stm32/dma: Make DMA2_Stream3 exclusive to SDIO when CYW43 enabled.

This prevents SPI4/5 from being used if SDIO and CYW43 are enabled, because
the DMA for the SDIO is used on an IRQ and must be exclusivly available for
use by the SDIO peripheral.

Signed-off-by: Damien George <damien@micropython.org>

ports/stm32/dma.c

@@ -42,6 +42,10 @@
 
 #define ENABLE_SDIO (MICROPY_HW_ENABLE_SDCARD || MICROPY_HW_ENABLE_MMCARD || MICROPY_PY_NETWORK_CYW43)
 
+// If the CYW43 driver is enabled then SDIO DMA can happen preemptively (on an
+// IRQ) and so the SDIO needs exclusive access to its DMA resource.
+#define SDIO_NEEDS_EXCLUSIVE_DMA_ACCESS (MICROPY_PY_NETWORK_CYW43 && MICROPY_HW_SDIO_SDMMC == 1)
+
 typedef enum {
     dma_id_not_defined=-1,
     dma_id_0,
@@ -298,11 +302,13 @@ const dma_descr_t dma_SPI_1_RX = { DMA2_Stream2, DMA_CHANNEL_3, dma_id_10,  &dma
 #if MICROPY_HW_ENABLE_I2S
 const dma_descr_t dma_I2S_1_RX = { DMA2_Stream2, DMA_CHANNEL_3, dma_id_10,  &dma_init_struct_i2s };
 #endif
-const dma_descr_t dma_SPI_5_RX = { DMA2_Stream3, DMA_CHANNEL_2, dma_id_11,  &dma_init_struct_spi_i2c };
 #if ENABLE_SDIO
 const dma_descr_t dma_SDIO_0 = { DMA2_Stream3, DMA_CHANNEL_4, dma_id_11,  &dma_init_struct_sdio };
 #endif
+#if !SDIO_NEEDS_EXCLUSIVE_DMA_ACCESS
+const dma_descr_t dma_SPI_5_RX = { DMA2_Stream3, DMA_CHANNEL_2, dma_id_11,  &dma_init_struct_spi_i2c };
 const dma_descr_t dma_SPI_4_RX = { DMA2_Stream3, DMA_CHANNEL_5, dma_id_11,  &dma_init_struct_spi_i2c };
+#endif
 const dma_descr_t dma_SPI_5_TX = { DMA2_Stream4, DMA_CHANNEL_2, dma_id_12,  &dma_init_struct_spi_i2c };
 const dma_descr_t dma_SPI_4_TX = { DMA2_Stream4, DMA_CHANNEL_5, dma_id_12,  &dma_init_struct_spi_i2c };
 const dma_descr_t dma_SPI_6_TX = { DMA2_Stream5, DMA_CHANNEL_1, dma_id_13,  &dma_init_struct_spi_i2c };