRIDE 20 + +/** Flags for DMA transfer configuration. */ +typedef enum dma_mode_flags { + DMA_MINC_MODE = 1 << 7, /**< Auto-increment memory address */ + DMA_PINC_MODE = 1 << 6, /**< Auto-increment peripheral address */ + DMA_CIRC_MODE = 1 << 5, /**< Circular mode */ + DMA_FROM_MEM = 1 << 4, /**< Read from memory to peripheral */ + DMA_TRNS_ERR = 1 << 3, /**< Interrupt on transfer error */ + DMA_HALF_TRNS = 1 << 2, /**< Interrupt on half-transfer */ + DMA_TRNS_CMPLT = 1 << 1 /**< Interrupt on transfer completion */ +} dma_mode_flags; + +/** Source and destination transfer sizes. */ +typedef enum dma_transfer_size { + DMA_SIZE_8BITS = 0, + DMA_SIZE_16BITS = 1, + DMA_SIZE_32BITS = 2 +} dma_transfer_size; + +/** + * Initialize a DMA channel. If desired, attach an interrupt handler + * using dma_attach_interrupt(). Start the transfer using + * dma_start(). + * + * @param channel the channel number (1..7) + * @param paddr address of the peripheral + * @param psize peripheral size + * @param msize memory size + * @param mode OR of the dma_mode_flags + * @see dma_mode_flags + * @see dma_attach_interrupt() + * @see dma_start() */ +void dma_init(uint8 channel, volatile void *paddr, + dma_transfer_size psize, dma_transfer_size msize, + int mode); + +/** + * Begin a DMA transfer initialized with dma_init(). + * + * @param channel Channel transfer to start. + * @param buffer Buffer to write to (unless DMA_FROM_MEM was set in + * mode argument to dma_init(), in which case, buffer + * to read from). This must be aligned with msize + * argument to dma_init(). + * @param count Number of elements to transfer. + * @see dma_init() */ +void dma_start(uint8 channel, volatile void *buffer, uint16 count); + +/** + * Attach an interrupt handler for the given DMA channel. + * @param channel DMA channel (1..7) + * @param handler Interrupt handler to attach + * @see voidFuncPtr */ +void dma_attach_interrupt(uint8 channel, voidFuncPtr handler); + +/** + * Detach any handler associated with the given DMA channel. + * @param channel Channel whose interrupt handler to detach. */ +void dma_detach_interrupt(uint8 channel); + +#ifdef __cplusplus +} // extern "C" +#endif + +#endif |