-- 
Matteo Scordino / Embedded Software Consultant
Mobile: +44 (0)7463701446

On Mon, 2020-11-02 at 11:05 +0100, Maxime Ripard wrote:

Hi!

On Fri, Oct 30, 2020 at 11:43:22PM +0000, Matteo Scordino wrote:

quoted

The Elimo Engineering Impetus is an Open Source Hardware System-on-Module
based on the SoChip S3 SoC.

It is meant for integration into carrier boards or, more generally,
larger designs, and uses an M2 connector to facilitate that.

Interfaces on the M.2/NGFF 42mm connector:
WiFi IEEE 802. 11abgn (on-module Realtek)
Bluetooth 4.2/BLE (on-module Realtek)
RGB LCD Interface (on-module connector)
MIPI Camera Interface (on-module connector)
IEEE 802. 3u Ethernet MAC (external connecto)
USB2.0 (Host, Device, OTG) (external connector)
Audio Line In/Out (external connector)

Signed-off-by: Matteo Scordino <redacted>
---
 arch/arm/boot/dts/sun8i-s3-elimo-impetus.dtsi | 51 +++++++++++++++++++
 1 file changed, 51 insertions(+)
 create mode 100644 arch/arm/boot/dts/sun8i-s3-elimo-impetus.dtsi

diff --git a/arch/arm/boot/dts/sun8i-s3-elimo-impetus.dtsi b/arch/arm/boot/dts/sun8i-s3-elimo-impetus.dtsi
new file mode 100644
index 000000000000..f219188fc9ba
--- /dev/null
+++ b/arch/arm/boot/dts/sun8i-s3-elimo-impetus.dtsi

@@ -0,0 +1,51 @@
+// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+/*
+ * Copyright (C) 2020 Matteo Scordino <matteo@elimo.io>
+ */
+
+/dts-v1/;
+#include "sun8i-v3.dtsi"
+#include "sunxi-common-regulators.dtsi"
+
+/ {
+	model = "Elimo Impetus SoM";
+	compatible = "elimo,impetus", "sochip,s3", "allwinner,sun8i-v3";
+
+	aliases {
+		serial0 = &uart0;
+		serial1 = &uart1;
+	};
+
+	chosen {
+		stdout-path = "serial0:115200n8";
+	};
+};
+
+&mmc0 {
+	broken-cd;
+	bus-width = <4>;
+	vmmc-supply = <&reg_vcc3v3>;
+	status = "okay";
+};
+
+&uart0 {
+	pinctrl-0 = <&uart0_pb_pins>;
+	pinctrl-names = "default";
+	status = "okay";
+};
+
+&uart1 {
+	pinctrl-0 = <&uart1_pg_pins>;
+	pinctrl-names = "default";
+	status = "okay";
+};

What is uart1 used for? the BT chip?

Maxime

No, BT is provided over SDIO by a Cypress 43455.
When used with the Initium carrier board, UART1 goes to an FTDI bridge that is
connected to the same USB-C connector that is used for power.
The idea being, if want an application that uses the UART to communicate with a
PC, it's convenient to provide power+connectivity on a single port.

I guess your point is that we would be better off only defining this in the DTS
of the carrier board?