Re: [PATCH 2/2] ARM: dts: aspeed: asrock: Add ASRock X570D4U BMC

From: Zev Weiss
Date: Mon Nov 27 2023 - 21:45:44 EST


Hi Renze,

Happy to see this moving forward again! A few comments below, mostly pretty minor stuff.

On Mon, Nov 27, 2023 at 05:30:17PM PST, Renze Nicolai wrote:
This is a relatively low-cost AST2500-based Amd Ryzen 5000 Series
micro-ATX board that we hope can provide a decent platform for OpenBMC
development.

This initial device-tree provides the necessary configuration for
basic BMC functionality such as serial console, KVM support
and POST code snooping.

Signed-off-by: Renze Nicolai <renze@xxxxxxxxx>
---
arch/arm/boot/dts/aspeed/Makefile | 1 +
.../dts/aspeed/aspeed-bmc-asrock-x570d4u.dts | 344 ++++++++++++++++++
2 files changed, 345 insertions(+)
create mode 100644 arch/arm/boot/dts/aspeed/aspeed-bmc-asrock-x570d4u.dts

diff --git a/arch/arm/boot/dts/aspeed/Makefile b/arch/arm/boot/dts/aspeed/Makefile
index d3ac20e316d0..2205bd079d0c 100644
--- a/arch/arm/boot/dts/aspeed/Makefile
+++ b/arch/arm/boot/dts/aspeed/Makefile
@@ -10,6 +10,7 @@ dtb-$(CONFIG_ARCH_ASPEED) += \
aspeed-bmc-arm-stardragon4800-rep2.dtb \
aspeed-bmc-asrock-e3c246d4i.dtb \
aspeed-bmc-asrock-romed8hm3.dtb \
+ aspeed-bmc-asrock-x570d4u.dtb \
aspeed-bmc-bytedance-g220a.dtb \
aspeed-bmc-delta-ahe50dc.dtb \
aspeed-bmc-facebook-bletchley.dtb \
diff --git a/arch/arm/boot/dts/aspeed/aspeed-bmc-asrock-x570d4u.dts b/arch/arm/boot/dts/aspeed/aspeed-bmc-asrock-x570d4u.dts
new file mode 100644
index 000000000000..9fb1d76abacb
--- /dev/null
+++ b/arch/arm/boot/dts/aspeed/aspeed-bmc-asrock-x570d4u.dts
@@ -0,0 +1,344 @@
+// SPDX-License-Identifier: GPL-2.0+
+/dts-v1/;
+#include "aspeed-g5.dtsi"
+#include <dt-bindings/gpio/aspeed-gpio.h>
+
+/ {
+ model = "Asrock Rack X570D4U BMC";
+ compatible = "asrock,x570d4u-bmc";

This should probably be:

compatible = "asrock,x570d4u-bmc", "aspeed,ast2500";

+
+ chosen {
+ stdout-path = &uart5;
+ bootargs = "console=ttyS4,115200 earlycon";
+ };
+
+ memory@80000000 {
+ reg = <0x80000000 0x20000000>;
+ };
+
+ reserved-memory {
+ #address-cells = <1>;
+ #size-cells = <1>;
+ ranges;
+
+ pci_memory: region@9A000000 {
+ no-map;
+ reg = <0x9A000000 0x00010000>; /* 64K */

Minor style nit: while it's not completely universal, most device-trees (and kernel code in general) generally prefers lower-case letters in hex literals.

+ };
+
+ video_engine_memory: jpegbuffer {
+ size = <0x02800000>; /* 40M */
+ alignment = <0x01000000>;
+ compatible = "shared-dma-pool";
+ reusable;
+ };
+
+ gfx_memory: framebuffer {
+ size = <0x01000000>;
+ alignment = <0x01000000>;
+ compatible = "shared-dma-pool";
+ reusable;
+ };
+ };

The three blocks above (chosen, memory, reserved-memory) all have their bodies indented by an extra tab, which would be good to trim off.

