diff --git a/drivers/dma.c b/drivers/dma.c index 0cc80fe..f13f9f1 100644 --- a/drivers/dma.c +++ b/drivers/dma.c @@ -19,7 +19,7 @@ //--local definitions----------------------------------------------------------- static void configure_dma(volatile struct DMA* dma, enum DmaChannel channel, - enum DmaConfig config_mask, volatile void* periph, void* mem, + enum DmaConfig config_mask, volatile void* periph, volatile void* mem, uint16_t size); @@ -36,7 +36,7 @@ static volatile void* dma2_cb_params[5]; //--public functions------------------------------------------------------------ void dma_configure(enum DmaPeriph dma, enum DmaChannel channel, - enum DmaConfig config_mask, volatile void* periph, void* mem, + enum DmaConfig config_mask, volatile void* periph, volatile void* mem, uint16_t size, DmaCallback callback, volatile void* cb_param) { //reset peripheral first, to ensure proper configuration @@ -185,7 +185,7 @@ uint16_t dma_get_remaining(enum DmaPeriph dma, enum DmaChannel channel) //--local functions------------------------------------------------------------- static void configure_dma(volatile struct DMA* dma, enum DmaChannel channel, - enum DmaConfig config_mask, volatile void* periph, void* mem, + enum DmaConfig config_mask, volatile void* periph, volatile void* mem, uint16_t size) { volatile struct DMA_CHANNEL* regs = &dma->CHANNELS[channel]; diff --git a/drivers/dma.h b/drivers/dma.h index 14746f6..309f797 100644 --- a/drivers/dma.h +++ b/drivers/dma.h @@ -81,7 +81,7 @@ typedef void (*DmaCallback)(enum DmaIRQSource, volatile void* param); //--functions------------------------------------------------------------------- void dma_configure(enum DmaPeriph dma, enum DmaChannel channel, - enum DmaConfig config_mask, volatile void* periph, void* mem, + enum DmaConfig config_mask, volatile void* periph, volatile void* mem, uint16_t size, DmaCallback callback, volatile void* cb_param); void dma_configure_mem2mem(enum DmaPeriph dma, enum DmaChannel channel, diff --git a/drivers/dma_cbuf.c b/drivers/dma_cbuf.c new file mode 100644 index 0000000..52796a2 --- /dev/null +++ b/drivers/dma_cbuf.c @@ -0,0 +1,85 @@ +/** @file dma_cbuf.c + * Module handling Direct Memory Access controller's circular system + * + * The module provides a convenient tool to receive data from a peripheral in a + * buffered, low-latency, low-cpu usage, non-blocking way + */ + +//--includes-------------------------------------------------------------------- + +#include "dma_cbuf.h" + + +//--local definitions----------------------------------------------------------- + +static void cbuf_callback(enum DmaIRQSource src, volatile void* param); + + +//--local variables------------------------------------------------------------- + +//--public functions------------------------------------------------------------ + +void dma_cbuf_configure(volatile struct DmaCircBuffer* buffer, + volatile void* raw_buffer, volatile void* src, uint16_t buffer_size, + enum DmaPeriph dma, enum DmaChannel channel, enum DmaConfig config) +{ + #warning "check for null ptr" + + buffer->buffer = raw_buffer; + buffer->src = src; + + buffer->size = buffer_size; + buffer->begin = 0; + + buffer->dma = dma; + buffer->channel = channel; + buffer->config = config; + + buffer->dma_looped = false; + + dma_configure(buffer->dma, buffer->channel, buffer->config, buffer->src, + buffer->buffer, buffer->size, cbuf_callback, buffer); +} + +uint32_t dma_cbuf_read_byte(volatile struct DmaCircBuffer* buffer, + uint8_t* byte) +{ + //retreive the current end of the buffer based on the DMA's progress + uint16_t end = buffer->size + - dma_get_remaining(buffer->dma, buffer->channel); + + //check for bytes to read and overflow + if ((end > buffer->begin) && buffer->dma_looped) { + //TODO overflow + buffer->begin = end; + } else if ((buffer->begin == end) && !buffer->dma_looped) { + //TODO no data + return 1; + } + + //read the oldest byte and advance the buffer + uint8_t* raw_buffer = (uint8_t*)buffer->buffer; + *byte = raw_buffer[buffer->begin]; + ++buffer->begin; + if (buffer->begin >= buffer->size) { + buffer->begin = 0; + buffer->dma_looped = false; + } + + return 0; +} + +//--local functions------------------------------------------------------------- + +/** + * Callback called on DMA RX tranfert's completion. Sets a flag needed to + * properly handle the circular buffer + */ +static void cbuf_callback(enum DmaIRQSource src, volatile void* param) +{ + (void)src; //only transfer complete expected + volatile struct DmaCircBuffer* buffer = param; + buffer->dma_looped = true; +} + + diff --git a/drivers/dma_cbuf.h b/drivers/dma_cbuf.h new file mode 100644 index 0000000..d28a438 --- /dev/null +++ b/drivers/dma_cbuf.h @@ -0,0 +1,44 @@ +/** @file dma_cbuf.h + * Module handling Direct Memory Access controller's circular system + * + * The module provides a convenient tool to receive data from a peripheral in a + * buffered, low-latency, low-cpu usage, non-blocking way + */ + +#ifndef _DMA_CBUF_H_ +#define _DMA_CBUF_H_ + +//--includes-------------------------------------------------------------------- + +#include "dma.h" + + +//--type definitions------------------------------------------------------------ + +struct DmaCircBuffer { + volatile void* buffer; //the buffer to use as a circular buffer + volatile void* src; //source peripheral register + + uint16_t size; //the size of the buffer + uint16_t begin; //pointer to the current begin of the buffer + + enum DmaPeriph dma; //DMA peripheral, must correspond to peripheral + enum DmaChannel channel; //DMA channel, must correspond to peripheral + enum DmaConfig config; //DMA config, must correspond to peripheral + + bool dma_looped; //whether the DMA looped or not (buffer overflow) +}; + + +//--functions------------------------------------------------------------------- + +void dma_cbuf_configure(volatile struct DmaCircBuffer* buffer, + volatile void* raw_buffer, volatile void* src, uint16_t buffer_size, + enum DmaPeriph dma, enum DmaChannel channel, enum DmaConfig config); + +uint32_t dma_cbuf_read_byte(volatile struct DmaCircBuffer* buffer, + uint8_t* byte); + + +#endif //_DMA_CBUF_H_ + diff --git a/drivers/usart.c b/drivers/usart.c index 05e0cc8..c0f84c8 100644 --- a/drivers/usart.c +++ b/drivers/usart.c @@ -15,34 +15,27 @@ #include "rcc.h" #include "dma.h" #include "dma_mbuf.h" +#include "dma_cbuf.h" #include "stddef.h" //--local definitions----------------------------------------------------------- -#define DMA_CONFIG (DMA_CONFIG_IRQ_COMPLETE | DMA_CONFIG_FROM_MEM \ - | DMA_CONFIG_INC_MEM | DMA_CONFIG_PSIZE_8BITS \ - | DMA_CONFIG_MSIZE_8BITS | DMA_CONFIG_PRIO_LOW) +#define DMA_TX_CONFIG (DMA_CONFIG_IRQ_COMPLETE | DMA_CONFIG_FROM_MEM \ + | DMA_CONFIG_INC_MEM | DMA_CONFIG_PSIZE_8BITS \ + | DMA_CONFIG_MSIZE_8BITS | DMA_CONFIG_PRIO_LOW) +#define DMA_RX_CONFIG (DMA_CONFIG_IRQ_COMPLETE | DMA_CONFIG_FROM_PERIPH \ + | DMA_CONFIG_CIRCULAR | DMA_CONFIG_INC_MEM \ + | DMA_CONFIG_PSIZE_8BITS | DMA_CONFIG_MSIZE_8BITS \ + | DMA_CONFIG_PRIO_LOW) -struct CircularBuffer { - volatile uint8_t* buffer; //the buffer to use as a circular buffer - uint16_t size; //the size of the buffer - uint16_t begin; //pointer to the current begin of the buffer - bool dmaLooped; //whether the DMA looped or