samv7: add support for USART TX DMA transfers

This commit adds support for TX DMA transfers for USART peripheral. Code refactor in sam_serial.h was also required in order to have correct defines for all possible cases (both RX and TX DMA used, just one used, none used). Signed-off-by: Michal Lenc <[email protected]>
michallenc · Feb 27, 2024 · ff9ca3e · ff9ca3e
1 parent 1eaeef5
commit ff9ca3e
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diff --git a/arch/arm/src/samv7/Kconfig b/arch/arm/src/samv7/Kconfig
@@ -1729,6 +1729,14 @@ endmenu # SDRAM Configuration
 menu "Serial Driver Configuration"
 	depends on SAMV7_HAVE_USART0 || SAMV7_HAVE_USART1 || SAMV7_HAVE_USART2
 
+config SAMV7_SERIAL_TXDMA_BUFFER
+	int "Tx DMA buffer size"
+	default 128
+	range 32 4096
+	depends on SAMV7_HAVE_USART0 || SAMV7_HAVE_USART1 || SAMV7_HAVE_USART2
+	---help---
+		The DMA buffer size when using TX DMA to emulate a FIFO.
+
 config SAMV7_SERIAL_RXDMA_BUFFER
 	int "Rx DMA buffer size"
 	default 128