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Subject: Re: [PATCH v10 1/4] MIPS: Loongson64: dts: update the display
 controller device node
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To:     Sergei Shtylyov <sergei.shtylyov@gmail.com>,
        Maxime Ripard <mripard@kernel.org>,
        Thomas Zimmermann <tzimmermann@suse.de>,
        Roland Scheidegger <sroland@vmware.com>,
        Zack Rusin <zackr@vmware.com>,
        Christian Gmeiner <christian.gmeiner@gmail.com>,
        David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        Rob Herring <robh+dt@kernel.org>,
        Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
        Dan Carpenter <dan.carpenter@oracle.com>,
        Krzysztof Kozlowski <krzk@kernel.org>,
        Andrey Zhizhikin <andrey.zhizhikin@leica-geosystems.com>,
        Sam Ravnborg <sam@ravnborg.org>,
        "David S . Miller" <davem@davemloft.net>,
        Jiaxun Yang <jiaxun.yang@flygoat.com>,
        Lucas Stach <l.stach@pengutronix.de>,
        Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
        Ilia Mirkin <imirkin@alum.mit.edu>,
        Qing Zhang <zhangqing@loongson.cn>,
        suijingfeng <suijingfeng@loongson.cn>
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        devicetree@vger.kernel.org, dri-devel@lists.freedesktop.org
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From:   Sui Jingfeng <15330273260@189.cn>
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On 2022/2/21 17:19, Sergei Shtylyov wrote:
> On 2/20/22 5:55 PM, Sui Jingfeng wrote:
>
>> From: suijingfeng <suijingfeng@loongson.cn>
>>
>> The display controller is a pci device, its PCI vendor id is 0x0014
>> its PCI device id is 0x7a06.
>>
>> 1) In order to let the driver to know which chip the DC is contained
>>     in, the compatible string of the display controller is updated
>>     according to the chip's name.
>>
>> 2) Add display controller device node for ls2k1000 SoC
>>
>> Reported-by: Krzysztof Kozlowski <krzk@kernel.org>
>> Signed-off-by: suijingfeng <suijingfeng@loongson.cn>
>> Signed-off-by: Sui Jingfeng <15330273260@189.cn>
>> ---
>>   arch/mips/boot/dts/loongson/loongson64-2k1000.dtsi | 8 ++++++++
>>   arch/mips/boot/dts/loongson/ls7a-pch.dtsi          | 7 ++-----
>>   2 files changed, 10 insertions(+), 5 deletions(-)
>>
>> diff --git a/arch/mips/boot/dts/loongson/loongson64-2k1000.dtsi b/arch/mips/boot/dts/loongson/loongson64-2k1000.dtsi
>> index 768cf2abcea3..af9cda540f9e 100644
>> --- a/arch/mips/boot/dts/loongson/loongson64-2k1000.dtsi
>> +++ b/arch/mips/boot/dts/loongson/loongson64-2k1000.dtsi
>> @@ -209,6 +209,14 @@ gpu@5,0 {
>>   				interrupt-parent = <&liointc0>;
>>   			};
>>   
>> +			lsdc: display-controller@6,0 {
>     Shouldn't the node name just be "display", according to the section 2.2.2
> of the DT spec?
>
> [...]
>> diff --git a/arch/mips/boot/dts/loongson/ls7a-pch.dtsi b/arch/mips/boot/dts/loongson/ls7a-pch.dtsi
>> index 2f45fce2cdc4..ec35ea9b2fe8 100644
>> --- a/arch/mips/boot/dts/loongson/ls7a-pch.dtsi
>> +++ b/arch/mips/boot/dts/loongson/ls7a-pch.dtsi
>> @@ -160,11 +160,8 @@ gpu@6,0 {
>>   				interrupt-parent = <&pic>;
>>   			};
>>   
>> -			dc@6,1 {
>> -				compatible = "pci0014,7a06.0",
>> -						   "pci0014,7a06",
>> -						   "pciclass030000",
>> -						   "pciclass0300";
>> +			lsdc: display-controller@6,1 {
>     Same here...
>
> [...]
>
> MBR, Sergey

Display sounds like a panel or monitor, while we are the device that driven the display device.

Running find . -name "*.dtsi" -type f | xargs grep "display-controller"
at drm-tip/arch/ directory show that there are a number of vendors using
display controller as theirnode name, for example Atmel and STM32.


./arm/boot/dts/pxa3xx.dtsi:		gcu: display-controller@54000000 {
./arm/boot/dts/at91sam9n12.dtsi:				hlcdc-display-controller {
./arm/boot/dts/at91sam9n12.dtsi:					compatible = "atmel,hlcdc-display-controller";
./arm/boot/dts/at91-dvk_su60_somc_lcm.dtsi:	hlcdc-display-controller {
./arm/boot/dts/stm32h743.dtsi:		ltdc: display-controller@50001000 {
./arm/boot/dts/stm32mp151.dtsi:		ltdc: display-controller@5a001000 {
./arm/boot/dts/at91sam9x5dm.dtsi:	hlcdc-display-controller {
./arm/boot/dts/gemini.dtsi:		display-controller@6a000000 {
./arm/boot/dts/stm32f429.dtsi:		ltdc: display-controller@40016800 {
./arm/boot/dts/at91sam9x5_lcd.dtsi:				hlcdc-display-controller {
./arm/boot/dts/at91sam9x5_lcd.dtsi:					compatible = "atmel,hlcdc-display-controller";
./arm/boot/dts/sama5d2.dtsi:				hlcdc-display-controller {
./arm/boot/dts/sama5d2.dtsi:					compatible = "atmel,hlcdc-display-controller";
./arm/boot/dts/sama5d4.dtsi:				hlcdc-display-controller {
./arm/boot/dts/sama5d4.dtsi:					compatible = "atmel,hlcdc-display-controller";
./arm/boot/dts/sama5d3_lcd.dtsi:				hlcdc-display-controller {
./arm/boot/dts/sama5d3_lcd.dtsi:					compatible = "atmel,hlcdc-display-controller";
./arm/boot/dts/sam9x60.dtsi:				hlcdc-display-controller {
./arm/boot/dts/sam9x60.dtsi:					compatible = "atmel,hlcdc-display-controller";

./arm/boot/dts/at91-sama5d4_ma5d4evk.dts:				hlcdc-display-controller {
./arm/boot/dts/at91sam9n12ek.dts:				hlcdc-display-controller {
./arm/boot/dts/am335x-pdu001.dts:	display-controller@0 {
./arm/boot/dts/at91-nattis-2-natte-2.dts:	hlcdc-display-controller {
./arm/boot/dts/gemini-dlink-dir-685.dts:		display-controller@6a000000 {