Re: [PATCH 08/10] arm64: dts: add description for solidrun imx8mp hummingboard-iiot

[Josua Mayer <josua@solid-run.com>]

Hi Alex,

Am 29.10.25 um 10:23 schrieb Alexander Dahl:
> Hello Josua,
>
> Am Tue, Oct 28, 2025 at 12:24:36PM +0000 schrieb Josua Mayer:
>> Am 27.10.25 um 18:48 schrieb Josua Mayer:
>>
>>> Add description for the SolidRun i.MX8MP HummingBoard IIoT.
>>> The board is a new design around the i.MX8MP System on Module, not
>>> sharing much with previous HummingBoards.
>>>
>>> It comes with some common features:
>>> - 3x USB-3.0 Type A connector
>>> - 2x 1Gbps RJ45 Ethernet
>>> - USB Type-C Console Port
>>> - microSD connector
>>> - RTC with backup battery
>>> - RGB Status LED
>>> - 1x M.2 M-Key connector with PCI-E Gen. 3 x1
>>> - 1x M.2 B-Key connector with USB-2.0/3.0 + SIM card holder
>>> - 1x LVDS Display Connector
>>> - 1x DSI Display Connector
>>> - GPIO header
>>> - 2x RS232/RS485 ports (configurable)
>>> - 2x CAN
>>>
>>> In addition there is a board-to-board expansion connector to support
>>> custom daughter boards with access to SPI, a range of GPIOs and -
>>> notably - CAN and UART. Both 2x CAN and 2x UART can be muxed either
>>> to this b2b connector, or a termianl block connector on the base board.
>>>
>>> The routing choice for UART and CAN is expressed through gpio
>>> mux-controllers in DT and can be changed by applying dtb addons.
>>>
>>> Four dtb addons are provided:
>>>
>>> - dsi panel Winstar WJ70N3TYJHMNG0
>>> - lvds panel Winstar WF70A8SYJHLNGA
>>> - RS485 on UART port "A" (default rs232)
>>> - RS485 on UART port "B" (default rs232)
>>>
>>> Signed-off-by: Josua Mayer <josua@solid-run.com>
>>> ---
>>>  arch/arm64/boot/dts/freescale/Makefile             |   6 +
>>>  ...hummingboard-iiot-panel-dsi-WJ70N3TYJHMNG0.dtso |  70 ++
>>>  ...ummingboard-iiot-panel-lvds-WF70A8SYJHLNGA.dtso | 105 +++
>>>  .../imx8mp-hummingboard-iiot-rs485-a.dtso          |  18 +
>>>  .../imx8mp-hummingboard-iiot-rs485-b.dtso          |  18 +
>>>  .../dts/freescale/imx8mp-hummingboard-iiot.dts     | 710 +++++++++++++++++++++
>>>  6 files changed, 927 insertions(+)
>> cut
>>> diff --git a/arch/arm64/boot/dts/freescale/imx8mp-hummingboard-iiot.dts b/arch/arm64/boot/dts/freescale/imx8mp-hummingboard-iiot.dts
>>> new file mode 100644
>>> index 0000000000000..2e4cb676bc9da
>>> --- /dev/null
>>> +++ b/arch/arm64/boot/dts/freescale/imx8mp-hummingboard-iiot.dts
>> cut
>>> +	led-controller@30 {
>>> +		compatible = "ti,lp5562";
>>> +		reg = <0x30>;
>>> +		/* use internal clock, could use external generated by rtc */
>>> +		clock-mode = /bits/ 8 <1>;
>>> +		#address-cells = <1>;
>>> +		#size-cells = <0>;
>>> +
>>> +		multi-led@0 {
>>> +			reg = <0x0>;
>>> +			color = <LED_COLOR_ID_RGB>;
>>> +			#address-cells = <1>;
>>> +			#size-cells = <0>;
>>> +
>>> +			led@0 {
>>> +				reg = <0x0>;
>>> +				color = <LED_COLOR_ID_RED>;
>>> +				led-cur = /bits/ 8 <0x32>;
>>> +				max-cur = /bits/ 8 <0x64>;
>>> +			};
>>> +
>>> +			led@1 {
>>> +				reg = <0x1>;
>>> +				color = <LED_COLOR_ID_GREEN>;
>>> +				led-cur = /bits/ 8 <0x19>;
>>> +				max-cur = /bits/ 8 <0x32>;
>>> +			};
>>> +
>>> +			led@2 {
>>> +				reg = <0x2>;
>>> +				color = <LED_COLOR_ID_BLUE>;
>>> +				led-cur = /bits/ 8 <0x19>;
>>> +				max-cur = /bits/ 8 <0x32>;
>>> +			};
>>> +		};
>>> +
>>> +		led@3 {
>>> +			reg = <3>;
>>> +			chan-name = "D8";
>> chan-name gives the led the name D6 in sysfs.
>>
>> The bindings do not allow however setting chan-name on
>> the multi-led, and it has an auto-generated name in sysfs.
>>
>> Am I missing something? Can multi-leds have a custom name?
> The sysfs names are auto-generated based on the attributes "color",
> "function", and "label" with the last being discouraged for new
> designs.
Thank you for reminding me of this one!
> If the "ti,lp5562" driver does nothing special,you could
> add "function" to the multi-led node and see if that fits your needs.
The board is not a complete product by itself so we have not chosen
a specific function for each led.
Therefore only color and label are actually applicable.

After testing on v6.18-rc1 I can state that leds-lp5562 driver does
something special - function and label properties do not have any
impact on the names in sysfs.

However I could set label on both LEDs regardless?

>
> Adding linux-leds to Cc, because this is a LED related question.
>
> Greets
> Alex
>
>> In v6.6 leds-lp5562 driver if I set in each multi-led led@[0-2] sub-node
>> chan-name to the same string "D7" - then the sysfs name becomes D7.
>>
>>> +			color = <LED_COLOR_ID_GREEN>;
>>> +			led-cur = /bits/ 8 <0x19>;
>>> +			max-cur = /bits/ 8 <0x64>;
>>> +		};
>>> +	};