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stm32h7:Fix DMA Overrun error

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This commit is contained in:
David Sidrane 2020-04-02 12:06:58 -07:00 committed by patacongo
parent c191787ba4
commit fc3ab3e085
1 changed files with 44 additions and 34 deletions
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78
arch/arm/src/stm32h7/stm32_spi.c
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@ -1451,16 +1451,6 @@ static void spi_setmode(FAR struct spi_dev_s *dev, enum spi_mode_e mode)
spi_modifyreg(priv, STM32_SPI_CFG2_OFFSET, clrbits, setbits);
#ifdef CONFIG_STM32H7_SPI_DMA
/* Enabling SPI causes a spurious received character indication
* which confuse the DMA controller so we disable DMA during that
* enabling; and flush the SPI RX FIFO before re-enabling DMA.
*/
spi_modifyreg(priv, STM32_SPI_CFG1_OFFSET, SPI_CFG1_RXDMAEN |
SPI_CFG1_TXDMAEN, 0);
#endif
/* Re-enable SPI */
spi_enable(priv, true);
@ -1469,19 +1459,9 @@ static void spi_setmode(FAR struct spi_dev_s *dev, enum spi_mode_e mode)
{
/* Flush SPI read FIFO */
spi_getreg(priv, STM32_SPI_TXDR_OFFSET);
spi_getreg(priv, STM32_SPI_RXDR_OFFSET);
}
#ifdef CONFIG_STM32H7_SPI_DMA
/* Re-enable DMA (with SPI disabled) */
spi_enable(priv, false);
spi_modifyreg(priv, STM32_SPI_CFG1_OFFSET, 0, SPI_CFG1_RXDMAEN |
SPI_CFG1_TXDMAEN);
spi_enable(priv, true);
#endif
/* Save the mode so that subsequent re-configurations will be faster */
priv->mode = mode;
@ -1913,6 +1893,22 @@ static void spi_exchange(FAR struct spi_dev_s *dev, FAR const void *txbuffer,
static uint8_t rxdummy[4] __attribute__((aligned(4)));
static const uint16_t txdummy = 0xffff;
/* When starting communication using DMA, to prevent DMA channel
* management raising error events, these steps must be followed in
* order:
* 1. Enable DMA Rx buffer in the RXDMAEN bit in the SPI_CFG1 register,
* if DMA Rx is used.
* 2. Enable DMA requests for Tx and Rx in DMA registers, if the DMA is
* used.
* 3. Enable DMA Tx buffer in the TXDMAEN bit in the SPI_CFG1 register,
* if DMA Tx is used.
* 4. Enable the SPI by setting the SPE bit.
*/
spi_enable(priv, false);
spi_modifyreg(priv, STM32_SPI_CFG1_OFFSET, SPI_CFG1_TXDMAEN,
SPI_CFG1_RXDMAEN);
spiinfo("txbuffer=%p rxbuffer=%p nwords=%d\n",
txbuffer, rxbuffer, nwords);
DEBUGASSERT(priv->spibase != 0);
@ -1920,6 +1916,9 @@ static void spi_exchange(FAR struct spi_dev_s *dev, FAR const void *txbuffer,
spi_dmarxsetup(priv, rxbuffer, (uint16_t *)rxdummy, nbytes);
spi_dmatxsetup(priv, txbuffer, &txdummy, nbytes);
spi_modifyreg(priv, STM32_SPI_CFG1_OFFSET, 0, SPI_CFG1_TXDMAEN |
SPI_CFG1_RXDMAEN);
/* Flush cache to physical memory */
if (txbuffer)
@ -1927,19 +1926,17 @@ static void spi_exchange(FAR struct spi_dev_s *dev, FAR const void *txbuffer,
up_flush_dcache((uintptr_t)txbuffer, (uintptr_t)txbuffer + nbytes);
}
/* REVISIT: Master transfer start */
spi_modifyreg(priv, STM32_SPI_CR1_OFFSET, 0, SPI_CR1_CSTART);
#ifdef CONFIG_SPI_TRIGGER
/* Is deferred triggering in effect? */
if (!priv->defertrig)
{
/* No.. Start the DMAs */
/* No.. Start the DMAs then the SPI */
spi_dmarxstart(priv);
spi_dmatxstart(priv);
spi_enable(priv, true);
spi_modifyreg(priv, STM32_SPI_CR1_OFFSET, 0, SPI_CR1_CSTART);
}
else
{
@ -1948,20 +1945,32 @@ static void spi_exchange(FAR struct spi_dev_s *dev, FAR const void *txbuffer,
priv->trigarmed = true;
}
#else
/* Start the DMAs */
/* Start the DMAs then the SPI */
spi_dmarxstart(priv);
spi_dmatxstart(priv);
spi_enable(priv, true);
spi_modifyreg(priv, STM32_SPI_CR1_OFFSET, 0, SPI_CR1_CSTART);
#endif
/* Then wait for each to complete */
ret = spi_dmarxwait(priv);
if (ret >= 0)
{
ret = spi_dmatxwait(priv);
UNUSED(ret);
}
spi_dmarxwait(priv);
spi_dmatxwait(priv);
/* To close communication it is mandatory to follow these steps in
* order:
* 1. Disable DMA request for Tx and Rx in the DMA registers, if the
* DMA issued.
* 2. Disable the SPI by following the SPI disable procedure.
* 3. Disable DMA Tx and Rx buffers by clearing the TXDMAEN and RXDMAEN
* bits in the SPI_CFG1 register, if DMA Tx and/or DMA Rx are used.
*/
spi_enable(priv, false);
spi_modifyreg(priv, STM32_SPI_CFG1_OFFSET, SPI_CFG1_TXDMAEN |
SPI_CFG1_RXDMAEN, 0);
spi_enable(priv, true);
#ifdef CONFIG_SPI_TRIGGER
priv->trigarmed = false;
@ -2012,7 +2021,8 @@ static int spi_trigger(FAR struct spi_dev_s *dev)
spi_dmarxstart(priv);
spi_dmatxstart(priv);
spi_enable(priv, true);
spi_modifyreg(priv, STM32_SPI_CR1_OFFSET, 0, SPI_CR1_CSTART);
return OK;
#else
return -ENOSYS;