Steins7/stm32f1xx_HBL
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Add circular rx buffer management

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This commit is contained in:
Steins7 2023-07-11 11:44:54 +02:00
parent 46776ebfd3
commit f89fe12298
3 changed files with 56 additions and 11 deletions
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14
drivers/dma.c
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@ -133,6 +133,20 @@ void dma_disable(enum DmaPeriph dma, enum DmaChannel channel)
}
}
uint16_t dma_get_remaining(enum DmaPeriph dma, enum DmaChannel channel)
{
switch (dma) {
case DMA_PERIPH_1:
return dma1->CHANNELS[channel].CNDTR.NDT;
break;
case DMA_PERIPH_2:
return dma2->CHANNELS[channel].CNDTR.NDT;
break;
default:
return 0;
break;
}
}
//--local functions-------------------------------------------------------------

2
drivers/dma.h
View File

@ -94,6 +94,8 @@ void dma_enable(enum DmaPeriph dma, enum DmaChannel channel);
void dma_disable(enum DmaPeriph dma, enum DmaChannel channel);
uint16_t dma_get_remaining(enum DmaPeriph dma, enum DmaChannel channe);
#endif //_DMA_H_

51
drivers/usart.c
View File

@ -19,9 +19,12 @@
//--local definitions-----------------------------------------------------------
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;
struct CircularBuffer {
volatile uint8_t* buffer;
uint16_t size;
uint16_t begin;
bool dmaLooped;
};
static void configure_usart(volatile struct USART* regs,
enum UsartConfig config);
@ -29,7 +32,7 @@ static void configure_baudrate(volatile struct USART* regs, uint32_t clock,
uint32_t baudrate);
static uint32_t periph_regs(enum UsartPeriph periph,
volatile struct USART** regs);
static uint32_t read_from_buffer(volatile uint8_t* buffer,
static uint32_t read_from_buffer(struct CircularBuffer* buffer,
enum DmaChannel channel, uint8_t* byte);
static void usart1_rx_callback(enum DmaIRQSource src);
@ -37,7 +40,11 @@ static void usart1_rx_callback(enum DmaIRQSource src);
//--local variables-------------------------------------------------------------
static volatile uint8_t* usart1_rx_buffer;
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 struct CircularBuffer usart1_rx_buffer;
//--public functions------------------------------------------------------------
@ -87,13 +94,13 @@ 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 uint8_t* buffer;
struct CircularBuffer* buffer;
enum DmaChannel dma_channel;
switch (periph) {
case USART_PERIPH_1:
regs = usart1;
buffer = usart1_rx_buffer;
buffer = &usart1_rx_buffer;
dma_channel = DMA_CHANNEL_5;
break;
case USART_PERIPH_2:
@ -103,7 +110,7 @@ uint32_t usart_read_byte(enum UsartPeriph periph, uint8_t* byte)
break;
}
if (buffer) {
if (buffer->buffer) {
return read_from_buffer(buffer, dma_channel, byte);
} else {
if (regs->SR.RXNE) {
@ -126,7 +133,10 @@ void usart_set_rx_buffer(enum UsartPeriph periph, uint8_t* buffer,
| DMA_CONFIG_PSIZE_8BITS | DMA_CONFIG_MSIZE_8BITS
| DMA_CONFIG_PRIO_LOW, (void*)&usart1->DR, buffer,
size, usart1_rx_callback);
usart1_rx_buffer = buffer;
usart1_rx_buffer.buffer = buffer;
usart1_rx_buffer.size = size;
usart1_rx_buffer.begin = 0;
usart1_rx_buffer.dmaLooped = false;
reg_set(usart1->CR3, USART_CR3_DMAR);
break;
case USART_PERIPH_2:
@ -140,6 +150,7 @@ void usart_set_rx_buffer(enum UsartPeriph periph, uint8_t* buffer,
static void configure_usart(volatile struct USART* regs, enum UsartConfig config)
{
usart1_rx_buffer.buffer = NULL;
//configure parity
switch (config)
{
@ -247,16 +258,34 @@ static uint32_t periph_regs(enum UsartPeriph periph, volatile struct USART** reg
return 0;
}
static uint32_t read_from_buffer(volatile uint8_t* buffer,
static uint32_t read_from_buffer(struct CircularBuffer* buffer,
enum DmaChannel channel, uint8_t* byte)
{
uint16_t end = buffer->size - dma_get_remaining(DMA_PERIPH_1, channel);
if ((end > buffer->begin) && buffer->dmaLooped) {
//TODO overflow
buffer->begin = end;
} else if ((buffer->begin == end) && !buffer->dmaLooped) {
//TODO no data
return 1;
}
*byte = buffer->buffer[buffer->begin];
++buffer->begin;
if (buffer->begin >= buffer->size) {
buffer->begin = 0;
buffer->dmaLooped = false;
}
return 0;
}
//--callbacks-------------------------------------------------------------------
static void usart1_rx_callback(enum DmaIRQSource src)
{
(void)src; //only transfer complete expected
usart1_rx_buffer.dmaLooped = true;
}