From 0dcafa8ab800d1f534bb0cb51cd02a082cf34be6 Mon Sep 17 00:00:00 2001 From: Phil Elwell Date: Thu, 30 Apr 2020 12:43:05 +0100 Subject: [PATCH] ARM: dts: bcm2711: Allow 40-bit DMA for SPI Add the spi_dma4 DT parameter to enable use of the 40-bit DMA channels to drive SPI. Note that there are only 3-4 40-bit channels available, and using this parameter claims 2 of them. Usage: dtparam=spi_dma4 Signed-off-by: Phil Elwell --- arch/arm/boot/dts/bcm2711-rpi-4-b.dts | 2 ++ arch/arm/boot/dts/overlays/README | 4 ++++ 2 files changed, 6 insertions(+) --- a/arch/arm/boot/dts/bcm2711-rpi-4-b.dts +++ b/arch/arm/boot/dts/bcm2711-rpi-4-b.dts @@ -554,5 +554,7 @@ eth_led0 = <&phy1>,"led-modes:0"; eth_led1 = <&phy1>,"led-modes:4"; + spi_dma4 = <&spi0>, "dmas:0=", <&dma40>, + <&spi0>, "dmas:8=", <&dma40>; }; }; --- a/arch/arm/boot/dts/overlays/README +++ b/arch/arm/boot/dts/overlays/README @@ -159,6 +159,10 @@ Params: spi Set to "on" to enable the spi interfaces (default "off") + spi_dma4 Use to enable 40-bit DMA on spi interfaces + (the assigned value doesn't matter) + (2711 only) + random Set to "on" to enable the hardware random number generator (default "on")