patrick/zephyr
1
0
Fork 0
Code Issues Pull requests Actions 7 Packages Projects Releases Wiki Activity

drivers: spi: stm32 driver with dma checking spi busy status flag

Browse source 
Defines a function to control the spi busy state during DMA transfer.
After the DMA Tx, the spi might still have some data to Transmit.
The driver must wait for the SPI Tx before sending the next packet.
This is not required for the Rx part as the DMA Rx is already done.
Some mcus like stm32H7 have a TX complete bit, other must wait for the
TXE and BSY line.

Signed-off-by: Francois Ramu <francois.ramu@st.com>
This commit is contained in:
Francois Ramu 2022-01-05 16:41:35 +01:00 committed by Maureen Helm
parent 0ec7af9c17
commit 081e2d5a54
2 changed files with 17 additions and 8 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

8
drivers/spi/spi_ll_stm32.c
View file

@ -756,12 +756,8 @@ static int transceive_dma(const struct device *dev,
}
#endif
/* wait until TX buffer is really empty */
while (ll_func_tx_is_empty(spi) == 0) {
}
/* wait until hardware is really ready */
while (ll_func_spi_is_busy(spi) == 1) {
/* wait until spi is no more busy (spi TX fifo is really empty) */
while (ll_func_spi_dma_busy(spi) == 0) {
}
LL_SPI_DisableDMAReq_TX(spi);

17
drivers/spi/spi_ll_stm32.h
View file

@ -53,6 +53,20 @@ struct spi_stm32_data {
#endif
};
#ifdef CONFIG_SPI_STM32_DMA
/* checks that DMA Tx packet is fully transmitted over the SPI */
static inline uint32_t ll_func_spi_dma_busy(SPI_TypeDef *spi)
{
#ifdef LL_SPI_SR_TXC
return LL_SPI_IsActiveFlag_TXC(spi);
#else
/* the SPI Tx empty and busy flags are needed */
return (LL_SPI_IsActiveFlag_TXE(spi) &&
!LL_SPI_IsActiveFlag_BSY(spi));
#endif
}
#endif /* CONFIG_SPI_STM32_DMA */
static inline uint32_t ll_func_tx_is_empty(SPI_TypeDef *spi)
{
#if defined(CONFIG_SOC_SERIES_STM32MP1X) || \
@ -154,8 +168,7 @@ static inline uint32_t ll_func_spi_is_busy(SPI_TypeDef *spi)
#if defined(CONFIG_SOC_SERIES_STM32MP1X) || \
defined(CONFIG_SOC_SERIES_STM32H7X) || \
defined(CONFIG_SOC_SERIES_STM32U5X)
return (!LL_SPI_IsActiveFlag_MODF(spi) &&
!LL_SPI_IsActiveFlag_TXC(spi));
return LL_SPI_IsActiveFlag_EOT(spi);
#else
return LL_SPI_IsActiveFlag_BSY(spi);
#endif