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stm32f7:Serial fix for dropped data

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1) Revert the inherited dma bug from the stm32
     see df9ae3c13f
     for details.

  2) Most all CR1-CR3 settings can not be configured while UE
     is true. Threfore we make all operation atomic and disable
     UE and restore it's originalstate on exit.
This commit is contained in:
David Sidrane 2017-03-31 12:07:40 -10:00
parent 85e1d15835
commit fbb6cfc79c
1 changed files with 66 additions and 151 deletions
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217
arch/arm/src/stm32f7/stm32_serial.c
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@ -1,8 +1,9 @@
/****************************************************************************
* arch/arm/src/stm32f7/stm32_serial.c
*
* Copyright (C) 2015-2016 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
* Copyright (C) 2015-2017 Gregory Nutt. All rights reserved.
* Authors: Gregory Nutt <gnutt@nuttx.org>
* David Sidrane <david_s5@nscdg.com>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
@ -189,16 +190,6 @@
CONFIG_USART_DMAPRIO | \
DMA_SCR_PBURST_SINGLE | \
DMA_SCR_MBURST_SINGLE)
# ifdef CONFIG_SERIAL_IFLOWCONTROL
# define SERIAL_DMA_IFLOW_CONTROL_WORD \
(DMA_SCR_DIR_P2M | \
DMA_SCR_MINC | \
DMA_SCR_PSIZE_8BITS | \
DMA_SCR_MSIZE_8BITS | \
CONFIG_USART_DMAPRIO | \
DMA_SCR_PBURST_SINGLE | \
DMA_SCR_MBURST_SINGLE)
# endif
#endif /* SERIAL_HAVE_DMA */
/* Power management definitions */
@ -286,8 +277,7 @@ struct up_dev_s
#ifdef SERIAL_HAVE_DMA
DMA_HANDLE rxdma; /* currently-open receive DMA stream */
bool rxenable; /* DMA-based reception en/disable */
uint16_t rxdmain; /* Next byte in the DMA where hardware will write */
uint16_t rxdmaout; /* Next byte in the DMA buffer to be read */
uint32_t rxdmanext; /* Next byte in the DMA buffer to be read */
char *const rxfifo; /* Receive DMA buffer */
#endif
@ -1139,7 +1129,22 @@ static void up_set_format(struct uart_dev_s *dev)
uint32_t regval;
uint32_t usartdiv8;
uint32_t cr1;
uint32_t cr1_ue;
uint32_t brr;
irqstate_t flags;
flags = enter_critical_section();
/* Get the original state of UE */
cr1 = up_serialin(priv, STM32_USART_CR1_OFFSET);
cr1_ue = cr1 & USART_CR1_UE;
cr1 &= ~USART_CR1_UE;
/* Disable UE as the format bits and baud rate registers can not be
* updated while UE = 1 */
up_serialout(priv, STM32_USART_CR1_OFFSET, cr1);
/* In case of oversampling by 8, the equation is:
*
@ -1159,7 +1164,6 @@ static void up_set_format(struct uart_dev_s *dev)
/* Use oversamply by 8 only if the divisor is small. But what is small? */
cr1 = up_serialin(priv, STM32_USART_CR1_OFFSET);
if (usartdiv8 > 100)
{
/* Use usartdiv16 */
@ -1188,30 +1192,44 @@ static void up_set_format(struct uart_dev_s *dev)
/* Configure parity mode */
regval = up_serialin(priv, STM32_USART_CR1_OFFSET);
regval &= ~(USART_CR1_PCE | USART_CR1_PS | USART_CR1_M0);
cr1 &= ~(USART_CR1_PCE | USART_CR1_PS | USART_CR1_M0 | USART_CR1_M1);
if (priv->parity == 1) /* Odd parity */
{
regval |= (USART_CR1_PCE | USART_CR1_PS);
cr1 |= (USART_CR1_PCE | USART_CR1_PS);
}
else if (priv->parity == 2) /* Even parity */
{
regval |= USART_CR1_PCE;
cr1 |= USART_CR1_PCE;
}
/* Configure word length (Default: 8-bits) */
/* Configure word length (parity uses one of configured bits)
*
* Default: 1 start, 8 data (no parity), n stop, OR
* 1 start, 7 data + parity, n stop
*/
if (priv->bits == 7)
if (priv->bits == 9 || (priv->bits == 8 && priv->parity != 0))
{
regval |= USART_CR1_M1;
/* Select: 1 start, 8 data + parity, n stop, OR
* 1 start, 9 data (no parity), n stop.
