[PATCH 0/3] Arm China Linlon-D6 display controller support

[PATCH 0/3] Arm China Linlon-D6 display controller support

[Cunyuan Liu]

Adds Komeda DRM support for Arm China Linlon-D6. The IP is register-compatible
with Mali-D71, so we reuse the D71 code path.

  [1/3] dt-bindings: vendor-prefixes: add Arm Technology (China) "armchina"
  [2/3] dt-bindings: add armchina,linlon-d6 compatible (fallback to arm,mali-d71)
  [3/3] drm/komeda: add Linlon-D6 product ID and of_device_id, use D71 funcs

Tested on Radxa Orion O6 with Linlon-D6, basic display bring-up works as expected.

Thanks,
Cunyuan

Cunyuan Liu (3):
  dt-bindings: vendor-prefixes: Add Arm Technology (China) Co., Ltd.
  dt-bindings: display: arm,komeda: add Arm China Linlon D6 compatible
  drm/komeda: Add support for Arm China Linlon-D6

 Documentation/devicetree/bindings/display/arm,komeda.yaml | 3 +++
 Documentation/devicetree/bindings/vendor-prefixes.yaml    | 2 ++
 drivers/gpu/drm/arm/display/include/malidp_product.h      | 1 +
 drivers/gpu/drm/arm/display/komeda/d71/d71_dev.c          | 1 +
 drivers/gpu/drm/arm/display/komeda/komeda_drv.c           | 1 +
 5 files changed, 8 insertions(+)

-- 
2.53.0

[PATCH 1/3] dt-bindings: vendor-prefixes: Add Arm Technology (China) Co., Ltd.

[Cunyuan Liu]

Add "armchina" vendor prefix for Arm Technology (China) Co., Ltd.

Link: https://www.armchina.com/

Signed-off-by: Cunyuan Liu <cunyuan.liu@cixtech.com>
---
 Documentation/devicetree/bindings/vendor-prefixes.yaml | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Documentation/devicetree/bindings/vendor-prefixes.yaml b/Documentation/devicetree/bindings/vendor-prefixes.yaml
index ee7fd3cfe203..c7ca7f43925b 100644
--- a/Documentation/devicetree/bindings/vendor-prefixes.yaml
+++ b/Documentation/devicetree/bindings/vendor-prefixes.yaml
@@ -172,6 +172,8 @@ patternProperties:
     description: ARM Ltd.
   "^armadeus,.*":
     description: ARMadeus Systems SARL
+  "^armchina,.*":
+    description: Arm Technology (China) Co., Ltd.
   "^armsom,.*":
     description: ArmSoM Technology Co., Ltd.
   "^arrow,.*":
-- 
2.53.0

[PATCH 2/3] dt-bindings: display: arm,komeda: add Arm China Linlon D6 compatible

[Cunyuan Liu]

Add the Arm China Linlon D6 display controller compatible string.

Linlon D6 is register-compatible with Mali-D71, so describe it as a
vendor-specific compatible with a fallback to "arm,mali-d71".

Signed-off-by: Cunyuan Liu <cunyuan.liu@cixtech.com>
---
 Documentation/devicetree/bindings/display/arm,komeda.yaml | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Documentation/devicetree/bindings/display/arm,komeda.yaml b/Documentation/devicetree/bindings/display/arm,komeda.yaml
index 3ad3eef89ca8..56fb4103b0dd 100644
--- a/Documentation/devicetree/bindings/display/arm,komeda.yaml
+++ b/Documentation/devicetree/bindings/display/arm,komeda.yaml
@@ -21,6 +21,9 @@ properties:
       - items:
           - const: arm,mali-d32
           - const: arm,mali-d71
+      - items:
+          - const: armchina,linlon-d6
+          - const: arm,mali-d71
       - const: arm,mali-d71
 
   reg:
-- 
2.53.0

[PATCH 3/3] drm/komeda: Add support for Arm China Linlon-D6

[Cunyuan Liu]

Arm China Linlon-D6 is register-compatible with the Mali-D71 display
pipeline for the purpose of basic modesetting.

On Linlon-D6, the PRODUCT_ID register is located at the same offset as on
Mali-D71 and reports 0x0060. The IP also exposes the same Komeda top-level
block layout expected by the existing d71_identify() probing flow, so we
can reuse the D71 function table to bring up the display engine.