not (buffer overflow) -}; static void configure_usart(volatile struct USART* regs, enum UsartConfig config); static void configure_baudrate(volatile struct USART* regs, uint32_t clock, uint32_t baudrate); -static uint32_t read_from_buffer(volatile struct CircularBuffer* buffer, - enum DmaChannel channel, uint8_t* byte); - -static void usart1_rx_callback(enum DmaIRQSource src, volatile void* param); -static void usart2_rx_callback(enum DmaIRQSource src, volatile void* param); -static void usart3_rx_callback(enum DmaIRQSource src, volatile void* param); //--local variables------------------------------------------------------------- @@ -51,11 +44,11 @@ static volatile struct USART* const usart1 = (struct USART*)USART1_BASE_ADDRESS; static volatile struct USART* const usart2 = (struct USART*)USART2_BASE_ADDRESS; static volatile struct USART* const usart3 = (struct USART*)USART3_BASE_ADDRESS; -static volatile struct CircularBuffer usart1_rx_buffer; +static volatile struct DmaCircBuffer usart1_rx_buffer; static volatile struct DmaMultiBuffer usart1_tx_buffer; -static volatile struct CircularBuffer usart2_rx_buffer; +static volatile struct DmaCircBuffer usart2_rx_buffer; static volatile struct DmaMultiBuffer usart2_tx_buffer; -static volatile struct CircularBuffer usart3_rx_buffer; +static volatile struct DmaCircBuffer usart3_rx_buffer; static volatile struct DmaMultiBuffer usart3_tx_buffer; @@ -72,6 +65,7 @@ void usart_configure(enum UsartPeriph periph, enum UsartConfig config, rcc_enable(RCC_AHB_NONE, RCC_APB1_NONE, RCC_APB2_USART); configure_baudrate(usart1, clocks.apb2_freq, baudrate); configure_usart(usart1, config); +#warning "fix zeroed variables init" usart1_tx_buffer.buffers = NULL; usart1_rx_buffer.buffer = NULL; break; @@ -147,24 +141,20 @@ uint32_t usart_write_byte(enum UsartPeriph periph, uint8_t byte) uint32_t usart_read_byte(enum UsartPeriph periph, uint8_t* byte) { volatile struct USART* regs; - volatile struct CircularBuffer* buffer; - enum DmaChannel dma_channel; + volatile struct DmaCircBuffer* buffer; switch (periph) { case USART_PERIPH_1: regs = usart1; buffer = &usart1_rx_buffer; - dma_channel = DMA_CHANNEL_5; break; case USART_PERIPH_2: regs = usart2; buffer = &usart2_rx_buffer; - dma_channel = DMA_CHANNEL_6; break; case USART_PERIPH_3: regs = usart3; buffer = &usart3_rx_buffer; - dma_channel = DMA_CHANNEL_3; break; default: return 1; @@ -172,7 +162,7 @@ uint32_t usart_read_byte(enum UsartPeriph periph, uint8_t* byte) } if (buffer->buffer) { - return read_from_buffer(buffer, dma_channel, byte); + return dma_cbuf_read_byte(buffer, byte); } else { if (regs->SR.RXNE) { *byte = regs->DR.DR; @@ -190,17 +180,17 @@ void usart_set_tx_buffer(enum UsartPeriph periph, uint8_t** buffers, case USART_PERIPH_1: dma_mbuf_configure(&usart1_tx_buffer, (void**)buffers, &usart1->DR, buffer_size, buffer_nb, DMA_PERIPH_1, DMA_CHANNEL_4, - DMA_CONFIG); + DMA_TX_CONFIG); break; case USART_PERIPH_2: dma_mbuf_configure(&usart2_tx_buffer, (void**)buffers, &usart2->DR, buffer_size, buffer_nb, DMA_PERIPH_1, DMA_CHANNEL_7, - DMA_CONFIG); + DMA_TX_CONFIG); break; case USART_PERIPH_3: dma_mbuf_configure(&usart3_tx_buffer, (void**)buffers, &usart3->DR, buffer_size, buffer_nb, DMA_PERIPH_1, DMA_CHANNEL_2, - DMA_CONFIG); + DMA_TX_CONFIG); break; } } @@ -210,43 +200,19 @@ void usart_set_rx_buffer(enum UsartPeriph periph, uint8_t* buffer, { switch (periph) { case USART_PERIPH_1: - dma_configure(DMA_PERIPH_1, DMA_CHANNEL_5, - DMA_CONFIG_IRQ_COMPLETE | DMA_CONFIG_FROM_PERIPH - | DMA_CONFIG_CIRCULAR | DMA_CONFIG_INC_MEM - | DMA_CONFIG_PSIZE_8BITS | DMA_CONFIG_MSIZE_8BITS - | DMA_CONFIG_PRIO_LOW, (void*)&usart1->DR, buffer, - size, usart1_rx_callback, NULL); - usart1_rx_buffer.buffer = buffer; - usart1_rx_buffer.size = size; - usart1_rx_buffer.begin = 0; - usart1_rx_buffer.dmaLooped = false; + dma_cbuf_configure(&usart1_rx_buffer, buffer, (void*)&usart1->DR, + size, DMA_PERIPH_1, DMA_CHANNEL_5, DMA_RX_CONFIG); reg_set(usart1->CR3, USART_CR3_DMAR); break; case USART_PERIPH_2: - dma_configure(DMA_PERIPH_1, DMA_CHANNEL_6, - DMA_CONFIG_IRQ_COMPLETE | DMA_CONFIG_FROM_PERIPH - | DMA_CONFIG_CIRCULAR | DMA_CONFIG_INC_MEM - | DMA_CONFIG_PSIZE_8BITS | DMA_CONFIG_MSIZE_8BITS - | DMA_CONFIG_PRIO_LOW, (void*)&usart2->DR, buffer, - size, usart2_rx_callback, NULL); - usart2_rx_buffer.buffer = buffer; - usart2_rx_buffer.size = size; - usart2_rx_buffer.begin = 0; - usart2_rx_buffer.dmaLooped = false; + dma_cbuf_configure(&usart2_rx_buffer, buffer, (void*)&usart2->DR, + size, DMA_PERIPH_1, DMA_CHANNEL_6, DMA_RX_CONFIG); reg_set(usart2->CR3, USART_CR3_DMAR); break; case USART_PERIPH_3: - dma_configure(DMA_PERIPH_1, DMA_CHANNEL_3, - DMA_CONFIG_IRQ_COMPLETE | DMA_CONFIG_FROM_PERIPH - | DMA_CONFIG_CIRCULAR | DMA_CONFIG_INC_MEM - | DMA_CONFIG_PSIZE_8BITS | DMA_CONFIG_MSIZE_8BITS - | DMA_CONFIG_PRIO_LOW, (void*)&usart3->DR, buffer, - size, usart3_rx_callback, NULL); - usart3_rx_buffer.buffer = buffer; - usart3_rx_buffer.size = size; - usart3_rx_buffer.begin = 0; - usart3_rx_buffer.dmaLooped = false; + dma_cbuf_configure(&usart3_rx_buffer, buffer, (void*)&usart3->DR, + size, DMA_PERIPH_1, DMA_CHANNEL_3, DMA_RX_CONFIG); reg_set(usart3->CR3, USART_CR3_DMAR); break; @@ -354,68 +320,6 @@ static void configure_baudrate(volatile struct USART* regs, uint32_t clock, reg_write(regs->BRR, USART_BRR_DIV_Fraction, divider & 0xF); } -/** - * Reads the oldest byte from the given CircularBuffer if any. Returns 0 if the - * read was successfull, 1 otherwise - */ -static uint32_t read_from_buffer(volatile struct CircularBuffer* buffer, - enum DmaChannel channel, uint8_t* byte) -{ - //retreive the current end of the buffer based on the DMA's progress - uint16_t end = buffer->size - dma_get_remaining(DMA_PERIPH_1, channel); - - //check for bytes to read and overflow - if ((end > buffer->begin) && buffer->dmaLooped) { - //TODO overflow - buffer->begin = end; - } else if ((buffer->begin == end) && !buffer->dmaLooped) { - //TODO no data - return 1; - } - - //read the oldest byte and advance the buffer - *byte = buffer->buffer[buffer->begin]; - ++buffer->begin; - if (buffer->begin >= buffer->size) { - buffer->begin = 0; - buffer->dmaLooped = false; - } - - return 0; -} - -//--allbacks------------------------------------------------------------------- - -/** - * Callback called on DMA RX tranfert's completion. Sets a flag needed to - * properly handle the circular buffer - */ -static void usart1_rx_callback(enum DmaIRQSource src, volatile void* param) -{ - (void)src; //only transfer complete expected - usart1_rx_buffer.dmaLooped = true; -} - -/** - * Callback called on DMA RX tranfert's completion. Sets a flag needed to - * properly handle the circular buffer - */ -static void usart2_rx_callback(enum DmaIRQSource src, volatile void* param) -{ - (void)src; //only transfer complete expected - usart2_rx_buffer.dmaLooped = true; -} - -/** - * Callback called on DMA RX tranfert's completion. Sets a flag needed to - * properly handle the circular buffer - */ -static void usart3_rx_callback(enum DmaIRQSource src, volatile void* param) -{ - (void)src; //only transfer complete expected - usart3_rx_buffer.dmaLooped = true; -} - //--ISRs------------------------------------------------------------------------