*/
cr1 |= USART_CR1_M0;
}
else if (priv->bits == 9)
else if (priv->bits == 7 && priv->parity == 0)
{
regval |= USART_CR1_M0;
/* Select: 1 start, 7 data (no parity), n stop, OR
*/
cr1 |= USART_CR1_M1;
}
up_serialout(priv, STM32_USART_CR1_OFFSET, regval);
/* Else Select: 1 start, 7 data + parity, n stop, OR
* 1 start, 8 data (no parity), n stop.
*/
up_serialout(priv, STM32_USART_CR1_OFFSET, cr1);
/* Configure STOP bits */
@ -1230,7 +1248,8 @@ static void up_set_format(struct uart_dev_s *dev)
regval = up_serialin(priv, STM32_USART_CR3_OFFSET);
regval &= ~(USART_CR3_CTSE | USART_CR3_RTSE);
#if defined(CONFIG_SERIAL_IFLOWCONTROL) && !defined(CONFIG_STM32F7_FLOWCONTROL_BROKEN)
#if defined(CONFIG_SERIAL_IFLOWCONTROL) && \
!defined(CONFIG_STM32F7_FLOWCONTROL_BROKEN)
if (priv->iflow && (priv->rts_gpio != 0))
{
regval |= USART_CR3_RTSE;
@ -1245,6 +1264,8 @@ static void up_set_format(struct uart_dev_s *dev)
#endif
up_serialout(priv, STM32_USART_CR3_OFFSET, regval);
up_serialout(priv, STM32_USART_CR1_OFFSET, cr1 | cr1_ue);
leave_critical_section(flags);
}
#endif /* CONFIG_SUPPRESS_UART_CONFIG */
@ -1473,35 +1494,19 @@ static int up_dma_setup(struct uart_dev_s *dev)
priv->rxdma = stm32_dmachannel(priv->rxdma_channel);
#ifdef CONFIG_SERIAL_IFLOWCONTROL
if (priv->iflow)
{
/* Configure for non-circular DMA reception into the RX FIFO */
/* Configure for circular DMA reception into the RX FIFO */
stm32_dmasetup(priv->rxdma,
priv->usartbase + STM32_USART_RDR_OFFSET,
(uint32_t)priv->rxfifo,
RXDMA_BUFFER_SIZE,
SERIAL_DMA_IFLOW_CONTROL_WORD);
}
else
#endif
{
/* Configure for circular DMA reception into the RX FIFO */
stm32_dmasetup(priv->rxdma,
priv->usartbase + STM32_USART_RDR_OFFSET,
(uint32_t)priv->rxfifo,
RXDMA_BUFFER_SIZE,
SERIAL_DMA_CONTROL_WORD);
}
stm32_dmasetup(priv->rxdma,
priv->usartbase + STM32_USART_RDR_OFFSET,
(uint32_t)priv->rxfifo,
RXDMA_BUFFER_SIZE,
SERIAL_DMA_CONTROL_WORD);
/* Reset our DMA shadow pointer to match the address just
* programmed above.
*/
priv->rxdmaout = 0;
priv->rxdmain = 0;
priv->rxdmanext = 0;
/* Enable receive DMA for the UART */
@ -1509,26 +1514,12 @@ static int up_dma_setup(struct uart_dev_s *dev)
regval |= USART_CR3_DMAR;
up_serialout(priv, STM32_USART_CR3_OFFSET, regval);
#ifdef CONFIG_SERIAL_IFLOWCONTROL
if (priv->iflow)
{
/* Start the DMA channel, and arrange for callbacks at the full point
* in the FIFO. After buffer gets full, hardware flow-control kicks
* in and DMA transfer is stopped.
*/
/* Start the DMA channel, and arrange for callbacks at the half and
* full points in the FIFO. This ensures that we have half a FIFO
* worth of time to claim bytes before they are overwritten.
*/
stm32_dmastart(priv->rxdma, up_dma_rxcallback, (void *)priv, false);
}
else
#endif
{
/* Start the DMA channel, and arrange for callbacks at the half and
* full points in the FIFO. This ensures that we have half a FIFO
* worth of time to claim bytes before they are overwritten.
