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ext_uart.c
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Wed, Aug 21, 18:29
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10 KB
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text/x-c
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Fri, Aug 23, 18:29 (2 d)
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blob
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20069156
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R2671 HHRI-software
ext_uart.c
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#include "ext_uart.h"
#include "../lib/utils.h"
#define EXUART_RX_Pin GPIO_Pin_7
#define EXUART_RX_PinSource GPIO_PinSource7
#define EXUART_RX_Port GPIOB
#define EXUART_TX_Pin GPIO_Pin_6
#define EXUART_TX_PinSource GPIO_PinSource6
#define EXUART_TX_Port GPIOB
#define EXUART_PERIPH USART1
#define RX_DMA DMA2_Stream2
#define RX_DMA_CHANNEL DMA_Channel_4
#define TX_DMA DMA2_Stream7
#define TX_DMA_CHANNEL DMA_Channel_4
#define TX_BUFFER_SIZE 512
#define RX_BUFFER_SIZE 1024
#define USER_RX_QUEUE_SIZE 2048
uint8_t
exuart_txBuffer
[
2
][
TX_BUFFER_SIZE
];
uint8_t
exuart_currentTxBufferToWriteTo
;
uint16_t
exuart_txBufferIndex
;
uint16_t
exuart_nBytesToTransferDma
;
uint8_t
exuart_rxBuffer
[
RX_BUFFER_SIZE
];
uint8_t
const
*
exuart_rxBuffTail
;
uint8_t
exuart_userRxQueue
[
USER_RX_QUEUE_SIZE
];
cb_CircularBuffer
exuart_rxQueue
;
#define UART_DMA_TX_IS_BUSY (DMA_GetCmdStatus(TX_DMA) == ENABLE && DMA_GetCurrDataCounter(TX_DMA) > 0)
void
exuart_FlushTx
(
void
);
/**
* @brief Initializes the UART module.
* @param baudRate: UART communication frequency (baud rate) [b/s].
*/
void
exuart_Init
(
uint32_t
baudRate
)
{
GPIO_InitTypeDef
GPIO_InitStruct
;
USART_InitTypeDef
USART_InitStruct
;
DMA_InitTypeDef
DMA_InitStruct
;
// Enable UART and DMA peripherals clocks.
RCC_APB2PeriphClockCmd
(
RCC_APB2Periph_USART1
,
ENABLE
);
RCC_AHB1PeriphClockCmd
(
RCC_AHB1Periph_DMA2
,
ENABLE
);
// Setup GPIOs as UART pins.
GPIO_InitStruct
.
GPIO_Pin
=
EXUART_TX_Pin
;
GPIO_InitStruct
.
GPIO_Mode
=
GPIO_Mode_AF
;
GPIO_InitStruct
.
GPIO_Speed
=
GPIO_Speed_50MHz
;
GPIO_InitStruct
.
GPIO_OType
=
GPIO_OType_PP
;
GPIO_InitStruct
.
GPIO_PuPd
=
GPIO_PuPd_UP
;
GPIO_Init
(
EXUART_TX_Port
,
&
GPIO_InitStruct
);
GPIO_PinAFConfig
(
EXUART_TX_Port
,
EXUART_TX_PinSource
,
GPIO_AF_USART1
);
GPIO_InitStruct
.
GPIO_Pin
=
EXUART_RX_Pin
;
GPIO_Init
(
EXUART_RX_Port
,
&
GPIO_InitStruct
);
GPIO_PinAFConfig
(
EXUART_RX_Port
,
EXUART_RX_PinSource
,
GPIO_AF_USART1
);
// Setup the UART peripheral.
USART_InitStruct
.
USART_BaudRate
=
baudRate
;
USART_InitStruct
.
USART_WordLength
=
USART_WordLength_8b
;
USART_InitStruct
.
USART_StopBits
=
USART_StopBits_1
;
USART_InitStruct
.
USART_Parity
=
USART_Parity_No
;
USART_InitStruct
.