Signed-off-by: Cunyuan Liu <cunyuan.liu@cixtech.com>
---
 drivers/gpu/drm/arm/display/include/malidp_product.h | 1 +
 drivers/gpu/drm/arm/display/komeda/d71/d71_dev.c     | 1 +
 drivers/gpu/drm/arm/display/komeda/komeda_drv.c      | 1 +
 3 files changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/arm/display/include/malidp_product.h b/drivers/gpu/drm/arm/display/include/malidp_product.h
index 16a8a2c22c42..6f954bcdf40e 100644
--- a/drivers/gpu/drm/arm/display/include/malidp_product.h
+++ b/drivers/gpu/drm/arm/display/include/malidp_product.h
@@ -20,6 +20,7 @@
 /* Mali-display product IDs */
 #define MALIDP_D71_PRODUCT_ID	0x0071
 #define MALIDP_D32_PRODUCT_ID	0x0032
+#define LINLONDP_D6_PRODUCT_ID	0x0060
 
 union komeda_config_id {
 	struct {
diff --git a/drivers/gpu/drm/arm/display/komeda/d71/d71_dev.c b/drivers/gpu/drm/arm/display/komeda/d71/d71_dev.c
index 80973975bfdb..f105e3a2dce2 100644
--- a/drivers/gpu/drm/arm/display/komeda/d71/d71_dev.c
+++ b/drivers/gpu/drm/arm/display/komeda/d71/d71_dev.c
@@ -628,6 +628,7 @@ d71_identify(u32 __iomem *reg_base, struct komeda_chip_info *chip)
 	switch (product_id) {
 	case MALIDP_D71_PRODUCT_ID:
 	case MALIDP_D32_PRODUCT_ID:
+	case LINLONDP_D6_PRODUCT_ID:
 		funcs = &d71_chip_funcs;
 		break;
 	default:
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_drv.c b/drivers/gpu/drm/arm/display/komeda/komeda_drv.c
index 358c1512b087..4bb5f250e95e 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_drv.c
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_drv.c
@@ -104,6 +104,7 @@ static int komeda_platform_probe(struct platform_device *pdev)
 static const struct of_device_id komeda_of_match[] = {
 	{ .compatible = "arm,mali-d71", .data = d71_identify, },
 	{ .compatible = "arm,mali-d32", .data = d71_identify, },
+	{ .compatible = "armchina,linlon-d6", .data = d71_identify, },
 	{},
 };
 
-- 
2.53.0

Re: [PATCH 1/3] dt-bindings: vendor-prefixes: Add Arm Technology (China) Co., Ltd.

[Conor Dooley]

[-- Attachment #1: Type: text/plain, Size: 1039 bytes --]

On Wed, Mar 11, 2026 at 01:55:04PM +0800, Cunyuan Liu wrote:
> Add "armchina" vendor prefix for Arm Technology (China) Co., Ltd.

Is this not a subsidiary of arm, that should just use the arm prefix?

> 
> Link: https://www.armchina.com/
> 
> Signed-off-by: Cunyuan Liu <cunyuan.liu@cixtech.com>
> ---
>  Documentation/devicetree/bindings/vendor-prefixes.yaml | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/vendor-prefixes.yaml b/Documentation/devicetree/bindings/vendor-prefixes.yaml
> index ee7fd3cfe203..c7ca7f43925b 100644
> --- a/Documentation/devicetree/bindings/vendor-prefixes.yaml
> +++ b/Documentation/devicetree/bindings/vendor-prefixes.yaml
> @@ -172,6 +172,8 @@ patternProperties:
>      description: ARM Ltd.
>    "^armadeus,.*":
>      description: ARMadeus Systems SARL
> +  "^armchina,.*":
> +    description: Arm Technology (China) Co., Ltd.
>    "^armsom,.*":
>      description: ArmSoM Technology Co., Ltd.
>    "^arrow,.*":
> -- 
> 2.53.0
> 

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 228 bytes --]

Re: [PATCH 2/3] dt-bindings: display: arm,komeda: add Arm China Linlon D6 compatible

[Liviu Dudau]

Hi,

On Wed, Mar 11, 2026 at 01:55:05PM +0800, Cunyuan Liu wrote:
> Add the Arm China Linlon D6 display controller compatible string.
> 
> Linlon D6 is register-compatible with Mali-D71, so describe it as a
> vendor-specific compatible with a fallback to "arm,mali-d71".
> 
> Signed-off-by: Cunyuan Liu <cunyuan.liu@cixtech.com>

Thanks for the patch!

Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>

Best regards,
Liviu

> ---
>  Documentation/devicetree/bindings/display/arm,komeda.yaml | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/display/arm,komeda.yaml b/Documentation/devicetree/bindings/display/arm,komeda.yaml
> index 3ad3eef89ca8..56fb4103b0dd 100644
> --- a/Documentation/devicetree/bindings/display/arm,komeda.yaml
> +++ b/Documentation/devicetree/bindings/display/arm,komeda.yaml
> @@ -21,6 +21,9 @@ properties:
>        - items:
>            - const: arm,mali-d32
>            - const: arm,mali-d71
> +      - items:
> +          - const: armchina,linlon-d6
> +          - const: arm,mali-d71
>        - const: arm,mali-d71
>  
>    reg:
> -- 
> 2.53.0
> 

-- 
====================
| I would like to |
| fix the world,  |
| but they're not |
| giving me the   |
 \ source code!  /
  ---------------
    ¯\_(ツ)_/¯

Re: [PATCH 1/3] dt-bindings: vendor-prefixes: Add Arm Technology (China) Co., Ltd.

[Liviu Dudau]

On Wed, Mar 11, 2026 at 06:42:23PM +0000, Conor Dooley wrote:
> On Wed, Mar 11, 2026 at 01:55:04PM +0800, Cunyuan Liu wrote:
> > Add "armchina" vendor prefix for Arm Technology (China) Co., Ltd.
> 
> Is this not a subsidiary of arm, that should just use the arm prefix?

It is more complicated than that. For what the kernel is interested in
they should be treated as a separate entity as their products do not
carry automatic compatibility with arm's ones.

Best regards,
Liviu

> 
> > 
> > Link: https://www.armchina.com/
> > 
> > Signed-off-by: Cunyuan Liu <cunyuan.liu@cixtech.com>
> > ---
> >  Documentation/devicetree/bindings/vendor-prefixes.yaml | 2 ++
> >  1 file changed, 2 insertions(+)
> > 
> > diff --git a/Documentation/devicetree/bindings/vendor-prefixes.yaml b/Documentation/devicetree/bindings/vendor-prefixes.yaml
> > index ee7fd3cfe203..c7ca7f43925b 100644
> > --- a/Documentation/devicetree/bindings/vendor-prefixes.yaml
> > +++ b/Documentation/devicetree/bindings/vendor-prefixes.yaml
> > @@ -172,6 +172,8 @@ patternProperties:
> >      description: ARM Ltd.
> >    "^armadeus,.*":
> >      description: ARMadeus Systems SARL
> > +  "^armchina,.*":
> > +    description: Arm Technology (China) Co., Ltd.
> >    "^armsom,.*":
> >      description: ArmSoM Technology Co., Ltd.
> >    "^arrow,.*":
> > -- 
> > 2.53.0
> > 



-- 
====================
| I would like to |
| fix the world,  |
| but they're not |
| giving me the   |
 \ source code!  /
  ---------------
    ¯\_(ツ)_/¯

Re: [PATCH 3/3] drm/komeda: Add support for Arm China Linlon-D6

[Liviu Dudau]

On Wed, Mar 11, 2026 at 01:55:06PM +0800, Cunyuan Liu wrote:
> Arm China Linlon-D6 is register-compatible with the Mali-D71 display
> pipeline for the purpose of basic modesetting.
> 
> On Linlon-D6, the PRODUCT_ID register is located at the same offset as on
> Mali-D71 and reports 0x0060. The IP also exposes the same Komeda top-level
> block layout expected by the existing d71_identify() probing flow, so we
> can reuse the D71 function table to bring up the display engine.
> 
> Signed-off-by: Cunyuan Liu <cunyuan.liu@cixtech.com>

Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>

Best regards,
Liviu

> ---
>  drivers/gpu/drm/arm/display/include/malidp_product.h | 1 +
>  drivers/gpu/drm/arm/display/komeda/d71/d71_dev.c     | 1 +
>  drivers/gpu/drm/arm/display/komeda/komeda_drv.c      | 1 +
>  3 files changed, 3 insertions(+)
> 
> diff --git a/drivers/gpu/drm/arm/display/include/malidp_product.h b/drivers/gpu/drm/arm/display/include/malidp_product.h
> index 16a8a2c22c42..6f954bcdf40e 100644
> --- a/drivers/gpu/drm/arm/display/include/malidp_product.h
> +++ b/drivers/gpu/drm/arm/display/include/malidp_product.h
> @@ -20,6 +20,7 @@
>  /* Mali-display product IDs */
>  #define MALIDP_D71_PRODUCT_ID	0x0071
>  #define MALIDP_D32_PRODUCT_ID	0x0032
> +#define LINLONDP_D6_PRODUCT_ID	0x0060
>  
>  union komeda_config_id {
>  	struct {
> diff --git a/drivers/gpu/drm/arm/display/komeda/d71/d71_dev.c b/drivers/gpu/drm/arm/display/komeda/d71/d71_dev.c
> index 80973975bfdb..f105e3a2dce2 100644
> --- a/drivers/gpu/drm/arm/display/komeda/d71/d71_dev.c
> +++ b/drivers/gpu/drm/arm/display/komeda/d71/d71_dev.c
> @@ -628,6 +628,7 @@ d71_identify(u32 __iomem *reg_base, struct komeda_chip_info *chip)
>  	switch (product_id) {
>  	case MALIDP_D71_PRODUCT_ID:
>  	case MALIDP_D32_PRODUCT_ID:
> +	case LINLONDP_D6_PRODUCT_ID:
>  		funcs = &d71_chip_funcs;
>  		break;
>  	default:
> diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_drv.c b/drivers/gpu/drm/arm/display/komeda/komeda_drv.c
> index 358c1512b087..4bb5f250e95e 100644
> --- a/drivers/gpu/drm/arm/display/komeda/komeda_drv.c
> +++ b/drivers/gpu/drm/arm/display/komeda/komeda_drv.c
> @@ -104,6 +104,7 @@ static int komeda_platform_probe(struct platform_device *pdev)
>  static const struct of_device_id komeda_of_match[] = {
>  	{ .compatible = "arm,mali-d71", .data = d71_identify, },
>  	{ .compatible = "arm,mali-d32", .data = d71_identify, },
> +	{ .compatible = "armchina,linlon-d6", .data = d71_identify, },
>  	{},
>  };
>  
> -- 
> 2.53.0
> 

-- 
====================
| I would like to |
| fix the world,  |
| but they're not |
| giving me the   |
 \ source code!  /
  ---------------
    ¯\_(ツ)_/¯

Re: [PATCH 1/3] dt-bindings: vendor-prefixes: Add Arm Technology (China) Co., Ltd.

[Krzysztof Kozlowski]

On 11/03/2026 20:15, Liviu Dudau wrote:
> On Wed, Mar 11, 2026 at 06:42:23PM +0000, Conor Dooley wrote:
>> On Wed, Mar 11, 2026 at 01:55:04PM +0800, Cunyuan Liu wrote:
>>> Add "armchina" vendor prefix for Arm Technology (China) Co., Ltd.
>>
>> Is this not a subsidiary of arm, that should just use the arm prefix?
> 
> It is more complicated than that. For what the kernel is interested in
> they should be treated as a separate entity as their products do not
> carry automatic compatibility with arm's ones.

Yeah, it's joint venture, so not the same company. Also, according to
their website they have trademark agreement to use the name "Arm", FWIW.