+
+ leds {
+ compatible = "gpio-leds";
+
+ heartbeat {
+ /* led-heartbeat-n */
+ gpios = <&gpio ASPEED_GPIO(H, 6) GPIO_ACTIVE_LOW>;
+ linux,default-trigger = "timer";
+ };
+
+ system-fault {
+ /* led-fault-n */
+ gpios = <&gpio ASPEED_GPIO(Z, 2) GPIO_ACTIVE_LOW>;
+ panic-indicator;
+ };

For completeness these should have 'function' and 'color' attributes added as well (you'll need to #include <dt-bindings/leds/common.h> for the LED_FUNCTION_* and LED_COLOR_ID_* macros to use for that). Also, the preferred names for the nodes would now be led-0 and led-1 (the kernel will assign them more recognizable names in /sys/class/leds based on the color and function attributes).

+ };
+
+ iio-hwmon {
+ compatible = "iio-hwmon";
+ io-channels = <&adc 0>, <&adc 1>, <&adc 2>, <&adc 3>, <&adc 4>,
+ <&adc 5>, <&adc 6>, <&adc 7>, <&adc 8>, <&adc 9>,
+ <&adc 10>, <&adc 11>, <&adc 12>;
+ };
+};
+
+&gpio {
+ status = "okay";
+ gpio-line-names =
+ /*A0-A3*/ "status-locatorled-n", "", "button-nmi-n", "",
+ /*A4-A7*/ "", "", "", "",
+ /*B0-B3*/ "input-bios-post-cmplt-n", "", "", "",
+ /*B4-B7*/ "", "", "", "",
+ /*C0-C3*/ "", "", "", "",
+ /*C4-C7*/ "", "", "control-locatorbutton", "",
+ /*D0-D3*/ "button-power", "control-power", "button-reset", "control-reset",
+ /*D4-D7*/ "", "", "", "",
+ /*E0-E3*/ "", "", "", "",
+ /*E4-E7*/ "", "", "", "",
+ /*F0-F3*/ "", "", "", "",
+ /*F4-F7*/ "", "", "", "",
+ /*G0-G3*/ "output-rtc-battery-voltage-read-enable", "input-id0", "input-id1", "input-id2",
+ /*G4-G7*/ "input-alert1-n", "input-alert2-n", "input-alert3-n", "",
+ /*H0-H3*/ "", "", "", "",
+ /*H4-H7*/ "input-mfg", "", "led-heartbeat-n", "input-caseopen",
+ /*I0-I3*/ "", "", "", "",
+ /*I4-I7*/ "", "", "", "",
+ /*J0-J3*/ "output-bmc-ready", "", "", "",
+ /*J4-J7*/ "", "", "", "",
+ /*K0-K3*/ "", "", "", "",
+ /*K4-K7*/ "", "", "", "",
+ /*L0-L3*/ "", "", "", "",
+ /*L4-L7*/ "", "", "", "",
+ /*M0-M3*/ "", "", "", "",
+ /*M4-M7*/ "", "", "", "",
+ /*N0-N3*/ "", "", "", "",
+ /*N4-N7*/ "", "", "", "",
+ /*O0-O3*/ "", "", "", "",
+ /*O4-O7*/ "", "", "", "",
+ /*P0-P3*/ "", "", "", "",
+ /*P4-P7*/ "", "", "", "",
+ /*Q0-Q3*/ "", "", "", "",
+ /*Q4-Q7*/ "", "", "", "",
+ /*R0-R3*/ "", "", "", "",
+ /*R4-R7*/ "", "", "", "",
+ /*S0-S3*/ "input-bmc-pchhot-n", "", "", "",
+ /*S4-S7*/ "", "", "", "",
+ /*T0-T3*/ "", "", "", "",
+ /*T4-T7*/ "", "", "", "",
+ /*U0-U3*/ "", "", "", "",
+ /*U4-U7*/ "", "", "", "",
+ /*V0-V3*/ "", "", "", "",
+ /*V4-V7*/ "", "", "", "",
+ /*W0-W3*/ "", "", "", "",
+ /*W4-W7*/ "", "", "", "",
+ /*X0-X3*/ "", "", "", "",
+ /*X4-X7*/ "", "", "", "",
+ /*Y0-Y3*/ "", "", "", "",
+ /*Y4-Y7*/ "", "", "", "",
+ /*Z0-Z3*/ "", "", "led-fault-n", "output-bmc-throttle-n",
+ /*Z4-Z7*/ "", "", "", "",
+ /*AA0-AA3*/ "input-cpu1-thermtrip-latch-n", "", "input-cpu1-prochot-n", "",
+ /*AA4-AC7*/ "", "", "", "",
+ /*AB0-AB3*/ "", "", "", "",
+ /*AB4-AC7*/ "", "", "", "",
+ /*AC0-AC3*/ "", "", "", "",
+ /*AC4-AC7*/ "", "", "", "";
+
+
+ /* Assert output-bmc-ready to allow the BIOS to continue booting */
+ bmc-ready {
+ gpio-hog;
+ /* output-bmc-ready */
+ gpios = <ASPEED_GPIO(J, 0) GPIO_ACTIVE_LOW>;
+ output-high;
+ };

