diff options
Diffstat (limited to 'libmaple/dma.h')
| -rw-r--r-- | libmaple/dma.h | 57 |
1 files changed, 49 insertions, 8 deletions
diff --git a/libmaple/dma.h b/libmaple/dma.h index 8a6ca34..7072a1a 100644 --- a/libmaple/dma.h +++ b/libmaple/dma.h @@ -26,11 +26,15 @@ * @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 @@ -39,7 +43,7 @@ extern "C"{ #define DMA1_BASE 0x40020000 /** DMA Interrupt Status Register */ #define DMA1_ISR (DMA1_BASE + 0x00) -/** DMA Interrput Flag Clear Register */ +/** DMA Interrupt Flag Clear Register */ #define DMA1_IFCR (DMA1_BASE + 0x04) /** DMA Channel Configuration Register */ #define DMA1_CCR1 (DMA1_BASE + 0x08) @@ -52,19 +56,56 @@ extern "C"{ /** Spacing between channel registers */ #define DMA_CHANNEL_STRIDE 20 +/** Flags for DMA transfer configuration. */ typedef enum dma_mode_flags { - /** Auto-increment memory address */ - DMA_MINC_MODE = 4, - /** Auto-increment peripheral address */ - DMA_PINC_MODE = 2, - /** Circular mode */ - DMA_CIRC_MODE = 1, + 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; -void dma_init(uint8 channel, volatile void *peripheral, int from_peripheral, +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, dma_mode_flags mode); + +/** + * Begin a DMA transfer initialized with dma_init(). You may call + * this function repeatedly after a single call to 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); +void dma_attach_interrupt(uint8 channel, voidFuncPtr handler); +void dma_detach_interrupt(uint8 channel); + #ifdef __cplusplus } // extern "C" #endif |