*/
stm32_dmastart(priv->rxdma, up_dma_rxcallback, (void *)priv, true);
}
stm32_dmastart(priv->rxdma, up_dma_rxcallback, (void *)priv, true);
return OK;
}
@ -2226,49 +2217,27 @@ static bool up_rxflowcontrol(struct uart_dev_s *dev,
static int up_dma_receive(struct uart_dev_s *dev, unsigned int *status)
{
struct up_dev_s *priv = (struct up_dev_s *)dev->priv;
uint32_t rxdmain;
int c = 0;
/* If additional bytes have been added to the DMA buffer, then we will need
* to invalidate the DMA buffer before reading the byte.
*/
rxdmain = up_dma_nextrx(priv);
if (rxdmain != priv->rxdmain)
if (up_dma_nextrx(priv) != priv->rxdmanext)
{
/* Invalidate the DMA buffer */
arch_invalidate_dcache((uintptr_t)priv->rxfifo,
(uintptr_t)priv->rxfifo + RXDMA_BUFFER_SIZE - 1);
/* Since DMA is ongoing, there are lots of race conditions here. We
* just have to hope that the rxdmaout stays well ahead of rxdmain.
*/
/* Now read from the DMA buffer */
priv->rxdmain = rxdmain;
}
c = priv->rxfifo[priv->rxdmanext];
/* Now check if there are any bytes to read from the DMA buffer */
if (rxdmain != priv->rxdmaout)
{
c = priv->rxfifo[priv->rxdmaout];
priv->rxdmaout++;
if (priv->rxdmaout == RXDMA_BUFFER_SIZE)
priv->rxdmanext++;
if (priv->rxdmanext == RXDMA_BUFFER_SIZE)
{
#ifdef CONFIG_SERIAL_IFLOWCONTROL
if (priv->iflow)
{
/* RX DMA buffer full. RX paused, RTS line pulled up to prevent
* more input data from other end.
*/
}
else
#endif
{
priv->rxdmaout = 0;
}
priv->rxdmanext = 0;
}
}
@ -2276,41 +2245,6 @@ static int up_dma_receive(struct uart_dev_s *dev, unsigned int *status)
}
#endif
/****************************************************************************
* Name: up_dma_reenable
*
* Description:
* Call to re-enable RX DMA.
*
****************************************************************************/
#if defined(SERIAL_HAVE_DMA) && defined(CONFIG_SERIAL_IFLOWCONTROL)
static void up_dma_reenable(struct up_dev_s *priv)
{
/* Configure for non-circular DMA reception into the RX FIFO */
stm32_dmasetup(priv->rxdma,
priv->usartbase + STM32_USART_RDR_OFFSET,
(uint32_t)priv->rxfifo,
RXDMA_BUFFER_SIZE,
SERIAL_DMA_IFLOW_CONTROL_WORD);
/* Reset our DMA shadow pointer to match the address just programmed
* above.
*/
priv->rxdmaout = 0;
priv->rxdmain = 0;
/* Start the DMA channel, and arrange for callbacks at the full point in
* the FIFO. After buffer gets full, hardware flow-control kicks in and
* DMA transfer is stopped.
*/
stm32_dmastart(priv->rxdma, up_dma_rxcallback, (void *)priv, false);
}
#endif
/****************************************************************************
* Name: up_dma_rxint
*
@ -2333,15 +2267,6 @@ static void up_dma_rxint(struct uart_dev_s *dev, bool enable)
*/
priv->rxenable = enable;
#ifdef CONFIG_SERIAL_IFLOWCONTROL
if (priv->iflow && priv->rxenable && (priv->rxdmaout == RXDMA_BUFFER_SIZE))
{
/* Re-enable RX DMA. */
up_dma_reenable(priv);
}
#endif
}
#endif
@ -2362,7 +2287,7 @@ static bool up_dma_rxavailable(struct uart_dev_s *dev)
* do not match, then there are bytes to be received.
*/
return (up_dma_nextrx(priv) != priv->rxdmaout);
return (up_dma_nextrx(priv) != priv->rxdmanext);
}
#endif
@ -2486,16 +2411,6 @@ static void up_dma_rxcallback(DMA_HANDLE handle, uint8_t status, void *arg)
if (priv->rxenable && up_dma_rxavailable(&priv->dev))
{
uart_recvchars(&priv->dev);
#ifdef CONFIG_SERIAL_IFLOWCONTROL
if (priv->iflow && priv->rxenable &&
(priv->rxdmaout == RXDMA_BUFFER_SIZE))
{
/* Re-enable RX DMA. */
up_dma_reenable(priv);
}
#endif
}
}
#endif