target/linux/bcm27xx/patches-5.15/950-0679-overlays-Add-spi0-0cs-overlay.patch

   1 From 623f4a862134202e9f0705812cabe2abef6c2f9b Mon Sep 17 00:00:00 2001
   2 From: Phil Elwell <phil@raspberrypi.com>
   3 Date: Mon, 31 Jan 2022 21:01:25 +0000
   4 Subject: [PATCH] overlays: Add spi0-0cs overlay
   5
   6 An overlay to enable SPI0 without claiming any chip select GPIOs.
   7
   8 Signed-off-by: Phil Elwell <phil@raspberrypi.com>
   9 ---
  10  arch/arm/boot/dts/overlays/Makefile           |  1 +
  11  arch/arm/boot/dts/overlays/README             |  8 ++++
  12  .../boot/dts/overlays/spi0-0cs-overlay.dts    | 39 +++++++++++++++++++
  13  3 files changed, 48 insertions(+)
  14  create mode 100644 arch/arm/boot/dts/overlays/spi0-0cs-overlay.dts
  15
  16 --- a/arch/arm/boot/dts/overlays/Makefile
  17 +++ b/arch/arm/boot/dts/overlays/Makefile
  18 @@ -195,6 +195,7 @@ dtbo-$(CONFIG_ARCH_BCM2835) += \
  19         spi-gpio35-39.dtbo \
  20         spi-gpio40-45.dtbo \
  21         spi-rtc.dtbo \
  22 +       spi0-0cs.dtbo \
  23         spi0-1cs.dtbo \
  24         spi0-2cs.dtbo \
  25         spi1-1cs.dtbo \
  26 --- a/arch/arm/boot/dts/overlays/README
  27 +++ b/arch/arm/boot/dts/overlays/README
  28 @@ -3115,6 +3115,14 @@ Params: ds3232                  Select t
  29          cs_high                 This device requires an active-high CS
  30
  31
  32 +Name:   spi0-0cs
  33 +Info:   Don't claim any CS pins for SPI0. Requires a device with its chip
  34 +        select permanently enabled, but frees a GPIO for e.g. a DPI display.
  35 +Load:   dtoverlay=spi0-0cs,<param>=<val>
  36 +Params: no_miso                 Don't claim and use the MISO pin (9), freeing
  37 +                                it for other uses.
  38 +
  39 +
  40  Name:   spi0-1cs
  41  Info:   Only use one CS pin for SPI0
  42  Load:   dtoverlay=spi0-1cs,<param>=<val>
  43 --- /dev/null
  44 +++ b/arch/arm/boot/dts/overlays/spi0-0cs-overlay.dts
  45 @@ -0,0 +1,39 @@
  46 +/dts-v1/;
  47 +/plugin/;
  48 +
  49 +/ {
  50 +       compatible = "brcm,bcm2835";
  51 +
  52 +       fragment@0 {
  53 +               target = <&spi0_cs_pins>;
  54 +               frag0: __overlay__ {
  55 +                       brcm,pins;
  56 +               };
  57 +       };
  58 +
  59 +       fragment@1 {
  60 +               target = <&spi0>;
  61 +               __overlay__ {
  62 +                       cs-gpios;
  63 +                       status = "okay";
  64 +               };
  65 +       };
  66 +
  67 +       fragment@2 {
  68 +               target = <&spidev1>;
  69 +               __overlay__ {
  70 +                       status = "disabled";
  71 +               };
  72 +       };
  73 +
  74 +       fragment@3 {
  75 +               target = <&spi0_pins>;
  76 +               __dormant__ {
  77 +                       brcm,pins = <10 11>;
  78 +               };
  79 +       };
  80 +
  81 +       __overrides__ {
  82 +               no_miso = <0>,"=3";
  83 +       };
  84 +};