USART_HardwareFlowControl
=
USART_HardwareFlowControl_None
;
USART_InitStruct
.
USART_Mode
=
USART_Mode_Tx
|
USART_Mode_Rx
;
USART_Init
(
EXUART_PERIPH
,
&
USART_InitStruct
);
USART_Cmd
(
EXUART_PERIPH
,
ENABLE
);
// Setup the DMA for RX.
DMA_DeInit
(
RX_DMA
);
DMA_InitStruct
.
DMA_Channel
=
RX_DMA_CHANNEL
;
DMA_InitStruct
.
DMA_PeripheralBaseAddr
=
(
uint32_t
)
&
EXUART_PERIPH
->
DR
;
DMA_InitStruct
.
DMA_Memory0BaseAddr
=
(
uint32_t
)
&
exuart_rxBuffer
[
0
];
DMA_InitStruct
.
DMA_DIR
=
DMA_DIR_PeripheralToMemory
;
DMA_InitStruct
.
DMA_BufferSize
=
RX_BUFFER_SIZE
;
DMA_InitStruct
.
DMA_PeripheralInc
=
DMA_PeripheralInc_Disable
;
DMA_InitStruct
.
DMA_MemoryInc
=
DMA_MemoryInc_Enable
;
DMA_InitStruct
.
DMA_PeripheralDataSize
=
DMA_PeripheralDataSize_Byte
;
DMA_InitStruct
.
DMA_MemoryDataSize
=
DMA_MemoryDataSize_Byte
;
DMA_InitStruct
.
DMA_Mode
=
DMA_Mode_Circular
;
DMA_InitStruct
.
DMA_Priority
=
DMA_Priority_Medium
;
DMA_InitStruct
.
DMA_FIFOMode
=
DMA_FIFOMode_Disable
;
DMA_InitStruct
.
DMA_MemoryBurst
=
DMA_MemoryBurst_Single
;
DMA_InitStruct
.
DMA_PeripheralBurst
=
DMA_PeripheralBurst_Single
;
DMA_Init
(
RX_DMA
,
&
DMA_InitStruct
);
USART_DMACmd
(
EXUART_PERIPH
,
USART_DMAReq_Rx
|
USART_DMAReq_Tx
,
ENABLE
);
DMA_ITConfig
(
RX_DMA
,
DMA_IT_TC
,
ENABLE
);
DMA_Cmd
(
RX_DMA
,
ENABLE
);
exuart_rxBuffTail
=
&
exuart_rxBuffer
[
0
];
// Setup the DMA for TX.
DMA_DeInit
(
TX_DMA
);
DMA_InitStruct
.
DMA_Channel
=
TX_DMA_CHANNEL
;
DMA_InitStruct
.
DMA_PeripheralBaseAddr
=
(
uint32_t
)
&
EXUART_PERIPH
->
DR
;
DMA_InitStruct
.
DMA_Memory0BaseAddr
=
(
uint32_t
)
&
exuart_txBuffer
[
0
][
0
];
DMA_InitStruct
.
DMA_DIR
=
DMA_DIR_MemoryToPeripheral
;
DMA_InitStruct
.
DMA_BufferSize
=
TX_BUFFER_SIZE
;
DMA_InitStruct
.
DMA_PeripheralInc
=
DMA_PeripheralInc_Disable
;
DMA_InitStruct
.
DMA_MemoryInc
=
DMA_MemoryInc_Enable
;
DMA_InitStruct
.
DMA_PeripheralDataSize
=
DMA_PeripheralDataSize_Byte
;
DMA_InitStruct
.
DMA_MemoryDataSize
=
DMA_MemoryDataSize_Byte
;
DMA_InitStruct
.
DMA_Mode
=
DMA_Mode_Normal
;
DMA_InitStruct
.
DMA_Priority
=
DMA_Priority_Medium
;
DMA_InitStruct
.
