85 lines
2.1 KiB
Diff
85 lines
2.1 KiB
Diff
From 623f4a862134202e9f0705812cabe2abef6c2f9b Mon Sep 17 00:00:00 2001
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From: Phil Elwell <phil@raspberrypi.com>
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Date: Mon, 31 Jan 2022 21:01:25 +0000
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Subject: [PATCH] overlays: Add spi0-0cs overlay
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An overlay to enable SPI0 without claiming any chip select GPIOs.
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Signed-off-by: Phil Elwell <phil@raspberrypi.com>
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---
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arch/arm/boot/dts/overlays/Makefile | 1 +
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arch/arm/boot/dts/overlays/README | 8 ++++
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.../boot/dts/overlays/spi0-0cs-overlay.dts | 39 +++++++++++++++++++
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3 files changed, 48 insertions(+)
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create mode 100644 arch/arm/boot/dts/overlays/spi0-0cs-overlay.dts
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--- a/arch/arm/boot/dts/overlays/Makefile
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+++ b/arch/arm/boot/dts/overlays/Makefile
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@@ -195,6 +195,7 @@ dtbo-$(CONFIG_ARCH_BCM2835) += \
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spi-gpio35-39.dtbo \
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spi-gpio40-45.dtbo \
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spi-rtc.dtbo \
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+ spi0-0cs.dtbo \
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spi0-1cs.dtbo \
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spi0-2cs.dtbo \
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spi1-1cs.dtbo \
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--- a/arch/arm/boot/dts/overlays/README
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+++ b/arch/arm/boot/dts/overlays/README
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@@ -3115,6 +3115,14 @@ Params: ds3232 Select t
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cs_high This device requires an active-high CS
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+Name: spi0-0cs
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+Info: Don't claim any CS pins for SPI0. Requires a device with its chip
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+ select permanently enabled, but frees a GPIO for e.g. a DPI display.
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+Load: dtoverlay=spi0-0cs,<param>=<val>
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+Params: no_miso Don't claim and use the MISO pin (9), freeing
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+ it for other uses.
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+
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+
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Name: spi0-1cs
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Info: Only use one CS pin for SPI0
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Load: dtoverlay=spi0-1cs,<param>=<val>
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--- /dev/null
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+++ b/arch/arm/boot/dts/overlays/spi0-0cs-overlay.dts
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@@ -0,0 +1,39 @@
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+/dts-v1/;
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+/plugin/;
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+
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+/ {
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+ compatible = "brcm,bcm2835";
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+
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+ fragment@0 {
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+ target = <&spi0_cs_pins>;
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+ frag0: __overlay__ {
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+ brcm,pins;
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+ };
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+ };
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+
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+ fragment@1 {
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+ target = <&spi0>;
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+ __overlay__ {
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+ cs-gpios;
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+ status = "okay";
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+ };
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+ };
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+
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+ fragment@2 {
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+ target = <&spidev1>;
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+ __overlay__ {
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+ status = "disabled";
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+ };
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+ };
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+
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+ fragment@3 {
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+ target = <&spi0_pins>;
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+ __dormant__ {
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+ brcm,pins = <10 11>;
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+ };
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+ };
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+
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+ __overrides__ {
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+ no_miso = <0>,"=3";
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+ };
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+};
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