Add DMA configuration in stm32mp15x uart nodes by selecting dma direct mode and alternate REQ/ACK dma protocol for uart. DMA direct mode allows to bypass DMA FIFO. Each DMA request immediately initiates a transfer from/to the memory. This allows USART to get data transferred, even when the transfer ends before the DMA FIFO completion. Default REQ/ACK DMA protocol consists in maintaining ACK signal up to the removal of REQuest and the transfer completion. In case of alternative REQ/ACK protocol, ACK de-assertion does not wait the removal of the REQuest, but only the transfer completion. Due to a possible DMA stream lock when transferring data to/from STM32 USART/UART, select this alternative protocol in STM32 USART/UART nodes. Signed-off-by: Valentin Caron <valentin.caron@xxxxxxxxxxx> Signed-off-by: Erwan Le Ray <erwan.leray@xxxxxxxxxxx> diff --git a/arch/arm/boot/dts/stm32mp151.dtsi b/arch/arm/boot/dts/stm32mp151.dtsi index 1cfc2f011e70..e86006ae137b 100644 --- a/arch/arm/boot/dts/stm32mp151.dtsi +++ b/arch/arm/boot/dts/stm32mp151.dtsi @@ -455,6 +455,9 @@ interrupts-extended = <&exti 27 IRQ_TYPE_LEVEL_HIGH>; clocks = <&rcc USART2_K>; wakeup-source; + dmas = <&dmamux1 43 0x400 0x15>, + <&dmamux1 44 0x400 0x11>; + dma-names = "rx", "tx"; status = "disabled"; }; @@ -464,6 +467,9 @@ interrupts-extended = <&exti 28 IRQ_TYPE_LEVEL_HIGH>; clocks = <&rcc USART3_K>; wakeup-source; + dmas = <&dmamux1 45 0x400 0x15>, + <&dmamux1 46 0x400 0x11>; + dma-names = "rx", "tx"; status = "disabled"; }; @@ -473,6 +479,9 @@ interrupts-extended = <&exti 30 IRQ_TYPE_LEVEL_HIGH>; clocks = <&rcc UART4_K>; wakeup-source; + dmas = <&dmamux1 63 0x400 0x15>, + <&dmamux1 64 0x400 0x11>; + dma-names = "rx", "tx"; status = "disabled"; }; @@ -482,6 +491,9 @@ interrupts-extended = <&exti 31 IRQ_TYPE_LEVEL_HIGH>; clocks = <&rcc UART5_K>; wakeup-source; + dmas = <&dmamux1 65 0x400 0x15>, + <&dmamux1 66 0x400 0x11>; + dma-names = "rx", "tx"; status = "disabled"; }; @@ -588,6 +600,9 @@ interrupts-extended = <&exti 32 IRQ_TYPE_LEVEL_HIGH>; clocks = <&rcc UART7_K>; wakeup-source; + dmas = <&dmamux1 79 0x400 0x15>, + <&dmamux1 80 0x400 0x11>; + dma-names = "rx", "tx"; status = "disabled"; }; @@ -597,6 +612,9 @@ interrupts-extended = <&exti 33 IRQ_TYPE_LEVEL_HIGH>; clocks = <&rcc UART8_K>; wakeup-source; + dmas = <&dmamux1 81 0x400 0x15>, + <&dmamux1 82 0x400 0x11>; + dma-names = "rx", "tx"; status = "disabled"; }; @@ -678,6 +696,9 @@ interrupts-extended = <&exti 29 IRQ_TYPE_LEVEL_HIGH>; clocks = <&rcc USART6_K>; wakeup-source; + dmas = <&dmamux1 71 0x400 0x15>, + <&dmamux1 72 0x400 0x11>; + dma-names = "rx", "tx"; status = "disabled"; }; -- 2.17.1