Best regards,
Krzysztof

Re: [PATCH 2/3] dt-bindings: display: arm,komeda: add Arm China Linlon D6 compatible

[Krzysztof Kozlowski]

On 11/03/2026 06:55, Cunyuan Liu wrote:
> Add the Arm China Linlon D6 display controller compatible string.
> 
> Linlon D6 is register-compatible with Mali-D71, so describe it as a
> vendor-specific compatible with a fallback to "arm,mali-d71".
> 
> Signed-off-by: Cunyuan Liu <cunyuan.liu@cixtech.com>
> ---
>  Documentation/devicetree/bindings/display/arm,komeda.yaml | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/display/arm,komeda.yaml b/Documentation/devicetree/bindings/display/arm,komeda.yaml
> index 3ad3eef89ca8..56fb4103b0dd 100644
> --- a/Documentation/devicetree/bindings/display/arm,komeda.yaml
> +++ b/Documentation/devicetree/bindings/display/arm,komeda.yaml
> @@ -21,6 +21,9 @@ properties:
>        - items:
>            - const: arm,mali-d32
>            - const: arm,mali-d71
> +      - items:
> +          - const: armchina,linlon-d6

So that's enum in previous d32 entry.

> +          - const: arm,mali-d71
>        - const: arm,mali-d71
>  
>    reg:


Best regards,
Krzysztof

Re: [PATCH 1/3] dt-bindings: vendor-prefixes: Add Arm Technology (China) Co., Ltd.

[Rob Herring (Arm)]

On Wed, 11 Mar 2026 13:55:04 +0800, Cunyuan Liu wrote:
> Add "armchina" vendor prefix for Arm Technology (China) Co., Ltd.
> 
> Link: https://www.armchina.com/
> 
> Signed-off-by: Cunyuan Liu <cunyuan.liu@cixtech.com>
> ---
>  Documentation/devicetree/bindings/vendor-prefixes.yaml | 2 ++
>  1 file changed, 2 insertions(+)
> 

Acked-by: Rob Herring (Arm) <robh@kernel.org>

Re: [PATCH 2/3] dt-bindings: display: arm,komeda: add Arm China Linlon D6 compatible

[Cunyuan Liu]

> On 11/03/2026 06:55, Cunyuan Liu wrote:
> > Add the Arm China Linlon D6 display controller compatible string.
> >
> > Linlon D6 is register-compatible with Mali-D71, so describe it as a
> > vendor-specific compatible with a fallback to "arm,mali-d71".
> >
> > Signed-off-by: Cunyuan Liu <cunyuan.liu@cixtech.com>
> > ---
> >  Documentation/devicetree/bindings/display/arm,komeda.yaml | 3 +++
> >  1 file changed, 3 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/display/arm,komeda.yaml
> > b/Documentation/devicetree/bindings/display/arm,komeda.yaml
> > index 3ad3eef89ca8..56fb4103b0dd 100644
> > --- a/Documentation/devicetree/bindings/display/arm,komeda.yaml
> > +++ b/Documentation/devicetree/bindings/display/arm,komeda.yaml
> > @@ -21,6 +21,9 @@ properties:
> >        - items:
> >            - const: arm,mali-d32
> >            - const: arm,mali-d71
> > +      - items:
> > +          - const: armchina,linlon-d6
> 
> So that's enum in previous d32 entry.

Hi Krzysztof,

Thanks for the comments.

To make sure I understood correctly: you are suggesting to merge the
linlon-d6 and mali-d32 cases into a single entry and use an enum for
the first compatible string, like this:
compatible:
    oneOf:
      - items:
          - enum:
              - arm,mali-d32
              - armchina,linlon-d6
          - const: arm,mali-d71
      - const: arm,mali-d71

If so, I will send an updated patch later.

Thanks,
Cunyuan

> 
> > +          - const: arm,mali-d71
> >        - const: arm,mali-d71
> >
> >    reg:
> 
> 
> Best regards,
> Krzysztof

Re: [PATCH 2/3] dt-bindings: display: arm,komeda: add Arm China Linlon D6 compatible

[Krzysztof Kozlowski]

On 12/03/2026 09:15, Cunyuan Liu wrote:
> 
> Thanks for the comments.
> 
> To make sure I understood correctly: you are suggesting to merge the
> linlon-d6 and mali-d32 cases into a single entry and use an enum for
> the first compatible string, like this:
> compatible:
>     oneOf:
>       - items:
>           - enum:
>               - arm,mali-d32
>               - armchina,linlon-d6
>           - const: arm,mali-d71
>       - const: arm,mali-d71

Yes


Best regards,
Krzysztof