I did this on the e3c246d4i and I'm not sure it was entirely the right choice -- it does solve the problem of avoiding the host's boot sequence
sitting there waiting for a timeout to expire before proceeding, but it does so by essentially lying and asserting readiness at all times (when the host is probably expecting that to mean that the BMC is actually prepared to respond to IPMI commands on the KCS interface and such). In practice the only time I think it might cause any noticeable problems is if the host happens to reboot at just the wrong time relative to a BMC reboot, but ideally we'd have some more honest userspace logic to assert it at an appropriate time when it actually means something (though exactly what might be up for some discussion). Under the circumstances this may be the pragmatic approach for now, but if OpenBMC does ever arrive at something to solve that particular problem this would need to be backed out to make room for it.

+};
+
+&fmc {
+ status = "okay";
+ flash@0 {
+ status = "okay";
+ label = "bmc";
+ m25p,fast-read;
+ spi-max-frequency = <10000000>;

Over-indented block body again here.

+#include "openbmc-flash-layout-64.dtsi"
+ };
+};
+
+&uart5 {
+ status = "okay";
+};
+
+&vuart {
+ status = "okay";
+};
+
+&mac0 {
+ status = "okay";
+ pinctrl-names = "default";
+ pinctrl-0 = <&pinctrl_rgmii1_default &pinctrl_mdio1_default>;
+};
+
+&mac1 {
+ status = "okay";
+ pinctrl-names = "default";
+ pinctrl-0 = <&pinctrl_rmii2_default &pinctrl_mdio2_default>;
+ use-ncsi;
+};

mac0 & mac1 could make use of the recently-added support for retrieving MAC addresses from a location specified by an nvmem-cells property; see https://lore.kernel.org/openbmc/20231120121901.19817-6-zev@xxxxxxxxxxxxxxxxx/T/#u for an example (already mentioned off-list, just including here for the sake of completeness).

+
+&i2c0 {
+ status = "okay";
+};
+
+&i2c1 {
+ status = "okay";
+
+ w83773g@4c {
+ compatible = "nuvoton,w83773g";
+ reg = <0x4c>;
+ };
+};
+
+&i2c2 {
+ status = "okay";
+};
+
+&i2c3 {
+ status = "okay";
+};
+
+&i2c4 {
+ status = "okay";
+
+ i2c-switch@70 {

I'm guessing this mux is for the PCIe slots? (A brief comment indicating that might be nice if so, and maybe which channels are mapped to which specific slots if you happen to have worked that out.)

It'd probably also be good to add some aliases for the sub-busses of the mux so they get assigned consistent, predictable numbers.

