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
6 An overlay to enable SPI0 without claiming any chip select GPIOs.
8 Signed-off-by: Phil Elwell <phil@raspberrypi.com>
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
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) += \
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
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
41 Info: Only use one CS pin for SPI0
42 Load: dtoverlay=spi0-1cs,<param>=<val>
44 +++ b/arch/arm/boot/dts/overlays/spi0-0cs-overlay.dts
50 + compatible = "brcm,bcm2835";
53 + target = <&spi0_cs_pins>;
54 + frag0: __overlay__ {
68 + target = <&spidev1>;
70 + status = "disabled";
75 + target = <&spi0_pins>;
77 + brcm,pins = <10 11>;