DMA_FIFOMode
=
DMA_FIFOMode_Disable
;
DMA_InitStruct
.
DMA_MemoryBurst
=
DMA_MemoryBurst_Single
;
DMA_InitStruct
.
DMA_PeripheralBurst
=
DMA_PeripheralBurst_Single
;
DMA_Init
(
TX_DMA
,
&
DMA_InitStruct
);
USART_DMACmd
(
EXUART_PERIPH
,
USART_DMAReq_Rx
|
USART_DMAReq_Tx
,
ENABLE
);
DMA_ITConfig
(
TX_DMA
,
DMA_IT_TC
,
ENABLE
);
// Initialize the RX circular buffer.
cb_Init
(
&
exuart_rxQueue
,
exuart_userRxQueue
,
USER_RX_QUEUE_SIZE
);
// Initialize the variables for the UART TX.
exuart_currentTxBufferToWriteTo
=
0
;
exuart_txBufferIndex
=
0
;
exuart_nBytesToTransferDma
=
0
;
}
/**
* @brief Gets the number of bytes received and ready to read.
* @return the number of bytes ready to be acquired with exuart_GetByte().
* @remark This function must called often, otherwise the DMA RX buffer may be
* full, and data will be lost.
*/
uint16_t
exuart_ReceivedBytesCount
(
void
)
{
// Get the location of the location currently pointed by the DMA.
uint8_t
const
*
head
=
exuart_rxBuffer
+
RX_BUFFER_SIZE
-
DMA_GetCurrDataCounter
(
RX_DMA
);
// Even if the STM32F4 reference manual (RM0090) states that the NDTR
// register is decremented after the transfer, this is not the case.
// So we wait a few cycles to be sure that the DMA actually performed the
// transfer.
utils_DelayUs
(
1
);
// RX: add the received bytes into the user queue.
while
(
exuart_rxBuffTail
!=
head
)
{
uint8_t
b
=
*
exuart_rxBuffTail
;
cb_Push
(
&
exuart_rxQueue
,
b
);
exuart_rxBuffTail
++
;
if
(
exuart_rxBuffTail
>=
exuart_rxBuffer
+
RX_BUFFER_SIZE
)
exuart_rxBuffTail
-=
RX_BUFFER_SIZE
;
}
// Return the number of bytes ready to get.
return
cb_ItemsCount
(
&
exuart_rxQueue
);
}
/**
* @brief Gets the next received byte.
* @return the value of the received byte.
* @remark call exuart_ReceivedBytesCount() before calling this function.
* @warning this function return 0 if no byte is available.
*/
uint8_t
exuart_GetByte
(
void
)
{
if
(
cb_ItemsCount
(
&
exuart_rxQueue
)
>
0
)
return
cb_Pull
(
&
exuart_rxQueue
);
else
return
0
;
}
/**
* @brief Starts the DMA transfer to send bytes to UART peripheral.
*/
void
exuart_StartDma
(
void
)
{
DMA_InitTypeDef
DMA_InitStruct
;
//
exuart_nBytesToTransferDma
=
exuart_txBufferIndex
;
exuart_currentTxBufferToWriteTo
=
!
exuart_currentTxBufferToWriteTo
;
exuart_txBufferIndex
=
0
;
// Start the DMA transfer.
DMA_DeInit
(
TX_DMA
);
DMA_InitStruct
.
DMA_Channel
=
TX_DMA_CHANNEL
;
DMA_InitStruct
.
DMA_PeripheralBaseAddr
=
(
uint32_t
)
&
EXUART_PERIPH
->
DR
;
DMA_InitStruct
.
DMA_Memory0BaseAddr
=
(
uint32_t
)
&
exuart_txBuffer
[
!
exuart_currentTxBufferToWriteTo
][
0
];
DMA_InitStruct
.
DMA_DIR
=
DMA_DIR_MemoryToPeripheral
;
DMA_InitStruct
.
DMA_BufferSize
=
exuart_nBytesToTransferDma
;
DMA_InitStruct
.
