target/linux/bcm27xx/patches-5.4/950-0701-ARM-dts-bcm2711-Allow-40-bit-DMA-for-SPI.patch

   1 From 0dcafa8ab800d1f534bb0cb51cd02a082cf34be6 Mon Sep 17 00:00:00 2001
   2 From: Phil Elwell <phil@raspberrypi.com>
   3 Date: Thu, 30 Apr 2020 12:43:05 +0100
   4 Subject: [PATCH] ARM: dts: bcm2711: Allow 40-bit DMA for SPI
   5
   6 Add the spi_dma4 DT parameter to enable use of the 40-bit DMA channels
   7 to drive SPI. Note that there are only 3-4 40-bit channels available,
   8 and using this parameter claims 2 of them.
   9
  10 Usage: dtparam=spi_dma4
  11
  12 Signed-off-by: Phil Elwell <phil@raspberrypi.com>
  13 ---
  14  arch/arm/boot/dts/bcm2711-rpi-4-b.dts | 2 ++
  15  arch/arm/boot/dts/overlays/README     | 4 ++++
  16  2 files changed, 6 insertions(+)
  17
  18 --- a/arch/arm/boot/dts/bcm2711-rpi-4-b.dts
  19 +++ b/arch/arm/boot/dts/bcm2711-rpi-4-b.dts
  20 @@ -554,5 +554,7 @@
  21                 eth_led0 = <&phy1>,"led-modes:0";
  22                 eth_led1 = <&phy1>,"led-modes:4";
  23
  24 +               spi_dma4 = <&spi0>, "dmas:0=", <&dma40>,
  25 +                          <&spi0>, "dmas:8=", <&dma40>;
  26         };
  27  };
  28 --- a/arch/arm/boot/dts/overlays/README
  29 +++ b/arch/arm/boot/dts/overlays/README
  30 @@ -159,6 +159,10 @@ Params:
  31          spi                     Set to "on" to enable the spi interfaces
  32                                  (default "off")
  33
  34 +        spi_dma4                Use to enable 40-bit DMA on spi interfaces
  35 +                                (the assigned value doesn't matter)
  36 +                                (2711 only)
  37 +
  38          random                  Set to "on" to enable the hardware random
  39                                  number generator (default "on")
  40