+ compatible = "nxp,pca9545";
+ #address-cells = <1>;
+ #size-cells = <0>;
+ reg = <0x70>;
+
+ interrupt-parent = <&i2c_ic>;
+ interrupts = <4>;
+ interrupt-controller;
+ #interrupt-cells = <2>;
+
+ i2c@0 {
+ #address-cells = <1>;
+ #size-cells = <0>;
+ reg = <0>;
+ };
+
+ i2c@1 {
+ #address-cells = <1>;
+ #size-cells = <0>;
+ reg = <1>;
+ };
+
+ i2c@2 {
+ #address-cells = <1>;
+ #size-cells = <0>;
+ reg = <2>;
+ };
+
+ i2c@3 {
+ #address-cells = <1>;
+ #size-cells = <0>;
+ reg = <3>;
+ };
+ };
+};
+
+&i2c5 {
+ status = "okay";
+};
+
+&i2c7 {
+ status = "okay";
+
+ eeprom@57 {
+ compatible = "st,24c128", "atmel,24c128";
+ reg = <0x57>;
+ pagesize = <16>;
+ };

I assume this is the motherboard's FRU eeprom; if so and this is anything like the other ASRR boards I've dealt with, the BMC MAC addresses should be at offsets 0x3f80 (dedicated) and 0x3f88 (NCSI) within it.

+};
+
+&gfx {
+ status = "okay";
+};
+
+&pinctrl {
+ aspeed,external-nodes = <&gfx &lhc>;
+};
+
+&vhub {
+ status = "okay";
+};
+
+&ehci1 {
+ status = "okay";
+};
+&uhci {
+ status = "okay";
+};
+
+&kcs3 {
+ aspeed,lpc-io-reg = <0xca2>;
+ status = "okay";
+};
+
+&lpc_ctrl {
+ status = "okay";
+};
+
+&lpc_snoop {
+ status = "okay";
+ snoop-ports = <0x80>;
+};
+
+&p2a {
+ status = "okay";
+ memory-region = <&pci_memory>;
+};
+
+&video {
+ status = "okay";
+ memory-region = <&video_engine_memory>;
+};
+
+&pwm_tacho {
+ status = "okay";
+ pinctrl-names = "default";
+ pinctrl-0 = <&pinctrl_pwm0_default
+ &pinctrl_pwm1_default
+ &pinctrl_pwm2_default
+ &pinctrl_pwm3_default
+ &pinctrl_pwm4_default
+ &pinctrl_pwm5_default>;
+ fan@0 {
+ reg = <0x00>;
+ aspeed,fan-tach-ch = /bits/ 8 <0x00 0x01>;
+ };
+ fan@1 {
+ reg = <0x01>;
+ aspeed,fan-tach-ch = /bits/ 8 <0x02 0x03>;
+ };
+ fan@2 {
+ reg = <0x02>;
+ aspeed,fan-tach-ch = /bits/ 8 <0x04 0x05>;
+ };
+ fan@3 {
+ reg = <0x03>;
+ aspeed,fan-tach-ch = /bits/ 8 <0x06 0x07>;
+ };
+ fan@4 {
+ reg = <0x04>;
+ aspeed,fan-tach-ch = /bits/ 8 <0x08 0x09>;
+ };
+ fan@5 {
+ reg = <0x05>;
+ aspeed,fan-tach-ch = /bits/ 8 <0x0a 0x0b>;
+ };

Minor style nit: it's common (and nice IMO) to include a blank line between sibling nodes.

+};
+
+&adc {
+ status = "okay";
+ pinctrl-names = "default";
+ pinctrl-0 = <&pinctrl_adc0_default
+ &pinctrl_adc1_default
+ &pinctrl_adc2_default
+ &pinctrl_adc3_default
+ &pinctrl_adc4_default
+ &pinctrl_adc5_default
+ &pinctrl_adc6_default
+ &pinctrl_adc7_default
+ &pinctrl_adc8_default
+ &pinctrl_adc9_default
+ &pinctrl_adc10_default
+ &pinctrl_adc11_default
+ &pinctrl_adc12_default
+ &pinctrl_adc13_default
+ &pinctrl_adc14_default
+ &pinctrl_adc15_default>;
+};
--
2.43.0