sergiotarxz/nuttx
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

arm/stm32 add STM32_SPI_DMATHRESHOLD

Browse Source
This commit is contained in:
Daniel Agar 2020-03-02 16:02:54 -05:00 committed by Abdelatif Guettouche
parent 0be87af99d
commit afb2248b7a
2 changed files with 36 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
arch/arm/src/stm32/Kconfig
View File

@ -8820,6 +8820,15 @@ config STM32_SPI1_DMA
---help---
Use DMA to improve SPI1 transfer performance.
config STM32_SPI_DMATHRESHOLD
int "SPI DMA threshold"
default 4
depends on STM32_SPI_DMA
---help---
When SPI DMA is enabled, small DMA transfers will still be performed
by polling logic. But we need a threshold value to determine what
is small.
config STM32_SPI2_DMA
bool "SPI2 DMA"
default n

31
arch/arm/src/stm32/stm32_spi.c
View File

@ -1677,16 +1677,39 @@ static void spi_exchange(FAR struct spi_dev_s *dev, FAR const void *txbuffer,
{
FAR struct stm32_spidev_s *priv = (FAR struct stm32_spidev_s *)dev;
#ifdef CONFIG_STM32_DMACAPABLE
DEBUGASSERT(priv != NULL);
#ifdef CONFIG_STM32_SPI_DMATHRESHOLD
/* Convert the number of word to a number of bytes */
size_t nbytes = (priv->nbits > 8) ? nwords << 1 : nwords;
/* If this is a small SPI transfer, then let spi_exchange_nodma() do the work. */
if (nbytes <= CONFIG_STM32_SPI_DMATHRESHOLD)
{
spi_exchange_nodma(dev, txbuffer, rxbuffer, nwords);
return;
}
#endif
if ((priv->rxdma == NULL) || (priv->txdma == NULL) ||
(txbuffer && !stm32_dmacapable((uint32_t)txbuffer, nwords, priv->txccr)) ||
(rxbuffer && !stm32_dmacapable((uint32_t)rxbuffer, nwords, priv->rxccr)) ||
up_interrupt_context())
{
/* Invalid DMA channels, unsupported memory region, or interrupt context, fall
/* Invalid DMA channels, or interrupt context, fall
* back to non-DMA method.
*/
spi_exchange_nodma(dev, txbuffer, rxbuffer, nwords);
return;
}
#ifdef CONFIG_STM32_DMACAPABLE
if ((txbuffer && !stm32_dmacapable((uint32_t)txbuffer, nwords, priv->txccr)) ||
(rxbuffer && !stm32_dmacapable((uint32_t)rxbuffer, nwords, priv->rxccr)))
{
/* Unsupported memory region fall back to non-DMA method. */
spi_exchange_nodma(dev, txbuffer, rxbuffer, nwords);
}
else