kumquat-buildroot/board/lego/ev3/patches/linux/0001-adc-device-tree-node.patch
David Lechner da6d097881 lego: ev3: use mainline kernel
It is finally possible to boot LEGO MINDSTORMS EV3 from the mainline
Linux kernel. This patch updates the defconfg to use the mainline kernel
instead of the custom ev3dev kernel.

[Peter: lock kernel headers version]
Signed-off-by: David Lechner <david@lechnology.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
2017-05-16 22:55:37 +02:00

57 lines
1.4 KiB
Diff

From 8a81ff173c5c9a0ab1df84fab17971dbcce8490a Mon Sep 17 00:00:00 2001
From: David Lechner <david@lechnology.com>
Date: Tue, 7 Feb 2017 13:22:07 -0600
Subject: ARM: da850-lego-ev3: Add device tree node for A/DC
This adds a node for the TI ADS7957 analog/digital converter on LEGO
MINDSTORMS EV3 as well as a regulator node that is used by the A/DC node.
Signed-off-by: David Lechner <david@lechnology.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
---
arch/arm/boot/dts/da850-lego-ev3.dts | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)
diff --git a/arch/arm/boot/dts/da850-lego-ev3.dts b/arch/arm/boot/dts/da850-lego-ev3.dts
index 112ec92..0309537 100644
--- a/arch/arm/boot/dts/da850-lego-ev3.dts
+++ b/arch/arm/boot/dts/da850-lego-ev3.dts
@@ -139,6 +139,19 @@
enable-active-high;
regulator-boot-on;
};
+
+ /*
+ * This is a simple voltage divider on VCC5V to provide a 2.5V
+ * reference signal to the ADC.
+ */
+ adc_ref: regulator2 {
+ compatible = "regulator-fixed";
+ regulator-name = "adc ref";
+ regulator-min-microvolt = <2500000>;
+ regulator-max-microvolt = <2500000>;
+ regulator-boot-on;
+ vin-supply = <&vcc5v>;
+ };
};
&pmx_core {
@@ -293,6 +306,14 @@
};
};
};
+
+ adc: adc@3 {
+ compatible = "ti,ads7957";
+ reg = <3>;
+ #io-channel-cells = <1>;
+ spi-max-frequency = <10000000>;
+ vref-supply = <&adc_ref>;
+ };
};
&gpio {
--
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