DMA_PeripheralInc
=
DMA_PeripheralInc_Disable
;
DMA_InitStruct
.
DMA_MemoryInc
=
DMA_MemoryInc_Enable
;
DMA_InitStruct
.
DMA_PeripheralDataSize
=
DMA_PeripheralDataSize_Byte
;
DMA_InitStruct
.
DMA_MemoryDataSize
=
DMA_MemoryDataSize_Byte
;
DMA_InitStruct
.
DMA_Mode
=
DMA_Mode_Normal
;
DMA_InitStruct
.
DMA_Priority
=
DMA_Priority_Medium
;
DMA_InitStruct
.
DMA_FIFOMode
=
DMA_FIFOMode_Disable
;
DMA_InitStruct
.
DMA_MemoryBurst
=
DMA_MemoryBurst_Single
;
DMA_InitStruct
.
DMA_PeripheralBurst
=
DMA_PeripheralBurst_Single
;
DMA_Init
(
TX_DMA
,
&
DMA_InitStruct
);
DMA_Cmd
(
TX_DMA
,
ENABLE
);
}
/**
* @brief Asynchronously sends the given byte through the UART bus.
* @param data the data byte to send.
*/
void
exuart_SendByteAsync
(
uint8_t
data
)
{
// Check that it is possible to write in the current buffer.
if
(
exuart_txBufferIndex
>=
TX_BUFFER_SIZE
)
{
// If the DMA is idle, switch to the other buffer.
if
(
UART_DMA_TX_IS_BUSY
)
{
utils_TrapCpu
();
// Error, can't write anywhere!
return
;
}
else
exuart_StartDma
();
}
// Write the byte in the buffer.
exuart_txBuffer
[
exuart_currentTxBufferToWriteTo
][
exuart_txBufferIndex
]
=
data
;
exuart_txBufferIndex
++
;
// If the buffer is full, start the DMA transfer.
if
(
exuart_txBufferIndex
==
TX_BUFFER_SIZE
)
exuart_StartDma
();
//
exuart_FlushTx
();
}
/**
* @brief Asynchronously sends the given bytes through the UART bus.
* @param data pointer to the data bytes array to send.
* @param length number of bytes to send (array size).
*/
void
exuart_SendBytesAsync
(
uint8_t
*
data
,
int
length
)
{
while
(
length
>
0
)
{
uint16_t
nBytesToWriteInBuf
;
// Check that it is possible to write in the current buffer.
if
(
exuart_txBufferIndex
>=
TX_BUFFER_SIZE
)
{
// If the DMA is idle, switch to the other buffer.
if
(
UART_DMA_TX_IS_BUSY
)
{
utils_TrapCpu
();
// Error, can't write anywhere!
return
;
}
else
exuart_StartDma
();
}
// Write as many bytes as possible in the current buffer.
nBytesToWriteInBuf
=
TX_BUFFER_SIZE
-
exuart_txBufferIndex
;
if
(
nBytesToWriteInBuf
>
length
)
nBytesToWriteInBuf
=
length
;
memcpy
(
&
exuart_txBuffer
[
exuart_currentTxBufferToWriteTo
][
exuart_txBufferIndex
],
data
,
nBytesToWriteInBuf
);
exuart_txBufferIndex
+=
nBytesToWriteInBuf
;
data
+=
nBytesToWriteInBuf
;
length
-=
nBytesToWriteInBuf
;
// If the buffer is full, start the DMA transfer.
if
(
exuart_txBufferIndex
==
TX_BUFFER_SIZE
)
exuart_StartDma
();
}
//
exuart_FlushTx
();
}
/**
* @brief Start the DMA to send the bytes waiting in the intermediate buffer.
*/
void
exuart_FlushTx
(
void
)
{
if
(
exuart_txBufferIndex
>
0
&&
!
UART_DMA_TX_IS_BUSY
)
exuart_StartDma
();
}
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