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Diffstat (limited to 'target/linux/bcm27xx/patches-5.4/950-0692-ARM-dts-bcm2711-Allow-40-bit-DMA-for-SPI.patch')
-rw-r--r--target/linux/bcm27xx/patches-5.4/950-0692-ARM-dts-bcm2711-Allow-40-bit-DMA-for-SPI.patch40
1 files changed, 40 insertions, 0 deletions
diff --git a/target/linux/bcm27xx/patches-5.4/950-0692-ARM-dts-bcm2711-Allow-40-bit-DMA-for-SPI.patch b/target/linux/bcm27xx/patches-5.4/950-0692-ARM-dts-bcm2711-Allow-40-bit-DMA-for-SPI.patch
new file mode 100644
index 0000000000..ac6543fe4f
--- /dev/null
+++ b/target/linux/bcm27xx/patches-5.4/950-0692-ARM-dts-bcm2711-Allow-40-bit-DMA-for-SPI.patch
@@ -0,0 +1,40 @@
+From 0dcafa8ab800d1f534bb0cb51cd02a082cf34be6 Mon Sep 17 00:00:00 2001
+From: Phil Elwell <phil@raspberrypi.com>
+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 <phil@raspberrypi.com>
+---
+ 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")
+